Change search
Refine search result
2451245224532454245524562457 122651 - 122700 of 127988
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.
  • 122651.
    Yang, Geng
    et al.
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Mao, Jia
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK. KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Design of a self-organized Intelligent Electrode for synchronous measurement of multiple bio-signals in a wearable healthcare monitoring system2010In: 2010 3rd International Symposium on Applied Sciences in Biomedical and Communication Technologies, ISABEL 2010, 2010Conference paper (Other academic)
    Abstract [en]

    This paper presents an Intelligent Electrodes and Active Cable based wearable medical system. Within each Intelligent Electrode, an Application Specific Integrated Circuit (ASIC) is integrated which includes a gain-bandwidth selectable analog front-end circuit, an 8-bit SAR ADC and a digital controller. The key of the ASIC is the analog front-end circuit with tunable gain and bandwidth which can be configured for Electrocardiogram (ECG), Electroencephalogram (EEG) or Electromyogram (EMG) measurement. Common mode interference is effectively rejected due to the circuit’s high Common Mode Rejection Ratio (CMRR), which is higher than 135 dB up to 100 Hz and better than 110dB up to 1 kHz. Since a dedicated data transmission protocol is implemented on chip, the Intelligent Electrodes can establish a self-organized network and perform synchronous measurements for multiple bio-signals.

  • 122652.
    Yang, Geng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Wan, Qiansu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Bio-Chip ASIC and Printed Flexible Cable on Paper Substrate for Wearable Healthcare Applications2011In: Proceeding ISABEL '11 Proceedings of the 4th International Symposium on Applied Sciences in Biomedical and Communication Technologies, 2011Conference paper (Refereed)
    Abstract [en]

    In this paper, we describe two cutting-edge technologies for the emerging wearable healthcare applications: application specific integrated circuit (ASIC) and printed electronics on a flexible paper substrate. The ASIC enables a compact integration of active circuit blocks on a chip. Due to its tiny size, the ASIC makes the wearable unit unobtrusive and maximizes the wearer's comfort. The electrical performance of a paper based inkjet printed flexible cable is also exhibited. Combining the two technologies together, an example of electrocardiogram (ECG) signal recording is presented.

  • 122653.
    Yang, Geng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Xie, Li
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Mantysalo, Matti
    Zhou, Xiaolin
    Pang, Zhibo
    Xu, Li Da
    Kao-Walter, Sharon
    Chen, Qiang
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    A Health-IoT Platform Based on the Integration of Intelligent Packaging, Unobtrusive Bio-Sensor, and Intelligent Medicine Box2014In: IEEE Transactions on Industrial Informatics, ISSN 1551-3203, E-ISSN 1941-0050, Vol. 10, no 4, p. 2180-2191Article in journal (Refereed)
    Abstract [en]

    In-home healthcare services based on the Internet-of-Things (IoT) have great business potential; however, a comprehensive platform is still missing. In this paper, an intelligent home-based platform, the iHome Health-IoT, is proposed and implemented. In particular, the platform involves an open-platform-based intelligent medicine box (iMedBox) with enhanced connectivity and interchangeability for the integration of devices and services; intelligent pharmaceutical packaging (iMedPack) with communication capability enabled by passive radio-frequency identification (RFID) and actuation capability enabled by functional materials; and a flexible and wearable bio-medical sensor device (Bio-Patch) enabled by the state-of-the-art inkjet printing technology and system-on-chip. The proposed platform seamlessly fuses IoT devices (e. g., wearable sensors and intelligent medicine packages) with in-home healthcare services (e. g., telemedicine) for an improved user experience and service efficiency. The feasibility of the implemented iHome Health-IoT platform has been proven in field trials.

  • 122654.
    Yang, Geng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Xie, Li
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Mäntysalo, Matti
    Department of Electronics, Tampere University of Technology.
    Chen, Jian
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Tenhunen, Hannu
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Li-Rong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Bio-Patch Design and Implementation Based on a Low-Power System-on-Chip and Paper-Based Inkjet Printing Technology2012In: IEEE transactions on information technology in biomedicine, ISSN 1089-7771, E-ISSN 1558-0032, Vol. 16, no 6, p. 1043-1050Article in journal (Refereed)
    Abstract [en]

    This paper presents the prototype implementation of a Bio-Patch using fully integrated low-power System-on-Chip (SoC) sensor and paper-based inkjet printing technology. The SoC sensor is featured with programmable gain and bandwidth to accommodate a variety of bio-signals. It is fabricated in a 0.18-µm standard CMOS technology, with a total power consumption of 20 µW from a 1.2 V supply. Both the electrodes and interconnections are implemented by printing conductive nano-particle inks on a flexible photo paper substrate using inkjet printing technology. A Bio-Patch prototype is developed by integrating the SoC sensor, a soft battery, printed electrodes and interconnections on a photo paper substrate. The Bio-Patch can work alone or operate along with other patches to establish a wired network for synchronous multiple-channel bio-signals recording. The measurement results show that electrocardiogram and electromyogram are successfully measured in in-vivo tests using the implemented Bio-Patch prototype.

  • 122655.
    Yang, Geng
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Xie, Li
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Zheng, Lirong
    KTH, School of Information and Communication Technology (ICT), Electronic Systems. KTH, School of Information and Communication Technology (ICT), Centres, VinnExcellence Center for Intelligence in Paper and Packaging, iPACK.
    Evaluation of non-contact flexible electrodes connected with a customized IC-steps towards a fully integrated ECG sensor2013In: NORCHIP, 2013, IEEE , 2013, p. 6702023-Conference paper (Refereed)
    Abstract [en]

    This study investigates the performance of a noncontact capacitive bioelectric sensor for electrocardiogram (ECG) measurement. A straightforward comparison is made on the measured ECG signals using conventional pre-gelled electrodes and the developed non-contact electrodes on a hairy chest, with the same bio-sensing readout circuits. The measurement results show that pre-gelled electrodes have difficulties in the measurement of ECG signal from a hairy chest. A pair of non-contact electrodes are designed and implemented on flexible copper foil. With the help of high performance readout circuits, ECG signal is successfully measured via implemented non-contact electrodes from a hairy chest. Discussions are made based on the preliminary in-vivo measurement results. It is believed that this non-contact ECG measurement approach brings a promising solution for the future fully integrated wearable ECG sensors.

  • 122656.
    YANG, GEPENG
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    ADOLFSSON, JONATHAN
    KTH, School of Industrial Engineering and Management (ITM).
    Modular Scaled Development Platform for Steering Algorithms using LEGO Mindstorms.2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The topic of the thesis is to build physically similar systems to simulate behaviors of real-life heavy-duty vehicles using LEGO Mindstorms as hardware platform and Buckingham π theorem as theoretical basis for the parameter scaling. The thesis work includes software and hardware system design and theoretical research in order to prove a newly proposed concept: Using LEGO to build a scaled model of real-life vehicles with specific similar physical properties. To implement the work described above, scaled models were built with LEGO and a software and hardware system was developed for controlling the scaled model. Tests were performed both on real-life vehicles and scaled models. A generalized mathematical model for the vehicle was derived in order to interpret the behaviors of the vehicle in a scientific way. Then, test results of both real-life vehicles and the corresponding scaled model were compared with the mathematical model in order to investigate if they have similar behaviors. Finally it was concluded that the scaled model built with LEGO Mindstorms combined with Buckingham π theorem could calculate the speed and turning radius of the physically similar real-life vehicle with an average accuracy of 94.68% within low speed, conservatively speaking. For further investigation and research, similar research could be performed with higher speeds to generalize the conclusions and results.

  • 122657.
    Yang, Guanda
    et al.
    Friedrich Alexander Univ Erlangen Nuremberg, Inst Polymer Mat, Martensstr 7, D-91058 Erlangen, Germany.
    Nilsson, Fritjof
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Schubert, Dirk W.
    A Study of Finite Size Effects and Periodic Boundary Conditions to Simulations of a Novel Theoretical Self-Consistent Mean-Field Approach2019In: Macromolecular Theory and Simulations, ISSN 1022-1344, E-ISSN 1521-3919, article id 1900023Article in journal (Refereed)
    Abstract [en]

    In a previous work, a very promising mathematical model for predicting the electrical conductivity below the electrical percolation threshold, for both isotropic and anisotropic composites, was published by Schubert. In this work, periodic boundary condition of the simulation is utilized. The results are also compared to the previous work and other theoretical models. The truncated fibers due to finite size of the simulation volume are considered as two individual pieces so that the real aspect ratios will also be taken into consideration. A comparison is made between two groups, in which the length and the radius of the carbon fibers are changed, respectively, under certain aspect ratios. With three different sizes of the simulation volumes, the influence on the results due to the finite size effect is calculated.

  • 122658.
    Yang, Guanda
    et al.
    Friedrich Alexander Univ Erlangen Nuremberg, Inst Polymer Mat, Martensstr 7, D-91058 Erlangen, Germany..
    Schubert, Dirk W.
    Friedrich Alexander Univ Erlangen Nuremberg, Inst Polymer Mat, Martensstr 7, D-91058 Erlangen, Germany.;Bavarian Polymer Inst, Key Lab Adv Fiber Technol, Dr Mack Str 77, D-90762 Furth, Germany..
    Qu, Muchao
    Friedrich Alexander Univ Erlangen Nuremberg, Inst Polymer Mat, Martensstr 7, D-91058 Erlangen, Germany..
    Nilsson, Fritjof
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Novel Theoretical Self-Consistent Mean-Field Approach to Describe the Conductivity of Carbon Fiber-Filled Thermoplastics: PART II. Validation by Computer Simulation2018In: Macromolecular Theory and Simulations, ISSN 1022-1344, E-ISSN 1521-3919, Vol. 27, no 4, article id 1700105Article in journal (Refereed)
    Abstract [en]

    The electrical conductivity of polymeric fiber composites is generally strongly dependent on the constituent conductivities, the fiber filler fraction, the fiber aspect ratio, and on the orientation of the fibers. Even though electrically conductive polymer composites are emerging materials of high scientific and commercial interest, accurate mathematical models for describing such materials are rare. A very promising mathematical model for predicting the electrical conductivity below the electrical percolation threshold, for both isotropic and anisotropic composites, is however recently published by Schubert. The shortcomings of that study are that the model includes so far only one predicted parameter and that it is not sufficiently validated. In the current study, finite element modeling is used to successfully validate the model of Schubert for isotropic fiber composites and to accurately determine the predicted parameter. These theoretical predictions are finally compared with experimental conductivity data for isotropic carbon fiber/poly(methyl methacrylate) (PMMA) composites with fiber filler fractions in the range 0-12 vol% and fiber aspect ratios from 5 to 30. The model forecasts, without any adjustable parameters, are satisfactory close to the experimental data.

  • 122659.
    Yang, Guang
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Throughput and Latency of Millimeter-Wave Networks: Performance Analyses and Design Principles2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Nowadays, the ever-increasing demands on higher data rates and better serviceperformance have posed extremely huge challenges to the existing wireless communicationswithin sub-6 GHz bands, mainly due to the spectrum scarcity in lowerfrequency bands. In recent years, the millimeter-wave (mm-wave) technology, as apromising candidate to meet the aforementioned demands, have attracted extensiveresearch attention, and has been regarded as one of the key enablers for theforthcoming the 5th generation (5G) mobile communications. The main featuresof mm-wave communications include: abundant spectral resources, high penetrationloss, severe path loss, weak multi-path effects, and narrow antenna beams, andthese particular features make the potential challenges and solutions with mm-wavediffer a lot from those in the conventional 6-GHz systems.

    It is known that the high throughput and the low latency are two critical qualityof-service (QoS) aspects in future mobile networks, while the related research withmm-wave are fairly recent and insufficient in the past few years. Motived by theurgent needs for further development and the blanks remained in previous works,in this doctoral thesis, we investigate the throughput and the latency in mm-wavenetworks through conducting performance analyses and identifying design principles,with the objective of seeking clues for improving the QoS of mm-wave wirelesscommunications in practice.

    Our main research regarding throughput and latency in mm-wave networksthat are included in this doctoral thesis can be categorized from the following threeaspects:

    (i) Throughput of mm-wave relay networks: For indoor scenarios, we study thehalf-duplex (HD) relaying with mm-wave in the presence of random linkblockages, where a distance-based routing algorithm is proposed to maximizethe throughput. For outdoor scenarios, focusing on a two-hop amplifyand-forward (AF) relay network in the HD or the full-duplex (FD) mode, weinvestigate the impacts of beamwidth, ground reflections, and self-interferencecoefficient on the throughput, where Gaussian-type directional antenna modeland two-ray channel model are jointly adopted.

    (ii) Latency analysis via stochastic network calculus: With the aid of stochasticnetwork calculus, we derive upper bounds for the probabilistic delay tokeep track of the latency performance of buffer-aided mm-wave networks. We mainly study mm-wave systems designed in tandem or parallel manners,and also consider a hybrid design that combines the tandem and parallelschemes in a flexible manner. Moreover, the capability of achieving low-latencymm-wave communications is characterized and investigated in terms of effectivecapacity, and the comparison among different transmission schemes isconducted to identify the respective strengths and proper conditions for theirapplications.

    (iii) Traffic allocation for low-latency mm-wave systems: Traffic allocation schemesfor low latency in buffer-aided mm-wave networks are investigated. Due tothe use of buffers, the delay optimization problem hereby differs from thosewithout buffers, where the conventional graph-based network optimizationtechniques become intractable. We demonstrate the impacts of different trafficallocation schemes on the latency. For multi-hop networks with multipleparallel channels in each hop, we consider both local and global traffic allocationschemes, quantify their resulting end-to-end (E2E) latencies, and analyzethe respective strengths and weaknesses.

  • 122660.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Du, Jinfeng
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre. MIT.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Communication Theory. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Maximum Throughput Path Selection with Random Blockage for Indoor 60 GHz Relay Networks2015In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 63, no 10, p. 3511-3524Article in journal (Refereed)
    Abstract [en]

    Indoor communications in the 60 GHz band is capable to support multi-gigabit wireless access thanks to the abundant spectrum and the possibility of using dense antenna arrays. However, the high directivity and penetration loss make it vulnerable to blockage events which can be frequent in indoor environments. Given network topology information in sufficient precision, we investigate the average throughput and outage probability when the connection between any two nodes can be established either via the line-of-sight (LOS) link, through a reflection link, or by a half-duplex relay node. We model the reflection link as an LOS with extra power loss and derive the closed-form expression for the relative reflection loss. For networks with a central coordinator and multiple relays, we also propose a generic algorithm, maximum throughput path selection (MTPS), to select the optimal path that maximizes the throughput. The complexity of the MTPS algorithm is O(n2) for networks equipped with n relays, whereas a brute-forced algorithm has complexity of O(n · n!). Numerical results show that increasing the number of relays can significantly increase the average throughput and decrease the outage probability, and resorting to reflection paths provides significant gains when the probability of link blockage is high.

  • 122661.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Haenggi,, Martin
    Xiao, Ming
    Traffic Allocation for Low- Latency Multi-Hop Networks with BuffersManuscript (preprint) (Other academic)
  • 122662.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Haenggi, Martin
    Univ Notre Dame, Dept Elect Engn, Notre Dame, IN 46556 USA..
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Traffic Allocation for Low-Latency Multi-Hop Networks With Buffers2018In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 66, no 9, p. 3999-4013Article in journal (Refereed)
    Abstract [en]

    For buffer-aided tandem networks consisting of relay nodes and multiple channels per hop, we consider two traffic allocation schemes, namely local allocation and global allocation, and investigate the end-to-end latency of a file transfer. We formulate the problem for generic multi-hop queuing systems and subsequently derive closed-form expressions of the end-to-end latency. We quantify the advantages of the global allocation scheme relative to its local allocation counterpart, and we conduct an asymptotic analysis on the performance gain when the number of channels in each hops increases to infinity. The traffic allocations and the analytical delay performance are validated through simulations. Furthermore, taking a specific two-hop network with millimeter-wave (mm-wave) as an example, we derive lower bounds on the average end-to-end latency, where Nakagami-m fading is considered. Numerical results demonstrate that, compared with the local allocation scheme, the advantage of global allocation grows as the number of relay nodes increases, at the expense of higher complexity that linearly increases with the number of relay nodes. It is also demonstrated that a proper deployment of relay nodes in a linear mm-wave network plays an important role in reducing the average end-to-end latency, and the average latency decays as the mm-wave channels become more deterministic. These findings provide insights for designing multi-hop mm-wave networks with low end-to-end latency.

  • 122663.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Ming, Xiao
    Vincent, H.
    Low-Latency Millimeter-Wave Communications: Traffic Dispersion or Network Densification2018In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 66, no 8, p. 3526-3539Article in journal (Other academic)
    Abstract [en]

    Low latency is critical for many applications in wireless communications, e.g., vehicle-to-vehicle (V2V), multimedia, and industrial control networks. Meanwhile, for the capability of providing multi-gigabits per second (Gbps) rates, millimeter-wave (mm-wave) communication has attracted substantial research interest recently. This paper investigates two strategies to reduce the communication delay in future wireless networks: traffic dispersion and network densification. A hybrid scheme that combines these two strategies is also considered. The probabilistic delay and effective capacity are used to evaluate performance. For probabilistic delay, the violation probability of delay, i.e., the probability that the delay exceeds a given tolerance level, is characterized in terms of upper bounds, which are derived by applying stochastic network calculus theory. In addition, to characterize the maximum affordable arrival traffic for mmwave systems, the effective capacity, i.e., the service capability with a given quality-of-service (QoS) requirement, is studied. The derived bounds on the probabilistic delay and effective capacity are validated through simulations. These numerical results show that, for a given sum power budget, traffic dispersion, network densification, and the hybrid scheme exhibit different potentials to reduce the end-to-end communication delay. For instance, traffic dispersion outperforms network densification when high sum power budget and arrival rate are given, while it could be the worst option, otherwise. Furthermore, it is revealed that, increasing the number of independent paths and/or relay density is always beneficial, while the performance gain is related to the arrival rate and sum power, jointly. Therefore, a proper transmission scheme should be selected to optimize the delay performance, according to the given conditions on arrival traffic and system service capability.

  • 122664.
    Yang, Guang
    et al.
    KTH.
    Xiao, Ming
    KTH.
    Blockage robust millimeter-wave networks2017In: Science China Information Sciences, ISSN 1674-733X, E-ISSN 1869-1919, Vol. 60, no 8, article id 080307Article in journal (Refereed)
  • 122665.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Information Science and Engineering.
    Interference statistics of regular ring-structured networks with 60 GHz directional antennas2017In: 2017 IEEE International Conference on Communications, Institute of Electrical and Electronics Engineers (IEEE), 2017, article id 7996400Conference paper (Refereed)
    Abstract [en]

    To overcome the severe path loss and provide higher spectral efficiency for 60 GHz wireless communications, highly directional antennas, which indicate high antenna gains, are widely employed. In this work, we focus on the trade-off between the beamwidth of directional antennas and the interference produced by random concurrent transmissions, in terms of two important statistics, i.e., the expectation and variance. A specific regular network is considered, which consists of multi-layer rings, and a typical receiver with a fixed orientation is placed in the network center.We derive closed-form expressions of interference statistics associated with the beamwidth, which are followed by upper and lower bounds. In addition, we demonstrate that the performance gain provided by directional antennas approximately grows in the fashion of the reciprocal of beamwidth, and an approximation for the expectation of signal-to-interference-and-noise ratio (SINR) is also presented. Numerical results show that, analytic expressions coincide with simulations, and derived bounds are valid. The benefits of utilizing directional antennas are quantified and verified. Furthermore, the impacts of the factors, such as path loss exponent and side-lobe gain, are also studied, comprehensively.

  • 122666.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Performance Analysis of Millimeter-Wave Relaying: Impacts of Beamwidth and Self-Interference2018In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 66, no 2, p. 589-600Article in journal (Refereed)
    Abstract [en]

    We study the maximum achievable rate of a two-hop amplified-and-forward (AF) relaying millimeter-wave (mm-wave) system, where two AF relaying schemes, i.e., half-duplex (HD) and full-duplex (FD) are discussed. By considering the two-ray mm-wave channel and the Gaussian-type directional antenna, jointly, the impacts of the beamwidth and the self-interference coefficient on maximum achievable rates are investigated. Results show that, under a sum-power constraint, the rate of FD-AF mm-wave relaying outperforms its HD counterpart only when antennas with narrower beamwidth and smaller self-interference coefficient are applied. However, when the sum-power budget is sufficiently high or the beamwidth of directional antenna is sufficiently small, direct transmission becomes the best strategy, rather than the AF relaying schemes. For both relaying schemes, we show that the rates of both AF relaying schemes scale as O(min{theta(-1)(m),theta(-2)(m)})with respect to beamwidth theta(m), and the rate of FD-AF relaying scales as O(mu(-(1/2))) with respect to self-interference coefficient mu. Also, we show that ground reflections may significantly affect the performance of mm-wave communications, constructively or destructively. Thus, the impact of ground reflections deserves careful considerations for analyzing or designing future mm-wave wireless networks.

  • 122667.
    Yang, Guang
    et al.
    KTH.
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Alam, M.
    Huang, Y.
    Low-Latency Heterogeneous Networks with Millimeter-Wave Communications2018In: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 56, no 6, p. 124-129Article in journal (Refereed)
    Abstract [en]

    The heterogeneous network (HetNet) is a key enabler to largely boost network coverage and capacity in the forthcoming 5G and beyond. To support the explosively growing mobile data volumes, wireless communications with millimeter- wave (mmWave) radios have attracted massive attention, and is widely considered as a promising candidate in 5G HetNets. In this article, we give an overview on the end-to-end latency of HetNets with mmWave communications. In general, it is rather challenging to formulate and optimize the delay problem with buffers in mmWave communications, since conventional graph-based network optimization techniques are not applicable when queues are considered. Toward this end, we develop an adaptive low-latency strategy, which uses cooperative networking to reduce the end-to-end latency. Then we evaluate the performance of the introduced strategy. Results reveal the importance of proper cooperative networking in reducing the end-toend latency. In addition, we have identified several challenges in future research for low-latency mmWave HetNets.

  • 122668.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Alam, Muhammad
    Huang, Yongming
    Low-Latency Heterogeneous Networks with Millimeter-Wave CommunicationsManuscript (preprint) (Other academic)
  • 122669.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Al-Zubaidy, Hussein
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Huang, Yongming
    Gross, James
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Analysis of Millimeter-Wave Multi-Hop Networks With Full-Duplex Buffered Relays2018In: IEEE/ACM Transactions on Networking, ISSN 1063-6692, E-ISSN 1558-2566, Vol. 26, no 1, p. 576-590Article in journal (Refereed)
    Abstract [en]

    The abundance of spectrum in the millimeter-wave (mm-wave) bands makes it an attractive alternative for future wireless communication systems. Such systems are expected to provide data transmission rates in the order of multi-gigabits per second in order to satisfy the ever-increasing demand for high rate data communication. Unfortunately, mm-wave radio is subject to severe path loss, which limits its usability for long-range outdoor communication. In this paper, we propose a multi-hop mm-wave wireless network for outdoor communication, where multiple full-duplex buffered relays are used to extend the communication range, while providing end-to-end performance guarantees to the traffic traversing the network. We provide a cumulative service process characterization for the mm-wave propagation channel with self-interference in terms of the moment generating function of its channel capacity. Then, we then use this characterization to compute probabilistic upper bounds on the overall network performance, i.e., total backlog and end-to-end delay. Furthermore, we study the effect of self-interference on the network performance and propose an optimal power allocation scheme to mitigate its impact in order to enhance network performance. Finally, we investigate the relation between relay density and network performance under a sum power constraint. We show that increasing relay density may have adverse effects on network performance, unless the selfinterference can be kept sufficiently small.

  • 122670.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Xiao, Ming
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Gross, James
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Al-Zubaidy, Hussein
    KTH, School of Electrical Engineering (EES), Communication Theory.
    Huang, Yongming
    Delay and Backlog Analysis for 60 GHz Wireless Networks2016In: 2016 IEEE Global Communications Conference, GLOBECOM 2016 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2016, article id 7841725Conference paper (Refereed)
    Abstract [en]

    To meet the ever-increasing demands on higher throughput and better network delay performance, 60 GHZ networking is proposed as a promising solution for the next generation of wireless communications. To successfully deploy such networks, its important to understand their performance first. However, due to the unique fading characteristic of the 60 GHz channel, the characterization of the corresponding service process, offered by the channel, using the conventional methodologies may not be tractable. In this work, we provide an alternative approach to derive a closed-form expression that characterizes the cumulative service process of the 60 GHz channel in terms of the moment generating function (MGF) of its instantaneous channel capacity. We then use this expression to derive probabilistic upper bounds on the backlog and delay that are experienced by a flow traversing this network, using results from the MGF-based network calculus. The computed bounds are validated using simulation. We provide numerical results for different networking scenarios and for different traffic and channel parameters and we show that the 60 GHz wireless network is capable of satisfying stringent quality-of-Service (QoS) requirements, in terms of network delay and reliability. With this analysis approach at hand, a larger scale 60 GHz network design and optimization is possible.

  • 122671.
    Yang, Guang
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Xiao, Ming
    KTH, School of Electrical Engineering and Computer Science (EECS), Information Science and Engineering.
    Pang, Zhibo
    ABB Corp Res, Vasterås, Sweden.
    Delay Analysis of Traffic Dispersion with Nakagami-m Fading in Millimeter-Wave Bands2018In: 2018 IEEE WIRELESS COMMUNICATIONS AND NETWORKING CONFERENCE (WCNC), IEEE , 2018Conference paper (Refereed)
    Abstract [en]

    We analyze the delay performance of traffic dispersion in millimeter-wave (mm-wave) communications, where Nakagami-m fading channel is considered. To apply (mm, +)algebra network calculus in wireless communications, we develop a closed-form expression based on moment generating function (MGF), which characterizes the stochastic service process by staying in the bit domain, rather than transferring to the SNR domain. Subsequently, for traffic dispersion with mm-wave, we derive probabilistic delay bounds and effective capacity based on the obtained MGF of the cumulative service process. Besides, the impacts of several factors, e.g., the number of independent path, system gain (including antenna gain and adopted radio frequency) or Nakagami parameter, on the delay performance are studied. We not only comprehensively study the delay performance of traffic dispersion with mm-wave, but also demonstrate the feasibility and tractability of performance analysis.

  • 122672.
    Yang, Guang-Zhong
    et al.
    Imperial Coll London, Hamlyn Ctr Robot Surg, London, England..
    Dario, Paolo
    Scuola Super Sant Anna, Biomed Robot, Pisa, Italy..
    Kragic, Danica
    KTH, School of Electrical Engineering and Computer Science (EECS), Robotics, perception and learning, RPL. KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for Autonomous Systems, CAS.
    Social robotics-Trust, learning, and social interaction2018In: Science Robotics, ISSN 2470-9476, Vol. 3, no 21, article id UNSP eaau8839Article in journal (Other academic)
  • 122673.
    Yang, Guoliang
    KTH, School of Information and Communication Technology (ICT).
    Monitoring End-User Power Consumption Data Using AMI and GIS System in a Designated Swedish Area2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The awareness of power consumption is considered to be an important step of driving energy- saving technologies development. With the ‘Smart Grid’ technologies, Sweden has deployed Advanced Metering Infrastructure (AMI) nationwide. How to present and operate the data be collected by AMI devices in an effective and friendly way has become a problem worth to research on.

    This thesis project aims to provide an energy consumption monitoring system, which integrate power consumption information from AMI, and geographic information from coordinates, for both customers and power companies, practical for the latter one. Based on that, active web map services of Geographic Information Systems (GIS) in Swedish market are also been analyzed in this thesis report, in order to investigate the features which may be applied in this system.

    The energy consumption monitoring system presented in this project is developed on the GIS of Google Maps, web-browser based. With the open Google Maps API for Javascript and WAMP environment support, a working system is given locally. In this project, at a designated Swedish area, Smedjebacken, there are 50 end-users with AMI data periodically recorded at the interval level of one hour for a whole year, and 3 substations connecting part of the end-users, all of them have the coordinates to position. AMI data is used to simulate a real-time scenario to test the monitoring function.

    Functions of this system are separated into two aspects, customers and power companies. Customers can check their power consumption in many different ways, including latest hour’s consumption, any past single day’s consumption, generate whole year’s consumption column chart, comparing with the average consumption level with a certain range of neighbors. Power companies have global view and access authorities of all customers and substations. In addition, an alarm will be triggered if any of the substation’s power loss is over 5%.

    As a result of analysis, the advantage lay with Google Map on cost of developing, open API and documentations. In the end, a working monitoring system is given under the simulated real-time power consumption scenario.

  • 122674. Yang, Guo-liang
    et al.
    Ahlgren, Per
    Department for Library services, Language and ARC, KTH, School of Education and Communication in Engineering Science (ECE), Library, Publication Infrastructure.
    Yang, Li-ying
    Rousseau, Ronald
    Ding, Jie-lan
    Grading Countries/Territories Using DEA Frontiers2015In: PROCEEDINGS OF ISSI 2015 ISTANBUL: 15TH INTERNATIONAL SOCIETY OF SCIENTOMETRICS AND INFORMETRICS CONFERENCE, Leuven University Press, 2015, p. 436-447Conference paper (Refereed)
    Abstract [en]

    Several approaches exist related to categorizing academic journals/institutions/countries into different levels. Most existing grading methods use either a weighted sum of quantitative indicators (including the case of one properly defined quantitative indicator) or quantified peer review results. An important issue of concern for science and technology management is the efficiency of resource utilization. In this paper we deal with this issue and use multi-level frontiers of data envelopment analysis (DEA) models to grade countries/territories. Research funding and numbers of researchers as used as inputs, while papers and citations are output variables. The research results show that using DEA frontiers we can grade countries/territories on six levels. These levels reflect the corresponding countries' level of efficiency in S&T resource utilization. Furthermore, we use papers and citations as single outputs (with research funding and researchers as inputs) to show changes in country/territory level.

  • 122675. Yang, Guoliang
    et al.
    Ahlgren, Per
    KTH, School of Education and Communication in Engineering Science (ECE), Department for Library services, Language and ARC, Library, Publication Infrastructure.
    Yang, Liying
    Rousseau, Ronald
    Ding, Jielan
    Reply to 'Comment on "Using multi-level frontiers in DEA models to grade countries/territories" by G.-I. Yang et al. [Journal of Informetrics 10(1) (2016), 238-253]'2017In: Journal of Informetrics, ISSN 1751-1577, E-ISSN 1875-5879, Vol. 11, no 3, p. 647-648Article in journal (Refereed)
  • 122676. Yang, Guoliang
    et al.
    Ahlgren, Per
    KTH, School of Education and Communication in Engineering Science (ECE), Department for Library services, Language and ARC, Publication Infrastructure.
    Yang, Liying
    Rousseau, Ronald
    Ding, Jielan
    Using multi-level frontiers in DEA models to grade countries/territories2016In: Journal of Informetrics, ISSN 1751-1577, E-ISSN 1875-5879, Vol. 10, no 1, p. 238-253Article in journal (Refereed)
    Abstract [en]

    Several investigations to and approaches for categorizing academic journals/institutions/countries into different grades have been published in the past. To the best of our knowledge, most existing grading methods use either a weighted sum of quantitative indicators (including the case of one properly defined quantitative indicator) or quantified peer review results. Performance measurement is an important issue of concern for science and technology (S&T) management. In this paper we address this issue, leading to multi-level frontiers resulting from data envelopment analysis (DEA) models to grade selected countries/territories. We use research funding and researchers as input indicators, and take papers, citations and patents as output indicators. Our research results show that using DEA frontiers we can unite countries/territories by different grades. These grades reflect the corresponding countries' levels of performance with respect to multiple inputs and outputs. Furthermore, we use papers, citations and patents as single output (with research funding and researchers as inputs), respectively, to show country/territory grade changes. In order to increase the insight in this approach, we also incorporate a simple value judgment (that the number of citations is more important than the number of papers) as prior information into the DEA models to study the resulting changes of these Countries/Territories' performance grades.

  • 122677.
    Yang, Guomin
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Interfacial properties of calcium montmorillonite in aqueous solutions: Density functional theory and classical molecular dynamics studies on the electric double layer2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The swelling properties of Bentonite are highly affected by clay content and the clay-water interactions that arise from the ion distribution in the diffuse double layer formed near the charged montmorillonite (or smectite) surfaces. Existing continuum models describing the electric double layers, such as classical Poisson-Boltzmann and DLVO theory, ignore the ion-ion correlations, which are especially important for multivalent ions at high surface charge and ionic strength. To better understand the clay-water interactions, atomistic models were developed using both density functional theory of fluids (DFT) as well as classical molecular dynamics (MD) methods. In order to increase our understanding of water-saturated, swelling smectite clays, a DFT, technique was initially developed that allowed more accurate predictions of important thermodynamic properties of the diffuse double layers. This DFT approach was then extended to handle systems with mixtures of different sizes and charges. The extended DFT model was verified against experiments and Monte-Carlo simulations. One practical application was to predict the ion exchange equilibria in Bentonite clays, which have wide practical usage in different areas. Nevertheless, in the DFT work it was realized that DFT demands that the particles, ions in this case, which are described as hard spheres, realistically cannot be described as such at low water loadings, when ion specific hydration forces govern the electric double layer properties. To study how the deformation of the hydration shells of Ca2+ influences the properties of compacted smectite clays, MD simulations using the CLAYFF forcefield were employed in order to account for the deformation of the hydration shells. Comparisons of DFT and MD modeling then allowed to demonstrate under which conditions DFT modeling becomes increasingly inaccurate and when it still can give accurate results.

  • 122678.
    Yang, Guomin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Liu, Longcheng
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    A systematic comparison of different approaches of density functional theory for the study of electrical double layers2015In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 142, no 19, article id 194110Article in journal (Refereed)
    Abstract [en]

    Based on the best available knowledge of density functional theory (DFT), the reference-fluid perturbation method is here extended to yield different approaches that well account for the cross correlations between the Columbic interaction and the hard-sphere exclusion in an inhomogeneous ionic hard-sphere fluid. In order to quantitatively evaluate the advantage and disadvantage of different approaches in describing the interfacial properties of electrical double layers, this study makes a systematic comparison against Monte Carlo simulations over a wide range of conditions. The results suggest that the accuracy of the DFT approaches is well correlated to a coupling parameter that describes the coupling strength of electrical double layers by accounting for the steric effect and that can be used to classify the systems into two regimes. In the weak-coupling regime, the approaches based on the bulk-fluid perturbation method are shown to be more accurate than the counterparts based on the reference-fluid perturbation method, whereas they exhibit the opposite behavior in the strong-coupling regime. More importantly, the analysis indicates that, with a suitable choice of the reference fluid, the weighted correlation approximation (WCA) to DFT gives the best account of the coupling effect of the electrostatic-excluded volume correlations. As a result, a piecewise WCA approach can be developed that is robust enough to describe the structural and thermodynamic properties of electrical double layers over both weak- and strong-coupling regimes.

  • 122679.
    Yang, Guomin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Neretnieks, Ivars
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Holmboe, Michael
    Umeå University.
    Atomistic simulations of cation hydration in sodium and calcium montmorillonite nanopores2017In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 147, no 8, article id 084705Article in journal (Refereed)
    Abstract [en]

    facile synthesis of 3d-metal based electro-catalysts directly incorporated into a carbon support was carried out by.-radiation. Transition metals of period 4, i.e. Ni and Co, were precipitated and reduced from their respective salt solutions. The obtained materials were characterized by XRD, SEM, SQUID and the BET methods. Thereafter, the electrodes for fuel cells were fabricated out of synthesized material and their electrochemical performance for the oxygen reduction reaction in 6 M KOH was measured. Although the concentrations of Co and Ni in the electrode material were low (3.4% Co and 0.4% Ni) after reduction by irradiation, both the Ni and Co-based gas diffusion electrodes showed high catalytic activity for oxygen reduction both at room temperature and at 60 degrees C.

  • 122680.
    Yang, Guomin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Neretnieks, Ivars
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Moreno, Luis
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Wold, Susanna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Density functional theory of electrolyte solutions in slit-like nanopores I. The RFD/WCA approach extended to non-restricted primitive model2017In: APPLIED CLAY SCIENCE, ISSN 0169-1317, Vol. 135, p. 526-531Article in journal (Refereed)
    Abstract [en]

    An extended reference fluid density approach/weighted correlation approximation (RFD/WCA) of density functional theory (DFT) is tested for the description of the non-restricted primitive model of electrolyte solutions in slit-like nanopores. The RFD/WCA approach of modeling size-asymmetric ions is validated by reproducing the density and electrostatic potential profiles of planar electrical double layer systems in the presence of mixtures of mono- and multivalent ions. The results from the DFT agree quite well with Monte Carlo simulations and satisfy the contact density sum rules of ionic fluid under a wide range of conditions. These findings suggest that a generic RFD/WCA approach can be formulated within the framework of the restricted and non-restricted primitive model to further investigate the swelling and ion exchange of clay minerals.

  • 122681.
    Yang, Guomin
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Neretnieks, Ivars
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Moreno, Luis
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Wold, Susanna
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    Density functional theory of electrolyte solutions in slit-like nanopores II. Applications to forces and ion exchange2016In: Applied Clay Science, ISSN 0169-1317, E-ISSN 1872-9053, Vol. 132, p. 561-570Article in journal (Refereed)
    Abstract [en]

    An extended reference fluid density approach/weighted correlation approximation (RFD/WCA) of density functional theory (DFT) for size-asymmetric electrolytes presented in part I is applied to calculate the forces and the ion exchange for Ca- and Na-montmorillonite systems in equilibrium with salt solutions. Our modeling shows that the DFT calculations are in excellent agreement with Monte Carlo simulations and experimental results. The results indicate that the ion size plays an important role in force-distance relation. Due to the excluded volume effect, the osmotic pressure curve predicted by DFT is shifted towards larger separation distances with increasing the diameter of counterions. Additionally, the interaction can be switched from attraction to repulsion with increasing diameter of counterions from standard to hydrated ionic size. Furthermore, the quantitative characterization of the exchange of calcium for sodium at room temperature on Wyoming bentonite is investigated with the DFT modeling in aqueous solutions at pH 7.0. It is found that a significant variation of the selectivity coefficient could be observed with the surface charge density, ionic diameter and interlayer separations. This implies that ion selectivity in compacted bentonite differs from that in dilute smectite dispersions.

  • 122682. Yang, Guosheng
    et al.
    Tang, Yunyu
    Li, Xin
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Xie, Yongshu
    Efficient Solar Cells Based on Porphyrin Dyes with Flexible Chains Attached to the Auxiliary Benzothiadiazole Acceptor: Suppression of Dye Aggregation and the Effect of Distortion2017In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 9, no 42, p. 36875-36885Article in journal (Refereed)
    Abstract [en]

    Donor-pi-acceptor-type porphyrin dyes have been widely used for the fabrication of efficient dye-sensitized solar cells (DSSCs) owing to their strong absorption in the visible region and the ease of modifying their chemical structures and photovoltaic behavior. On the basis of our previously reported efficient porphyrin dye XW11, which contains a phenothiazine-based electron donor, a pi-extending ethynylene unit, and an auxiliary benzothiadiazole acceptor, we herein report the syntheses of novel porphyrin dyes XW26- XW28 by introducing one or two alkyl/alkoxy chains into the auxiliary acceptor. The introduced chains can effectively suppress dye aggregation. As a result, XW26 XW28 show excellent photovoltages of 700, 701, and 711 mV, respectively, obviously higher than 645 mV obtained for XW11. Nevertheless, the optimized structures of XW26 and XW27 exhibit severe distortion, showing large dihedral angles of 57.2(circle) and 44.0(circle), respectively, between the benzothiadiazole and benzoic acid units, resulting from the steric hindrance between the benzoic acid unit and the neighboring alkyl/alkoxy chain on the benzothiadiazole unit, and thus blue-shifted absorption, decreased photocurrents. and low efficiencies of 5.19% and 6.42% were observed for XW26 and XW27, respectively. Interestingly, XW26 exhibits a more blue -shifted absorption spectrum relative to XW27, indicating that the steric hindrance of the alkyl/alkoxy chains has a more pronounced effect than the electronic effect. Different from XW26 and XW27, XW28 contains only one alkyl chain neighboring the ethynylene unit, which does not induce obvious steric hindrance with the benzoic acid unit, and thus distortion of the molecule is not seriously aggravated compared with XW11. Hence, its absorption spectrum and photocurrent are similar to those of XW11. As a result, a higher efficiency of 9.12% was achieved for XW28 because of its suppressed dye aggregation and higher photovoltage. It is worth noting that a high efficiency of 10.14% was successfully achieved for XW28 upon coadsorption with CD CA, which is also higher than the corresponding efficiency obtained for XW11. These results provide a novel approach for developing efficient porphyrin dyes by introducing chains into the suitable position of the auxiliary benzothiadiazolyl moiety to suppress dye aggregation, without seriously aggravating distortion of the dye molecules.

  • 122683. Yang, H.
    et al.
    Zhao, D.
    Chuwongin, S.
    Seo, J. -H
    Yang, W.
    Shuai, Y.
    Berggren, Jesper
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Hammar, Mattias
    KTH, School of Information and Communication Technology (ICT), Integrated Devices and Circuits.
    Ma, Z.
    Zhou, W.
    Transfer-printed stacked nanomembrane lasers on silicon2012In: Nature Photonics, ISSN 1749-4885, E-ISSN 1749-4893, Vol. 6, no 9, p. 615-620Article in journal (Refereed)
    Abstract [en]

    The realization of silicon-based light sources has been the subject of a major research and development effort worldwide. Such sources may help make integrated photonic and electronic circuitry more cost-effective, with higher performance and greater energy efficiency. The hybrid approach, in which silicon is integrated with a III-V gain medium, is an attractive route in the development of silicon lasers because of its potential for high efficiency. Hybrid lasers with good performance have been reported that are fabricated by direct growth or direct wafer-bonding of the gain medium to silicon. Here, we report a membrane reflector surface-emitting laser on silicon that is based on multilayer semiconductor nanomembrane stacking and a stamp-assisted transfer-printing process. The optically pumped laser consists of a transferred III-V InGaAsP quantum-well heterostructure as the gain medium, which is sandwiched between two thin, single-layer silicon photonic-crystal Fano resonance membrane reflectors. We also demonstrate high-finesse single-or multiwavelength vertical laser cavities.

  • 122684.
    Yang, Haiyan
    KTH, School of Electrical Engineering and Computer Science (EECS).
    Dimensioning of rural residential broadband solutions with LTE-based FWA and LEO satellite network2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Broadband provision in rural areas has been a restriction to the implementation of Internet connection worldwide. In recent years, some wireless broadband technologies began to target the rural market, from the perspective of not only expanding corporate’s profits but also social sustainable development. Among them, LTE-based FWA network and LEO satellite system are two most promising solutions for rural residential broadband market. In this thesis project, we evaluated these two communication systems from both technical and economic aspects. The main purpose is to obtain the required number of infrastructures for a generic rural area under consideration. Network dimensioning is applied to set up a system configuration model. Based on the coverage and capacity demand, the output of the dimension model is the required number of LTE sites and LEO satellites. Then the approximate cost of these two solutions were compared based on reasonable cost estimation.

    The results show that for LTE-based FWA solution, the network is always uplink budget limited for the purpose of coverage constraint, which means parameters on the receiver side like CPE’s transmit power, antenna gain and effective installation height are crucial factors affecting the required number of sites. If combined with the system capacity demand, we can see when the data usage less than 2.6GB per month, the final required number of sites is limited by the coverage, otherwise, it is restricted by the capacity demand in any case. According to the network configuration requirements in this thesis project, we can see the final required number of LTE sites and LEO satellites are both merely limited by the system capacity demand. We used parameters of Oneweb’s satellite as the reference to dimension the required number of satellites. However, after investigated the cost of the LEO satellite from the existing satellite system and other literature, we found Oneweb’s self-estimated cost of satellite is far lower than the industry average level, so we used two different reference cost for the satellite system, one is an assumption based on industry average standard, the other is Oneweb’s own cost estimation. Through the cost comparison, we can see the cost of satellite system is always lower than the LTE network if using Oneweb’s claimed cost, if using the industry reference cost, we can see satellite system is more cost-efficient than LTE sites under the condition that the cost of per satellite less than $ 12 million, or the user density below 3.9 per km2.

  • 122685.
    Yang, Hao
    et al.
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Li, Fusheng
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Wu, Xiujuan
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Zhang, Peili
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Li, Wenlong
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Cao, Suyan
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Shan, Yu
    Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China..
    Sun, Licheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry. Dalian Univ Technol, State Key Lab Fine Chem, IAP, Dalian 116024, Peoples R China.
    Improving the performance of water splitting electrodes by composite plating with nano-SiO22018In: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 281, p. 60-68Article in journal (Refereed)
    Abstract [en]

    The electrochemical splitting of water requires efficient functional electrodes. Herein, we report the fabrication of electrocatalyst consisted of an electrodeposited NiFeP alloy film which was composite plated with nano-SiO2 on nickel foam. The structure and morphology of the film were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the surface area of this NiFeP-SiO2 co-deposition alloy film can be significantly increased after electrochemical etching in a KOH solution. The water splitting properties of the alloy film were evaluated using electrochemistry. By using the NiFeP-SiO2/NF(Etched) as a bifunctional electrode, total water splitting has been demonstrated in a two-electrode cell with a current density of 10 mAcm(-2) at an applied voltage of 1.57 V, which exhibited enhanced water splitting activity in comparison to the analogue cell using the pristine NiFeP/NF electrode.

  • 122686.
    Yang, Heng
    et al.
    China Inst Water Resources & Hydropower Res, State Key Lab Simulat & Regulat Water Cycles Rive, Beijing 100038, Peoples R China..
    Jin, Ziliang
    KTH, School of Industrial Engineering and Management (ITM), Production Engineering.
    Wang, Jianhua
    China Inst Water Resources & Hydropower Res, State Key Lab Simulat & Regulat Water Cycles Rive, Beijing 100038, Peoples R China..
    Zhao, Yong
    China Inst Water Resources & Hydropower Res, State Key Lab Simulat & Regulat Water Cycles Rive, Beijing 100038, Peoples R China..
    Wang, Hejia
    China Inst Water Resources & Hydropower Res, State Key Lab Simulat & Regulat Water Cycles Rive, Beijing 100038, Peoples R China..
    Xiao, Weihua
    China Inst Water Resources & Hydropower Res, State Key Lab Simulat & Regulat Water Cycles Rive, Beijing 100038, Peoples R China..
    Data-Driven Stochastic Scheduling for Energy Integrated Systems2019In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 12, article id 2317Article in journal (Refereed)
    Abstract [en]

    As the penetration of intermittent renewable energy increases and unexpected market behaviors continue to occur, new challenges arise for system operators to ensure cost effectiveness while maintaining system reliability under uncertainties. To systematically address these uncertainties and challenges, innovative advanced methods and approaches are needed. Motivated by these, in this paper, we consider an energy integrated system with renewable energy and pumped-storage units involved. In addition, we propose a data-driven risk-averse two-stage stochastic model that considers the features of forbidden zones and dynamic ramping rate limits. This model minimizes the total cost against the worst-case distribution in the confidence set built for an unknown distribution and constructed based on data. Our numerical experiments show how pumped-storage units contribute to the system, how inclusions of the aforementioned two features improve the reliability of the system, and how our proposed data-driven model converges to a risk-neutral model with historical data.

  • 122687.
    Yang, Hong
    et al.
    KTH, School of Industrial Engineering and Management (ITM).
    Luo, Dan
    KTH, School of Industrial Engineering and Management (ITM).
    A Study of Additive Manufacturing Technology’s Development and Impact Through the Multi-Level Perspective Framework and the Case of Adidas2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Additive Manufacturing (AM) technology, known as 3D printing, is regarded as the ‘next generation of manufacturing’. It is classified as a disruptive technology and AM has attracted scholars worldwide and received extensive attention in various industries, which is significantly changing the way we design, produce, distribute and consume. This paper reviews how the AM development can be explained as a process of technological transition from a radical technological innovation to a social level technology, through integrating the technological innovation and the multilevel perspective (MLP) theories. In this way, we present a conceptual framework that provides a foundation for discussing AM trajectory and discover a development prediction of AM technology in the lens of MLP theoretical perspective. Secondly, the paper elaborates how AM is impacting businesses within the scope of open innovation through a case study on Adidas, to provide empirical support for similar industrial players to better predict the innovation trajectory through AM applications.

  • 122688.
    Yang, Hongliang
    KTH, Superseded Departments, Alfvén Laboratory.
    Numerical simulation of continuous casting of steel with applied magnetic field2002Doctoral thesis, comprehensive summary (Other scientific)
  • 122689.
    Yang, Hongliang
    KTH, Superseded Departments, Alfvén Laboratory.
    Self-consistent computation of the free surface in the electro-magnetic process2000Licentiate thesis, comprehensive summary (Other scientific)
  • 122690.
    Yang, Hongxing
    et al.
    Hong Kong Polytech Univ, Hong Kong, Hong Kong, Peoples R China..
    Leung, Dennis Y. C.
    Univ Hong Kong, Hong Kong, Hong Kong, Peoples R China..
    Yan, Jinyue
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes. Mälardalen Univ, Västerås, Sweden.
    First International Congress on Applied Energy, Hong Kong, January 5-7, 20092010In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083, Vol. 7, no 3, p. 223-223, article id PII 922586049Article in journal (Other academic)
  • 122691.
    Yang, Huaiyu
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Investigations intothe crystallization of butyl paraben2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In thisproject, solubility of butyl paraben in 7 puresolvents and 5 ethanol aqueous solvents has been determined at from 1 ℃to 50 ℃. Thermodynamic properties of butyl paraben have been measured by DifferentialScanning Calorimetey. Relationship between molar solubility of butyl paraben in6 pure solvents and thermodynamic properties has been analyzed. Thisrelationship suggests a method of estimating activity of solute at equilibrium fromcombining solubility data with DSC measurements. Then, activity coefficient accordingto the solubility at different temperatures can be estimated.

    Duringthe solubility measurements in ethanol aqueous solvents, it is found that whenbutyl paraben is added into aqueous solutions with certain proportion ethanol,solutions separates into two immiscible liquid layers in equilibrium. Water andethanol are primary in top layer, while the butyl paraben is primary in bottomlayer, but the solution turns to cloudy when two layers of solution are mixed. Theaim of this work was to present the phase behaviour of liquid-liquid-phaseseparation for (butyl paraben + water + ethanol) ternary system from 1 ℃ to 50 ℃at atmospheric pressure. Thearea of liquid-liquid-phase separation region in the ternary phase diagram increaseswith the increasing temperature from 10 ℃to 50 ℃.

    In thisstudy, more than several hundreds of nucleation experiments of butyl paraben havebeen investigated in ethyl acetate, propanol, acetone and 90% ethanol aqueoussolution. Induction time of butyl paraben has been determined at 3 differentsupersaturation levels in these solvents, respectively. Free energy ofnucleation, solid-liquid interfacial energy, and nuclei critical radius havebeen determined according to the classical nucleation theory. Statistical analysis ofinduction time reveals that the nucleation is a stochastic process with widevariation even at the same experiment condition. Butyl paraben nucleates most difficultlyin 90 % ethanol than in other 3 solvents, and most easily in acetone. The interfacialenergy of butyl paraben in these solvents tends to increasing with decreasemole fraction solubility in these solvents.

    Coolingcrystallizations with different proportions of butyl paraben, water and ethanolhave been observed by Focused Beam Reflectance Method, Parallel VirtualMachine, and On-line Infrared. The FBRM, IR curves and the PVM photos show someof the solutions appeared liquid-liquid phase separation during coolingcrystallization process. The results suggest that if solutions went throughliquid-liquid phase separation region during the cooling crystallizationprocess the distribution of crystals crystal was poor. Droplets from solutions withsame proportion butyl paraben but different proportions of water and ethanolhave been observed under microscope. Induction time of the droplets has been determinedunder the room temperature. Droplets from top layer or bottom layer of solutionwith liquid-liquid phase separation on small glass or plastic plates were alsoobserved under microscope. The microscope photos show that the opposite flows ofcloudy solution on the glass and the plastic plate before nucleation. The resultsof the cooling and evaporation crystallization experiments both revealed thatnucleation would be prevented by the liquid-liquid phase separation.

  • 122692.
    Yang, Huaiyu
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology. Univ Strathclyde, Scotland.
    Relation between metastable zone width and induction time of butyl paraben in ethanol2015In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 17, no 3, p. 577-586Article in journal (Refereed)
    Abstract [en]

    A relation between induction time and metastable zone width in cooling crystallization has been developed based on Classical Nucleation Theory, and an interpretation equation of this relation has been used to extrapolate metastable zone width from the induction time results in homogenous primary nucleation. The metastable zone width is determined by the interfacial energy and the pre-exponential factor. 440 metastable zone experiments of butyl paraben in ethanol at five different cooling rates have been performed. The experimental metastable zone widths of butyl paraben in ethanol are fairly close to those extrapolated from the induction time results. The positive correlation between the cooling rate and the experimental metastable zone width is in good agreement with the interpretation equation, from which the relations between stirring rate, saturation temperature and volume of solution with estimated metastable zone width have been investigated.

  • 122693.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Ake C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Solubility of Butyl Paraben in Methanol, Ethanol, Propanol, Ethyl Acetate, Acetone, and Acetonitrile2010In: Journal of Chemical and Engineering Data, ISSN 0021-9568, E-ISSN 1520-5134, Vol. 55, no 11, p. 5091-5093Article in journal (Refereed)
    Abstract [en]

    The solubility of butyl paraben (butyl 4-hydroxybenzoate) have been determined in methanol, ethanol, propanol, acetone, ethyl acetate, and acetonitrile in the temperature range of (10 to 50) C by the gravimetric method. The order of the solubility of butyl paraben in the different solvents as mass fraction at 20 C is: methanol > ethanol > acetone > propanol > ethyl acetate > acetonitrile. In terms of mole fraction solubility, the corresponding order is acetone > propanol > ethanol > ethyl acetate > methanol > acetonitrile, which shows that both nonpolar and polar groups of the paraben molecule influence the solubility in the different solvents.

  • 122694.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. Limerick University.
    Crystallization in droplets of butyl parabenManuscript (preprint) (Other academic)
  • 122695.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Crystallization of butyl paraben in mixtures of water and ethanolManuscript (preprint) (Other academic)
  • 122696.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. Limerick University.
    Nucleation of butyl paraben in different solvents2013In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 13, no 10, p. 4226-4238Article in journal (Refereed)
    Abstract [en]

    The primary nucleation induction time of butyl paraben in pure solvents: acetone, ethyl acetate, methanol, ethanol, and propanol and in 70% and 90% ethanol aqueous mixtures has been determined. At each condition, about 100 experiments have been performed in 5 mL scale to capture the statistics of the nucleation process. The induction times at each condition show a wide variation. The data has been evaluated within the framework of the classical nucleation theory using several of the current approaches. Overall, the data obtained from the different methods of evaluation are surprisingly consistent. At comparable driving forces, nucleation is clearly fastest in acetone and slowest in propanol, with methanol, ethyl acetate, and ethanol in between. Adding water to the ethanol leads to a clear reduction in the nucleation rate. The solid-solution interfacial energy of butyl paraben in the different solvents decreases in the order: 70% ethanol > 90% ethanol > propanol > ethanol > ethyl acetate > methanol > acetone, which is surprisingly well-correlated to a decreasing solvent boiling point. It is shown that the same trend can be found for other systems in the literature. With the assumption that the stronger the bonding in the bulk phases, the higher the interfacial energy becomes, this observation is paralleled by the fact that a metastable polymorph has a lower interfacial energy than the stable form and that a solid compound with a higher melting point appears to have a higher solid-melt and solid-solution interfacial energy.

  • 122697.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. Solid-State Research Group, Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, United Kingdom .
    Rasmuson, Åke
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. University of Limerick, Department of Chemical and Environmental Science, Materials and Surface Science Institute, Ireland .
    Sandwich crystals of butyl paraben2014In: CRYSTENGCOMM, ISSN 1466-8033, Vol. 16, no 37, p. 8863-8873Article in journal (Refereed)
    Abstract [en]

    Butyl paraben crystals having a porous layer in between two solid non-porous layers have been produced by cooling crystallization in mixtures of ethanol and water. The outer layers are transparent and fully crystalline, while the middle layer appears to be polycrystalline and is full of pores of various dimensions, down to below 0.1 mu m diameters. The thickness of the porous layer reaches about 40% of the whole crystal. The crystals contain one polymorph only and appear to be essentially fully crystalline. They are stable for more than a year when stored on the shelf at room temperature. When the crystals dissolve, the porous layer dissolves faster, leaving the outer layers for slower dissolution. The sandwich crystals are easily cleaved through the middle layer parallel to the (100) plane. This type of sandwich crystals may provide new useful properties to pharmaceutical solids, e. g. larger specific surface area, higher dissolution rates and improved compaction properties.

  • 122698.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena.
    Rasmuson, Åke
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. Limerick University.
    Ternary diagrams of ethyl paraben and propyl parabenManuscript (preprint) (Other academic)
  • 122699.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology. University of Strathclyde, United Kingdom .
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. University of Limerick, Ireland .
    Phase equilibrium and mechanisms of crystallization in liquid-liquid phase separating system2015In: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 385, p. 120-128Article in journal (Refereed)
    Abstract [en]

    The influence of liquid-liquid phase separation (LLPS) in a crystallizing system is examined, and the liquid-liquid tie lines are determined in the ternary system of butyl paraben, water and ethanol. Crystallization by evaporation in droplets (solution of butyl paraben in ethanol and water mixtures) of homogeneous solution and two-phase liquid mixtures on plates of different materials: glass, plastic, steel, and tin were investigated by microscopy. Different crystallization and liquid-liquid phase separation behaviour are observed depending on initial droplet composition and the surface material. This work reveals that crystallization in the LLPS solution of butyl paraben in ethanol-water mixtures starts in the butyl paraben rich phase as can be explained by a higher butyl paraben concentration, and a lower solid-liquid interfacial energy.

  • 122700.
    Yang, Huaiyu
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. Univ Strathclyde, Strathclyde Inst Pharm & Pharmaceut Sci, EPSRC Ctr Innovat Mfg Continuous Mfg & Crystallis, Glasgow, Lanark, United Kingdom .
    Rasmuson, Åke C.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Transport Phenomena. Univ Limerick, Mat & Surface Sci Inst, Solid State Pharmaceut Cluster, Dept Chem & Environm Sci, Limerick, Ireland.
    Ternary phase diagrams of ethyl paraben and propyl paraben in ethanol aqueous solvents2014In: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 376, p. 69-75Article in journal (Refereed)
    Abstract [en]

    Three ternary phase diagrams of ethyl paraben, ethanol, water and propyl paraben, ethanol, water have been determined. The liquid-liquid phase separation has been reported in these three ternary diagrams. In pure water the ethyl paraben and propyl paraben solubility is both below 1 mg/g, while in pure ethanol the solubility is more than three orders of magnitude higher. While the solution saturated with propyl paraben is homogeneous at 30.0 degrees C, and the solution saturated with ethyl paraben is homogenous at 40.0 degrees C, however, the higher temperatures induce liquid-liquid phase separation in the ethanol-water mixtures, and the ternary phase diagrams contain five different regions. The size of the liquid-liquid phase separation region increases with increasing temperature. The systematic changes of thermodynamic properties between butyl paraben, propyl paraben and ethyl paraben have been investigated.

2451245224532454245524562457 122651 - 122700 of 127988
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