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  • 301.
    Strandberg, Anna
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Holmgren, Per
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Wagner, David R.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Molinder, Roger
    Wiinikka, Henrik
    Umeki, Kentaro
    Broström, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Effects of pyrolysis conditions and ash formation on gasification rates of biomass char2017Inngår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 31, nr 6, s. 6507-6514Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Pyrolysis conditions and the presence of ash-forming elements significantly influence char properties and its oxidation or gasification reactivity. In this study, intrinsic gasification rates of char from high heating rate pyrolysis were analyzed with isothermal thermogravimetry. The char particles were prepared from two biomasses at three size ranges and at two temperatures. Reactivity dependence on original particle size was found only for small wood particles that had higher intrinsic char gasification rates. Pyrolysis temperature had no significant effect on char reactivity within the range tested. Observations of ash formation highlighted that reactivity was influenced by the presence of ash-forming elements, not only at the active char sites but also through prohibition of contact between char and gasification agent by ash layer formation with properties highly depending on ash composition.

  • 302.
    Suarez, J. A.
    et al.
    Universidad de Oriente, Santiago de Cuba, Cuba.
    Beaton, P. A.
    Universidad de Oriente, Santiago de Cuba, Cuba.
    Zanzi, Rolando
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    A phenomenological energy model of biomass pyrolysis under autothermal fluidized bed conditions2006Inngår i: Energy Sources Part a-Recovery Utilization and Environmental Effects, ISSN 1556-7036, Vol. 28, nr 8, s. 705-714Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In Cuba a variety of types of biomass is being investigated for energy conversion through thermochemical processes into solid, liquid, and gas products. A continuous bench fluidized bed pyrolysis has been designed and is currently under testing. In this article, a transport model has been developed to simulate the axial temperature fields in a bench. The model and experimental results indicated that (1) two zones exist inside of the fluidization column, the dense bed where the exothermic and endothermic reactions are active, and the freeboard zone where the temperature of the pyrolysis product decreases continuously; (2) the bed temperature increases with an increase in the air factor. The predicted temperature is in quantitative agreement with experimental measurements.

  • 303.
    Suarez, J. A.
    et al.
    Universidad de Oriente, Santiago de Cuba, Cuba.
    Beaton, P. A.
    Universidad de Oriente, Santiago de Cuba, Cuba.
    Zanzi, Rolando
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Grimm, A.
    Autothermal fluidized bed pyrolysis of Cuban pine sawdust2006Inngår i: Energy Sources Part a-Recovery Utilization and Environmental Effects, ISSN 1556-7036, Vol. 28, nr 8, s. 695-704Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Oxidative pyrolysis of Cuban pine sawdust was investigated using an autothermal fluidized bed reactor. Biomass particles were fed continuously (8.13 Kg/h) in a bed, fluidized by air gas. Experiments were conduced at three different dimensionless air factors 1, 1.5, and 2 (defined as ratio of actual air flow rate to stoichiometric air flow rate). The various physical and chemical characteristics of the pyrolysis products acquired in these conditions were identified. The results indicated that (1) the operating temperature can be correlated with the air factor; (2) the higher air factor promotes high temperature and contributes to the secondary reactions, which lead to less liquid; (3) the physicochemical characterization of the pyrolysis products indicated that the air factor, in the range studied, does not have a notable influence in their properties; (4) the liquid and char products obtained may be a potentially valuable source of chemical feedstocks.

  • 304. Sugiyama, J.
    et al.
    Umegaki, I.
    Matsumoto, M.
    Miwa, K.
    Nozaki, H.
    Higuchi, Y.
    Noritake, T.
    Forslund, Ola Kenji
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Material- och nanofysik.
    Månsson, Martin
    KTH, Skolan för teknikvetenskap (SCI), Tillämpad fysik, Material- och nanofysik.
    Cottrell, S. P.
    Koda, A.
    Ansaldo, E. J.
    Brewer, J. H.
    Desorption reaction in MgH 2 studied with in situ μ + SR2019Inngår i: Sustainable Energy and Fuels, ISSN 2398-4902, Vol. 3, nr 4, s. 956-964Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to study the mechanism determining the desorption temperature (T d ) of hydrogen storage materials, we have measured positive muon spin rotation and relaxation (μ + SR) in MgH 2 over a wide temperature range including its T d . The pressure in the sample cell due to desorbed H 2 was measured in parallel with the μ + SR measurements under static conditions. Such in situ μ + SR measurements revealed that hydrogen starts to diffuse in MgH 2 well below T d . This indicates the important role of hydrogen diffusion in accelerating the desorption reaction by removing the reaction product, i.e. H 2 , from the reaction system.

  • 305.
    Svens, Pontus
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Methods for Testing and Analyzing Lithium-Ion Battery Cells intended for Heavy-Duty Hybrid Electric Vehicles2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Lithium-ion batteries designed for use in heavy-duty hybrid vehicles are continuously improved in terms of performance and longevity, but they still have limitations that need to be considered when developing new hybrid vehicles.               

    The aim of this thesis has been to study and evaluate potential test and analysis methods suitable for being used in the design process when maximizing lifetime and utilization of batteries in heavy-duty hybrid vehicles.

    A concept for battery cell cycling on vehicles has been evaluated. The work included development of test equipment, verification of hardware and software as well as an extended period of validation on heavy-duty trucks. The work showed that the concept has great potential for evaluating strategies for battery usage in hybrid vehicles, but is less useful for accelerated aging of battery cells.                            

    Battery cells encapsulated in flexible packaging material have been investigated with respect to the durability of the encapsulation in a demanding heavy-duty hybrid truck environment. No effect on water intrusion was detected after vibration and temperature cycling of the battery cells.                   

    Aging of commercial battery cells of the type lithium manganese oxide - lithium cobalt oxide / lithium titanium oxide (LMO-LCO/LTO) was investigated with different electrochemical methods to gain a deeper understanding of the origin of performance deterioration, and to understand the consequences of aging from a vehicle manufacturer's perspective. The investigation revealed that both capacity loss and impedance rise were largely linked to the positive electrode for this type of battery chemistry.                          

    Postmortem analysis of material from cycle-aged and calendar-aged battery cells of the type LMO-LCO/LTO and LiFePO4/graphite was performed to reveal details about aging mechanisms for those cell chemistries. Analysis of cycle-aged LMO-LCO/LTO cells revealed traces of manganese in the negative electrode and that the positive electrode exhibited the most severe aging. Analysis of cycle-aged LFP/graphite cells revealed traces of iron in the negative electrode and that the negative electrode exhibited the most severe aging.

  • 306.
    Svensson, Karolina
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Södergren, Simon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Andersson, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Klintberg, Lena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    Hjort, Klas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Mikrosystemteknik.
    High-pressure microfluidic electrochemical and image analysis dual detection for HPLC2018Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    High-performance liquid chromatography (HPLC) is often set as the lab-based golden standard. For point-of-care and point-of-site applications, making HPLC portable, easy to use and low cost, is very desirable. To reach lower costs, one important task is the development of suitable detectors. Because of the potential for low cost and high performance, a dual-detection microfluidic chip with an electrochemical detector (ECD) and optical access for image analysis was evaluated at high pressure, downstream an HPLC column. For the image analysis, a camera and near-UV-light was used to extract absorption data. To validate the response, a spectrometer was coupled downstream the chip. The results of the three different detectors were comparable, with the camera providing similar absorbance-time chromatograms as the spectrometer. However, the ECD registered only peaks from one of two analytes. To conclude, this experimental setup has potential to provide better understanding of the capability for microfluidic HPLC systems.

  • 307. Syed, Hanif Uddin
    et al.
    Nebamoh, Ikechukwu Patrick
    BillerudKorsnäs AB.
    Germgård, Ulf
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper.
    A comparison of cold and hot caustic extraction of a spruce dissolving sulfite pulp prior to final bleaching2013Inngår i: Appita journal, ISSN 1038-6807, Vol. 66, nr 3, s. 229-234Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A magnesium sulfite pulp producer modified its pulping process to dissolving pulping in 2011 and needed a purification stage after the digester to obtain a sufficiently low hemicellulose content. The dissolving pulp was intended for viscose production and an R-18 value of at least 95% and an intrinsic viscosity below 550 dm(3)/kg was requested. The results showed, as could be expected, a correlation between lower dissolving pulp yield and a higher degree Of purification with respect to cellulose. The R-18 values and the intrinsic viscosities of the dissolving pulps were found to increase with increasing sodium hydroxide concentration and/or higher temperature in the extraction Stage. The pulp yield was found to be higher with higher temperature for the cold caustic extraction stage (CCE); for hot caustic extraction (HQ E) the pulp yield became lower with higher temperature. The specified R-18 value was easiest to reach using hot caustic extraction.

  • 308.
    Tammela, Petter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Oorganisk kemi.
    Preparation and characterization of a metal hydride electrode2012Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Metal hydrides are used as anode material in nickel metal hydride batteries and are of particular interest because of the potential to be a part of energy systems completely involving renewable sources (e.g. solar power, wind power etc.). Preparation and electrochemical characterization of metal hydride electrodes have not previously been performed at the Department of Chemistry – Ångström Laboratory. Two basic techniques that are desired to be used in the characterization are cyclic voltammetry and chronopotentiometry. This thesis work is aimed at preparation and electrochemical characterization of a metal hydride electrode and, as a complement, study the electrode with X-ray diffraction.

    LaNi3.55Co0.75Mn0.4Al0.3, a standard material for metal hydride electrodes previously studied by Khaldi et al. was chosen, to ensure that electrochemical absorption of hydrogen was possible, and to be able to compare electrochemical results [1-3]. LaNi3.55Co0.75Mn0.4Al0.3 was synthesized with arc melting, with additional annealing at 900˚C for five days, ground in a cemented carbide ball mill and sieved to less than 56 µm.

    Electrodes were prepared containing 90 wt.-% of LaNi3.55Co0.75Mn0.4Al0.3 powder, 5 wt.-% of polytetrafluoroethylene and 5 wt.-% of carbon black. The hydrogen absorption and desorption capabilities of the electrode were studied electrochemically with cyclic voltammetry and chronopotentiometry, and the structural changes associated with absorption of hydrogen was studied with X-ray diffraction.

    The capacity increased, probably from activation of the material, during initial cycling up to the maximum capacity of 294 mAh/g, obtained after 9 cycles, followed by a small decrease, probably caused by corrosion and passivation of the material, in capacity of the remaining 11 cycles. Activation of the material causes the charge and the discharge potential to shift to a more positive and a more negative value, respectively. The final values for the charge potential and the discharge potential were -841mV and -945 mV vs. Hg/HgO, respectively, after 16 cycles. Khalid et al. [1-3]reported a maximum capacity of 300 mAh/g, a charge potential of about -960 mV and a discharge potential of about -840 mV after 16 cycles the results obtained in this study are considered to be in good agreement with those reported.

    X-ray diffraction of the electrodes revealed, as expected, a cell volume change of the charged electrode compared to the discharged electrode. The change in cell volume corresponds to an estimated capacity of 303 mAh/g, which is very close to the, above mentioned, electrochemically obtained maximum capacity of 294 mAh/g.

  • 309.
    Tavast, Daniel
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknologi, Träkemi och massateknologi.
    Improved Usage of Wood Raw Material through Modification of the Kraft Process2015Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

       The kraft process is a complex system with many variables, and though the process is fairly well understood, there is still much we do not know.

     

       This thesis examines some aspects of the kraft process that could prove to be of interest for the pulp and paper industry, specifically, the impact of wood chip impregnation and of the chemical structure of xylan on spruce kraft pulp. The intent is to suggest modifications to the kraft process as it is used today.

     

       The effect of wood chip impregnation varies with the prevalent conditions, and increases the effect of the subsequent kraft cook. Longer impregnation at a lower temperature was found to increase screened pulp yield, reduce shives content, make it possible to reach a certain kappa number at a lower H-factor, and make it possible to reach a certain kappa number at a lower total alkali consumption.

     

       Xylan has previously been found to have a strength-enhancing effect on pulp, and the chemical structure of the xylan in question was found to be the main strength-enhancing factor. For spruce xylan, the structure that provides the largest increase in strength is not the same as the structure that increases the yield the most. Removing xylan was determined to have a negative impact on pulp strength.

     

       Xylan extracted from agro waste can be used as an additive to increase pulp strength. This could be viable, especially when combined with the production of green plastics from hemicelluloses extracted from the agro waste.

     

       A suggested configuration of a future pulp mill is presented, incorporating the following modifications to the now standard kraft cooking system:

    • impregnation at a lower temperature for a longer time;
    • extracting xylan-enriched black liquor at an early stage of the impregnation or cook, and adding this liquor at a late stage of the cook;
    • terminating the cook at a higher kappa number;
    • increasing oxygen delignification to compensate for the increased kappa number at the end of the cook, keeping the kappa number constant going into the bleaching plant; and
    • adding agro-waste xylan during oxygen delignification.
  • 310.
    TENGQVIST, MARIA
    KTH, Skolan för kemivetenskap (CHE).
    Teknoekonomisk studie för fullskalig produktion av biomassa från mikroalger2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Microalgae have received a surge in attention in the past decade as a source for renewable

    energy. They are currently used to produce high-value products but have the

    potential to produce biofuels such as bioethanol, biodiesel and biohydrogen among

    others. The present work is an evaluation of the feasibility of a process producing

    microalgae as a wet biomass paste through modeling of a real process. The production

    process of microalgal-derived low-value products has yet to be realized due to

    the low productivity in current culture systems, the high cost of such systems and

    the high cost of harvesting the microalgal biomass. An accurate and efficient model

    of this process is key in allowing for scale up to where it can contribute sufficiently

    to a more sustainable society.

    The model constructed evaluates the best alternative out of twelve configurations

    using data supplied by the user. The model is flexible in that it allows for modeling

    of different microalgae and different scales of production. Genetic engineering of the

    microalgae is modeled as three different cases: a reduction in the light-harvesting

    antennae, the expression of a fluorescent protein that by absorbing UV light emits

    photosynthetically active radiation and a combination of the two. The model is then

    run for the case relevant to the user. To evaluate the performance of the model and

    the viability of the modeled process, it was ran for the microalgae P. tricornutum and

    an annual production demand of 1000 ton wet biomass paste. The break-even price

    of the biomass was 8.79 Ä for the base case and 5.68 Ä with both cases of genetic

    engineering of the microalgal cell. The best configuration was found to be a tubular

    photobioreactor in the cultivation stage with flocculation-sedimentation followed by

    filtration in the harvesting stage.

    The model is capable of producing results that are in line with the current research

    and are thus deemed reasonable. With the level of accuracy that the model presently

    contains, it is a good representation of the production of microalgal biomass as a

    whole. However, to be able to draw definitive conclusions, more time and research

    is required.

  • 311.
    Trubetskaya, Anna
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Broström, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Kling, J.
    Brown, A.
    Tompsett, G.
    Umeki, K.
    Effects of Lignocellulosic Compounds on the Yield, Nanostructure and Reactivity of Soot from Fast Pyrolysis at High Temperatures2017Konferansepaper (Annet vitenskapelig)
  • 312.
    Trubetskaya, Anna
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Broström, Markus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för tillämpad fysik och elektronik.
    Larsen Andersen, Mogens
    Talbro Barsberg, Søren
    Modeling of radical structures in biochar using DFT calculations2017Inngår i: ECI Digital Archives / [ed] Franco Berruti, Raffaella Ocone and Ondrej Masek, Digital Commons , 2017Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Carbon is a key ingredient for producing metals used for cellphones, laptop computers, photovoltaic panels, and related solid state silicon devices employed by mankind. Thus, introduction of an alternative reductant based on bioresources into steel manufacturing without significant investments in a new technology is of high importance and wide impact. The production of iron, steel, and many other metals can employ biocarbon as the needed reductant; but because of cost, coals are usually used instead. The anthropogenic CO2 emissions can be decreased by substitution of biochar in the production of silicon and metals due to the lower regeneration time of biomass < 10 years compared to 106-107 years for bituminous coal.

    This study aims to develop and to provide knowledge on the biochar structure at the molecular level including the presence of free radicals and oxygen heteroatoms that is essential for the understanding and prediction of biochar valuable properties in metallurgical applications. Both yields and biochar properties are important parameters for the optimization of pyrolysis conditions. Therefore, the pyrolysis conditions for the biochar application as a reducing agent in steel industry were optimized, and the molecular structure of the biochar by the combined use of experimental chemistry (Raman spectroscopy and Fourier transform infrared spectroscopy) and quantum chemistry computations (Density Functional Theory methods) was modified.

    The results indicated the formation of stable radicals from biomass pyrolysis at their termination stage which were quantified by the electron spin resonance spectroscopy. Based on the experimental and fitting results, PAH structures were selected as initial compounds for the DFT modeling. The comparison of hydroxylated with methylated PAH structures showed that hydroxylated PAH are excellent candidate to represent the radical structure based on the low bond dissociation energes. The bond dissociation energy of -10 Kcal mol-1 is in the range of the best known antioxidants. The results showed that the present DFT model predicts reasonably the biochar molecular structure, and can capture changes in the biochar molecular structure under different pyrolysis conditions.

  • 313.
    Uddin, Arth
    et al.
    KTH, Skolan för kemivetenskap (CHE).
    Hosseini, Ashkan
    KTH, Skolan för kemivetenskap (CHE).
    Modeling a computational program with mass and energy balances2012Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    After the extension of the boiler 6 at Högdalenverket during 2010, there has been some problems in the form of increased carbon monoxide levels. There may be several explanations for this problem, which means that complete combustion doesent take place. There have also been problems with the ash-handling system and the sand returning systemt, this results in higher operating costs because it requires a higher consumption of inert material.The project was first divided into two phases, the first phase was to develop material and energy balances for the boiler but also introduce the parameters that we wanted to investigate further in order to possibly identify the causes of the problems that the boiler had. In the second phase experiments were going to be designed in consultation with the contact staff at Fortum to explore these parameters.During the project changes have been made in the project description, as it will require more time and more accurate planning to perform  the desired tests on the boiler. Three proposals on parameters that could be the cause of carbon monoxide problem was presented at the end of phase one and it was found that two of the proposals was not possible to carry out during the project because it would have affected economically and the availibility of the boilier.The third parameter, the bed quality effect on combustion experiment was designed in consultation with those responsible at Fortum.This experiment could also not be performed as there was some operational difficulties with the boiler during the project time. Instead, a description of the design for the experiment has been added to this project, which may at a later stage be used to investigate the bed quality impact on the carbon monoxide issues.Recent changes to the project description meant that purpose instead was to further develop the computational program created during the project's first phase and at the end of the project shall be submitted to the operators at Fortum. This calculation program takes into account the significant parameters that the boiler regulator is governed by today. The simulation program is developed using Microsoft Excel and is based on material and energy balances. This program can be used internally by Fortum to get an idea of ​​how the different mass flow rates would vary at different operating conditions and how the energy balance for the boiler would look like during the changes.When compared with materials and energy made by the boiler supplier revealed that the deviations are very small compared to what the program come up with and is caused mainly due to the assumptions made. These assumptions can be eliminated by performing experiments and collecting more data.The results gained by the calculation program has been compared with the results that was presented by the supplier during their boiler mapping, comparisons have been made regarding flue gas flows, fuel flows, combustion air flow, ash production and energy balances. It has apperad that the deviations are relatively small and the presented scheme provides a theoretical overall perspective of the boiler in line with reality.Although discussions have taken into consideration for the problem of elevated levels of carbon monoxide, and whether the measurement program can be developed further in the future.

  • 314.
    Valavi, Masood
    et al.
    University of Limerick, Ireland.
    Svärd, Michael
    University of Limerick, Ireland.
    Rasmuson, Åke C.
    University of Limerick, Ireland.
    Improving Estimates of the Crystallization Driving Force: Investigation into the Dependence on Temperature and Composition of Activity Coefficients in Solution2016Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 16, nr 12, s. 6951-6960Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influence of temperature and composition on solution activity coefficients has been investigated. Under most conditions, the temperature dependence of the activity coefficient is much weaker than the composition dependence. A novel and more accurate approach to estimate crystallization driving forces is proposed, where, rather than neglecting the activity coefficient ratio, it can be estimated from solid−liquid equilibrium data.

  • 315.
    Vera, C. M.
    et al.
    Phenomenex Australia, Pty Ltd, Lane Cove, NSW 2067, Australia.
    Shock, D.
    Phenomenex Australia, Pty Ltd, Lane Cove, NSW 2067, Australia.
    Dennis, G. R.
    Australian Centre for Research on Separation Science, School of Science and Health, University of Western Sydney, Penrith, NSW 2751, Australia.
    Samuelsson, Jörgen
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper.
    Enmark, Martin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper.
    Fornstedt, Torgny
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper.
    Shalliker, R. Andrew
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper. Australian Centre for Research on Separation Science, School of Science and Health, University of Western Sydney, Penrith, NSW 2751, Australia.
    A preliminary study on the selectivity of linear polynuclear aromatic hydrocarbons in SFC using phenyl-type stationary phases2015Inngår i: Microchemical journal (Print), ISSN 0026-265X, E-ISSN 1095-9149, Vol. 121, s. 136-140Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The retention behaviour of a homologous series of polyaromatic hydrocarbons was evaluated on two phenyl-type stationary phases in reversed phase supercritical fluid chromatography (SFC). These phases were the Synergi polar-RP phase and the Cosmosil 5PBB phase, both of which are polar end-capped and incorporate an ether in a propyl chain that tethers the phenyl ring to the silica surface. The Cosmosil 5PBB phase also has five bromine atoms on the phenyl ring. The retention capacity of the Cosmosil column was substantially greater than the Synergi column. However, selectivity on the Cosmosil column was effectively independent of the acetonitrile modifier composition in the CO2 mobile phase, whereas, selectivity on the Synergi column was greatly affected by the acetonitrile modifier in the CO2 mobile phase. The results from this study showed that selectivity and retention studies in HPLC cannot be used to predict selectivity and retention behaviour in SFC. (C) 2015 Elsevier B.V. All rights reserved.

  • 316.
    Vilaplana, Francisco
    et al.
    Division of Glycoscience, School of Biotechnology, AlbaNova University Centre, KTH Royal Institute of Technology, Stockholm, Sweden / Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Nilsson, Johanna
    Department of CollectionsThe Royal Armoury, Skokloster Castle, Hallwyl Museum, Stockholm, Sweden.
    Sommer, Dorte V. P.
    School of Conservation, Royal Danish Academy of Fine Arts Schools of Architecture, Design and Conservation, Copenhagen, Denmark.
    Karlsson, Sigbritt
    Högskolan i Skövde. Department of Fibre and Polymer Technology, School of Chemical Science and Engineering, KTH Royal Institute of Technology, Stockholm, Sweden.
    Analytical markers for silk degradation: comparing historic silk and silk artificially aged in different environments2015Inngår i: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 407, nr 5, s. 1433-1449Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Suitable analytical markers to assess the degree of degradation of historic silk textiles at molecular and macroscopic levels have been identified and compared with silk textiles aged artificially in different environments, namely (i) ultraviolet (UV) exposure, (ii) thermo-oxidation, (iii) controlled humidity and (iv) pH. The changes at the molecular level in the amino acid composition, the formation of oxidative moieties, crystallinity and molecular weight correlate well with the changes in the macroscopic properties such as brightness, pH and mechanical properties. These analytical markers are useful to understand the degradation mechanisms that silk textiles undergo under different degradation environments, involving oxidation processes, hydrolysis, chain scission and physical arrangements. Thermo-oxidation at high temperatures proves to be the accelerated ageing procedure producing silk samples that most resembled the degree of degradation of early seventeenth-century silk. These analytical markers will be valuable to support the textile conservation tasks currently being performed in museums to preserve our heritage.

  • 317. Wang, Baoyuan
    et al.
    Cai, Yixiao
    Xia, Chen
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Kim, Jung-Sik
    Liu, Yanyan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Dong, Wenjing
    Wang, Hao
    Afzal, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Li, Junjiao
    Raza, Rizwan
    Zhu, Bin
    KTH, Skolan för datavetenskap och kommunikation (CSC), Medieteknik och interaktionsdesign, MID.
    Semiconductor-ionic Membrane of LaSrCoFe-oxide-doped Ceria Solid Oxide Fuel Cells2017Inngår i: Electrochimica Acta, ISSN 0013-4686, E-ISSN 1873-3859, Vol. 248, s. 496-504Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel semiconductor-ionic La0.6Sr0.4Co0.2Fe0.8O3-delta (LSCF)-Sm/Ca co-doped CeO2 (SCDC) nanocomposite has been developed as a membrane, which is sandwiched between two layers of Ni0.8Co0.15Al0.05Li-oxide (NCAL) to construct semiconductor-ion membrane fuel cell (SIMFC). Such a device presented an open circuit voltage (OCV) above 1.0 V and maximum power density of 814 mW cm(-2) at 550 degrees C, which is much higher than 0.84 V and 300 mW cm(-2) for the fuel cell using the SCDC membrane. Moreover, the SIMFC has a relatively promising long-term stability, the voltage can maintain at 0.966 V for 60 hours without degradation during the fuel cells operation and the open-circuit voltage (OCV) can return to 1.06 V after long-term fuel cell operation. The introduction of LSCF electronic conductor into the membrane did not cause any short circuit but brought significant enhancement of fuel cell performances. The Schottky junction is proposed to prevent the internal electrons passing thus avoiding the device short circuiting problem.

  • 318. Wang, Huijiao
    et al.
    Mustafa, Majid
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Yu, Gang
    Östman, Marcus
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Cheng, Yi
    Wang, Yujue
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Oxidation of emerging biocides and antibiotics in wastewater by ozonation and the electro-peroxone process2019Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 235, s. 575-585Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study investigated the abatement of a number of antimicrobials frequently detected in municipal wastewater by conventional ozonation and a recently developed ozone-based advanced oxidation process, the electro-peroxone (E-peroxone) process. A synthetic water and a real secondary wastewater effluent were spiked with fourteen antimicrobials, including antibiotics and biocides, and then treated by the two processes. The results show that most of the antibiotics investigated (e.g., ofloxacin, trimethoprim, norfloxacin, and ciprofloxacin) readily react with ozone (O3) and could therefore be efficiently eliminated from the water matrices by direct O3 oxidation during both processes. In contrast, most of the biocides tested in this study (e.g., clotrimazole, pentamidine, bixafen, propiconazole, and fluconazole) were only moderately reactive, or non-reactive, with O3. Therefore, these biocides were removed at considerably lower rate than the antibiotics during the two ozone-based processes, with hydroxyl radical (OH) oxidation playing an important role in their abatement mechanisms. When compared with conventional ozonation, the E-peroxone process is defined by the in situ electrogeneration of hydrogen peroxide, which considerably enhances the transformation of O3 to OH. As a result, the E-peroxone process significantly accelerated the abatement of biocides and required a considerably shorter treatment time to eliminate all of the tested compounds from the water matrices than conventional ozonation. In addition, the E-peroxone process enhanced the contributions of OH fractions to the abatement of moderately ozone reactive benzotriazoles. These results demonstrate that the E-peroxone process holds promise as an effective tertiary treatment option for enhancing the abatement of ozone-resistant antimicrobials in wastewater.

  • 319.
    Wang, Yuming
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten. Nanjing Tech Univ, Peoples R China.
    Jafari, Mohammad Javad
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Wang, Nana
    Nanjing Tech Univ, Peoples R China.
    Qian, Deping
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Zhang, Fengling
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Ederth, Thomas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Moons, Ellen
    Karlstad Univ, Sweden.
    Wang, Jianpu
    Nanjing Tech Univ, Peoples R China.
    Inganäs, Olle
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Huang, Wei
    Nanjing Tech Univ, Peoples R China.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Light-induced degradation of fullerenes in organic solar cells: a case study on TQ1:PC71BM2018Inngår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 6, nr 25, s. 11884-11889Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The stability of organic solar cells (OSCs) is critical for practical applications of this emerging technology. Unfortunately, in spite of intensive investigations, the degradation mechanisms in OSCs have not been clearly understood yet. In this report, we employ a range of spectroscopic and transport measurements, coupled with drift-diffusion modelling, to investigate the light-induced degradation mechanisms of fullerene-based OSCs. We find that trap states formed in the fullerene phase under illumination play a critical role in the degradation of the open-circuit voltage (V-OC) in OSCs. Our results indicate that the degradation is intrinsic to the fullerenes in OSCs and that alternative acceptor materials are desired for the development of stable OSCs.

  • 320. Watterson, Samuel
    et al.
    Hudson, Sarah
    Svärd, Michael
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Teknisk strömningslära. SSPC, University of Limerick, Ireland.
    Rasmuson, Åke C.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Teknisk strömningslära. University of Limerick, Ireland.
    Thermodynamics of fenofibrate and solubility in pure organic solvents2014Inngår i: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 367, s. 143-150Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Calorimetric data on the melting of 1-methylethyl 2-[4-(4-chlorobenzoyl)-phenoxyl-2-methylpropanoate (fenofibrate) and the heat capacity of the solid and the melt have been determined, from which the Gibbs energy, enthalpy and entropy of fusion are calculated. Solid-liquid solubility data have been collected by a gravimetric method in seven pure solvents (methanol, ethanol, 1-propanol, 2-propanol, ethyl acetate, acetonitrile, and acetone) across a range of temperatures. Fenofibrate is much more soluble in ethyl acetate, acetonitrile and acetone compared to alcohols. In the alcohols the solubility increases with aliphatic chain length. The Gibbs energy of fusion is used to estimate the activity of the solid within a Raoult's law framework. Except for ethyl acetate solutions which are almost ideal, solutions in all evaluated solvents exhibit positive deviation from Raoult's law, and in the alcohols the activity coefficient ranges up to 25. It is shown that the heat capacity component of the enthalpy of fusion is not negligible at room temperature, in spite of the proximity to the melting point, and furthermore that the temperature dependence of the activity coefficient in the saturated solution has a governing influence on the van't Hoff enthalpy of solution in acetonitrile and the alcohols. Crystals obtained by two different methods from a range of solvents have been analysed by PXRD, FTIR and NMR spectroscopy, TGA and DSC, and have in all cases been shown to consist of the stable polymorph (form l).

  • 321.
    Wiezell, Katarina
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Holmström, Nicklas
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Studying Low-Humidity Effects in PEFCs Using EIS II: Modeling2012Inngår i: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 159, nr 8, s. F379-F392Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electrochemical impedance spectroscopy (EIS) and steady-state models have been developed to investigate the influence of water transport on the membrane and electrode performance, with focus on the low-frequency impedance. Models for the membrane, hydrogen anode and oxygen cathode were connected in order to take the influence of water concentration on proton conductivity and hydrogen kinetics into account. At low frequencies, below 1 Hz, a pseudo-inductive loop was predicted, resulting from the overlap of the responses from anode and membrane. The anode response could be coupled to changes in the kinetics and polymer conductivity in the active layer, and the membrane response to changes in conductivity with changing water profile. The low frequency capacitive part was attributed to drying of the anode side of the membrane, while the inductive part was attributed to the rehydration of the membrane with water produced at the cathode. The loop appeared at a frequency proportional to 1/L-2, where L is the membrane thickness. The model was successfully fitted to experimental data at different membrane thicknesses, relative humidities and current densities. The modeled data follow the same trends as experimental data, giving an increase in impedance at dry conditions and with thicker membranes.

  • 322.
    Wikström, Martina
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Energiprocesser.
    Hansson, Lisa
    Linköpings Universitet.
    Alvfors, Per
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Energiprocesser.
    Socio-technical experiences from electric vehicle utilisation in commercial fleets2014Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 123, s. 82-93Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Commercial vehicle fleets are in many ways an attractive entry for electric vehicles into the transport system. In total, 174 electric vehicles have operated in commercial vehicle fleets and gathered socio-technical data over a period of 18 months, resulting in 302,000 all electric kilometres. This paper presents two perspectives regarding electric vehicle operations in commercial vehicle fleets - the functionality perspective, illustrated by the vehicle actions, and the user perspective that addresses the implementation of the task. The socio-technical analysis has resulted in four major findings. With time, the overall usage and the driving distance between charging occasions increase. It is not the passage of time that has influenced this behaviour but it may be explained as the result of accumulated experience. Swedish winter conditions show regression in usage, foremost due to users not familiar with the range reduction caused by the heating system. The need for public charging has been shown to be modest, which in an introductory phase with limited development of charging infrastructure, makes commercial vehicle fleets favourable to electrify over private vehicle fleets. According to deployment strategy, the different user groups' ability to incorporate the electric vehicles in their daily activities has been explored and this paper shows large potential for substituting traditional internal combustion engine vehicles within commercial vehicle fleets. Electric vehicles have been made available through a technology procurement scheme and have generated both kilometres and experience, which has come to increase the understanding of the usage of electric vehicles in commercial vehicle fleets.

  • 323.
    Willgert, Markus
    et al.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Ytbehandlingsteknik.
    Leijonmarck, Simon
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi. Swerea SICOMP AB, Sweden.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Malmström Jonsson, Eva
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Ytbehandlingsteknik.
    Johansson, Mats K. G.
    KTH, Skolan för kemivetenskap (CHE), Fiber- och polymerteknik, Ytbehandlingsteknik.
    Cellulose nanofibril reinforced composite electrolytes for lithium ion battery applications2014Inngår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 2, nr 33, s. 13556-13564Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The present study describes the synthesis and characterization of a series of four composite electrolytes for lithium ion battery applications. The two-phase electrolytes are composed of a soft, ionic conductive poly(ethylene glycol) (PEG) matrix having stiff nanofibrillated cellulose (CNF) paper as reinforcement to provide mechanical integrity. The reinforcing CNF is modified in order to create covalent bonds between the phases which is particularly beneficial when swelling the composite with a liquid electrolyte to enhance the ionic conductivity. After swelling the composite polymer electrolyte, forming a gelled structure, values of ionic conductivity at 5 x 10(-5) S cm(-1) and an elastic modulus around 400 MPa at 25 degrees C are obtained.

  • 324.
    Wreland Lindström, Rakel
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Bränsleceller och material: Rapport från arbetsseminarium 16 juni 20112011Rapport (Annet (populærvitenskap, debatt, mm))
  • 325.
    Wreland Lindström, Rakel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Aguinaga, Luis Guerrero
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Oyarce, Alejandro
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Ubeda, Diego
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Ingratta, Mark
    Jannasch, Patric
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Fuel cell performance using a phosphonated polysulphone ionomer (PSUgPVPA) in the PEM cathode electrode2013Inngår i: Fuel Cell Membranes, Electrode Binders, And Mea Performance, Electrochemical Society, 2013, nr 23, s. 33-45Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Inexpensive and environmentally friendly electrolyte polymers that can be operated at higher temperatures and drier conditions are highly interesting for PEM fuel cells for automotive, portable power and stationary electricity generation applications. In this study an ionomer based on polysulfone grafted with poly(vinylphosphonic acid) (PSUgPVPA) in the cathode Pt/C catalyst layer (CL) was electrochemically characterized and compared to Nafion (R). The performance at different levels of humidity at 80 degrees C was evaluated by polarization and cyclic voltammetry. The results show that the performance of the PSUgPVPA-based cathode CL is comparable to that of Nafion (R) at 100% relative humidity (RH) but with some instabilities. However, at drier conditions significant losses of performance for the PSUgPVPA-based cathode was observed, concomitant to a reduced electrochemical surface area. The lower performance at low humidity is concluded to be due to a combination of lower proton conductivity and wettability or interference with oxygen reduction reaction at lower RH.

  • 326.
    Wreland Lindström, Rakel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Hildebrandt, Lars
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Polymera bränsleceller (PEMFC): Teknikbevakningsrapport 20092009Rapport (Annet (populærvitenskap, debatt, mm))
  • 327.
    Wreland Lindström, Rakel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Kortsdottir, Katrin
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Pérez Ferriz, Francisco Javier
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Conde Lopez, Julio Jose
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lagergren, Carina
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    The Effect of Hydrocarbon Impurities in the Hydrogen Fuel on the Anode Activity in PEMFC2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The reformate fuel cell has recently gained increasing attention both for APUs in vehicles

    operating on diesel and in stationary applications such as micro-CHP operating on natural

    or biogas. In addition to hydrogen gas, reformate contain considerable amounts of CO2,

    nitrogen, water vapour and traces of CO, sulphur species and hydrocarbons. CO and H2S

    are well known poisons to the anode [1] but the influence of hydrocarbon species in the

    fuel cell has not been much investigated. We have previously investigated toluene [2] and

    ethene [3] on the anode Pt/C catalyst in the PEM fuel cell. In this paper we will discuss the

    influences of alkenes and alkanes in the light of some novel results on the effect of

    propene, propane and methane in the PEM fuel cell. We have especially focused on the

    adsorption and deactivation phenomena of low concentrations of contaminant on a Pt/C

    catalyst. In the experiments, in situ stripping voltammetry and on-line mass spectrometer

    were employed. The effects of adsorption potential and temperature are discussed. We

    show that propene is more poisonous to the Pt/C catalyst than ethene as it is adsorbed on

    the catalyst surface within the Hupd region and forms an adlayer that can be oxidized in two

    steps between 0.5-1 V (at 80°C, 90%RH) or be hydrogenated to propane in the Hupd region

    and in the presence of hydrogen.

  • 328.
    Wreland Lindström, Rakel
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Lindbergh, Göran
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Tillämpad elektrokemi.
    Teknikbevakning av polymera bränsleceller (PEFC)2011Rapport (Annet (populærvitenskap, debatt, mm))
  • 329.
    Xu, Johanna
    et al.
    Lulea Univ Technol, Dept Engn Sci & Math, S-97189 Lulea, Sweden..
    Lindbergh, Göran
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik.
    Varna, Janis
    Lulea Univ Technol, Dept Engn Sci & Math, S-97189 Lulea, Sweden..
    Multiphysics modeling of mechanical and electrochemical phenomena in structural composites for energy storage: Single carbon fiber micro-battery2018Inngår i: Journal of reinforced plastics and composites (Print), ISSN 0731-6844, E-ISSN 1530-7964, Vol. 37, nr 10, s. 701-715Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a framework for multiphysics modeling of a novel type of multifunctional composite material, structured on microscale, with ability to function as battery cell in addition to carry mechanical load. The micro-battery consists of a single carbon fiber surrounded by very thin solid electrolyte coating and embedded in a matrix which is a porous material containing active particles able to intercalate lithium. During battery operation (discharging and charging) the structural battery constituents undergo volume changes, caused by lithium-ion movement. The presented mathematical model is solved numerically using COMSOL software and results are used to analyze the physical phenomena occurring in the structural battery material. Parametric analysis is performed to reveal the significance of geometrical parameters like fiber volume fraction in the battery and the porosity content in the matrix on the multifunctional performance of the composite unit including its swelling/shrinking during charging/discharging.

  • 330.
    Xu, Xingxing
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik. Uppsala University.
    Makaraviciute, Asta
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Pettersson, Jean
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Zhang, Shi-Li
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Zhang, Zhen
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Fasta tillståndets elektronik.
    Considerations for the Cyclic Voltammetry of Gold in Sulfuric Acid Solutions2018Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    A comprehensive understanding of the cyclic voltammetry (CV) for gold surfaces is essential for advanced applications. In the present study, a series of experiments were designed to investigate CV for gold under different experimental conditions when using a conventional configuration of a Ag/AgCl/sat. KCl reference electrode and a platinum wire counter electrode. The interferences introduced by the configuration were reflected in the three fingerprint regions of the voltammograms. It was found that the shape of the voltammograms was less reproducible at a lower sample volume when the cycle number was increased. This observation could be explained by different concentrations of Cl- leaking from the reference electrode and platinum dissolved from the counter electrode. The reproducibility of the gold oxidation and reduction (Ox/Re) region in the voltammograms was improved when gold dissolution and re-deposition caused by Cl- leakage was eliminated by using a bridge. In the hydrogen evolution and oxidation reactions (HER/HOR) region the catalytic performance of the gold electrode could be minimized by replacing the platinum counter electrode with a graphite rod. Alternatively, it could be enhanced by increasing the surface ratio of the co-deposited platinum to gold. In the electric double layer (EDL) region, peaks dependent on the concentrations of Cl- and SO42- were observed. To account for the occurrence of these peaks, a new mechanism based on the formation of neutral gold (I) complexes at very low Au+ concentrations, was proposed. 

  • 331.
    Yakkala, Bhaskarrao
    et al.
    Saveetha Univ, Saveetha Sch Engn, Dept Elect & Commun Engn, Chennai, Tamil Nadu, India..
    Narayanan, R.
    Sch Mech & Business Sci, VIT Chennai Campus, Chennai, Tamil Nadu, India..
    Sreejith,
    KTH.
    COMPUTATIONAL DENSITY FUNCTIONAL THEORY (DFT) APPROACH ON SMART CATALYSTS UTILIZED IN FUEL CELL TECHNOLOGY2018Inngår i: The IIOAB Journal, ISSN 0976-3104, Vol. 9, s. 14-17Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Concepts of nanotechnology are utilized in numerous fields. Sustainable or non-conventional source of power is one area in which this smart technology is widely applied. The catalytic property of nanomaterials in Fuel Cell Technology (FCT) is worth mentioning as it would increase efficiency to a great extent. In this work, Monte-Carlo calculations are carried out to check the adsorption of OH-molecule on various platinum catalysts doped with Ru, W, Co and Pd. The catalyst was then made to adsorb on two separate amorphous carbon blocks that acted as cathode and anode respectively. The Membrane Electrode Assembly (MEA) of the fuel cell was made with nafion membrane and Co-doped Pt electrodes. Adsorption of OH- molecule on the final restructured MEA of the fuel cell was studied.

  • 332.
    Yang, Jiayi
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kemiteknik.
    Dahlström, Christina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kemiteknik.
    Lindman, Björn
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för kemiteknik.
    pH-responsive cellulose–chitosan nanocomposite films with slow release of chitosan2019Inngår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 26, nr 6, s. 3763-3776Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cellulose–chitosan films were preparedusing a physical method in which cellulose andchitosan were separately dissolved via freeze thawingin LiOH/urea and mixed in different proportions, theresulting films being cast and regenerated in water/ethanol. X-ray diffraction and Fourier transforminfrared spectroscopy (FT-IR) spectroscopy verifiedthe composition changes in the nanocomposites due todifferent mixing ratios between the polymers. Tensilestress–strain measurements indicated that the mechan-ical performance of the cellulose–chitosan nanocom-posites slightly worsened with increasing chitosancontent compared with that of films comprisingcellulose alone. Field emission scanning electronmicroscopy revealed the spontaneous formation ofnanofibers in the films; these nanofibers were subse-quently ordered into lamellar structures. Water uptakeand microscopy analysis of film thickness changesindicated that the swelling dramatically increased atlower pH and with increasing chitosan content, thisbeing ascribed to the Gibbs–Donnan effect. Slowmaterial loss appeared at acidic pH, as indicated by aloss of weight, and quantitative FT-IR analysisconfirmed that chitosan was the main componentreleased.Asample containing 75% chitosan reached amaximum swelling ratio and weight loss of 1500%and 55 wt%, respectively, after 12 h at pH 3. Thestudy presents a novel way of preparing pH-responsivecellulose–chitosan nanocomposites with slow-releasecharacteristics using an environmentally friendlyprocedure and without any chemical reactions.

  • 333. Yang, Lin
    et al.
    Li, Xin
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Qu, Yi
    Qu, Weisong
    Zhang, Xiao
    Hang, Yandi
    Ågren, Hans
    KTH, Skolan för bioteknologi (BIO), Teoretisk kemi och biologi.
    Hua, Jianli
    Red turn-on fluorescent phenazine-cyanine chemodosimeters for cyanide anion in aqueous solution and its application for cell imaging2014Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 203, s. 833-847Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two chemodosimeters PDMI and PMI for cyanide detection were designed and synthesized based onphenazinecyanine dyes with N-methyl indolium group as receptor unit. According to the specific reactivity of indolium C-N+ bond against cyanide anion, both of them featured high sensitivity with detectionlimit of 1.4 mu M and 200 nM, respectively, and high selectivity against other anions. The quenching effecton phenazine-cyanine fluorophore by strong intramolecular charge transfer (ICT) from phenazine donorto indolium receptor made both PDMI and PMI non-emissive at the original state. After addition ofcyanide, the ICT effect decreased and vanished leading to dramatic " off-on" fluorescence enhancement. PDMI which proceeded bilateral electrophilic reaction toward cyanide anion provided an emission signal at 580 nm in HEPES buffer with naked-eye detectable color change. Probe PMI utilized an unreactiveformyl group instead of one reactive N-methyl indolium group as the electron-withdrawing component. Due to the unilateral recognition process for cyanide the ICT orientation of PMI was redirectedthus exhibited fluorescence enhancement with maximum emission at 630 nm. Meanwhile, PMI wasapplied for monitoring intracellular cyanide in Hela cells and proved to achieve "off-on" fluorescentsignal confirmed by confocal laser scanning microscopic imaging.

  • 334.
    Yang, Weihong
    et al.
    KTH, Tidigare Institutioner, Materialvetenskap.
    Blasiak, Wlodzimierz
    KTH, Tidigare Institutioner, Materialvetenskap.
    Length and volume in LPG flame using high-temperature and low oxygen oxidizer2004Inngår i: International Symposium on Combustion, Abstracts of Works-in-Progress Posters, 2004Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The effect of a high temperature combustion oxidizer at different oxygen concentration on flame length and volume was numerically studied. LPG was used as the fuel. Flame length increased with either the decrease of oxygen content, or increase of oxidizer temperature, or decrease of fuel temperature. The flame length was independent of the fuel flow rate and the diameter of the fuel nozzle for studies cases. Flame volume increased either with the decrease of oxygen content and increase of oxidizer temperature, or with the reduction of fuel temperature, or with the increasing in fuel firing rate. Flame volume depended very much on the oxygen concentration in the oxidizer. This is an abstract of a paper presented at the 30th International Symposium on combustion (Chicago, IL 7/25-30/2004).

  • 335. Yuan, K.
    et al.
    Yu, Y.
    Lu, X.
    Ji, X.
    Zhu, Bin
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    A new technology for spraying advanced low-temperature (300∼600 °C) Solid oxide fuel cells2017Inngår i: Proceedings of the International Thermal Spray Conference, ASM International , 2017, s. 132-137Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Solid oxide fuel cell (SOFC) has been developed for a hundred year and met a great challenge on material design and marketing. In recent years, new SOFC materials are dug up to achieve high energy-output performance at lower working temperature (300∼600 °C), namely low-temperature SOFC (LTSOFC). In this study, Ni-Co-Al-Li oxide (NCAL) was used for making dense, thin and uniform coatings on grooved bipolar electrode substrate for LTSOFC. Low-pressure plasma spray (LPPS) technology was applied to manufacture the NCAL coatings. The performance of a fuel cell package using the coated bipolars was tested between 350 and 600 °C, showing 6∼8 W power output with 4 single fuel cells (active area of 25 cm2). The LPPS technology is believed to be one of the ultimate ways for manufacturing the thin film/coatings for SOFC applications in future. 

  • 336.
    Zanzi Vigouroux, Rolando
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Birbas, Daniella
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Márquez Montesino, Francisco
    niversidad de Pinar del Río, Departamento de Quimica, Pinarde de Río, Cuba,.
    Preparation of Activated Carbon: Forest residues activated with Phosphoric Acid and ZincSulfate2011Inngår i: VII EDICIÓN DE LA CONFERENCIA CIENTÍFICA INTERNACIONAL MEDIOAMBIENTE SIGLO XXI, MAS XXI 2011, 2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper describes the preparation of activated carbon by chemical activation. The selected biomass used as precursor is sawdust from both Cuban and Swedish Pine tree. Phosphoric acid and Zinc Sulphate are the chemical reagents. The objective is to study the influence of acid concentration, impregnation ratio and activation temperature on adsorption performance of the obtained activated carbon.

    The experiments with phosphoric acid activation show that treatment with 40% acid concentration at 400 °C produce an activated carbon with good properties for ammonia adsorption and good iodine number. If a 30% phosphoric acid is used for activation, an activation temperature of 500 °C is recommended. With an impregnation ratio of 1, good adsorption was obtained in the activated carbon produced from Swedish pine while using Cuban pine a higher adsorption was obtained with an impregnation ratio of 2.

    The experiments with Zinc Sulphate activation show that activation conditions of 20% zinc sulphate concentration, 400 °C and impregnation ratio: 1 are enough to produce an activated carbon with good properties for ammonia adsorption. The adsorption of carbon tetrachloride was lower. Activated carbons produced with 10 % zinc sulphate concentration, 0.5 impregnation ratio and 400 °C activation temperature (the mildest studied conditions) show already good iodine number and BET surface area.    

  • 337.
    Zanzi Vigouroux, Rolando
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Björnbom, Emilia
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk reaktionsteknik.
    Grimm, Alejandro
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk reaktionsteknik.
    Biosorbentes para la remoción de cobre (II) en soluciones acuosas2005Konferansepaper (Fagfellevurdert)
  • 338.
    Zanzi Vigouroux, Rolando
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Majari, Mehdi
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Björnbom, Emilia
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk reaktionsteknik.
    Biomass pre-treatment by torrefaction2008Konferansepaper (Fagfellevurdert)
  • 339.
    Zanzi Vigouroux, Rolando
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk teknologi.
    Tsyntsarski, B.
    Institute of Organic Chemistry, Bulgarian Academy of Sciences.
    Budinova, T.
    Institute of Organic Chemistry, Bulgarian Academy of Sciences.
    Petrov, N.
    Institute of Organic Chemistry, Bulgarian Academy of Sciences.
    Influence of the chemical composition of agricultural by-products on their behavior during thermal treatment2008Konferansepaper (Fagfellevurdert)
  • 340.
    Zeb, Hassan
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap.
    Bleaching of Old Newsprint Paper at Metsä Tissue2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 341.
    Zeglinski, Jacek
    et al.
    Univ Limerick, Synth & Solid State Pharmaceut Ctr, Bernal Inst, Dept Chem Sci, Limerick V94 T9PX, Ireland..
    Kuhs, Manuel
    Univ Limerick, Synth & Solid State Pharmaceut Ctr, Bernal Inst, Dept Chem Sci, Limerick V94 T9PX, Ireland..
    Devi, K. Renuka
    Univ Limerick, Synth & Solid State Pharmaceut Ctr, Bernal Inst, Dept Chem Sci, Limerick V94 T9PX, Ireland..
    Khamar, Dikshitkumar
    Univ Limerick, Synth & Solid State Pharmaceut Ctr, Bernal Inst, Dept Chem Sci, Limerick V94 T9PX, Ireland..
    Hegarty, Avril C.
    Univ Limerick, Dept Math & Stat, MACSI, Limerick, Ireland..
    Thompson, Damien
    Univ Limerick, Synth & Solid State Pharmaceut Ctr, Bernal Inst, Dept Chem Sci, Limerick V94 T9PX, Ireland.;Univ Limerick, Dept Phys & Energy, Limerick, Ireland..
    Rasmuson, Åke C.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Teknisk strömningslära.
    Probing Crystal Nucleation of Fenoxycarb from Solution through the Effect of Solvent2019Inngår i: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 19, nr 4, s. 2037-2049Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Induction time experiments, spectroscopic and calorimetric analysis, and molecular modeling were used to probe the influence of solvent on the crystal nucleation of fenoxycarb (FC), a medium-sized, flexible organic molecule. A total of 800 induction times covering a range of supersaturations and crystallization temperatures in four different solvents were measured to elucidate the relative ease of nucleation. To achieve similar induction times, the required thermodynamic driving force, RT In S, increases in the order: ethyl acetate < toluene < ethanol < isopropanol. This is roughly matched by the order of interfacial energies calculated using the classical nucleation theory. Solvent solute interaction strengths were estimated using three methods: solvent-solute enthalpies derived from calorimetric solution enthalpies, solvent-solute interactions from molecular dynamics simulations, and the FTIR shifts in the carbonyl stretching corresponding to the solvent solute interaction. The three methods gave an overall order of solvent solute interactions increasing in the order toluene < ethyl acetate < alcohols. Thus, with the exception of FC in toluene, it is found that the nucleation difficulty increases with stronger binding of the solvent to the solute.

  • 342.
    Zhan, Lingling
    et al.
    Zhejiang Univ, Peoples R China.
    Li, Shuixing
    Zhejiang Univ, Peoples R China.
    Zhang, Huotian
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Gao, Feng
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biomolekylär och Organisk Elektronik. Linköpings universitet, Tekniska fakulteten.
    Lau, Tsz-Ki
    Chinese Univ Hong Kong, Peoples R China.
    Lu, Xinhui
    Chinese Univ Hong Kong, Peoples R China.
    Sun, Danyang
    Zhejiang Univ, Peoples R China.
    Wang, Peng
    Zhejiang Univ, Peoples R China.
    Shi, Minmin
    Zhejiang Univ, Peoples R China.
    Li, Chang-Zhi
    Zhejiang Univ, Peoples R China.
    Chen, Hongzheng
    Zhejiang Univ, Peoples R China.
    A Near-Infrared Photoactive Morphology Modifier Leads to Significant Current Improvement and Energy Loss Mitigation for Ternary Organic Solar Cells2018Inngår i: ADVANCED SCIENCE, ISSN 2198-3844, Vol. 5, nr 8, artikkel-id 1800755Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Herein, efficient organic solar cells (OSCs) are realized with the ternary blend of a medium band gap donor (poly[(2,6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)-benzo[1,2-b:4,5-b]dithiophene))-alt-(5,5-(1,3-di-2-thienyl-5,7-bis(2-ethylhexyl)benzo[1,2-c:4,5-c]dithiophene-4,8-dione)] (PBDB-T)) with a low band gap acceptor (2,2-((2Z,2Z)-(((2,5-difluoro-1,4-phenylene)bis(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b]dithiophene-6,2-diyl))bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (HF-PCIC)) and a near-infrared acceptor (2,2-((2Z,2Z)-(((4,4,9,9-tetrakis(4-hexylphenyl)-4,9-dihydro-s-indaceno[1,2-b:5,6-b]dithiophene-2,7-diyl)bis(4-((2-ethylhexyl)oxy)thiophene-5,2-diyl))bis(methanylylidene))bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (IEICO-4F)). It is shown that the introduction of IEICO-4F third component into PBDB-T:HF-PCIC blend increases the short-circuit current density (J(sc)) of the ternary OSC to 23.46 mA cm(-2), with a 44% increment over those of binary devices. The significant current improvement originates from the broadened absorption range and the active layer morphology optimization through the introduction of IEICO-4F component. Furthermore, the energy loss of the ternary cells (0.59 eV) is much decreased over that of the binary cells (0.80 eV) due to the reduction of both radiative recombination from the absorption below the band gap and nonradiative recombination upon the addition of IEICO-4F. Therefore, the power conversion efficiency increases dramatically from 8.82% for the binary cells to 11.20% for the ternary cells. This work provides good examples for simultaneously achieving both significant current enhancement and energy loss mitigation in OSCs, which would lead to the further construction of highly efficient ternary OSCs.

  • 343.
    Zhang, Chi
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Energiprocesser.
    Sustainable Business Innovation of Photovoltaic Water Pumping Systems2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The development of renewable energy technology provides an effective approach to replace fossil fuels for greenhouse gas (GHG) emission. Technological innovation and transfer are the main driving forces in promoting renewable energy usage, because of the better efficiency and economic payback under an emission reduction target. With three of the mechanisms of emission trading originating from the Kyoto Protocol, the most wildly accepted and important mechanism between developed and developing countries is the Clean Development Mechanism (CDM). The CDM has been implemented contributing the most of the trading carbon credits. In this study, by extracting and building an exclusive database of issued Chinese CDM projects, a modified multivariable logistic regression model for technology transfer’s correlation test with 11 extended indicators was investigated for the first time. Renewable energy projects were analyzed with certified emission reduction (CER) sizes, economic development, and geographic scopes.In addition, technological innovation should also be enhanced with new business developments to demonstrate and scale up technologies for better economic and environmental performances. This doctoral thesis studied photovoltaic water pumping (PVWP) technology as a technological solution for integration with the new business model for development and co-benefits. The integration of PVWP with water saving irrigation techniques and sustainable management of water resources, leads to technical innovations, economic benefits, and climate benefits. Field measurements at a pilot PVWP system in Inner Mongolia were conducted with detailed economic performance analyses. Different scenarios for PVWP systems considering variant market incentives were proposed with internal rate of return (IRR), and discounted payback period analyses to develop a new business model approach for implementing PVWP systems with multi-value propositions. The environmental externalities were successfully addressed by evaluating the CO2 emission reduction credits. The economic assessment of feasible and optimal production processes for implementing PVWP systems in dairy milk production was conducted with self-supplied energy and forage assumptions. In comparison with other financing mechanisms, discrete choice model analyses were employed with interviews and costumer behavior surveys to explore the willingness to purchase through crowd funding mechanisms in financing integrated PVWP systems.The results showed that emission reduction mechanisms, such as CDM, have promoted the renewable energy development in China with the national incentives at an entrance level. Yet, the limited sizes and lower income from CERs of renewable energy projects than other projects, required renewable energy projects to develop more advanced technological innovations and business model innovations.  The PVWP systems represent the better technical and economic solutions under a feasible innovated business model in comparison with traditional photovoltaic (PV) systems and current PV business models. The dairy farms with integrated PVWP systems and self-sufficient feeds could improve their investment performance through extra energy saving and CO2 emission reductions. The semi-structured interviews and customer surveys’ results showed that customers can tolerate high prices, and are willing to crowd-fund nutritious and secure cow milk with environmental compensation characters. The results from the PVWP technology integration in China as a specific PV application study can be further applied for the business model of innovation of renewable energy systems in other regions of the world under emission reduction targets leading to economic and environmental benefits.

  • 344.
    Zhang, Keliang
    et al.
    Qilu Univ Technol, Shandong Acad Sci, Coll Mat Sci & Engn, Jinan 250353, Shandong, Peoples R China.
    Zhang, Xudong
    Qilu Univ Technol, Shandong Acad Sci, Coll Mat Sci & Engn, Jinan 250353, Shandong, Peoples R China.
    He, Wen
    Qilu Univ Technol, Shandong Acad Sci, Coll Mat Sci & Engn, Jinan 250353, Shandong, Peoples R China.
    Xu, Wangning
    Qilu Univ Technol, Shandong Acad Sci, Coll Mat Sci & Engn, Jinan 250353, Shandong, Peoples R China.
    Xu, Guogang
    Shandong Univ Sci & Technol, Coll Mat Sci & Engn, Qingdao 266590, Shandong, Peoples R China.
    Yi, Xinli
    Qilu Univ Technol, Shandong Acad Sci, Coll Mat Sci & Engn, Jinan 250353, Shandong, Peoples R China.
    Yang, Xuena
    Qilu Univ Technol, Shandong Acad Sci, Coll Mat Sci & Engn, Jinan 250353, Shandong, Peoples R China.
    Zhu, Jie-Fang
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Rational design and kinetics study of flexible sodium-ion full batteries based on binder-free composite film electrodes2019Inngår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, nr 16, s. 9890-9902Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A high-performance flexible sodium-ion full battery (FSIFB) is developed by using binder-free composite film (BFCF) electrodes without using conductive carbon and current collectors. Hard carbon fibers decorated with different electrochemical active materials are used as the supporting framework and 3D conductive network of FSIFBs for the first time. Different pre-sodiated anodes and the electrolyte additives are designed for well-matched FSIFBs. Using a porous Na3V2(PO4)(3) coated hard carbon fiber film with a mass loading of 2.34 mg cm(-2) as the cathode and a pre-sodiated graphene/SiC/hard carbon fiber film with a mass loading of 1.50 mg cm(-2) as the anode, an optimized FSIFB is designed. It delivers high output voltage (3.34 V), high energy density (234.1 W h kg(-1) at a high-current rate of 0.5 A g(-1)), ultralong cyclability (over 2905 cycles at 0.5 A g(-1) and 1000 cycles at 5 A g(-1)), and high coulombic efficiency (approaching 100%), which surpasses those of all FSIFBs reported so far. Furthermore, this FSIFB still maintains good electrochemical attributes even at serious bending states in water. The models of the solid electrolyte interphase behavior on the surface of electrodes in the FSIFB are studied by using EIS, and a reaction mechanism and an equivalent electrical circuit are proposed. We also provide the videos of the preparation process for a pouch-type FSIFB to demonstrate its simple operability and potential applications.

  • 345. Ziaei Tabari, Hassan
    et al.
    Nourbakhsh, Amir
    Hosseinpourpia, Reza
    Danesh, Mohammad Amin
    Evaluation of mechanical and morphological behavior of polypropylene/wood fiber nanocomposite prepared by melts compounding2010Inngår i: International Conference on Nanotechnology and Biosensors, 28th to 30th December 2010, Hong Kong, Singapore, 2010, Vol. 2, s. 20-23Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Weak flexural properties of wood plastic composites(WPCs) limit their structural application. Recentlyinvestigation of nano particles looks promising to enhancebending properties of WPCs. In this study, the authors haveinvestigated the effect of different concentrations of nanoclay(modified montmorillonite) and coupling agent on themechanical and micro-structural properties of polypropylene/wood-fiber composites. We Bath internal mixer in certainprocessing conditions used for making the samples and then allsamples molded using injection molding for making samplesfor performing mechanical measurements. Samples preparedin four different concentration of nanoclay 0, 1, 3 and 5 wt%(total weight) and two different concentrations of maleicanhydride grafting (MAPP) 5 and 10 wt%. Mechanical resultsindicate that both flexural and impact strength of thecomposites increasing in sample containing 3% nano clay. Inother trend, Scanning Electron Microscope (SEM) imagesshow better interaction of wood fibers and polymer matrixwhen the authors added 5 wt% MAPP as coupling agent.

  • 346.
    Åkerlund, Elin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Tillämpad materialvetenskap.
    Development of polymer based composite filaments for 3D printing2019Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The relatively new and still growing field of 3D-printing has opened up the possibilities to manufacture patient-specific medical devices with high geometrical accuracy in a precise and quick manner. Additionally, biocompatible materials are a demand for all medical applications while biodegradability is of importance when developing scaffolds for tissue growth for instance. With respect to this, this project consisted of developing biocompatible and bioresorbable polymer blend and composite filaments, for fused deposition modeling (FDM) printing. Poly(lactic acid) (PLA) and polycaprolactone (PCL) were used as supporting polymer matrix while hydroxyapatite (HA), a calcium phosphate with similar chemical composition to the mineral phase of human bone, was added to the composites to enhance the biological activity. PLA and PCL content was varied between 90–70 wt% and 10-30 wt%, respectively, while the HA content was 15 wt% in all composites. All materials were characterized in terms of mechanical properties, thermal stability, chemical composition and morphology. An accelerated degradation study of the materials was also executed in order to investigate the degradation behavior as well as the impact of the degradation on the above mentioned properties. The results showed that all processed materials exhibited higher mechanical properties compared to the human trabecular bone, even after degradation with a mass loss of around 30% for the polymer blends and 60% for the composites. It was also apparent that the mineral accelerated the polymer degradation significantly, which can be advantageous for injuries with faster healing time, requiring only support for a shorter time period.

  • 347.
    Åkesson, Dan
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Foltynowicz, Zenon
    Christéen, Jonas
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Microwave pyrolysis as a method of recycling glass fibre from used blades of wind turbines2012Inngår i: Journal of reinforced plastics and composites (Print), ISSN 0731-6844, E-ISSN 1530-7964, Vol. 31, nr 17, s. 1136-1142Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The possibility of recycling glass fibre-reinforced composites by using microwave pyrolysis was examined. A scrap blade from a wind turbine was fragmented and microwave-pyrolysed. The glass fibre recovered after pyrolysis represented 70% of the initial mass of glass fibre-reinforced composites. The tensile strength of the glass fibre recovered was measured after pyrolysis and compared to the tensile strength of untreated glass fibre. The test showed that the fibres lost about 25% of their tenacity. Non-woven fibre mats were prepared from the recovered fibres. Laminates were then prepared from the non-woven mats obtained, together with virgin glass fibre mats. Mechanical testing of the laminates showed that it is possible to prepare composites using 25 wt% of recycled fibres, with relatively good mechanical properties.

  • 348.
    Åkesson, Dan
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Skrifvars, Mikael
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Recycling of glass fibre reinforce plastics using microwave pyrolysis2012Konferansepaper (Annet vitenskapelig)
4567 301 - 348 of 348
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