Change search
Refine search result
47484950 2451 - 2463 of 2463
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 2451. Çakir, S.
    et al.
    Eriksson, Magnus
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Martinelle, Mats
    KTH, School of Biotechnology (BIO), Industrial Biotechnology.
    Koning, C. E.
    Multiblock copolymers of polyamide 6 and diepoxy propylene adipate obtained by solid state polymerization2016In: European Polymer Journal, ISSN 0014-3057, E-ISSN 1873-1945, Vol. 79, p. 13-22Article in journal (Refereed)
    Abstract [en]

    Polyesteramide multiblock copolymers based on polyamide 6 and diepoxy propylene adipate blocks were synthesized. For this purpose a carboxyl-terminated polyamide 6 (Mn = 2400 g/mol, Tm = 205.5 °C) and diepoxy propylene adipate (Mn = 450 g/mol) were separately synthesized and characterized. The incorporation of the oligoester into the polyamide 6 backbone was performed by solid state polymerization (SSP) well below the melting temperature of the polyamide (80-140 °C) so that the physical and thermal properties of the original polyamide 6 block were retained. Formation of the multiblock structure was confirmed by following the increase in molecular weight by SEC, reaction of the end groups by 1H NMR and by following the maintained melting temperature after the copolymerization. These segmented copolymers have molecular weights up to 10 kg/mol, thermal stability of 325 °C at 5% weight loss and a melting temperature of 205 °C.

  • 2452.
    Öberg, Emma
    KTH, School of Chemical Science and Engineering (CHE).
    Investigation of mineral oils as a compatibilizer between metallocene polyolefins and rosin resins in hot melt adhesives2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Limning är en gammal fogningsteknik som har många olika användningsområden. Marknaden för limmer växer, smältlim förväntas ha stor tillväxt även med hårdare miljölagstiftning då appliceringen av limmet sker utan lösningsmedel.

    För att ta fram och tillverka lim används idag polymerer i stor utsträckning. Metallocen polyolefin (mPO) är en typ av polymer som används i limmer på grund av dess utmärkta prestanda som uppnås genom en smal molekylviktsdistribution (MWD). Detta gör det lätt att tillverka limmer med önskade egenskaper. Den här typen av polymerer tenderar dock att vara opolära vilket gör att de är inkompatibla med tallhartser, som ger klibbighet till limmet, eftersom tallhartserna har en högre poläritet.

    Mineraloljor används i limmer som mjukgörare, men används också i vissa fall för att öka kompabiliteten i olika typer av limmer. Därför har det undersökts om de kan användas i limmer med mPO och tallharts för att öka kompabiliteten.

    ”Cloud point”-tester och reologistudier har utförts för att undersöka om kompabiliteten påverkades av tillsatt mineral olja. Peel tester har också utförts för att mäta limegenskaperna för formuleringarna av smältlim.

    Resultaten visar att även om formuleringarna av smältlim har relativt låg peel styrka, så ökade kompabiliteten signifikant mellan mPO och tallhartser vid användning av mineraloljor.

  • 2453.
    Öberg Hed, Kim
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Coating Technology.
    Advanced polymeric scaffolds for functional materials in biomedical applications2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Advancements in the biomedical field are driven by the design of novel materials with controlled physical and bio-interactive properties. To develop such materials, researchers rely on the use of highly efficient reactions for the assembly of advanced polymeric scaffolds that meet the demands of a functional biomaterial. In this thesis two main strategies for such materials have been explored; these include the use of off-stoichiometric thiol-ene networks and dendritic polymer scaffolds. In the first case, the highly efficient UV-induced thiol-ene coupling (TEC) reaction was used to create crosslinked polymeric networks with a predetermined and tunable excess of thiol or ene functionality. These materials rely on the use of readily available commercial monomers. By adopting standard molding techniques and simple TEC surface modifications, patterned surfaces with tunable hydrophobicity could be obtained. Moreover, these materials are shown to have great potential for rapid prototyping of microfluidic devices. In the second case, dendritic polymer scaffolds were evaluated for their ability to increase surface interactions and produce functional 3D networks. More specifically, a self-assembled dendritic monolayer approach was explored for producing highly functional dendronized surfaces with specific interactions towards pathogenic E. coli bacteria. Furthermore, a library of heterofunctional dendritic scaffolds, with a controllable and exact number of dual-purpose azide and ene functional groups, has been synthesized. These scaffolds were explored for the production of cell interactive hydrogels and primers for bone adhesive implants. Dendritic hydrogels decorated with a selection of bio-relevant moieties and with Young’s moduli in the same range as several body tissues could be produced by facile UV-induced TEC crosslinking. These gels showed low cytotoxic response and relatively rapid rates of degradation when cultured with normal human dermal fibroblast cells. When used as primers for bone adhesive patches, heterofunctional dendrimers with high azide-group content led to a significant increase in the adhesion between a UV-cured hydrophobic matrix and the wet bone surface (compared to patches without primers).

  • 2454.
    Öberg, Viktor
    KTH, School of Chemical Science and Engineering (CHE).
    Macroalgae as a renewable resource: Extraction and Characterization of the Major Components in Saccharina Latissima2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A fractionation strategy was developed that made it possible to extract alginate, mannitol, laminarin and cellulose under various conditions from the brown algae Saccharina Latissima (previously known as Laminara Saccharina). The algae were harvested on the west coast of Sweden in the late summer of 2013. After extraction, the alginate and mannitol samples were identified and characterized using 1H nuclear magnetic resonance (1H NMR), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The yield of alginate (in its sodium salt form) was estimated to be around 18,5 %, and the yield of mannitol was around 9 %. Mild hydrolysis and 1H NMR was performed on the alginate to estimate the ratio of mannuronic and guluronic acids, i.e. the M/G-ratio. The M/G-ratio was calculated to be around 1 for neutral batches and around 1,1 for batches extracted at low or high pH. Laminarin was identified and characterized by 1H NMR, FT-IR, TGA, size exclusion chromatography (SEC) and ion chromatography (IC). Approximately 12 % laminarin was extracted. Cellulose was identified and characterized by FT-IR and IC, and the yield was approximately 2,5 to 3,5 %.

    A three-level statistical factorial screening of the parameters temperature and pH was also performed using multiple linear regression (MLR) from 6 responses: the alginate, laminarin, cellulose, mannitol and total yield as well as the M/G-ratio. However, the yields of alginate, cellulose and mannitol were not possible to assess due to divergent data points. High temperature (75 °C) and pH 2 or 12 degrades alginate, thus decreasing the yield. The screening of laminarin yield showed that a decrease in pH had a significant positive effect. The screening of total yield indicated a negative effect when temperature was increased from 40 °C to 75 °C. At 3 or 40 °C, the M/G-ratio was significantly lower at neutral pH compared to those at pH 2 or 12. At 75 °C and pH 12, a degradation decreased the M/G-ratio to 0,83.

  • 2455.
    Ödborn, Sofia
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH).
    The Science of Deodorants2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Deodorants are cosmetic products that are consumed by people regularly and globally. In this thesis, the opportunities to develop a deodorant for the Swedish cosmetics brand IDUN Minerals AB is investigated. The deodorant market in Swedish pharmacies, deodorant formulation and deodorant packaging are studied. Furthermore, controversial ingredients, such as synthetic aluminum compounds, are explored.

    The scientific aspects of using synthetic aluminum compounds, which are used as antiperspirant in deodorants, are investigated. There is a general fear that they may increasethe risk of developing breast cancer. However, after a full review of exciting scientific evidence, it is clear that there is currently no study that can prove or disprove the suspicions. The use of aluminum-based antiperspirants therefore continues to be a controversial topic.

    The conclusion of this thesis is that there is a market opening for IDUN Minerals, especially since they aim for a synthetic aluminum-free, unperfumed and preservative-free deodorant. Furthermore, it is concluded that a Nordic Swan Ecolabel would make their product uniquein its product category. Lastly, it is determined that traditional plastic packaging is more accessible and possesses many favorable properties, but that bioplastics should be further researched.

  • 2456.
    Örnek, Cem
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science. KTH Royal Inst Technol, Sch Engn Sci Chem Biotechnol & Hlth, Div Surface & Corros Sci, Drottning Kristinas Vag 51, S-10044 Stockholm, Sweden..
    Stress Corrosion Cracking and Hydrogen Embrittlement of Type 316L Austenitic Stainless Steel Beneath MgCl2 and MgCl2: FeCl3 Droplets2019In: Corrosion, ISSN 0010-9312, E-ISSN 1938-159X, Vol. 75, no 6, p. 657-667Article in journal (Refereed)
    Abstract [en]

    The atmospheric corrosion, as well as environmentally assisted cracking behavior of 316L austenitic stainless steel (UNS S31603) beneath MgCl2 and MgCl2: FeCl3 droplets under elastic and elastic-plastic strain exposed for 6 months at 50 degrees C and 30% relative humidity were investigated. Shallow and deep corrosion sites with filiform corrosion along with stress corrosion cracking (SCC) were formed beneath the salt-laden droplets, and the potential role of hydrogen embrittlement (HE) and crevice corrosion in damage evolution elucidated. Elastic strain (0.1%) was sufficient to cause SCC cracking as well as HE under droplets with 145 mu g/cmth> of chloride, with the severity of cracking increasing with increasing chloride deposition density (CDD). Elastic-plastic strain (0.2%) increased the propensity to both corrosion and SCC/HE, with cracks seen under droplets having CDD as low as 14.5 mu g/cm(2). Elastic-plastic strain was further seen to facilitate and accelerate pitting corrosion, leading to pits with more penetration depth. The extent of corrosion and cracking increases with increasing chloride deposition density, with ferric ions having more severe effect, in particular promoting localized corrosion with multiple nucleation sites. The work reported here was brought into a larger context of stainless steel corrosion and discussed in light of better understanding atmospheric corrosion of structural components such as nuclear waste storage containers.

  • 2457.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Leygraf, Christopher
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Pan, Jinshan
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Passive film characterisation of duplex stainless steel using scanning Kelvin probe force microscopy in combination with electrochemical measurements2019In: npJ Materials Degradation, ISSN 2397-2106, Vol. 3, no 1, p. 1-8Article in journal (Refereed)
    Abstract [en]

    The characterisation of passive oxide films on heterogeneous microstructures is needed to assess local degradation (corrosion, cracking) in aggressive environments. The Volta potential is a surface-sensitive parameter which can be used to assess the surface nobility and hence passive films. In this work, it is shown that the Volta potential, measured on super duplex stainless steel by scanning Kelvin probe force microscopy, correlates with the electrochemical properties of the passive film, measured by electrochemical impedance spectroscopy and potentiodynamic polarisation. Natural oxidation by ageing in ambient air as well as artificial oxidation by immersion in concentrated nitric acid improved the nobility, both reflected by increased Volta potentials and electrochemical parameters. Passivation was associated with vanishing of the inherent Volta potential difference between the ferrite and austenite, thereby reducing the galvanic coupling and hence improving the corrosion resistance of the material. Hydrogen-passive film interactions, triggered by cathodic polarisation, however, largely increased the Volta potential difference between the phases, resulting in loss of electrochemical nobility, with the ferrite being more affected than the austenite. A correlative approach of using the Volta potential in conjunction with electrochemical data has been introduced to characterise the nobility of passive films in global and local scale.

  • 2458.
    Örnek, Cem
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Långberg, Marie
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Surface and Corrosion Science.
    Evertsson, Jonas
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Harlow, Gary
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Linpe, Weronica
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Rullik, Lisa
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Carla, Francesco
    European Synchrotron Radiat Facil, F-38000 Grenoble, France..
    Felici, Roberto
    Area Ric Roma 2 Tor Vergata, SPINCNR, I-00133 Rome, Italy..
    Bettini, Eleonora
    Sandvik Mat Technol, SE-81181 Sandviken, Sweden..
    Kivisakk, Ulf
    Sandvik Mat Technol, SE-81181 Sandviken, Sweden..
    Lundgren, Edvin
    Lund Univ, Div Synchrotron Radiat Res, SE-22100 Lund, Sweden..
    Pan, Jinshan
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    In-situ synchrotron GIXRD study of passive film evolution on duplex stainless steel in corrosive environment2018In: Corrosion Science, ISSN 0010-938X, E-ISSN 1879-0496, Vol. 141, p. 18-21Article in journal (Refereed)
    Abstract [en]

    This paper presents new findings about the passive film formed on super duplex stainless steel in ambient air and corrosive environments, studied by synchrotron grazing-incidence X-ray diffraction (GIXRD). The passive film, formed in air, was seen to be a nano-crystalline mixed-oxide. Electrochemical polarisation to the passive region in aqueous 1 M NaCl at room temperature resulted in an increase of the passive film thickness, preferential dissolution of Fe, and partial loss of crystallinity. After termination of polarization to the transpassive regime, reformation of the mixed-oxides was observed, showing a thicker, semi-crystalline, and more defective nature (more vacancies) with further new oxides/hydroxides.

  • 2459.
    Örnek, Cem
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Surface and Corrosion Science. University of Manchester, UK.
    Walton, J.
    Hashimoto, T.
    Ladwein, T. L.
    Lyon, S. B.
    Engelberg, D. L.
    Characterization of 475 degrees C Embrittlement of Duplex Stainless Steel Microstructure via Scanning Kelvin Probe Force Microscopy and Magnetic Force Microscopy2017In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 164, no 6, p. C207-C217Article in journal (Refereed)
    Abstract [en]

    Scanning Kelvin probe force microscopy (SKPFM) measured local Volta potentials in microstructure of 22Cr-5Ni duplex stainless steel have been correlated to microstructure development with aging treatments at 475 degrees C. Magnetic force microscopy (MFM) was employed to differentiate crystallographic phases to provide complementary information. The absolute Volta potentials of both ferrite and austenite increased after 5 hours of aging, indicating electrochemical ennoblement of the entire microstructure. Longer aging resulted in a gradual decrease of measured Volta potentials in both phases. The microstructure showed after 255 hours aging up to 2.5-times larger potential differences than in the as-received condition, indicating impaired electrochemical nobility. In the as-received microstructure, the ferrite phase was less noble than the austenite, whereas after 5 hours aging both phases had similar, balanced Volta potentials which indicated a balanced nobility of ferrite and austenite. Longer aging treatment caused severe loss of nobility for the entiremicrostructure, with ferrite showing larger changes in Volta potential than the austenite. Spinodal microstructure decomposition and associated phase reactions of the ferrite, with elemental redistribution in the austenite, are the reason for the observed changes in microstructure nobility.

  • 2460.
    Österberg, Anna
    KTH, School of Chemical Science and Engineering (CHE).
    Removal and Recycling of Phosphorus from Wastewater Using Reactive Filter Material Polonite®2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Literature reviews and laboratory work were used to examine the phosphorus removal efficiency of the reactive filter material Polonite®. This material is produced from the calcium carbonate and silica based rock Opoka. The thesis mainly focuses on adsorption of phosphorus from wastewater with Polonite® but also discuss the possibilities of recycling the filter and the adsorbed phosphorus back into agriculture. This would be beneficial to the environment and a path to a sustainable use of phosphorus. It is important to reduce the employment of phosphorus because of the upcoming “Peak Phosphorus” and the negative impact that an excess of the nutrient has on water bodies. The two main objectives of this thesis were to evaluate and display the phosphorus sorption capacity of Polonite® in a breakthrough curve and to obtain adsorption isotherms of phosphorus on Polonite®.  To achieve these objectives experiments were performed in a pilot-plant and in a laboratory at Hammarby Sjöstadsverk. A 500 kg Polonite® filter was connected to flow of wastewater of 400 L/hr and samples were collected and analyzed regularly. The filter did not perform as well as expected, having already shown promising results in other experiments. This is most likely due to the high flow of wastewater and to a too short residence time. The phosphorus reduction was down to 60 % after approximately 30 days and a breakthrough was noticed after 53 days. When saturated, the filter contained 0.6 kg of phosphorus, the equivalent of a sorption capacity of 0.12 %. The pH in the effluent from the Polonite® filter was 10.2 at the first measurement but then dropped fast. When the filter was saturated the pH was down to 8.7. The breakthrough curve gave some indications of that the saturated Polonite® filter might be able to release adsorbed phosphorus. It was also concluded that the Polonite® filter was acting mainly by sorption and thus reduced the dissolved, but not much of the particular, phosphorus.Equilibrium experiments were conducted using solutions with different concentrations of phosphorus. 1 g of Polonite® was added to each solution which was then stirred. With the help of adsorption isotherms the maximum loading capacity was estimated at 330 mg of phosphorus per gram of Polonite®. This corresponds to a 33 % capacity and is a very high number.   

    Recommendations for future studies would be to further examine the wastewater residence time in the Polonite® filter to improve sorption capacity of phosphorus. It could also be interesting to redo the equilibrium experiments to obtain a more probable loading capacity. The possible presence of pharmaceuticals and/or heavy metals in the filter is also important to investigate, as is the economic aspect of the employment of Polonite® filters for removal of phosphorus from wastewater.

  • 2461.
    Österdahl, Kerstin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Crystallization of beta-FEF3.3H2O in mixtures of nitric and hydrofluoric acid2005In: VDI-Berichte 1901, V D I Verlag GmbH , 2005, p. 17-22Conference paper (Refereed)
    Abstract [en]

    The solubility of β-heh 3·3H 2U has been measured in solutions with a range of different hydrofluoric acid concentrations (2, 4 and 6 mol/kg) and constant nitric acid concentration (3 mol/kg) in order to calculate a solubility constant applicable at the present ionic strength and temperature. Crystal growth of β-FeF 3·3H 2O has been measured in 3molal hydrofluoric acid and 3molal nitric acid solutions at 50°C by performing seeded isothermal desupersaturation experiments (1 < S < 3). The supersaturation was recorded by taking out solution samples which were analysed for total iron concentration with inductively coupled plasma atomic emission spectrometry (ICP-AES). The true supersaturation driving force was estimated by a proper speciation to account for the complexation, using the software SSPEC and relevant stability constants. Parameters of a desired growth rate equation were estimated by fitting the supersaturation balance equation directly to the supersaturation measurements. The results show that growth of β-FeF 3·3H 2O follows a parabolic rate law (g= 2,0 ±0,2). The growth rate at S= 2 was found to be 4,6×10- 11 m/s (50°C). The growth order and the low value of the growth rate suggest that the rate is surface integration controlled.

  • 2462.
    Österdahl, Kerstin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke C
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Solubility of beta-FeF3 center dot 3H(2)O in mixtures of nitric and hydrofluoric acid2006In: Journal of Chemical and Engineering Data, ISSN 0021-9568, E-ISSN 1520-5134, Vol. 51, no 1, p. 223-229Article in journal (Refereed)
    Abstract [en]

    The solubility of beta-FeF(3) center dot 3H(2)O has been measured in solutions with different concentrations of nitric acid (0 to 7 in) and hydrofluoric acid (1 to 6 m) at the temperatures of (30, 40, and 50) degrees C. The total iron concentration at equilibrium was measured with inductively coupled plasma (ICP) spectroscopy. The solubility was evaluated in terms of the stepwise complexation of iron by fluoride ions at different ionic strength and temperature. The solubility of beta-FeF3-3H(2)O increases with decreasing concentration of HF and HNO3 and increasing temperature.

  • 2463.
    Österdahl, Kerstin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke Christoffer
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Tjus, Kåre
    IVL.
    Fortkamp, Uwe
    IVL.
    Schneiker, Torsten
    Åkesson, S.
    Precipitation of Iron Fluoride Trihydrate from Mixed Acid Pickle Liquors2006In: Iron control Technologies, Proc. 3rd Intern. Symp. on Iron Control in Hydrometallurgy / [ed] Dutrizac, J.E. and Riveros, P.A, Can. Inst. Of Mining, Metallurgy and Petroleum , 2006, p. 845-861Conference paper (Refereed)
47484950 2451 - 2463 of 2463
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf