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  • 251.
    Boltshauser, Rasmus
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Zheng, Jimmy
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Automatisering av skjuvvågselastografidata för kärldiagnostisk applikation.2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Sammanfattning

     

    Hjärt- och kärlsjukdommar är den ledande dödsorsaken i världen. En av det vanligaste hjärt- och kärlsjukdomarna är åderförkalkning. Sjukdomen kännetecknas av förhårdning samt plackansamling i kärl och bidrar till stroke och hjärtinfarkt. Information om kärlväggens styvhet kan spela en viktig roll vid diagnostiseringen av bland annat åderförkalkning. Skjuvvågselastografi (SWE) är en noninvasiv ultraljudsbaserad metod som idag används för att mäta elasticitet och styvhet av större mjuka vävnader som lever- och bröstvävnad. Dock används inte metoden inom kärlapplikationer, då få genomgående studier har utförts på SWE för kärl. Målet med projektet är att automatisera kvantifieringen av skjuvvågshastigheten för SWE och undersöka hur automatiseringens förmåga och begränsningar beror av automatiseringsinställningar. Med verktyg erhållna från CBH (skolan för kemi, bioteknologi och hälsa) skapades ett MATLAB-program med denna förmåga. Programmet applicerades på två fantommodeller. Automatiseringsinställningarna påverkade automatiseringen av dessa modeller olika, vilket innebar att generella optimala inställningar inte kunde finnas. Optimala inställningar beror på vad automatiseringen skall undersöka.

     

  • 252.
    Borghäll, David
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Lundström, Mathilda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Utveckling av handhållen prototyp för mätning av EKG och fingerpuls2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report represents a bachelor thesis at the Royal Institute of Technology, where the goal was to create a handheld prototype. The functions of the prototype were measuring pulse in a finger using the optical sensor TCRT1010 and electrocardiogram(ECG) with bipolar limb-lead. In this thesis, the focus was put on trying to develop a user-friendly and cost-effective prototype for use in developing countries, that can be found in Africa and Asia. The reason is because there's a lack of cheap and easy to use medical equipment in those areas.

    The work was performed by developing two circuits, given by our employer, that was designed on a circuitboard and constructed by a Swedish circuitboard constructor. All components were soldered on the circuitboard and was mounted in a box with socket and batteries. The finished prototype consists of a plastic box containing one circuitboard with the function to measure either the puls of a finger or ECG, which the user can choose between using a switch. The prototype is also equipped with a removable lid, two BNC plugs for connecting an oscilloskope, one for each ciruit, three sockets for the limb lead for the ECG and finally a 4-pole socket for the optical sensor. The signals acquired are not free of noise but contains the most important parameters of the two signals for guidance if further medical diagnostic is needed.

    The prototypes final cost was 1815,5 SEK, which was not considered achieving the goal for cost-efficiency, was still believed to be useful in developing countries because of its simpel design with removable lid and easily to change batteries. It's equipped with only one switch and the compact size makes it easy to handle. The signal processing is tested to give a clear signal which enables the health professionals to identify if further diagnostics are needed. Several improvements was identified for future work, such as to reduce the cost by buying cheaper components or buying the circuitboard in greater numbers, making a wireless connection to the measuring equipment or further reducing the noise.

  • 253.
    Borglund, Dan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Carlsson, Ulf
    KTH, School of Engineering Sciences (SCI).
    Colarieti-Tosti, Massimiliano
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Edström, Simon
    Havtun, Hans
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Henriksson, Ann-Sofie
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Hjelm, Niclas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Basic Science.
    Naimi-Akbar, Ida
    KTH, School of Education and Communication in Engineering Science (ECE), Learning, Learning in Engineering Sciences.
    Collaborative Course Evaluation and Development at KTH: Progress, Lessons Learned and Way Forward2017In: 6th USIU Conference, 2017, article id 68Conference paper (Refereed)
  • 254.
    Borglund, Dan
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Carlsson, Ulf
    KTH, School of Engineering Sciences (SCI).
    Colarieti-Tosti, Massimiliano
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Edström, Simon
    Havtun, Hans
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Hjelm, Niclas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Naimi-Akbar, Ida
    KTH, School of Industrial Engineering and Management (ITM), Learning.
    Collaborative course analysis and development at KTH: What's the next step and who needs to do what to make it happen?2017In: KTH SoTL, 2017Conference paper (Refereed)
  • 255.
    Borgström, Dennis
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Validation of a Smart shirt for tracking work postures of the trunk2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Background

    Ergonomists are interested in measuring the work postures and movements workers perform during their workday. The most common evaluation method to date, is observational studies, where the ergonomist visits the workplace and performs an evaluation. This is time consuming and different ergonomists tend to have low correlation between their evaluations. To make objective evaluations and speed up the process, a system to capture the work postures and movements would be helpful. Optical motion capture (OMC) systems have shown to have high accuracy and precision for capturing work postures and movements, but OMC systems are quite costly and often need a whole laboratory to be set up. This is not feasible in most workplaces. Inertial sensors on the other hand, enable sufficient capturing of the motions but still have the convenience of being mobile and easy to set up. The purpose of this thesis is to contribute to the development of a motion capture system, based on inertial sensors.

    Methods

    An existing Android application was modified for measuring the working postures of the trunk. To evaluate the construct validity, measurements of the inertial sensors were compared to an OMC system, which was used as a gold standard. Three different sensor-placements of the inertial sensors for the trunk was tested. The positions were above the C7, T4 and L1/S5 vertebrates and at the Sternum. The relative angle between L5/S1 and the Sternum, called SaSt, was calculated. Twelve participants performed a validation experiment, following a protocol for motions in a pace set by a metronome to 20 BPM. Four of the participants repeated the validation experiment wearing a Smart shirt. The participants performed a “Posture test”, where the participants were instructed to perform the uniaxially movements flexion/extension, lateral bending and rotation. Also, the participants performed two “Work-task tests”, called symmetrical- and asymmetrical lifting.

    Results

    In the Posture test’s result showed that the mean Root Mean Square Difference (RMSD) of all inertial sensors for all types of movements performed, was 4.1˚ and the inter-system correlation was generally high (≥0.782), compared to the OMC system. Symmetrical lifting, showed in the same manner, a mean RMSD of 13˚. The correlation was high (≥0.990) in flexion/extension (over the axis where movement occurred). Asymmetrical lifting, showed a mean RMSD of 26˚. The correlation was high (≥0.732) for all types of movements.

    Discussions and Conclusions

    For the Posture test, the sensor-placements T4 and C7 had the lowest RMSD for flexion/extension and lateral bending, compared to the OMC system, but SaSt had the least RMSD when the participants were performing rotation. For the symmetrical lifting task, T4 and C7 showed much lower RMSD than SaSt for flexion/extension. The same applies for asymmetrical lifting, but this time both for flexion/extension and lateral bending. To place the inertial sensors in a Smart shirt instead of on the skin, did not affect the accuracy for the movements flexion/extension and rotation. Only lateral bending was affected, probably because the shirt does not fit tight when lateral bending is performed. The tested inertial sensor-based motion capture system is comparable to an OMC system for uniaxially movements. The inertial sensors had high correlation and low RMSD compared to the OMC system, which is impaired when the participants combined movements over two or more planes.

  • 256.
    Borrarzo, Cristian
    et al.
    Sapienza Univ Rome, Dept Mol Med, Rome, Italy..
    Bettiol, Marco
    Sapienza Univ Rome, Dept Mol Med, Rome, Italy..
    Bennati, Paolo
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH). KTH, Sch Technol & Hlth, Stockholm, Sweden..
    Preziosi, Enrico
    Sapienza Univ Rome, Dept Mol Med, Rome, Italy.;Sapienza Univ Rome, SAIMLAL Dept, Morphofunct Sci, Rome, Italy..
    Fabbri, Andrea
    Univ Roma Tre, Ist Nazl Fis Nucl, Sez Roma 3, Rome, Italy..
    Scale, Raffaele
    Sapienza Univ Rome, Dept Mol Med, Rome, Italy..
    Pellegrini, Rosanna
    Sapienza Univ Rome, Dept Mol Med, Rome, Italy..
    Pani, Roberto
    Sapienza Univ Rome, Dept Medicosurg Sci & Biotechnol, Rome, Italy..
    Monte Carlo Simulation to Evaluate Factors Affecting Imaging Performances of Compact Scintillation Gamma Camara2016In: 2016 IEEE NUCLEAR SCIENCE SYMPOSIUM, MEDICAL IMAGING CONFERENCE AND ROOM-TEMPERATURE SEMICONDUCTOR DETECTOR WORKSHOP (NSS/MIC/RTSD), IEEE , 2016Conference paper (Refereed)
    Abstract [en]

    In recent years, a new generation of compact gamma cameras, based on monolithic scintillation crystals, has become increasingly widespread. The main advantages of small FoV gamma cameras with respect to the standard ones are high portability, low cost and low weight, allowing several clinical applications, from scintimammography to intraoperative tumor localization. In gamma cameras based on continuous scintillation crystals, intrinsic Spatial Resolution (SR) is mainly affected by two factors: scintillation light collection efficiency and overall crystal thickness. The first affects the counting statistics, the latter impacts on the light distribution width. To fully investigate the potentiality of these devices we took advantage of Monte Carlo simulations as a valuable tool to physically characterize the imaging systems and to establish a priori reference values. GEANT4 toolkit allows to completely describe the phenomenon of light emission and propagation through the media, providing control to all second-order factors existing in real systems. Results show clearly that SR is dependent on the number of photoelectrons produced and on the light spread. Furthermore, the role of refractive index has been unambiguously identified as an important factor affecting light collection and consequently SR.

  • 257. Boshkova, Katrin
    et al.
    Kronberg, Bengt
    Rutland, Mark W.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Imae, Toyoko
    Visco-elastic properties of thin surfactant films studied with the tribological surface force apparatus.2000Conference paper (Refereed)
  • 258.
    Boström, Caroline
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Messler, Olivia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Design and Evaluation of a 3D Printed Ionization Chamber2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Ionizing radiation is often used within medicine for diagnosis and treatments. Because ionizingradiation can be harmful to the body, it is important to know how it affects the tissue. Dosimetryis the study of how ionizing radiation deposits energy in a material. To measure how much ionizingradiation is deposited in the body, gas-filled detectors are often used. An ionization chamber isa type of gas-filled detector and exists in different shapes and sizes, depending on what kind ofmeasurements it is made for. Because ionization chambers are relatively expensive, it is often notpossible to buy one for each type of measurement that is to be done. This results in ionizationchambers being used for measurements they are not optimized for. This report evaluates thepossibility of 3D printing ionization chambers to make it easier to optimize them for specificmeasurements. The process included creating models of ionization chambers using CAD-software,slicing them and then 3D printing them. The 3D printed models were then brought to the SwedishRadiation Safety Authority for measurements. The ionization chambers were connected to highvoltage, and exposed to ionizing radiation in the form of high-intensity gamma-ray fields. Theoutput current of the ionization chamber was measured, which is proportional to the field intensity.The results were similar to those of a commercial ionization chamber. The conclusion is that it ispossible to 3D print ionization chambers. However, to get more accurate results, the design has tobe further optimized and more measurements need to be done.

  • 259.
    Boström, Fanny
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Experimental testing of adsorbents for H2S removal in industrial applications: A comparative study on lifetime and cost effectiveness of different materials2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Harmful emissions are a global issue and cause trouble for human health and for the environment. There is a wide variety of pollutants and one pollutant is hydrogen sulfide, H2S, that is a member of the group Volatile Sulfur Compounds. H2S is a compound that is known for its smell of rotten eggs and is detectable by the human nose at very low concentrations. At higher concentrations, H2S is highly toxic and even deadly for humans. It is also a corrosive gas, and can, therefore, cause problems for materials that are being exposed to it. This can be an issue when H2S is present in biogas since it can damage engines or pipes. It can also poison catalysts that are used for methane upgrading.

    There are different methods of removing H2S from air and common ones are to use adsorption media or catalytic oxidation for gas-solid reactions. The catalytic oxidation is oxidizing the H2S and converts it into elemental sulfur. A problem with these techniques is that they need replacement after some time when they have been saturated.

    The aim and objectives for this project are to find appropriate materials to test in a test rig that was finalized at the beginning of the project, to compare their lifetime. This was done to find the most cost effective material for H2S removal. The effect of humidity in the air was also examined.

    Eight different samples were tested. Two of these were activated carbonwithout impregnations and the other six were partial catalytic materials (impregnated carbons or metal oxide based materials). The partial catalytic materials were significantly better than the activated carbons. The lifetimes varied among the partial catalytic materials as well, andare believed to be due to different active compounds on the surfacesand the structure. When running the experiments with 70 % relative humidity, the lifetimes were significantly longer than when the same materials were run for 30 %. A lower concentration of H2S in low relative humidity showed lower or the same loading capacity than higher concentrations. Regeneration was tested for one of the metal based materials with a satisfactory result.

  • 260. Boström, M.
    et al.
    Corkery, Robert
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Lima, E. R. A.
    Malyi, O. I.
    Buhmann, S. Y.
    Persson, C.
    Brevik, I.
    Parsons, D. F.
    Fiedler, J.
    Dispersion Forces Stabilize Ice Coatings at Certain Gas Hydrate Interfaces That Prevent Water Wetting2019In: ACS Earth and Space Chemistry, ISSN 2472-3452, Vol. 3, no 6, p. 1014-1022Article in journal (Refereed)
    Abstract [en]

    Gas hydrates formed in oceans and permafrost occur in vast quantities on Earth representing both a massive potential fuel source and a large threat in climate forecasts. They have been predicted to be important on other bodies in our solar systems such as Enceladus, a moon of Saturn. CO 2 -hydrates likely drive the massive gas-rich water plumes seen and sampled by the spacecraft Cassini, and the source of these hydrates is thought to be due to buoyant gas hydrate particles. Dispersion forces can in some cases cause gas hydrates at thermal equilibrium to be coated in a 3-4 nm thick film of ice, or to contact water directly, depending on which gas they contain. As an example, the results are valid at a quadruple point of the water-CO 2 gas hydrate system, where a film is formed not only for the model with pure ice but also in the presence of impurities in water or in the ice layer. These films are shown to significantly alter the properties of the gas hydrate clusters, for example, whether they float or sink. It is also expected to influence gas hydrate growth and gas leakage.

  • 261.
    Boujemaoui, Assya
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Ansari, Farhan
    Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94305 USA..
    Berglund, Lars
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Nanostructural Effects in High Cellulose Content Thermoplastic Nanocomposites with a Covalently Grafted Cellulose-Poly(methyl methacrylate) Interface2019In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 2, p. 598-607Article in journal (Refereed)
    Abstract [en]

    A critical aspect in materials design of polymer nanocomposites is the nature of the nanoparticle/polymer interface. The present study investigates the effect of manipulation of the interface between cellulose nanofibrils (CNF) and poly(methyl methacrylate) (PMMA) on the optical, thermal, and mechanical properties of the corresponding nanocomposites. The CNF/PMMA interface is altered with a minimum of changes in material composition so that interface effects can be analyzed. The hydroxyl-rich surface of CNF fibrils is exploited to modify the CNF surface via an epoxide-hydroxyl reaction. CNF/PMMA nanocomposites are then prepared with high CNF content (similar to 38 wt %) using an approach where a porous CNF mat is impregnated with monomer or polymer. The nanocomposite interface is controlled by either providing PMMA grafts from the modified CNF surface or by solvent-assisted diffusion of PMMA into a CNF network (native and modified). The high content of CNF fibrils of similar to 6 nm diameter leads to a strong interface and polymer matrix distribution effects. Moisture uptake and mechanical properties are measured at different relative humidity conditions. The nanocomposites with PMMA molecules grafted to cellulose exhibited much higher optical transparency, thermal stability, and hygro-mechanical properties than the control samples. The present modification and preparation strategies are versatile and may be used for cellulose nanocomposites of other compositions, architectures, properties, and functionalities.

  • 262.
    Boutajangout, Allal
    et al.
    NYU, Ctr Cognit Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Psychiat, Langone Hlth, 550 1St Ave, New York, NY 10016 USA.;NYU, Langone Med Ctr, Dept Physiol & Neurosci, New York, NY USA..
    Lindberg, Hanna
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Awwad, Abdulaziz
    King Abdulaziz Univ, Sch Med, Jeddah, Saudi Arabia..
    Paul, Arun
    NYU, Ctr Cognit Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Neurol, Langone Hlth, New York, NY 10016 USA..
    Baitalmal, Rabaa
    NYU, Ctr Cognit Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Neurol, Langone Hlth, New York, NY 10016 USA..
    Almokyad, Ismail
    NYU, Ctr Cognit Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Neurol, Langone Hlth, New York, NY 10016 USA..
    Hoiden-Guthenberg, Ingmarie
    Affibody AB, Solna, Sweden..
    Gunneriusson, Elin
    Affibody AB, Solna, Sweden..
    Frejd, Fredrik Y.
    Affibody AB, Solna, Sweden..
    Hard, Torleif
    Swedish Univ Agr Sci SLU, Dept Chem & Biotechnol, Uppsala, Sweden..
    Löfblom, John
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Ståhl, Stefan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science.
    Wisniewski, Thomas
    NYU, Ctr Cognit Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Neurol, Langone Hlth, New York, NY 10016 USA.;NYU, Dept Psychiat, Langone Hlth, 550 1St Ave, New York, NY 10016 USA.;NYU, Sch Med, Dept Pathol, New York, NY 10016 USA..
    Affibody-Mediated Sequestration of Amyloid beta Demonstrates Preventive Efficacy in a Transgenic Alzheimer's Disease Mouse Model2019In: Frontiers in Aging Neuroscience, ISSN 1663-4365, E-ISSN 1663-4365, Vol. 11, article id 64Article in journal (Refereed)
    Abstract [en]

    Different strategies for treatment and prevention of Alzheimer's disease (AD) are currently under investigation, including passive immunization with anti-amyloid beta (anti-A beta) monoclonal antibodies (mAbs). Here, we investigate the therapeutic potential of a novel type of A beta-targeting agent based on an affibody molecule with fundamentally different properties to mAbs. We generated a therapeutic candidate, denoted Z(SYM73)-albumin-binding domain (ABD; 16.8 kDa), by genetic linkage of the dimeric Z(SYM73) affibody for sequestering of monomeric A beta-peptides and an ABD for extension of its in vivo half-life. Amyloid precursor protein (APP)/PS1 transgenic AD mice were administered with Z(SYM73)-ABD, followed by behavioral examination and immunohistochemistry. Results demonstrated rescued cognitive functions and significantly lower amyloid burden in the treated animals compared to controls. No toxicological symptoms or immunology-related side-effects were observed. To our knowledge, this is the first reported in vivo investigation of a systemically delivered scaffold protein against monomeric A beta, demonstrating a therapeutic potential for prevention of AD.

  • 263. Bouzek, K.
    et al.
    Cornell, Ann M.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Rodrigo, M. A.
    Preface on the special issue 2nd workshop on electrochemical engineering: new bridges for a new knowledge on electrochemical engineering2018In: Journal of Applied Electrochemistry, ISSN 0021-891X, E-ISSN 1572-8838, Vol. 48, no 12, p. 1305-1306Article in journal (Refereed)
  • 264. Bracher, J. M.
    et al.
    Verhoeven, M. D.
    Wisselink, H. W.
    Crimi, B.
    Nijland, J. G.
    Driessen, A. J. M.
    Klaassen, P.
    Van Maris, Antonius J.A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology. Delft University of Technology, Netherlands.
    Daran, J. -MG.
    Pronk, J. T.
    The Penicillium chrysogenum transporter PcAraT enables high-affinity, glucose-insensitive l-arabinose transport in Saccharomyces cerevisiae2018In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 11, no 1, article id 63Article in journal (Refereed)
    Abstract [en]

    Background: l-Arabinose occurs at economically relevant levels in lignocellulosic hydrolysates. Its low-affinity uptake via the Saccharomyces cerevisiae Gal2 galactose transporter is inhibited by d-glucose. Especially at low concentrations of l-arabinose, uptake is an important rate-controlling step in the complete conversion of these feedstocks by engineered pentose-metabolizing S. cerevisiae strains. Results: Chemostat-based transcriptome analysis yielded 16 putative sugar transporter genes in the filamentous fungus Penicillium chrysogenum whose transcript levels were at least threefold higher in l-arabinose-limited cultures than in d-glucose-limited and ethanol-limited cultures. Of five genes, that encoded putative transport proteins and showed an over 30-fold higher transcript level in l-arabinose-grown cultures compared to d-glucose-grown cultures, only one (Pc20g01790) restored growth on l-arabinose upon expression in an engineered l-arabinose-fermenting S. cerevisiae strain in which the endogenous l-arabinose transporter, GAL2, had been deleted. Sugar transport assays indicated that this fungal transporter, designated as PcAraT, is a high-affinity (K m = 0.13 mM), high-specificity l-arabinose-proton symporter that does not transport d-xylose or d-glucose. An l-arabinose-metabolizing S. cerevisiae strain in which GAL2 was replaced by PcaraT showed 450-fold lower residual substrate concentrations in l-arabinose-limited chemostat cultures than a congenic strain in which l-arabinose import depended on Gal2 (4.2 × 10-3 and 1.8 g L-1, respectively). Inhibition of l-arabinose transport by the most abundant sugars in hydrolysates, d-glucose and d-xylose was far less pronounced than observed with Gal2. Expression of PcAraT in a hexose-phosphorylation-deficient, l-arabinose-metabolizing S. cerevisiae strain enabled growth in media supplemented with both 20 g L-1 l-arabinose and 20 g L-1 d-glucose, which completely inhibited growth of a congenic strain in the same condition that depended on l-arabinose transport via Gal2. Conclusion: Its high affinity and specificity for l-arabinose, combined with limited sensitivity to inhibition by d-glucose and d-xylose, make PcAraT a valuable transporter for application in metabolic engineering strategies aimed at engineering S. cerevisiae strains for efficient conversion of lignocellulosic hydrolysates.

  • 265. Bracher, Jasmine M.
    et al.
    Martinez-Rodriguez, Oscar A.
    Dekker, Wijb JC
    Verhoeven, Maarten D.
    van Maris, Antonius
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Pronk, Jack T.
    Reassessment of requirements for anaerobic xylose fermentation by engineered, non-evolved Saccharomyces cerevisiae strains2019In: FEMS yeast research (Print), ISSN 1567-1356, E-ISSN 1567-1364, Vol. 19, no 1, article id foy104Article in journal (Refereed)
    Abstract [en]

    Expression of a heterologous xylose isomerase, deletion of the GRE3 aldose-reductase gene and overexpression of genes encoding xylulokinase (XKS1) and non-oxidative pentose-phosphate-pathway enzymes (RKI1, RPE1, TAL1, TKL1) enables aerobic growth of Saccharomyces cerevisiae on d-xylose. However, literature reports differ on whether anaerobic growth on d-xylose requires additional mutations. Here, CRISPR-Cas9-assisted reconstruction and physiological analysis confirmed an early report that this basic set of genetic modifications suffices to enable anaerobic growth on d-xylose in the CEN.PK genetic background. Strains that additionally carried overexpression cassettes for the transaldolase and transketolase paralogs NQM1 and TKL2 only exhibited anaerobic growth on d-xylose after a 7-10 day lag phase. This extended lag phase was eliminated by increasing inoculum concentrations from 0.02 to 0.2 g biomass L-1. Alternatively, a long lag phase could be prevented by sparging low-inoculum-density bioreactor cultures with a CO2/N-2-mixture, thus mimicking initial CO2 concentrations in high-inoculum-density, nitrogen-sparged cultures, or by using l-aspartate instead of ammonium as nitrogen source. This study resolves apparent contradictions in the literature on the genetic interventions required for anaerobic growth of CEN.PK-derived strains on d-xylose. Additionally, it indicates the potential relevance of CO2 availability and anaplerotic carboxylation reactions for anaerobic growth of engineered S. cerevisiae strains on d-xylose.

  • 266.
    Brantestig, Sandra
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Plasma fatty acid profile and the link to target protein expression of relevance for cardiovascular disease: a population-based study of 70-year old men and women: This master thesis project was performed at Uppsala University Department of Public Health and Caring Sciences, Clinical Nutrition and Metabolism2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Dietary fatty acids (FAs) have been extensively studied in terms of preventing cardiovascular disease (CVD) through a healthy diet. Certain FA patterns in plasma lipids have been related to increased risk to develop CVD whereas others seems to be preventative (e.g. high linoleic acid [LA], and low palmitoleic acid [16:1n-7]).However, the mechanism behind how FAs are involved in CVD remains unclear. It is believed to involve inflammation and cholesterol metabolism, conditions in which both FAs and a large variety of cardiovascular(CV) proteins are involved. The aim of this project was to investigate whether there are any linkage between plasma fatty acid patterns related to CVD and CV proteins. A cross-sectional analysis was performed in two independent population-based cohorts. The Prospective Investigation of the Vasculature in Uppsala Seniors(PIVUS) cohort was used as a discovery sample and The Prospective investigation of Obesity, Energy andMetabolism (POEM) cohort in Uppsala was used as a replicate sample. A factor analysis of FAs measured in plasma was conducted in respective cohort to identify fatty acid patterns related to CVD. Linear regressionmodels between FA patterns and 84 CV proteins measured in respective cohort (samples) were performed.The 81 proteins being found in both samples were meta-analyzed. Traditional CVD risk factors (sex, BMI,diabetes, systolic blood pressure, LDL and HDL-cholesterol and smoking) were adjusted for. Two factors(Low-LA-factor, Fatty-fish-Lipid-factor) (eigenvalue>1) built up by the same patterns of FAs in both samples and constituted of FAs previously related to CVD were disclosed. The Low-LA-factor was constituted of highloadings of palmitoleic acid (16:1n-7) and oleic acid (18:1n-9) and low loadings of linoleic acid (LA) (18:2n-6),previously recognized as a CVD risk pattern. The Fatty-fish-lipid-factor was constituted of high loading’s ofeicosapentaenoic acid (EPA) (20:5n-3) and docosahexaenoic acid (DHA) (22:6-n-3), previously recognized as cardio preventative FA pattern. In the linear regression meta-analysis, the Low-LA-factor was significantly positively related to 3 plasma proteins. The Fatty-fish-lipid-factor was significantly related negatively with 16plasma proteins and positively with one plasma protein. The majority of these CV proteins have previously been related to CVD but not connected with plasma fatty acid composition. Thus, these novel results confirmthat there are relationships between dietary FA patterns and proteins involved in CVD that potentially partially mediates the association between certain FA patterns and CVD risk. With further research oncausality between FAs and these proteins as well as potential mechanisms, these links may be used as a basisfor future and more tailored dietary strategies to prevent CVD in high-risk individuals.

  • 267.
    Brechmann, Nils Arnold
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology. AdBIOPRO, VINNOVA Competence Centre for Advanced BioProduction by Continuous Processing, Stockholm, Sweden.
    Eriksson, Per-Olov
    Eriksson, Kristofer
    Oscarsson, Sven
    Buijs, Jos
    Shokri, Atefeh
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology. AdBIOPRO, VINNOVA Competence Centre for Advanced BioProduction by Continuous Processing, Stockholm, Sweden.
    Hjälm, Göran
    Chotteau, Véronique
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology. AdBIOPRO, VINNOVA Competence Centre for Advanced BioProduction by Continuous Processing, Stockholm, Sweden.
    Pilot-scale process for magnetic bead purification of antibodies directly from non-clarified CHO cell culture2019In: Biotechnology progress (Print), ISSN 8756-7938, E-ISSN 1520-6033Article in journal (Refereed)
    Abstract [en]

    High capacity magnetic protein A agarose beads, LOABeads PrtA, were used in the development

    of a new process for affinity purification of monoclonal antibodies (mAbs) from non-clarified

    CHO cell broth using a pilot-scale magnetic separator. The LOABeads had a maximum binding

    capacity of 65 mg/mL and an adsorption capacity of 25–42 mg IgG/mL bead in suspension for an

    IgG concentration of 1 to 8 g/L. Pilot-scale separation was initially tested in a mAb capture step

    from 26 L clarified harvest. Small-scale experiments showed that similar mAb adsorptions were

    obtained in cell broth containing 40 Å~ 106 cells/mL as in clarified supernatant. Two pilot-scale

    purification runs were then performed on non-clarified cell broth from fed-batch runs of 16 L,

    where a rapid mAb adsorption ≥96.6% was observed after 1 h. This process using 1 L of magnetic beads had an overall mAb yield of 86% and 16 times concentration factor. After this single protein

    A capture step, the mAb purity was similar to the one obtained by column chromatography, while

    the host cell protein content was very low, <10 ppm. Our results showed that this magnetic bead

    mAb purification process, using a dedicated pilot-scale separation device, was a highly efficient

    single step, which directly connected the culture to the downstream process without cell clarification.

    Purification of mAb directly from non-clarified cell broth without cell separation can provide

    significant savings in terms of resources, operation time, and equipment, compared to legacy procedure of cell separation followed by column chromatography step.

  • 268.
    Bremer, Hanna D.
    et al.
    Swedish Univ Agr Sci, Dept Clin Sci, SE-75007 Uppsala, Sweden..
    Landegren, Nils
    Karolinska Inst, Karolinska Univ Hosp, Dept Med Solna, CMM, L8 01, SE-17176 Stockholm, Sweden.;Uppsala Univ, Dept Med Sci, Sci Life Lab, Uppsala, Sweden..
    Sjöberg, Ronald
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics. KTH, Centres, Science for Life Laboratory, SciLifeLab.
    Hallgren, Asa
    Karolinska Inst, Karolinska Univ Hosp, Dept Med Solna, CMM, L8 01, SE-17176 Stockholm, Sweden..
    Renneker, Stefanie
    Euroimmun AG, D-23560 Lubeck, Germany..
    Lattwein, Erik
    Euroimmun AG, D-23560 Lubeck, Germany..
    Leonard, Dag
    Uppsala Univ, Rheumatol & Sci Life Lab, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Eloranta, Maija-Leena
    Uppsala Univ, Rheumatol & Sci Life Lab, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Ronnblom, Lars
    Uppsala Univ, Rheumatol & Sci Life Lab, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Nordmark, Gunnel
    Uppsala Univ, Rheumatol & Sci Life Lab, Dept Med Sci, SE-75185 Uppsala, Sweden..
    Nilsson, Peter
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Protein Science, Affinity Proteomics.
    Andersson, Goran
    Swedish Univ Agr Sci, Dept Anim Breeding & Genet, SE-75007 Uppsala, Sweden..
    Lilliehook, Inger
    Swedish Univ Agr Sci, Dept Clin Sci, SE-75007 Uppsala, Sweden..
    Lindblad-Toh, Kerstin
    Broad Inst Harvard & MIT, Cambridge, MA 02142 USA.;Uppsala Univ, Sci Life Lab, IMBIM, SE-75123 Uppsala, Sweden..
    Kampe, Olle
    Karolinska Inst, Karolinska Univ Hosp, Dept Med Solna, CMM, L8 01, SE-17176 Stockholm, Sweden.;Uppsala Univ, Dept Med Sci, Sci Life Lab, Uppsala, Sweden.;Univ Bergen, Dept Clin Sci, N-5021 Bergen, Norway.;Univ Bergen, KG Jebsen Ctr Autoimmune Disorders, N-5021 Bergen, Norway.;Haukeland Hosp, Dept Med, N-5021 Bergen, Norway..
    Hansson-Hamlin, Helene
    Swedish Univ Agr Sci, Dept Clin Sci, SE-75007 Uppsala, Sweden..
    ILF2 and ILF3 are autoantigens in canine systemic autoimmune disease2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 4852Article in journal (Refereed)
    Abstract [en]

    Dogs can spontaneously develop complex systemic autoimmune disorders, with similarities to human autoimmune disease. Autoantibodies directed at self-antigens are a key feature of these autoimmune diseases. Here we report the identification of interleukin enhancer-binding factors 2 and 3 (ILF2 and ILF3) as autoantigens in canine immune-mediated rheumatic disease. The ILF2 autoantibodies were discovered in a small, selected canine cohort through the use of human protein arrays; a method not previously described in dogs. Subsequently, ILF3 autoantibodies were also identified in the same cohort. The results were validated with an independent method in a larger cohort of dogs. ILF2 and ILF3 autoantibodies were found exclusively, and at a high frequency, in dogs that showed a speckled pattern of antinuclear antibodies on immunofluorescence. ILF2 and ILF3 autoantibodies were also found at low frequency in human patients with SLE and Sjogren's syndrome. These autoantibodies have the potential to be used as diagnostic biomarkers for canine, and possibly also human, autoimmune disease.

  • 269.
    Brett, Calvin
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Mittal, Nitesh
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Ohm, Wiebke
    DESY, Hamburg, Germany..
    Söderberg, Daniel
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Roth, Stephan V.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites. DESY, Hamburg, Germany..
    GISAS study of spray deposited metal precursor ink on a cellulose template2019In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 257Article in journal (Other academic)
  • 270.
    Brett, Calvin
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. DESY, Photon Sci, Hamburg, Germany.
    Mittal, Nitesh
    KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Ohm, Wiebke
    DESY, Photon Sci, Hamburg, Germany..
    Söderberg, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Mechanics, Fluid Physics.
    Roth, Stephan V.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Biocomposites. DESY, Photon Sci, Hamburg, Germany..
    In situ self-assembly study in bio-based thin films2018In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 255Article in journal (Other academic)
  • 271.
    Bridlance, Cecile
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Neuronal activity in the regulation of microglial brain colonization2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The mammalian brain is a highly complex machinery which functioning relies on the emergence of neural networks composed of billions of neurons that process information and of glial cells, which support and modulate neuronal activity. Appropriate wiring and tuning of neural networks are essential to a well-functioning adult brain. Its development starts in the embryo during pre-natal period and is further remodeled during postnatal life when facing the external environment. Microglia, the brain resident macrophages, have been shown to play essential roles in this process: they participate to wiring, synaptic pruning, regulation of neurogenesis and are thus fundamental in normal brain development. Interestingly, these cells enter the brain very early on and progressively colonize it, following a specific spatiotemporal pattern. The heterogeneity of the density of microglia among brain regions is thought to be linked to their specific roles in time and space. Understanding which elements are influencing this microglial colonization is thus of great importance. Here, we show that neural activity can modulate the number and localization of microglia, both in the embryo and in young pups. We used several mice models in which neural activity was impaired in distinct ways: i) the hyperpolarization of inhibitory neurons in the embryo; ii) the postnatal excitation of this same subpopulation of neurons via the use of DREADDs; iii) the suppression of external sensory inputs from the whisker pad via sectioning of the infraorbital nerve. We found that modulating the activity of inhibitory neurons had a significant impact on the number of microglia in the cortex and striatum, with an increased activity leading to decreased microglia number. We also showed that the colonization of the somatosensory cortex is perturbed by the loss of external stimuli from the whiskers. As microglia is increasingly associated to various neurodevelopmental disorders as well as brain diseases, unraveling the mechanisms leading to the precise microglial colonization of the brain is of great interest. We believe that our work reveals interesting interactions between neurons and microglia, which could eventually help us understand the normal and pathological development of the brain.

  • 272.
    Brinck, Tore
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Nyberg Borrfors, Andre
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. KTH Royal Inst Technol, CBH, Dept Chem, Appl Phys Chem, SE-10044 Stockholm, Sweden..
    Electrostatics and polarization determine the strength of the halogen bond: a red card for charge transfer2019In: JOURNAL OF MOLECULAR MODELING, Vol. 25, no 5, article id 125Article in journal (Refereed)
    Abstract [en]

    A series of 20 halogen bonded complexes of the types R-Br center dot center dot center dot Br- (R is a substituted methyl group) and R '-CC-Br center dot center dot center dot Br- are investigated at the M06-2X/6-311+G(d,p) level of theory. Computations using a point-charge (PC) model, in which Br- is represented by a point charge in the electronic Hamiltonian, show that the halogen bond energy within this set of complexes is completely described by the interaction energy (E-PC) of the point charge. This is demonstrated by an excellent linear correlation between the quantum chemical interaction energy and E-PC with a slope of 0.88, a zero intercept, and a correlation coefficient of R-2=0.9995. Rigorous separation of E-PC into electrostatics and polarization shows the high importance of polarization for the strength of the halogen bond. Within the data set, the electrostatic interaction energy varies between 4 and-18kcal mol(-1), whereas the polarization energy varies between -4 and-10kcal mol(-1). The electrostatic interaction energy is correlated to the sum of the electron-withdrawing capacities of the substituents. The polarization energy generally decreases with increasing polarizability of the substituents, and polarization is mediated by the covalent bonds. The lower (more favorable) E-PC of CBr4---Br- compared to CF3Br center dot center dot center dot Br- is found to be determined by polarization as the electrostatic contribution is more favorable for CF3Br center dot center dot center dot Br-. The results of this study demonstrate that the halogen bond can be described accurately by electrostatics and polarization without any need to consider charge transfer.

  • 273.
    Brinck, Tore
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Stenlid, Joakim H.
    Stockholm Univ, AlbaNova Univ Ctr, Dept Phys, SE-10691 Stockholm, Sweden..
    The Molecular Surface Property Approach: A Guide to Chemical Interactions in Chemistry, Medicine, and Material Science2019In: ADVANCED THEORY AND SIMULATIONS, ISSN 2513-0390, Vol. 2, no 1, article id 1800149Article in journal (Refereed)
    Abstract [en]

    The current status of the molecular surface property approach (MSPA) and its application for analysis and prediction of intermolecular interactions, including chemical reactivity, are reviewed. The MSPA allows for identification and characterization of all potential interaction sites of a molecule or nanoparticle by the computation of one or more molecular properties on an electronic isodensity surface. A wide range of interactions can be analyzed by three properties, which are well-defined within Kohn-Sham density functional theory. These are the electrostatic potential, the average local ionization energy, and the local electron attachment energy. The latter two do not only reflect the electrostatic contribution to a chemical interaction, but also the contributions from polarization and charge transfer. It is demonstrated that the MSPA has a high predictive capacity for non-covalent interactions, for example, hydrogen and halogen bonding, as well as organic substitution and addition reactions. The latter results open u p applications within drug design and medicinal chemistry. The application of MSPA has recently been extended to nanoparticles and extended surfaces of metals and metal oxides. In particular, nanostructural effects on the catalytic properties of noble metals are rationalized. The potential for using MSPA in rational design of heterogeneous catalysts is discussed.

  • 274.
    Broberg, Henrik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Steaming of Wood Chips - Experimental determination of heating times and effect of different parameters2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The presteaming of wood chips is an important step in the chemical pulping industry. It removes the air from within wood chips, allowing the cooking liquor to better impregnate wood chips, which leads to a more uniform cooking process, and lowers the amount of rejects. When steaming at atmospheric pressure, it is important that the temperature of the wood chips reach 100ᴼ C, as otherwise there will be an equilibrium leaving some air left inside. Having poorly steamed chips in a process could cause severe problems when it comes to reaching the targeted kappa number, or having the adequate retention time in the digester. There are a few different ways in which the wood chips are presteamed within the industry, however, there is little experimental data regarding the heating time of wood chips that can be used when designing these systems. Most studies have mainly focused on the air removal, or improvement of the impregnation step, and the few studies that have included the heating of the wood chips were limited to only one type of wood chip, or failed to specify the experimental details.

    Therefore, handmade wood chips pine and birch, two tree species commonly found in Sweden, were steamed in an ATEX designed digester with a steam jacket. The wood chips had thermocouples inside them and the temperature and time was recorded, and the effect of different parameters on the heating could thus be studied.The results revealed that there could be more than a minute in average time difference between wood chips of different thicknesses, both for birch and pine, although the difference in heating time was more linearly correlated to thickness for the birch chips. Pine chips of different thickness were also studied when the pressure inside the digester was allowed to build up, which showed that it is mainly thicker chips that have reduced heating time under such circumstances, as the thinner chips stop heating for a while when the steam condensates on colder surroundings. When comparing heartwood and sapwood chips, it was noted that the difference in heating time could be around 1 minute at most for pine, but only a few seconds for birch. This was most likely due to the pine heartwood and sapwood having distinct moisture contents, 25 % and 58 % respectively, while it was 41% and 42 % in birch heartwood and sapwood. Birch and pine chips wee also steamed together, however, the difference in heating time was only a few seconds on average.

    When comparing these experimental results with simulation data of the steaming of wood chips, it fit rather well when it came to the general heating time. However, the effect of increased moisture content had a much larger impact in the simulations, which predicted that more moist wood chips would need several minutes more steaming time, while the experiments only showed at difference of, at most, around 1 minute. When comparing with old experimental data, that has been the basis for the design of older steaming processes, it gave very distinct results, where the effect of thickness did not have as big of an impact as in the old data. No further comparison could be made, however, as the experimental conditions for the old experimental data were not known. Based on these results, it was noted that a steaming time of at least 5 minutes would be needed to ensure that even the largest and more moist chips could reach 100ᴼ C in this system.

    Finally, the condensate from the handmade birch and pine chips was analyzed. It revealed the presence of low molecular weight compounds like methanol, formic acid and acetic acid. Common metal ions were also present,although the amount of sodium ions clearly surpassed the rest. The pH of the pine condensate was measured and it was very high, which implies that the condensate was contaminated.

  • 275.
    Brodin Kont, August
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics. KTH.
    Positioning and parking analysis for an indoor positioning system: A comparative study between Bluetooth Low Energy and Ultra Wideband technology2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The work done in this report as requested by H&D Wireless is performed by using an already developed real time positioning system called Griffin Enterprise Positioning Service and integratingit with ultrasound sensors for presence detection in order to enable assets to park in a visualized environment being actualized by tagging the asset with radio technology hardware. The testing environment was deployed with radio technology hardware equipped for transmitting and receiving radio signals for position estimation of tagged objects where hardware tags emits radio signals being received by sensing radio technology chips called sensepoints which also serves as communication links for further data processing.The thesis focus is on evaluating how different radio technologies combined with different positioning techniques perform in terms of accuracy and precision in positioning tests to assess eachones positioning performance characteristic and the technologies upsides and downsides.This was firstly evaluated by comparing three different technology positioning techniques based on one for Bluetooth Low Energy and two using Ultra Wideband technology being subject to generic tests including a static, dynamic and a walking positioning test for each technology.These initial tests were utilized as a foreground to evaluate which of the two positioning techniques based on Ultra Wideband technology that would compete in the parking tests alongside Bluetooth Low Energy that would serve as the primary objective to accomplish in the thesis.A final implication on parking tags between the two technologies is that Bluetooth Low Energy had to be implemented with higher requirement restrictions for parking due to insufficient relative accuracy and precision in parking positioning which also limited its ability to be parked in alternative manners explored but with power efficiency as a highly valuable aspect for consideration of this technology. Parking tag using Ultra Wideband technology proved highly successful as it saw large distance margins to be allowed parking in all test cases as well as exhibiting sufficient positioning performance to be considered for alternative parking methods without risk of exposure for failed attempts of parking.

  • 276.
    Bronken, Ida Antonia Tank
    et al.
    Natl Museum Art Architecture & Design, Dept Collect Management, Holmenkollveien 37b, N-0376 Oslo, Norway..
    Boon, Jaap J.
    JAAP Enterprise Art Sci Studies, Amsterdam, Netherlands..
    Corkery, Robert
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry.
    Steindal, Calin Constantin
    Univ Oslo, Museum Cultural Hist, Oslo, Norway..
    Changing surface features, weeping and metal soap formation in paintings by Karel Appel and Asger Jorn from 1946-19712019In: Journal of Cultural Heritage, ISSN 1296-2074, E-ISSN 1778-3674, Vol. 35, p. 279-287Article in journal (Refereed)
    Abstract [en]

    This paper presents results from ongoing investigations of soft and dripping oil paint in art works by CoBrA's Karel Appel (1921-2006) and Asger Jorn (1914-1973). The work is part of the PhD-project Investigation of soft and dripping paint in paintings from 1946-1971 where twenty-four paintings are being investigated. The paintings were chosen to represent a large variety of conditions: some with slightly soft and mainly stable paints, and others with deforming and dripping paints. All paintings chosen had some paint with uneven fluorescence emitted from specific paint colours. Earlier studies have shown that fluorescence can be an indicator of softening paint. The softening paints and drips on the surface of some of these paintings show similar polarity features with mid-chain functionalized stearic acids and azelaic acid moieties. Our findings show there are several physical and chemical alterations within one degradation symptom that have to be understood when conservation treatments are considered in the future.

  • 277.
    Brouzet, Christophe
    et al.
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Mittal, Nitesh
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Lundell, Fredrik
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Söderberg, Daniel
    KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Characterizing the Orientational and Network Dynamics of Polydisperse Nanofibers on the Nanoscale2019In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 52, no 6, p. 2286-2295Article in journal (Refereed)
    Abstract [en]

    Polydisperse fiber networks are the basis of many natural and manufactured structures, ranging from high-performance biobased materials to components of living cells and tissues. The formation and behavior of such networks are given by fiber properties such as length and stiffness as well as the number density and fiber-fiber interactions. Studies of fiber network behavior, such as connectivity or rigidity thresholds, typically assume monodisperse fiber lengths and isotropic fiber orientation distributions, specifically for nano scale fibers, where the methods providing time-resolved measurements are limited. Using birefringence measurements in a microfluidic flow-focusing channel combined with a flow stop procedure, we here propose a methodology allowing investigations of length-dependent rotational dynamics of nanoscale polydisperse fiber suspensions, including the effects of initial nonisotropic orientation distributions. Transition from rotational mobility to rigidity at entanglement thresholds is specifically addressed for a number of nanocellulose suspensions, which are used as model nanofiber systems. The results show that the proposed method allows the characterization of the subtle interplay between Brownian diffusion and nanoparticle alignment on network dynamics.

  • 278.
    Brouzet, Christophe
    et al.
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Mittal, Nitesh
    KTH, School of Engineering Sciences (SCI), Mechanics. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW.
    Söderberg, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics.
    Lundell, Fredrik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center. KTH, School of Engineering Sciences (SCI), Centres, Linné Flow Center, FLOW. KTH, School of Engineering Sciences (SCI), Mechanics.
    Size-Dependent Orientational Dynamics of Brownian Nanorods2018In: ACS Macro Letters, E-ISSN 2161-1653, Vol. 7, no 8, p. 1022-1027Article in journal (Refereed)
    Abstract [en]

    Successful assembly of suspended nanoscale rod-like particles depends on fundamental phenomena controlling rotational and translational diffusion. Despite the significant developments in fluidic fabrication of nanostructured materials, the ability to quantify the dynamics in processing systems remains challenging. Here we demonstrate an experimental method for characterization of the orientation dynamics of nanorod suspensions in assembly flows using orientation relaxation. This relaxation, measured by birefringence and obtained after rapidly stopping the flow, is deconvoluted with an inverse Laplace transform to extract a length distribution of aligned nanorods. The methodology is illustrated using nanocelluloses as model systems, where the coupling of rotational diffusion coefficients to particle size distributions as well as flow-induced orientation mechanisms are elucidated. 

  • 279.
    Brumboiu, Iulia
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology. Korea Adv Inst Sci & Technol, Dept Chem, Daejeon 34141, South Korea..
    Eriksson, Olle
    Uppsala Univ, Dept Phys & Astron, SE-75120 Uppsala, Sweden..
    Norman, P.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
    Atomic photoionization cross sections beyond the electric dipole approximation2019In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 150, no 4, article id 044306Article in journal (Refereed)
    Abstract [en]

    A methodology is developed to compute photoionization cross sections beyond the electric dipole approximation from response theory, using Gaussian type orbitals and plane waves for the initial and final states, respectively. The methodology is applied to compute photoionization cross sections of atoms and ions from the first four rows of the periodic table. Analyzing the error due to the plane wave description of the photoelectron, we find kinetic energy and concomitant photon energy thresholds above which the plane wave approximation becomes applicable. The correction introduced by going beyond the electric dipole approximation increases with photon energy and depends on the spatial extension of the initial state. In general, the corrections are below 10% for most elements, at a photon energy reaching up to 12 keV. 2019 Author(s).

  • 280.
    Brumboiu, Iulia
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Theoretical Chemistry and Biology.
    Haldar, Soumyajyoti
    Luder, Johann
    Eriksson, E.
    Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden..
    Herper, Heike C.
    Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden..
    Brena, Barbara
    Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden..
    Sanyal, Biplab
    Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden..
    Ligand Effects on the Linear Response Hubbard U: The Case of Transition Metal Phthalocyanines2019In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 123, no 14, p. 3214-3222Article in journal (Refereed)
    Abstract [en]

    It is established that density functional theory (DFT) + U is a better choice compared to DFT for describing the correlated electron metal center in organometallics. The value of the Hubbard U parameter may be determined from linear response, either by considering the response of the metal site alone or by additionally considering the response of other sites in the compound. We analyze here in detail the influence of ligand shells of increasing size on the U parameter calculated from the linear response for five transition metal phthalocyanines. We show that the calculated multiple-site U ligand atoms that are mainly responsible for this difference are is larger than the single-site U by as much as 1 eV and the ligand atoms that are mainly responsible for this difference are the isoindole nitrogen atoms directly bonded to the central metal atom. This suggests that a different U value may be required for computations of chemisorbed molecules compared to physisorbed and gas-phase cases.

  • 281. Brumer, Harry
    et al.
    Rutland, Mark W.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Sinnot, Michael
    Teeri, Tuula
    Zhou, Qi
    Crosslinking involving a polymeric carbohydrate material2006Patent (Other (popular science, discussion, etc.))
  • 282.
    Brusini, Irene
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Carneiro, Miguel
    Univ Porto, Ctr Invest Biodiversidade & Recursos Genet CIBIO, InBIO, P-4485661 Vairao, Portugal.;Univ Porto, Dept Biol, Fac Ciencias, P-4169007 Porto, Portugal..
    Wang, Chunliang
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Rubin, Carl-Johan
    Uppsala Univ, Sci Life Lab Uppsala, Dept Med Biochem & Microbiol, S-75236 Uppsala, Sweden..
    Ring, Henrik
    Uppsala Univ, Dept Neurosci, S-75236 Uppsala, Sweden..
    Afonso, Sandra
    Univ Porto, Ctr Invest Biodiversidade & Recursos Genet CIBIO, InBIO, P-4485661 Vairao, Portugal..
    Blanco-Aguiar, Jose A.
    Univ Porto, Ctr Invest Biodiversidade & Recursos Genet CIBIO, InBIO, P-4485661 Vairao, Portugal.;CSIC, Inst Invest Recursos Cineget IREC, Ciudad Real 13005, Spain.;UCLM, CSIC, Ciudad Real 13005, Spain..
    Ferrand, Nuno
    Univ Porto, Ctr Invest Biodiversidade & Recursos Genet CIBIO, InBIO, P-4485661 Vairao, Portugal.;Univ Porto, Dept Biol, Fac Ciencias, P-4169007 Porto, Portugal.;Univ Johannesburg, Dept Zool, ZA-2006 Auckland Pk, South Africa..
    Rafati, Nima
    Uppsala Univ, Sci Life Lab Uppsala, Dept Med Biochem & Microbiol, S-75236 Uppsala, Sweden..
    Villafuerte, Rafael
    CSIC, IESA, Cordoba 14004, Spain..
    Smedby, Örjan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Damberg, Peter
    Karolinska Univ Hosp, Karolinska Expt Res & Imaging Ctr, S-17176 Solna, Sweden..
    Hallbook, Finn
    Uppsala Univ, Dept Neurosci, S-75236 Uppsala, Sweden..
    Fredrikson, Mats
    Uppsala Univ, Dept Psychol, S-75236 Uppsala, Sweden.;Karolinska Inst, Dept Clin Neurosci, S-17177 Stockholm, Sweden..
    Andersson, Leif
    Uppsala Univ, Sci Life Lab Uppsala, Dept Med Biochem & Microbiol, S-75236 Uppsala, Sweden.;Texas A&M Univ, Coll Vet Med & Biomed Sci, Dept Vet Integrat Biosci, College Stn, TX 77843 USA.;Swedish Univ Agr Sci, Dept Anim Breeding & Genet, S-75007 Uppsala, Sweden..
    Changes in brain architecture are consistent with altered fear processing in domestic rabbits2018In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, no 28, p. 7380-7385Article in journal (Refereed)
    Abstract [en]

    The most characteristic feature of domestic animals is their change in behavior associated with selection for tameness. Here we show, using high-resolution brain magnetic resonance imaging in wild and domestic rabbits, that domestication reduced amygdala volume and enlarged medial prefrontal cortex volume, supporting that areas driving fear have lost volume while areas modulating negative affect have gained volume during domestication. In contrast to the localized gray matter alterations, white matter anisotropy was reduced in the corona radiata, corpus callosum, and the subcortical white matter. This suggests a compromised white matter structural integrity in projection and association fibers affecting both afferent and efferent neural flow, consistent with reduced neural processing. We propose that compared with their wild ancestors, domestic rabbits are less fearful and have an attenuated flight response because of these changes in brain architecture.

  • 283.
    Brusini, Irene
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Jörgens, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Smedby, Örjan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Moreno, Rodrigo
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Dependency of neural tracts'€™ curvature estimations on tractography methods2017Conference paper (Refereed)
  • 284.
    Brusini, Irene
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Jörgens, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Smedby, Örjan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Moreno, Rodrigo
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Influence of Tractography Algorithms and Settings on Local Curvature Estimations2017Conference paper (Refereed)
  • 285.
    Brusini, Irene
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Jörgens, Daniel
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Smedby, Örjan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Moreno, Rodrigo
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Voxel-Wise Clustering of Tractography Data for Building Atlases of Local Fiber Geometry2019Conference paper (Refereed)
    Abstract [en]

    This paper aims at proposing a method to generate atlases of white matter fibers’ geometry that consider local orientation and curvature of fibers extracted from tractography data. Tractography was performed on diffusion magnetic resonance images from a set of healthy subjects and each tract was characterized voxel-wise by its curvature and Frenet–Serret frame, based on which similar tracts could be clustered separately for each voxel and each subject. Finally, the centroids of the clusters identified in all subjects were clustered to create the final atlas. The proposed clustering technique showed promising results in identifying voxel-wise distributions of curvature and orientation. Two tractography algorithms (one deterministic and one probabilistic) were tested for the present work, obtaining two different atlases. A high agreement between the two atlases was found in several brain regions. This suggests that more advanced tractography methods might only be required for some specific regions in the brain. In addition, the probabilistic approach resulted in the identification of a higher number of fiber orientations in various white matter areas, suggesting it to be more adequate for investigating complex fiber configurations in the proposed framework as compared to deterministic tractography.

  • 286.
    Bryngelsson, Erik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Manufacturing optimization and film stability analysis of PbS quantum dot solar cells2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Semiconductor colloidal quantum dots have an interesting potential to increase solar cell efficiency, with strong absorption in the infrared region and a tunable band gap. In this work an attempt was made to adopt a manufacturing process for PbS quantum dot solar cells, proven successful at Uppsala University. Two optimizations were investigated and the stability of the quantum dot films was analyzed with regards to three storage conditions, varying oxygen accessibility and light exposure, and measured with UV-Vis spectroscopy and X-ray photoelectron spectroscopy. Functioning solar cells were obtained but with lower performance than the results from Uppsala. Optimizations were partly successful with regards to improved spreading of the EDT solution on the PbS quantum dot film using ethanol and methanol as solvents. No improved cell performance was observed by applying both QD films inside argon atmosphere, as opposed to only the first one. Clear differences in oxidization of the films and loss of iodine ligand could be identified for the different storage conditions, with best stability exhibited by films stored under argon atmosphere.

  • 287.
    Brännström, Sara
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Exploring bio-based monomers for UV-curable polymer networks2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Increased environmental awareness and concern has led to a high demand for sustainable, bio-based materials. Consequently, there is a need for research and development of new bio-based polymeric materials that can be synthesized via routes eliminating excessively toxic reactants and by-products. The work presented in this thesis has focused on the utilization of catalysis, mainly enzymatic, and photopolymerization in order to create efficient synthesis of polymeric networks from bio-based monomers.Polyesters from bio-based monomers have been polymerized in bulk and thereafter crosslinked by UV initiation to yield polymer networks with tunable properties. The synthesis was also studied more in detail by varying the different types of catalysts and comparing their effect on the polymer products. Polyesters are a promising class of polymers that can be made from bio-based resources due to the wide range of available bio-based carboxylic acids and alcohols that can be combined to yield many polymers with different properties. However, the synthesis of polyesters is rather time-consuming in order to reach high conversions.As a more efficient alternative, short chain esters monomers and oligomers that have vinyl ether (VE) functionalities were developed. These VE-esters can be synthesized partly from bio-based resources, such as acids, fatty acids and diols, and their synthesis is efficient with enzymatic catalysis. The VE functionality provides a reactive group which can be polymerized rapidly with cationic polymerization. In general, the vinyl ether-esters can be synthesized in less than one hour and crosslinked within a few minutes, which is significantly faster than traditional polyester-synthesis and crosslinking. The enzymatic synthesis of vinyl ether esters also provided a method for developing monomers with orthogonal functionality which was explored by developing functionalizable materials with a variety of macromolecular architectures.

  • 288.
    Brännström, Sara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Finnveden, Maja
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Martinelle, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Itaconate based polyesters: Selectivity and performance of esterification catalysts2018In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 103, p. 370-377Article in journal (Refereed)
    Abstract [en]

    The performance of different esterification catalysts was studied for the use in synthesis of renewable polyesters from dimethyl itaconate (DMI), dimethyl succinate (DMS) and 1,4-butanediol (BD). Itaconic acid and derivatives such as DMI are interesting monomers because of their multiple functionalities and previous work has shown great potential. However, the multiple functionalities also pose challenges to avoid side reactions such as thermally initiated, premature, radical crosslinking and/or isomerization of the 1,1-disubstituted unsaturation. Additionally, the two carboxylic acids have inherently different reactivity. One key factor to control reactions with IA is to understand the performance of different catalysts. In this study, six esterification catalysts were investigated; immobilized Candida antarctica lipase B (CalB), titanium(IV)butoxide (Ti(OBu)4), p-toluenesulfonic acid (pTSA), sulfuric acid (H2SO4), 1,8-diazabicycloundec-7-ene (DBU), and 1,5,7-triazabicyclodec-5-ene (TBD). CalB and Ti(OBu)4 were selected for further characterization with appreciable differences in catalytic activity and selectivity towards DMI. CalB was the most effective catalysts and was applied at 60 °C while Ti(OBu)4 required 160 °C for a reasonable reaction rate. CalB was selective towards DMS and the non-conjugated side of DMI, resulting in polyesters with itaconate-residues mainly located at the chain ends, while Ti(OBu)4 showed low selectivity, resulting in polyesters with more randomly incorporated itaconate units. Thermal analysis of the polyesters showed that the CalB-catalyzed polyesters were semi-crystalline, whereas the Ti(OBu)4-catalyzed polyesters were amorphous, affirming the difference in monomer sequence. The polyester resins were crosslinked by UV-initiated free radical polymerization and the material properties were evaluated and showed that the crosslinked materials had similar material properties. The films from the polyester resins catalyzed by CalB were furthermore completely free from discoloration whereas the film made from the polyester resins catalyzed with Ti(OBu)4 had a yellow color, caused by the catalyst. Thus, it has been shown that CalB can be used to attain sustainable unsaturated polyesters resins for coating applications, exhibiting equally good properties as resins obtained from traditional metal-catalysis.

  • 289.
    Brännström, Sara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Finnveden, Maja
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Razza, Nicolo
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Martinelle, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sangermano, Marco
    Politecn Torino, Dept Appl Sci & Technol, Corso Duca Abruzzi 24, I-10129 Turin, Italy..
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Tailoring Thermo-Mechanical Properties of Cationically UV-Cured Systems by a Rational Design of Vinyl Ether Ester Oligomers using Enzyme Catalysis2018In: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 219, no 21, article id 1800335Article in journal (Refereed)
    Abstract [en]

    There is a demand for new sustainable polymeric materials. Vinyl ethers are, in this context, attractive oligomers since they polymerize fast, are non-toxic, and can be polymerized under ambient conditions. The availability of vinyl ether oligomers is, however, currently limited due to difficulties in synthesizing them without using tedious synthesis routes. This work presents the synthesis of a series of vinyl ether ester oligomers using enzyme catalysis under solvent-free conditions and the subsequent photoinduced cationic polymerization to form polymer thermosets with T(g)s ranging from -10 to 100 degrees C. The whole process is very efficient as the synthesis takes less than 1 h with no need for purification and the crosslinking is complete within 2 min.

  • 290.
    Brännström, Sara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Enzymatically Synthesized Vinyl Ether-Disulfide Monomer Enabling an Orthogonal Combination of Free Radical and Cationic Chemistry toward Sustainable Functional Networks2019In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 3, p. 1308-1316Article in journal (Refereed)
    Abstract [en]

    This work demonstrates a versatile and environmentally friendly route for the development of new orthogonal monomers that can be used for postfunctionalizable polymer networks. A monomer containing both vinyl ether (VE) and cyclic disulfide moieties was synthesized via enzyme catalysis under benign reaction conditions. The bifunctional monomer could be polymerized to form macromolecues with differing architectures by the use of either cationic or radical photo polymerization. When cationic polymerization was performed, a linear polymer was obtained with pendant disulfide units in the side chain, whereas in the presence of radical initiator, the VE reacted with the disulfide to yield a branched structure. The monomer was thereafter used to design networks that could be postfunctionalized; the monomer was cross-linked with cationic initiation together with a difunctional VE oligomer and after cross-linking the unreacted disulfides were coupled to Rhodamine-VE by radical UV-initiation

  • 291.
    Brännström, Sara
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Johansson, Mats
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Malmström, Eva
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology, Coating Technology.
    Enzymatically Synthesized Vinyl Ether-Disulfide Monomer Enablingan Orthogonal Combination of Free Radical and Cationic Chemistrytoward Sustainable Functional Networks2019In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 3, p. 1308-1316, article id 10.1021/acs.biomac.8b01710Article in journal (Refereed)
    Abstract [en]

    This work demonstrates a versatile and environmentally friendly route for the development of new orthogonal monomers that can be used for postfunctionalizable polymer networks. A monomer containing both vinyl ether (VE) and cyclic disulfide moieties was synthesized via enzyme catalysis under benign reaction conditions. The bifunctional monomer could be polymerized to form macromolecues with differing architectures by the use of either cationic or radical photo polymerization. When cationic polymerization was performed, a linear polymer was obtained with pendant disulfide units in the side chain, whereas in the presence of radical initiator, the VE reacted with the disulfide to yield a branched structure. The monomer was thereafter used to design networks that could be postfunctionalized; the monomer was cross-linked with cationic initiation together with a difunctional VE oligomer and after cross-linking the unreacted disulfides were coupled to RhodamineVE by radical UV-initiation.

  • 292.
    Budnyak, Tetyana
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Aminzadeh, Selda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Pylypchuk, Ievgen
    Department of Molecular Sciences, Swedish University of Agricultural Sciences (SLU), Allmas alle 5, SE-750 07 Uppsala, Swede.
    Riazanova, Anastasiia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Tertykh, Valentin
    Chuiko Institute of Surface Chemistry, National Academy of Sciences of Ukraine, 17 General Naumov Str., 03164 Kyiv, Ukraine.
    Lindström, Mikael
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sevastyanova, Olena
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Peculiarities of synthesis and properties of lignin-silica nanocomposites prepared by sol-gel method2018In: Nanomaterials, ISSN 2079-4991, Vol. 8, no 11, p. 1-18, article id 950Article in journal (Refereed)
    Abstract [en]

    The development of advanced hybrid materials based on polymers from biorenewable sources and mineral nanoparticles is currently of high importance. In this paper, we applied softwood kraft lignins for the synthesis of lignin/SiO2 nanostructured composites. We described the peculiarities of composites formation in the sol-gel process through the incorporation of the lignin into a silica network during the hydrolysis of tetraethoxysilane (TEOS). The initial activation of lignins was achieved by means of a Mannich reaction with 3-aminopropyltriethoxysilane (APTES). In the study, we present a detailed investigation of the physicochemical characteristics of initial kraft lignins and modified lignins on each step of the synthesis. Thus, 2D-NMR, P-31-NMR, size-exclusion chromatography (SEC) and dynamic light scattering (DLS) were applied to analyze the characteristics of pristine lignins and lignins in dioxan:water solutions. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) were used to confirm the formation of the lignin-silica network and characterize the surface and bulk structures of the obtained hybrids. Termogravimetric analysis (TGA) in nitrogen and air atmosphere were applied to a detailed investigation of the thermal properties of pristine lignins and lignins on each step of modification. SEM confirmed the nanostructure of the obtained composites. As was demonstrated, the activation of lignin is crucial for the sol-gel formation of a silica network in order to create novel hybrid materials from lignins and alkoxysilanes (e.g., TEOS). It was concluded that the structure of the lignin had an impact on its reactivity during the activation reaction, and consequently affected the properties of the final hybrid materials.

  • 293.
    Budnyak, Tetyana M.
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov Str, UA-03164 Kiev, Ukraine..
    Aminzadeh, Selda
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Pylypchuk, Ievgen V.
    Swedish Univ Agr Sci SLU, Dept Mol Sci, Allmas Alle 5, SE-75007 Uppsala, Sweden..
    Sternik, Dariusz
    Marie Curie Sklodowska Univ, 2 M Curie Sklodowska Sq, PL-20031 Lublin, Poland..
    Tertykh, Valentin A.
    Natl Acad Sci Ukraine, Chuiko Inst Surface Chem, 17 Gen Naumov Str, UA-03164 Kiev, Ukraine..
    Lindström, Mikael E.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Sevastyanova, Olena
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Methylene Blue dye sorption by hybrid materials from technical lignins2018In: Journal of Environmental Chemical Engineering, ISSN 2160-6544, E-ISSN 2213-3437, Vol. 6, no 4, p. 4997-5007Article in journal (Refereed)
    Abstract [en]

    New hybrid sorbents were synthesized from technical lignins and silica and were applied for the removal of Methylene Blue dye (MB) from aqueous solution. Kraft softwood lignins from LignoBoost (LBL) and CleanFlowBlack (CFBL) processes were used to understand the influence of molecular weight and functionality of initial lignins on the properties of the final hybrids. The synthesized materials were applied as adsorbents for the removal of MB from aqueous solutions. The effects of parameters such as contact time, initial concentration of dye and initial pH on the adsorption capacity were evaluated. The hybrids exhibited higher adsorption capacity than the initial macromolecules of lignin with respect to MB. The hybrid based on CFBL exhibited an adsorption capacity of 60 mg/g; this value was 30% higher than the capacity of the hybrid based on LBL, which was 41.6 mg/g. Lignin hybrid materials extract 80-99% of the dye in a pH range from 3 to 10. The equilibrium and kinetic characteristics of MB uptake by the hybrids followed the Langmuir isotherm model and pseudosecond-order model, rather than the Freundlich and Temkin models, the pseudo-first-order or the intraparticle diffusion model. The attachment of the dye to the hybrid surface was confirmed via FE-SEM and FTIR spectroscopy. The mechanism for MB adsorption was proposed. Due to the high values of regeneration efficiency of the surface of both lignin-silica hybrid materials in 0.1 M HCl (up to 75%) and ethanol (99%), they could be applied as effective sorbents in industrial wastewater treatment processes.

  • 294.
    Buizza, Giulia
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems. Politecn Milan, CartCasLab, Dept Elect Informat & Bioengn, Piazza Leonardo Da Vinci 42, I-20133 Milan, Italy..
    Toma-Dasu, Iuliana
    Karolinska Univ Sjukhuset, Karolinska Inst, Dept Oncol Pathol, Med Radiat Phys, S-17176 Solna, Sweden..
    Lazzeroni, Marta
    Karolinska Univ Sjukhuset, Karolinska Inst, Dept Oncol Pathol, Med Radiat Phys, S-17176 Solna, Sweden..
    Paganelli, Chiara
    Politecn Milan, CartCasLab, Dept Elect Informat & Bioengn, Piazza Leonardo Da Vinci 42, I-20133 Milan, Italy..
    Riboldi, Marco
    Politecn Milan, CartCasLab, Dept Elect Informat & Bioengn, Piazza Leonardo Da Vinci 42, I-20133 Milan, Italy.;Ludwig Maximilians Univ Munchen, Fac Phys, Coloumbwall 1, D-5748 Garching, Germany..
    Chang, Yong Jun
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems.
    Smedby, Örjan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Wang, Chunliang
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Medical Imaging.
    Early tumor response prediction for lung cancer patients using novel longitudinal pattern features from sequential PET/CT image scans2018In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 54, p. 21-29Article in journal (Refereed)
    Abstract [en]

    Purpose: A new set of quantitative features that capture intensity changes in PET/CT images over time and space is proposed for assessing the tumor response early during chemoradiotherapy. The hypothesis whether the new features, combined with machine learning, improve outcome prediction is tested. Methods: The proposed method is based on dividing the tumor volume into successive zones depending on the distance to the tumor border. Mean intensity changes are computed within each zone, for CT and PET scans separately, and used as image features for tumor response assessment. Doing so, tumors are described by accounting for temporal and spatial changes at the same time. Using linear support vector machines, the new features were tested on 30 non-small cell lung cancer patients who underwent sequential or concurrent chemoradiotherapy. Prediction of 2-years overall survival was based on two PET-CT scans, acquired before the start and during the first 3 weeks of treatment. The predictive power of the newly proposed longitudinal pattern features was compared to that of previously proposed radiomics features and radiobiological parameters. Results: The highest areas under the receiver operating characteristic curves were 0.98 and 0.93 for patients treated with sequential and concurrent chemoradiotherapy, respectively. Results showed an overall comparable performance with respect to radiomics features and radiobiological parameters. Conclusions: A novel set of quantitative image features, based on underlying tumor physiology, was computed from PET/CT scans and successfully employed to distinguish between early responders and non-responders to chemoradiotherapy.

  • 295.
    Bujak, Klaudia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    Kartläggning av analysmetoder för mikroplaster från konstgräsplaner2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The presence of microplastics in marine and sedimentary environments is a relatively new problem. Presently, there are no clear standards to which methods that should be implored with sampling, treating and analysing microplastics. Because of this, some troubles occur when estimating field concentrations and comparing microplastics flow and composition.

    Artificial turf plants have been considered to be the second largest source of microplastic emissions in Sweden. Pre-emptive measures have been taken in several regions in Sweden in order to decrease spreading of microplastics. Because of this, it is important to be able to measure the amount of microplastics in marine environment and sediment in order to monitor how it changes when using different methods.

    The purpose of this study is to increase the knowledge of the methods available and suitable for sampling, treatment and analysis of microplastics from artificial turf in water and sediment environments.

    The aim is to provide a suggestion of measurement methods that may be suitable for analysis of microplastics from artificial turf in Ältasjön.

    In order to clarify the importance of a holistic view of the microplastics, an analytical chain has been developed. It is regarded to be a useful tool in order to further the develop a standardized method for the entire analytical process, from sampling to interpretation of results. This analytical chain is comprised by four major steps: sampling, laboratory preparation of samples, analysis and interpretation of the results.

    Sampling will be of crucial importance for the evaluation of final results, because the sampling efficiency has direct impact on the content of the sample which will proceed to the analysis. There are no standardized procedures for sampling of microplastics with regard to location, sampling equipment, volumes and sampling time. This results in a limited comparability with previous studies.

    The treatment is usually comprised of volume reduction, density separation and chemical or enzymatic purification. These treatment methods need to be adapted in regard to the expected content of the sample and the chosen analytical method.

    Analysis of microplastic could be done with the help of optical, spectrophotometric or chromatographic methods. The optical analysis enables to monitor the particles physical properties such as size, shape, colour and degree of degradation. The spectrophotometric and chromatographic methods provide information about chemical composition, polymer type and the additive content of microplastics. These methods investigate different properties and therefore they result in different answers. Each technique should be thought of and analysed from the information that is provided. Also, all analytic methods have different detection limits. These detection limits vary between and it is important to take into consideration when choosing the correct analytical method.

    If different studies use the same methods to gain the desired information, the results will be more easily compared. The combined results will help to complete more of the missing information and improve the monitoring of microplastics spreading to marine environments and sediment. Provided that all studies not only follow the same methods but also the same analytical chain from sampling to analyzing the results.

    From the information and knowledge that was gathered, it is expected that Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM-EDS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has the biggest potential to efficiently measure microplastics from artificial turf in water environment and sediment. Both SEM-EDS and ICP-MS makes it possible to detect all types of granulate and plastic straws from artificial turf even when the grain is between 10 and 20 mm. Further studies of these methods are recommended to build a reference library for each respective method and to find a working standard method when analysing microplastic from artificial grass.

  • 296.
    Busson, B.
    et al.
    Univ Paris Saclay, Univ Paris Sud, Lab Chim Phys, CNRS, Batiment 201 P2, F-91405 Orsay, France..
    Dalstein, Laetitia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Univ Paris Saclay, Univ Paris Sud, Lab Chim Phys, CNRS, Batiment 201 P2, F-91405 Orsay, France.;KTH Royal Inst Technol, Dept Chem, Sch Chem Sci & Engn, SE-10044 Stockholm, Sweden.;Acad Sinica, Inst Phys, Taipei 11529, Taiwan..
    Nonlinear optical response of a gold surface in the visible range: A study by two-color sum-frequency generation spectroscopy. III. Simulations of the experimental SFG intensities2018In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 149, no 15, article id 154701Article in journal (Refereed)
    Abstract [en]

    We model the amplitude line shape and absolute phase of the infrared-visible sum-frequency signals produced by a thiolated polycrystalline gold surface as a function of the visible wavelength. We follow two hypotheses: in the interband scenario, the resonant features are attributed to interband transitions, whereas in the effective surface state scenario, they stem mostly from the excitation of surface transitions. We find that both scenarios lead to a satisfactory account of the experimental data and that only free electrons may spill out of the gold bulk, as expected. For the interband scenario, the balance between free and bound electron contributions to sum-frequency generation has to be adjusted to fit the data. The surface transitions are shown to take their origin inside gold and we investigate the surface states involved in such transitions, with a comparison to the silver surfaces. We finally provide a work program dedicated to discriminate between the two scenarios. Published by AIP Publishing.

  • 297.
    Butchosa, Nuria
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Leijon, Felicia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Bulone, Vincent
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Zhou, Qi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Stronger cellulose microfibril network structure through the expression of cellulose-binding modules in plant primary cell walls2019In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, no 5, p. 3083-3094Article in journal (Refereed)
    Abstract [en]

    Cellulose-binding modules (CBMs) are non-catalytic domains typically occurring in glycoside hydrolases. Their specific interaction with diverse polysaccharides assists hydrolysis by the catalytic subunits. In this work, we have exploited the interactions between a CBM from family 3 (CBM3) and cell wall polysaccharides to alter the structure and mechanical properties of cellulose microfibrils from BY-2 tobacco cell suspension cultures. A CBM3 from Clostridium thermocellum was overexpressed in the cells using Agrobacterium-mediated transformation. Water suspensions of cellulose microfibrils were prepared by the removal of the non-cellulosic components of the primary cell walls, followed by mild disintegration using sonication. The morphology of the microfibrils was characterized by transmission electron microscopy and atomic force microscopy. These cellulose microfibrils were further hydrolyzed with 64wt% sulfuric acid to produce cellulose nanocrystals (CNCs). The average length of CNCs prepared from the CBM3-transformed cells was 201nm, higher than that from the wild-type cells (122nm). In addition, the mechanical properties and deformation mechanism of nanopapers prepared from suspensions of cellulose microfibrils were investigated. The nanopapers obtained from the CBM3-transformed cells exhibited enhanced tensile strength and work of fracture, 40% and 128% higher than those prepared from wild-type tobacco cells, respectively. [GRAPHICS] .

  • 298. Butchosa, Núria
    et al.
    Leijon, Felicia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Bulone, Vincent
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Zhou, Qi
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Stronger cellulose microfibrils network structure through the expression of cellulose-binding modules in plant primary cell wallsManuscript (preprint) (Other academic)
  • 299.
    Bylerius, Patrik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    Positionering av tågvagn med hjälp av ett Kalmanfilter2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Positioning of railcars is an important part of the railway industry. In Sweden there are 1000 of trains on the railway which leads to a security risk if a railcar is lost.

    This project examined if it were possible to position a railcar in real time using Kalman filter on a raspberry pi with the variable’s latitude and longitude. The project also examined if the Kalman filter could replace an GPS were there was no coverage in that area.

    A prototype was produced and evaluated with a Kalman filter programmed and implemented on it together with a GPS-module. Simulations of several values was made to secure the values that the algorithm did show.

    The prototype shows that the method in this project is within the error margin that the railway demands for a safe system. The results show a deviation of the position that was sought after with the Kalman filter. The coordinates for latitude had a difference of 0,9 m compared to the Kalman filter that was programmed. Longitude also had a difference but with 0,001 m compared to the values that the GPS-module generated.

  • 300.
    Bäbler, Matthäus
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Liberzon, A.
    Saha, D.
    Holzner, M.
    Soos, M.
    Lüthi, B.
    Kinzelbach, W.
    Breakup of individual colloidal aggregates in turbulent flow investigated by 3D particle tracking velocimetry2018In: Multiphase Flow Phenomena and Applications: Memorial Volume in Honor of Gad Hetsroni, World Scientific Publishing Co. Pte. Ltd. , 2018, p. 83-96Chapter in book (Other academic)
    Abstract [en]

    Aggregates grown in mild shear flow are released, one at a time, into homogeneous isotropic turbulence where their breakup is recorded by three-dimensional particle tracking velocimetry (3D-PTV). The aggregates have an open structure with fractal dimension around 2.2, and their size varies from 0.9 to 3.1 mm which is large compared to the Kolmogorov length scale η = 0.15 mm. 3D-PTV allows for the simultaneous measurement of aggregate trajectories and the full velocity gradient tensor along their pathlines which enables us to access the Lagrangian stress history of individual breakup events. The analysis suggests that aggregates are mostly broken due to accumulation of drag stress over a time interval of order Kolmogorov time scale, O(τη). This finding is explained by the fact that the aggregates are large, which gives their motion inertia and which increases the time for stress propagation inside the aggregate.

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