Дисертації з теми "Cell based studies"
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1
Lähdesmäki, Ilkka Johannes. "Flow injection methods for drug-receptor interaction studies, based on probing cell metabolism /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/8590.
Повний текст джерела
2
Shiratori, Masaru Ken. "Studies of a TMV-based expression vector in plant cell cultures /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.
Повний текст джерела
3
Mier, Alexandro Castellanos. "Poly(N-Isopropylacrylamide) based BioMEMS/NEMS for cell manipulation." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001814.
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4
Stacy, Stephen. "Characterization of porous media in proton exchange membrane fuel cell based on percolation studies." Thesis, Michigan Technological University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1552771.
Повний текст джерелаАнотація:
Water management in the porous media of proton exchange membrane (PEM) fuel cells, catalyst layer and porous transport layers (PTL) is confronted by two issues, flooding and dry out, both of which result in improper functioning of the fuel cell and lead to poor performance and degradation. The data that has been reported about water percolation and wettability within a fuel cell catalyst layer is limited to porosimetry. A new method and apparatus for measuring the percolation pressure in the catalyst layer has been developed. The experimental setup is similar to a Hele-Shaw experiment where samples are compressed and a fluid is injected into the sample. Pressure-Wetted Volume plots as well as Permeability plots for the catalyst layers were generated from the percolation testing. PTL samples were also characterizes using a Hele-Shaw method. Characterization for the PTLs was completed for the three states: new, conditioned and aged. This is represented in a Ce-t* plots, which show a large offset between new and aged samples.
5
Kösling, Stefanie Kristine [Verfasser], Reza [Gutachter] Ahmadian, and Alfred [Gutachter] Wittinghofer. "Cell-based studies of ciliary transport / Stefanie Kristine Kösling ; Gutachter: Reza Ahmadian, Alfred Wittinghofer." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2018. http://d-nb.info/1160753237/34.
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6
Gafri, Fadia Mohamed. "An assessment of the effects of novel anti-inflammatory compounds in cell based studies." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=19010.
Повний текст джерелаАнотація:
NF-κB and AP-1 are transcription factors with an evolutionary conserved role in the triggering and coordination of both innate and adaptive immune responses. Since they regulate a large number of inflammatory genes, they are considered as potential targets for anti-inflammatory drugs. In the current study, natural SU182 and synthetic alkaloid compounds, SU331, SU432 and minor groove binder compounds AIK18/85/1 and AIK18/70 obtained from the library associated with University of Strathclyde CRUK-Small Molecule Drug Discovery (SMDD) were investigated for possible anti-inflammatory effects at μM concentrations. In NCTC2544 human keratinocyte cells stably transfected with either NF-κB- or AP-1-linked luciferase reporter plasmids, tumour necrosis factor-α (TNF-α) and phorbol-12-myristate- 13 acetate (PMA) well characterized stimuli for canonical NF-κB pathway induced NF-κB and AP-1 transcriptional activity respectively. However, all tested compounds inhibited NF-κB transcriptional activity; in particular AIK18/85/1 prevented the TNF-α-induced translocation of NFκB (p65) to the nucleus assessed by indirect immunoflouresnce. This effect of AIK18/85/1 was also reflected in the significant reduction of nuclear extract NF-κB-DNA binding activity as detected by Electrophoresis Mobility Shift Assay (EMSA), but without affecting the degradation of IκBα protein induced by TNF-α. Furthermore, AIK18/70 also decreased TNF-α-induced NF-κB-DNA binding activity but neither affected the phosphorylation of p65 nor the degradation of IκBα. On the other hand, both SU331 and SU432 inhibited the IκBα loss and resultant NF-κB-DNA binding activity in a concentration dependent manner. Although none of these compounds inhibited TNF-α-induced phosphorylation of NF-κB (Ser536-p65), their mode of inhibition on NF-κB signalling was sufficient to prevent the expression of NF-κB dependent proteins such as COX-2 and iNOS in LPS stimulated RAW 264.7 macrophage cells. Intriguingly, in contrast to other compounds SU182 was only effective at the level of NF-κB and AP-1 transcriptional activities, but without affecting the expression level of iNOS and COX-2 enzymes. Taken together these data indicate the potential for tested compounds to interfere with NF-κB signalling as IKK inhibitors or novel translocation inhibitor and thus may considered to be useful leads for the development of novel anti-inflammatory and anticancer drugs.
7
Xia, Jixiang. "Development of molecular and cellular imaging tools to evaluate gene and cell based therapeutic strategies in vivo." Doctoral diss., University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4724.
Повний текст джерелаАнотація:
Molecular imaging modalities are important tools to evaluate the efficacy of gene delivery systems and cell-based therapies. Development and application of these modalities will advance our understanding of the mechanism of transgene expression and cell fate and functions. Physical gene transfer methods hold many advantages over viral vectors among gene therapeutic strategies. Here, we evaluated the efficacy of biolistic ("gene gun") gene targeting to tissues with non-invasive bioluminescence imaging (BLI) methods. Plasmids carrying the firefly luciferase reporter gene were transfected into mouse skin and liver using biolistics, and BLI was measured at various time points after transfer. With optimized DNA loading ratio (DLRs), reporter gene expression reached to peak 1 day after transfer to mouse skin, and the maximum depth of tissue penetration was between 200-300[mu]m. Similar peak expression of reporter gene was found in mouse liver but the expression was relatively stable 4-8 days post-biolistic gene transfer and remained for up to two weeks afterward. Our results demonstrated BLI was an efficient strategy for evaluation of reporter gene expression in the same animals over a period of up to two weeks in vivo. Different tissues showed different expression kinetics, suggesting that this is an important parameter to consider when developing gene therapy strategies for different target tissues. We also employed BLI to measure differentiation of mouse embryonic stem (ES) cells into beating cardiomyocytes in vitro and in vivo. A subset of these cardiomyocytes appears to be derived from an adrenergic lineage that ultimately contribute to substantial numbers of cardiomyocytes primarily on the left side of the heart. At present, it is unclear what the precise role of these cardiac adrenergic cells is with respect to heart development, though it is known that adrenergic hormones (adrenaline and noradrenaline) are essential for embryonic development since mice lacking them die from apparent heart failure during the prenatal period. To identify and characterize cardiac adrenergic cells, we developed a novel mouse genetic model in which the nuclear-localized enhanced green fluorescent protein (nEGFP) reporter gene was targeted to the first exon of the Phenylethanoamine N-transferase (Pnmt) gene, which encodes for the enzyme that converts noradrenaline to adrenaline, and hence serves as a marker for adrenergic cells. Our results demonstrate this knock-in strategy effectively marked adrenergic cells in both fetal and adult mice. Expression of nEGFP was found in Pnmt-positive cells of the adult adrenal medulla, as expected. Pnmt-nEGFP expression also recapitulated endogenous Pnmt expression in the embryonic mouse heart. In addition, nEGFP and Pnmt expression were induced in parallel during differentiation of pluripotent mouse ES cells into beating cardiomyocytes. This new mouse genetic model provides a useful new tool for studying the properties of adrenergic cells in different tissues. We also identified two limitations of the Pnmt-nEGFP model. One is that the amount of nEGFP expressed within individual adrenergic cells was highly variable. Secondly, expression of nEGFP in the embryonic heart was of low abundance and difficult to distinguish from background autofluorescence. To overcome these limitations, we developed two alternative genetic models to investigate adrenergic cells: (1) Mouse embryonic stem cells, which have been previously targeted with Pnmt-Cre recombinase gene, were additionally targeted with a dual reporter plasmid which covered both a loxP-flanked cDNA of red fluorescence protein (HcRed) and also EGFP. Under the undifferentiated status, cells emit red fluorescence as transcription stops before EGFP coding sequence. After differentiation into beating cardiomyoctyes, some cells switch fluorescence from red to green, indicating that excision of loxP-flanked sequences by Cre since Pnmt had been activated. (2) A surface marker, truncated low-affinity nerve growth factor receptor ([delta]LNGFR) was used as the reporter gene as cells expressing this marker can be enriched by magnetic-activated cell sorting (MACS), a potentially efficient way to yield highly purified positive cells at low input abundance in a population. Through a series of subcloning steps, the targeting construct, Pnmt-[delta]LNGFR-Neo-DTA was created and electroporated into 7AC5EYFP embryonic stem cells. Correctly targeted cells were selected by positive and negative screening. These cells provide a new tool with which to identify, isolate, and characterize the function of adrenergic cells in the developing heart, adrenal gland, and other tissues where adrenergic cells make important contributions.ID: 031001454; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Title from PDF title page (viewed July 3, 2013).; Thesis (Ph.D.)--University of Central Florida, 2011.; Includes bibliographical references (p. 122-130).
Ph.D.
Doctorate
Molecular Biology and Microbiology
Medicine
Biomedical Sciences
8
Stokes, Stephen J. "Atomistic modelling studies of fluorite- and perovskite-based oxide materials." Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.527142.
Повний текст джерелаАнотація:
Fast oxide-ion and proton conductors are the subject of considerable research due to their technological applications in sensors, ceramic membranes and solid oxide fuel cells (SOFCs). This thesis describes the use of computer modelling techniques to study point defects, dopants and clustering effects in fluorite-and perovskitetype ion conductors with potential SOFC applications. Bi2O3 related phases are being developed with the objective of high oxide-ion conductivities at lower operating temperatures than 1000°C, as in current generation SOFC electrolytes. Doped Bi2O3 phases have shown promise as materials capable of accomplishing this goal. First, the Y-doped phase, Bi3YO6, has been investigated including the ordering of intrinsic vacancies. The defect and dopant characteristics of Bi3YO6 have been examined and show that a highly mobile oxygen sub-lattice exists in this material. A preliminary structural modelling study of a new Re-doped Bi2O3 phase was also undertaken. A comprehensive investigation of the proton-conducting perovskites BaZrO3, BaPrO3 and BaThO3 is then presented. Our results suggest that intrinsic atomic disorder in BaZrO3 and BaThO3 is unlikely, but reduction of Pr4+ in BaPrO3 is favourable. The water incorporation energy is found to be less exothermic for BaZrO3 than for BaPrO3 and BaThO3, but in all cases the results suggest that the proton concentration would decrease with increasing temperature, in accord with experimental data. The high binding energies for all the dopant-OH pair clusters in BaPrO3 and BaThO3 suggest strong proton trapping effects. Finally, a study of multiferroic BiFeO3 is presented, in which the defect, dopant and migration properties of this highly topical phase are investigated. The reduction process involving the formation of oxygen vacancies and Fe2+ is the most favourable redox process. In addition, the results suggest that oxide-ion migration is anisotropic within this system.
9
Yu, Zhiqiang. "Transient Studies of Ni-, Cu-Based Electrocatalysts in CH4 Solid Oxide Fuel Cell." Akron, OH : University of Akron, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1194625466.
Повний текст джерелаАнотація:
Dissertation (Ph. D.)--University of Akron, Dept. of Chemical Engineering, 2007."December, 2007." Title from electronic dissertation title page (viewed 03/12/2008) Advisor, Steven S. C. Chuang; Committee members, Lu-Kwang Ju, Edward Evans, W. B. Arbuckle, Stephen Z. D. Cheng; Department Chair, Lu-Kwang Ju; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.
10
Vickerman, Vernella V. V. (Vernella Velonie Verlin). "Microfluidic-based 3D cell culture for studies of biophysical and biochemical regulation of endothelial function." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76487.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 210-229).
New and more biologically relevant in vitro models are needed for use in drug development, regenerative medicine, and fundamental scientific investigations. The ultimate challenge lies in replicating the native cell/tissue environment ex vivo. Certain key features of living tissues such as the three dimensionality, biophysical and biochemical microenvironment cannot be readily replicated in traditional culture platforms. Moreover, the capability for multi-parameter manipulation, on a single platform, with the optical resolution to monitor the dynamics of individual cells or small populations is lacking. In this thesis, we developed a novel multiparameter microfluidic-based cell culture platform. The system permits 2D or 3D culture of cells on/in biologically-derived or synthetic hydrogel scaffolds and allows for controlled flow rates, pressure and concentration gradients while directly visualizing cellular response. In addition to the realtime and post-fixation imaging using optical microscopy, methods were developed to extend post-fixation analysis to transmission electron microscopy (TEM). The platform was subsequently used to demonstrate for the first time, two microfluidicbased 3D in vitro assays with direct relevance to tumor development and glaucoma. For the first assay, biochemical induced sprouting was demonstrated. Endothelial cells sprout from an intact monolayer to form multicellular capillary-like structures. Furthermore, using time-lapse microscopy the cellular dynamics during sprouting angiogenesis were observed with great detail, showing tip cell dynamics, cell division events and lumen formation. Of particular relevance to tissue engineering community, we demonstrated that endothelial cells when cultured for several days can assemble into vascular networks with open, perfusable lumen. Using this new system, we present novel findings and results supporting a potential mechanism for flow-mediated mechanical regulation of angiogenesis by transendothelial fluid flow. We demonstrate that flow direction is sufficient to define an angiogenic ON or OFF state. The balance is tipped by forces generated at mechano-sensitive cell-matrix adhesions involving FAK-mediated signaling. These results provide one explanation for the bias towards angiogenesis occurring from the venous side of the circulation. For the second assay, an aqueous humor (AH) outflow model was developed. Subsequent proof-of-concept experiments confirmed its capability for studying the role of the inner wall endothelium in the regulation of AH outflow dynamics.
by Vernella V. V. Vickerman.
Ph.D.
11
Silva, Santos Bruno Miguel Carvalho. "T cell development and lineage commitment : studies based on differential gene expression in thymocyte subsets." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.398218.
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12
Han, Fang. "AMYLOID A-BETA PEPTIDE: IN-CELL STUDIES AND MECHANISM OF POLYPHENOL-BASED INHIBITION TO AGGREGATION." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1404771350.
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13
Liu, Chen. "Structural Studies of Pt-Based Electrocatalysts for Polymer Electrolyte Fuel Cells." Doctoral thesis, Kyoto University, 2021. http://hdl.handle.net/2433/263807.
Повний текст джерелаАнотація:
付記する学位プログラム名: 京都大学大学院思修館京都大学
新制・課程博士
博士(総合学術)
甲第23346号
総総博第19号
京都大学大学院総合生存学館総合生存学専攻
(主査)教授 寶 馨, 教授 内本 喜晴, 特定教授 橋本 道雄
学位規則第4条第1項該当
Doctor of Philosophy
Kyoto University
DFAM
14
Abdur, Rahman Abdur Rub. "CellMap: An Automated Multielectrode Array Cell Culture Analysis System Based on Electrochemical Impedance Spectroscopy." [Tampa, Fla] : University of South Florida, 2007. http://purl.fcla.edu/usf/dc/et/SFE0002185.
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15
Choi, Taeyun Paul. "A recourse-based solution approach to the design of fuel cell aeropropulsion systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22676.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--Aerospace Engineering, Georgia Institute of Technology, 2008.Committee Chair: Mavris, Dimitri; Committee Member: German, Brian; Committee Member: Haynes, Comas; Committee Member: Masson, Philippe; Committee Member: Soban, Danielle.
16
Endoh, Takashi. "Studies on a Novel System for Cell-free Protein Synthesis Based on the Hyperthermophilic Archaeon, Thermococcus kodakaraensis." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/57248.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(工学)
甲第13792号
工博第2896号
新制||工||1427(附属図書館)
26008
UT51-2008-C708
京都大学大学院工学研究科合成・生物化学専攻
(主査)教授 今中 忠行, 教授 青山 安宏, 教授 濵地 格
学位規則第4条第1項該当
17
Ma, Jiaoni, and 馬姣妮. "Multiphoton based biofabrication of 3D protein micro-structures and micro-patterns : voxel and cell matrix niche studies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/208048.
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18
Espiritu, Richard. "Polyethylene-based anion exchange membrane for alkaline fuel cell and electrolyser application : synthesis, characterisation and degradation studies." Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3702.
Повний текст джерелаАнотація:
Alkaline anion exchange membranes (AAEM) have been fabricated using polyethylene as the base polymer offering a low cost AAEM for electrolyser and fuel cell applications. This study focused on the synthesis and characterisation of AAEM with controlled degree of grafting (DOG) and ion-exchange capacity (IEC) with the following parameters investigated: low density polyethylene (LDPE) film thickness 30-130 μm, gamma radiation dose and monomer concentration. The corresponding IEC, water uptake (WU) and degree of swelling (DS) are reported. The performance of 74.6% DOG membrane in a hydrogen fuel cell showed a high open circuit voltage of 1.06 V, with a peak power density of 608 mW cm-2 at 50 °C under oxygen. The use of a membrane with a high DOG does not impact fuel cross-over significantly and provides improved fuel cell performance due to its high conductivity, water transport and resilience to dehydration. The AAEMs showed long term stability, at 80 °C, exhibiting a conductivity of ca. 0.11 S cm-1 over a period of 3300 h under nitrogen. The membrane showed a degradation rate of 5.7 and 24.3 mS kh-1 under nitrogen and oxygen, respectively. With the membrane lifetime defined as the duration of fuel cell operation until the conductivity of the membrane has reduced to a cut-off value of 0.02 S cm-1, the estimated lifetime of the membrane is 2 years under nitrogen and 5 months under oxygen operating at 80 °C. The fabricated anion exchange membranes were subjected to degradation tests in deionised water for electrolyser/fuel cell operation. After the degradation test, the decrease in ion exchange capacity (IEC) of the AEM, hence decrease in ionic conductivity, was influenced by the applied gamma radiation dose rate. The use of a high radiation dose rate produced membranes with improved stability in terms of % IEC loss due to shorter, more uniformly distributed vinylbenzyl chloride (VBC) grafts. For LDPE-based AEMs, increasing the applied radiation dose rate during grafting from 30 to 2000 Gy h-1 significantly reduced AEM % IEC loss from 38 to 11%, respectively. Analyses of both the aged functionalised membranes and their resulting degradation products confirmed the loss of not only the functional group, but also the VBC group, which has not been reported previously in the literature. Investigation of other amine functional groups revealed similar degradation via the removal of both VBC and head group. Oxidation reactions iii taking place at pH close to neutral are the main contributor to the IEC loss, in contrast to the widely reported E2 or SN2 attack on the head group in high alkalinity solutions. A parallel degradation mechanism is proposed to explain head group loss of AEMs, that involves peroxide radicals which are more dominant in low alkalinity solutions. The investigation of the degradation of a commercially available AEM (A201, Tokuyama Corp.) was performed and compared with the fabricated LDPE AEMs. Using similar membrane thickness, results revealed that the fabricated AEM exhibited superior stability to the commercial A201 membrane in terms of % IEC loss and ionic conductivity, both in fuel cell and electrolyser modes. It is believed that the faster degradation rate of the A201 membrane could possibly be due to the attack of OH- ions on both the head group and on the polymer backbone, the latter of which was not observed on the fabricated AEMs.
19
Linares, Moya Douglas De Jesus. "Fundamental and applied studies on the development of an alkaline anion exchange membrane-based direct alcohol fuel cell." Thesis, University of Newcastle upon Tyne, 2012. http://hdl.handle.net/10443/1367.
Повний текст джерела
20
He, Jinshan. "Proteomics-based studies on structure and function of cell-surface proteins responsible for alginate import in Sphingomonas sp. A1." Kyoto University, 2009. http://hdl.handle.net/2433/126545.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第14950号
農博第1791号
新制||農||976(附属図書館)
学位論文||H21||N4499(農学部図書室)
27388
UT51-2009-M864
京都大学大学院農学研究科食品生物科学専攻
(主査)教授 村田 幸作, 教授 安達 修二, 教授 三上 文三
学位規則第4条第1項該当
21
Lu, Lanying. "Studies of anode supported solid oxide fuel cells (SOFCs) based on La- and Ca-Doped SrTiO₃." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7068.
Повний текст джерелаАнотація:
Solid oxide fuel cells (SOFCs) have attracted much interest as the most efficient electrochemical device to directly convert chemical energy to usable electrical energy. The porous Ni-YSZ anode known as the state-of-the-art cermet anode material is found to show serious degradation when using hydrocarbon as fuel due to carbon deposition, sulphur poisoning, and nickel sintering. In order to overcome these problems, doped strontium titanate has been investigated as a potential anode material due to its high electronic conductivity and stability in reducing atmosphere. In this work, A-site deficient strontium titanate co-doped with lanthanum and calcium, La₀.₂Sr₀.₂₅Ca₀.₄₅TiO₃ (LSCT[sub](A-)), was examined. Flat multilayer ceramics have been produced using the aqueous tape casting technique by controlling the sintering behaviour of LSCT[sub](A-), resulting in a 450µm thick porous LSCT[sub](A-) scaffold with a well adhered 40µm dense YSZ electrolyte. Impregnation of CeO₂ and Ni results in a maximum power density of 0.96Wcm⁻² at 800°C, higher than those of without impregnation (0.124Wcm⁻²) and with impregnation of Ni alone (0.37Wcm⁻²). The addition of catalysts into LSCT[sub](A-) anode significantly reduces the polarization resistance of the cells, suggesting an insufficient electrocatalytic activity of the LSCT[sub](A-) backbone for hydrogen oxidation, but LSCT[sub](A-) can provide the electronic conductivity required for anode. Later, the cells with the configuration of LSCT[sub](A-)/YSZ/LSCF-YSZ were prepared by the organic tape casting and impregnation techniques with only 300-m thick anode as support. The effects of metallic catalysts in the anode supports on the initial performance and stability in humidified hydrogen were discussed. The nickel and iron impregnated LSCT[sub](A-) cell exhibits a maximum powder density of 272mW/cm² at 700°C, much larger than 43mW/cm² for the cell without impregnation and 112mW/cm² for the cell with nickel impregnation. Simultaneously, the bimetal Ni-Fe impregnates have significantly reduced the degradation rates in humidified hydrogen (3% H₂O) at 700°C. The enhancement from impregnation of the bi-metal can possibly be the result of the presence of ionic conducting Wustite Fe₁₋ₓO that resides underneath the Ni-Fe metallic particles and better microstructure. Third, in order to improve the ionic conductivity of the anode support and increase the effective TPBs, ionic conducting ceria was impregnated into the LSCT[sub](A-) anode, along with the metallic catalysts. The CeO₂-LSCT[sub](A-) cell shows a poor performance upon operation in hydrogen atmosphere containing 3% H₂O; and with addition of metallic catalysts, the cell performance increases drastically by almost three-fold. However, the infiltrated Ni particles on the top of ceria layer cause the deposition of carbon filament leading to cell cracking when exposure to humidified methane (3% H₂O). No such behaviour was observed on the CeO₂-NiFe impregnated anode. The microstructure images of the impregnated anodes at different times during stability testing demonstrate that the grain growth of catalysts, the interaction between the anode backbone and infiltrates, and the spalling of the agglomerated catalysts are the main reasons for the performance degradation. Fourth, the YSZ-LSCT[sub](A-) composites including the YSZ contents of 5-80wt.% were investigated to determine the percolation threshold concentration of YSZ to achieve electronic and ionic conducting pathways when using the composite as SOFC anode backbone. The microstructure and dilatometric curves show that when the YSZ content is below 30%, the milled sample has a lower shrinkage than the unmilled one due to the blocking effect from the well distributed YSZ grains within LSCT[sub](A-) bulk. However, at the YSZ above 30% where two phases start to form the individual and interconnected bulk, the composites without ball milling process show a lower densification. The impact of YSZ concentration and ball milling process on the electrical properties of the composites reveals that the percolation threshold concentration is not only dependant on the actual concentration, but also related to the local arrangement of two phases. In Napier University, the electroless nickel-ceramic co-depositon process was investigated as a manufacturing technique for the anodes of planar SOFCs, which entails reduced costs and reduced high-temperature induced defects, compared with conventional fabrication techniques. The Ni-YSZ anodes prepared by the electroless co-deposition technique without the addition of surfactant adhere well to the YSZ electrolyte before and after testing at 800°C in humidified hydrogen. Ni-YSZ anodes co-deposited with pore-forming starch showed twice the maximum power density compared with those without the starch. It has therefore been demonstrated that a porous Ni-YSZ cermet structure was successfully manufactured by means of an electroless plating technique incorporating pore formers followed by firing at 450°C in air. Although the use of surfactant (CTAB) increases the plating thickness, it induces the formation of a Ni-rich layer on the electrolyte/anode interface, leading to the delamination of anode most likely due to the mismatched TECs with the adjacent YSZ electrolyte.
22
Wang, Zhen. "Towards a liposome-based synthetic hepatitis B surface antigen (HBsAG) peptide vaccine : immunological studies at T and B-cell levels." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300174.
Повний текст джерела
23
Lai, Kuei-Hung. "Studies on anti-leukemic terpenoids from medicinal mushrooms and marine sponges with ChemGPS-NP-based targets investigation of lead compounds." Doctoral thesis, Uppsala universitet, Avdelningen för farmakognosi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-317554.
Повний текст джерелаАнотація:
This thesis investigates the anti-leukemic activity of terpenoids isolated from medicinal mushrooms and marine sponges, as well as their possible targets and mechanisms of action. In the first section, we focused on studying the triterpenoidal components of three triterpenoid-enriched medicinal mushrooms Antrodia cinnamomea, Ganoderma lucidum, and Poria cocos, which have been used in folk medicine for centuries and also developed into several contemporary marketed products. We isolated the major and characteristic triterpenoids from these mushrooms, together with six new lanostanoids (II-1–II-6). The anti-leukemic activity of the isolates was evaluated in vitro using MTT proliferative assay and seven of them exhibited potential anti-leukemic effect. The active lead compounds were further subjected to computational analyses utilizing the ChemGPS-NP tool. We established a database for the anti-leukemic relevant chemical space of triterpenoids isolated from these three medicinal mushrooms, which could be used as a reference database for further research on anti-leukemic triterpenoids. Our results indicated that the anti-leukemic effect of the active lead compounds was mediated not only through topoisomerases inhibition but also through inhibiting DNA polymerases. The second and third sections focused on isolation of anti-leukemic sesterterpenoids from sponges. The investigation of Carteriospongia sp. led to the isolation of two new scalarane-type sesterterpenoids (III-1 and III-2) and one known tetraprenyltoluquinol-related metabolite (III-3). All isolates exhibit an apoptotic mechanism of action against Molt 4 cells, found to be mediated through the disruption of the mitochondrial membrane potential (MMP) and inhibition of topoisomerase IIα expression. Detailed investigation of the apoptotic mechanism of action using molecular docking analysis revealed that compound III-1 might target Hsp90 protein. The apoptotic-inducing effect of III-3 was supported by in vivo experiment by suppressing the volume of xenograft tumor growth (47.58%) compared with the control. In the final section of this thesis we studied manoalide and its derivatives, sesterterpenoids isolated from the sponge Luffariella sp.. Manoalide has been studied as a potential anti-inflammatory agent for the last thirty years with more than 200 publications and 40 patents. However, the configurations at positions 24 and 25 were never revealed. In the current study, ten manoalide-type sesterterpenoids (IV-1–IV-10) were isolated from Luffariella sp. and their stereoisomers at positions 24 and 25 were identified and separated for the first time. The configuration at positions 24 and 25 showed to have a significant effect on the anti-leukemic activity of manoalide derivatives, with the 24R,25S-isomer exhibiting the most potent anti-leukemic activity. The apoptotic mechanism of action of compound IV-7 against Molt 4 cells was investigated, and the compound was found to trigger MMP disruption and intracellular reactive oxygen species (ROS) generation. Compound IV-7 also inhibited activity against both human topoisomerases, I and II. The in vivo experiment further supported the anti-leukemic effect of IV-7 with a 66.11% tumor volume suppression compared to the control.
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Nestor, Marika. "Antibody-Based Radionuclide Targeting for Diagnostics and Therapy : Preclinical Studies on Head and Neck Cancer." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-7341.
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Mudiyanselage, Charith Malinga Rathnayaka. "Meshfree-based numerical modelling of three-dimensional (3-D) microscale deformations of plant food cells during drying." Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/118069/1/Charith_Malinga_Rathnayaka_Mudiyanselage_Thesis.pdf.
Повний текст джерелаАнотація:
Numerical modelling has been a helpful tool for analysing plant cellular structure and associated dynamics. It generally consumes less time, money and other resources compared to experimenting with real plant structures. In this context, investigating the morphological changes that take place in the plant cellular structure under different circumstances has recently been an important application. Drying is one of the most common and cost effective techniques for extending the shelf life of food-plant materials (for instance, fruits and vegetables). During the drying process, food-plant cellular structure undergoes structural deformations that influence drying operations in terms of performance as well as food quality. To engineer effective and efficient food drying processes, it is important to establish a good understanding of cell morphological changes and underlying mechanisms. Grid-based approaches and meshfree methods are the two main categories of numerical modelling techniques used to analyse food-plant drying phenomena. Grid-based methods encounter drawbacks in some applications due to the inherent 'grid' behaviour and subsequent inability to successfully model problems with large deformations and multiphase phenomena. To overcome these drawbacks, meshfree (or meshless) based numerical modelling and simulation methods have been developed.
There are recently reported efforts to numerically model the micro mechanics of food-plant matter using coupled Smoothed Particle Hydrodynamics (SPH) and Discrete Element Method (DEM)-based approaches. Some of these studies focus only on fresh plant cellular structures and their behaviour under external mechanical loading. There are other studies considering both fresh and dried plant cellular structures in two dimensions (2-D) along with their morphological characteristics. The overall computational approach in those investigations show a promising capacity to be further extended towards more realistic scales. However, it is difficult to describe a truly 3-D phenomenon like cellular scale drying phenomena by means of a 2-D approach. Thus, in order to approximate the morphological changes of cellular scale food-plant drying phenomena in a more detailed manner, there is a requirement to extend that approach into the 3-D level. In addition, there are conceptual constraints in using the Discrete Element Method (DEM) to represent the cell wall membrane in a completely meshfree numerical model. The literature suggests that conceptually, a Coarse-Grained (CG) approach could be more suited for this application, as there is a stronger conceptual and fundamental matching in an SPH-CG coupling than in an SPH-DEM coupling.
Within this background, this investigation aimed to develop a 3-D Smoothed Particle Hydrodynamics (SPH) and Coarse Grained method (CG) coupled numerical model, which could successfully approximate the morphological behaviour of foodplant cells during drying. Initially, the fundamentals of microscale plant cellular drying phenomena were studied. The applicability of a coupled SPH-CG 3-D approach was evaluated through a basic 3-D plant cell drying model. Next, an experimental investigation was carried out to observe the real morphological changes taking place in plant cellular structure during drying. Through the learning gleaned from both the basic numerical and experimental studies, an improved 3-D SPH-CG cell drying model was developed. The 3-D nature of this model allows it to predict the morphological changes on a more realistic scale compared to the previous 2-D models developed using a SPH-DEM coupling. The numerical results are found to be well comparable, both qualitatively and quantitatively, with the experimental findings.
As the next step, the developed 3-D numerical approach was successfully applied to model different types of food-plant cells (e.g. apple, potato, grape and carrot). The agreement between the model predictions and the experimental findings was found to be favourable for all four food-plant categories selected. The 3-D SPH-CG numerical model investigated in this study can successfully model dryness states of food-plant cells in a larger moisture content range with stable results compared to the recently reported Finite Element Modelling (FEM)-based and meshfree-based plant cell drying models. The computational accuracy of the numerical modelling scheme has been maintained at a high value through limiting the percentage model consistency error to less than 1%. This developed 3-D model will provide a source of guidance for industrial practitioners to optimise food drying operations in terms of final product quality, nutritious value and overall process performance. In addition, the developed computational framework has potential future applications in modelling a wide range of plant cells and animal cells.
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Takagi, Toshiyuki. "Studies on breeding of yeast Saccharomyces cerevisiae for effective macroalgae utilization based on the metabolism of marine bacterium." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225665.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(農学)
甲第20440号
農博第2225号
新制||農||1049(附属図書館)
学位論文||H29||N5061(農学部図書室)
京都大学大学院農学研究科応用生命科学専攻
(主査)教授 植田 充美, 教授 小川 順, 教授 渡邊 隆司
学位規則第4条第1項該当
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Watanabe, Miki. "Development of DNA aptamer as a HMGA inhibitor for cancer therapy and NMR-based metabonomics studies in human/mouse cell lines." Miami University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=miami1322753081.
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Yi, Sung Wook. "Cysteine Based PNA (CPNA): Design, Synthesis and Application." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002346.
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Taylor, Sarah E. "Mass spectrometric studies of the biological fate of platinum-based drugs and selenium supplementation in cancer chemotherapy." Thesis, Loughborough University, 2014. https://dspace.lboro.ac.uk/2134/17448.
Повний текст джерелаАнотація:
Platinum-based drugs are an important group of alkylating-like agents which are used in cancer chemotherapy treatment. Cisplatin and oxaliplatin in particular are still commonly used today and are the focus of this thesis. As with most chemotherapy drugs, the efficacy of these drugs are limited by toxicity as well as tumour resistance, and therefore by increasing our understanding of these areas it is hoped to one day achieve personalised chemotherapy. The use of ICP-MS in the study of bio-sciences is still relatively new, however it has the ability to provide robust, fast and accurate methods for the quantification of platinum in biological samples. The research presented here utilised mass spectrometry in the study of the formation of Pt-DNA adducts in the clinical samples, the binding of oxaliplatin to short peptides and the effect of selenium supplementation on oxaliplatin in colorectal cancer cell lines. A comparison in the number of Pt-DNA adducts in saliva and leukocyte samples obtained from patients undergoing Pt-based chemotherapy demonstrated a lack of correlation between the two sample types. Samples were taken pre- and post-treatment and analysed via SF-ICP-MS and significant inter-patient variability was observed as expected. In both leukocyte and saliva samples, not only was Pt from previous chemotherapy cycles observed, but Pt was detected in the DNA in both sample types 1 hour after treatment. However a lack of correlation between platinum levels seen in the blood and saliva, combined with unexpected difficulties obtaining patient adherence to the saliva sampling protocol, indicated that saliva does not at present offer a reliable alternative to leukocytes for this assay. The binding of oxaliplatin to short nitrogen and sulfur rich peptides was investigated. Platinum binding to the peptides was observed and no significant differences in the level of binding were observed between the range of N and S rich peptides studied in this investigation. Partly due to the inability to reproduce biological conditions in this study, oxaliplatin was observed as a whole molecule, and furthermore dimers and multimers were also observed. The effect of selenium supplementation on the total cellular uptake of platinum was investigated in cultured cells via ICP-MS and LA-ICP-MS. It was observed that selenium decreased the amount of Pt taken up by the cancer cells. This was seen in analysis of populations of cells as well as by single cell analysis. Furthermore, while problems were encountered measuring selenium in subcellular experiments, the effect of selenium on the subcellular distribution of platinum as well as the number of Pt-DNA adducts could be determined.
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Liyanage, Arawwawala Don T. "FLUORINATED ARENE, IMIDE AND UNSATURATED PYRROLIDINONE BASED DONOR ACCEPTOR CONJUGATED POLYMERS: SYNTHESIS, STRUCTURE-PROPERTY AND DEVICE STUDIES." UKnowledge, 2013. http://uknowledge.uky.edu/chemistry_etds/23.
Повний текст джерелаАнотація:
FLUORINATED ARENE, IMIDE AND LACTAM-FUNCTIONALIZED DONOR ACCEPTOR CONJUGATED POLYMERS: SYNTHESIS, STRUCTURE-PROPERTY AND DEVICE STUDIES
After the discovery of doped polyacetylene, organic semiconductor materials are widely studied as high impending active components in consumer electronics. They have received substantial consideration due to their potential for structural tailoring, low cost, large area and mechanically flexible alternatives to common inorganic semiconductors. To acquire maximum use of these materials, it is essential to get a strong idea about their chemical and physical nature. Material chemist has an enormous role to play in this novel area, including development of efficient synthetic methodologies and control the molecular self-assembly and (opto)-electronic properties. The body of this thesis mainly focuses on the substituent effects: how different substituent’s affect the (opto)-electronic properties of the donor-acceptor (D-A) conjugated polymers. The main priority goes to understand, how different alkyl substituent effect to the polymer solubility, crystallinity, thermal properties (eg: glass transition temperature) and morphological order. Three classes of D-A systems were extensively studied in this work. The second chapter mainly focuses on the synthesis and structure-property study of fluorinated arene (TFB) base polymers. Here we used commercially available 1,4-dibromo-2,3,5,6-tetrafluorobenzene (TFB) as the acceptor material and prepare several polymers using 3,3’-dialkyl(3,3’-R2T2) or 3,3’-dialkoxy bithiophene (3,3’-RO2T2) units as electron donors. A detail study was done using 3,3’-bithiophene donor units incorporating branched alkoxy-functionalities by systematic variation of branching position and chain length. The study allowed disentangling the branching effects on (i) aggregation tendency, intermolecular arrangement, (iii) solid state optical energy gaps, and (iv) electronic properties in an overall consistent picture, which might guide future polymer synthesis towards optimized materials for opto-electronic applications. The third chapter mainly focused on the structure-property study of imide functionalized D-A polymers. Here we used thiophene-imide (TPD) as the acceptor moiety and prepare several D-A polymers by varying the donor units. When selecting the donor units, more priority goes to the fused ring systems. One main reason to use imide functionality is due to the, open position of the imide nitrogen, which provides an attaching position to alkyl substituent. Through this we can easily manipulate solubility and solid state packing arrangement. Also these imide acceptors have low-lying LUMOs due to their electron deficient nature and this will allow tuning the optical energy gap by careful choice of donor materials with different electron donating ability. The fourth chapter mainly contribute to the synthesis and structure property study of a completely novel electron acceptor moiety consist of a unsaturated pyrrolidinone unit known as Pechmann dye (PD) core. Pechmann dyes are closely related to the Indigo family. This can refer as 3-butenolide dimer connected via an alkene bridge, containing a benzene ring at the 5 and 5’ positions of the lactone rings. We have prepared several D-A polymers using this PD system with benzodithiophene (BDT) as the donor unit. Different to common D-A polymers the HOMO and LUMO of the PD acceptor moiety are energetically located within the gap of the BDT, so that the electronic and optical properties (HOMO-LUMO transition) are dictated by the PD properties. The promising electronic properties, band gaps, high absorption coefficients and broad absorption suggest this new D-A polymers as an interesting donor material for organic solar cell (OSC) applications.
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Ambreen, Ghazala [Verfasser], and Udo [Akademischer Betreuer] Bakowsky. "Evaluation of CRPV based cell systems for the therapeutic studies of papilloma virus associated head and neck cancer / Ghazala Ambreen ; Betreuer: Udo Bakowsky." Marburg : Philipps-Universität Marburg, 2021. http://d-nb.info/1227580282/34.
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Sankaran, Hariharan. "High-level synthesis framework for crosstalk minimization in VLSI ASICs." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002775.
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Merz, Clifford Ronald. "Investigation and evaluation of a bi-polar membrane based seawater concentration cell and its suitability as a low power energy source for energy harvesting/MEMS devices." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002671.
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Mocke, Charl Anthony. "Location based services : developing mobile GIS applications." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1648.
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Pryor, Donald Edward. "Synthesis and Bioactivity Studies of Nanoparticles Based on Simple Inorganic and Coordination Gallium Compounds as Cellular Delivering Vehicles of Ga(III) Ions for Potential Therapeutic Applications." Kent State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=kent1543554532063877.
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Dharmadasa, Ruvini. "Studies of composite metal oxide based ETA solar cells." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9117.
Повний текст джерелаАнотація:
The drive to produce low cost and efficient solar cells to replace solid state silicon cells has led to the rapid growth of nanotechnology in the PV sector. The extremely thin absorber (ETA) layer solar cell is a device that relies on the use of nanostructured anodes. The very high surface area of the metal oxides enhances the efficiency of the devices by increasing light harvesting in the cell. TiO2 has been the most common material of choice in these cells. However, alternative materials such as composite electrodes ZnO/TiO2, ZnO/SnO2, ZnO/Al2O3 have been considered. These systems also have the ability to improve charge carrier separation and broaden their photoresponse region. In addition to selecting materials with the correct energetics, the morphology of the metal oxide particles plays an important role in these devices. The ability to manipulate the shape, size, and surface to volume ratio of these oxides is critical in influencing the materials chemical, electronic and optical properties. In this thesis the fabrication of composite (ZnO,SnO2) electrodes by aerosol assisted chemical vapor deposition (AACVD) was investigated. By simply varying the Zn:Sn ratio in the precursor solution, a range of (ZnO,SnO2) composite materials along with single phase ZnO and SnO2 has been fabricated. It has been found that the morphology of the deposited electrodes is highly dependent on the Zn content with electrodes with morphologies ranging from nanoplates, to nanocolumns, to highly compact structures have been deposited. The dependence of the Zn content in the deposition solution on the photoelectrochemical (PEC), optoelectronic, photon to electron conversion efficiency (APCE) and photovoltaic characterization was investigated. ETA solar cells with FTO/(ZnO,SnO2)/In2S3/PbS/PEDOT:PSS/Cgraphite/FTO structures were successfully fabricated to demonstrate the suitability of (ZnO,SnO2) anodes in these devices. This work has shown that AACVD is a useful technique for engineering the properties of semiconducting electrodes for PV applications.
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Hindson, James Crosby. "Morphological and materials studies on organic-based photovoltaic devices." Thesis, University of Cambridge, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609434.
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Waters, Richard Huw Robert. "Characterisation and lifetime studies of CPDT- and BT- based photovoltaic cells." Thesis, Bangor University, 2015. https://research.bangor.ac.uk/portal/en/theses/characterisation-and-lifetime-studies-of-cpdt-and-bt-based-photovoltaic-cells(fa955bc1-38f9-4805-a5ee-d8f82eb28f28).html.
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Matter, Paul H. "Electrocatalytic and fuel processing studies for portable fuel cells." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1149037376.
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Mohanakrishnaswamy, Venkatesh. "Processing and characterization of CIGS - based solar cells." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000368.
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Shermadini, Zurab. "Iron based pnictide and chalcogenide superconductors studied by muon spin spectroscopy." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-148934.
Повний текст джерелаАнотація:
In the present thesis the superconducting properties of the Iron-based Ba_{1-x}Rb_{x}Fe_{2}As_{2} arsenides, and A_{x}Fe_{2-y}Se_{2} (A = Cs, Rb, K) chalcogenides are investigated by means of Muon Spin Rotation Spectroscopy. The temperature and pressure dependence of the magnetic penetration depth is obtained form muSR experiments and analyzed to probe the superconducting gap-symmetries for each samples.
The Ba_{1-x}Rb_{x}Fe_{2}As_{2} system is described within the multi-gap s+s-wave scenario and results are discussed in the light of the suppression of inter-band processes upon hole doping. Due to the lowered upper critical field Bc2 and reduced Tc, a large section of B-T-p phase diagram is studied for the hole-overdoped x=1 case. By applying hydrostatic pressure, the RbFe_{2}As_{2} system exhibits a classical BCS superconducting characteristics. The A_{x}Fe_{2-y}Se_{2} chalcogenide represents a system containing magnetically ordered and superconducting phases simultaneously. In all investigated chalcogenide samples, about 90% of the total volume show the strong antiferromagnetic phase and 10% exhibit a paramagnetic behavior.
Magnetization measurements reveal a 100% Meissner effect, while muSR clearly indicates that the paramagnetic phase is a perfect superconductor. Up to now, there is no clear evidence whether the antiferromagnetic phase is also superconducting. The microscopic coexistence and/or phase separation of superconductivity and magnetism is discussed. Moreover, a new hydrostatic double-wall pressure cell is developed and produced, satisfying the demands of muSR experiments. The designs and characteristics of the new pressure cell are reviewed in the present thesis.
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Gao, Jiajia. "Electrolyte-Based Dynamics: Fundamental Studies for Stable Liquid Dye-Sensitized Solar Cells." Doctoral thesis, KTH, Tillämpad fysikalisk kemi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187025.
Повний текст джерелаАнотація:
The long-term outdoor durability of dye-sensitized solar cells (DSSCs) is still a challenging issue for the large-scale commercial application of this promising photovoltaic technique. In order to study the degradation mechanism of DSSCs, ageing tests under selected accelerating conditions were carried out. The electrolyte is a crucial component of the device. The interactions between the electrolyte and other device components were unraveled during the ageing test, and this is the focus of this thesis. The dynamics and the underlying effects of these interactions on the DSSC performance were studied. Co(bpy)32+/3+-mediated solar cells sensitized by triphenylamine-based organic dyes are systems of main interest. The changes with respect to the configuration of both labile Co(bpy)32+ and apparently inert Co(bpy)33+ redox complexes under different ageing conditions have been characterized, emphasizing the ligand exchange problem due to the addition of Lewis-base-type electrolyte additives and the unavoidable presence of oxygen. Both beneficial and adverse effects on the DSSC performance have been separately discussed in the short-term and long-term ageing tests. The stability of dye molecules adsorbed on the TiO2 surface and dissolved in the electrolyte has been studied by monitoring the spectral change of the dye, revealing the crucial effect of cation-based additives and the cation-dependent stability of the device photovoltage. The dye/TiO2 interfacial electron transfer kinetics were compared for the bithiophene-linked dyes before and after ageing in the presence of Lewis base additives; the observed change being related to the light-promoted and Lewis-base-assisted performance enhancement. The effect of electrolyte co-additives on passivating the counter electrode was also observed. The final chapter shows the effect of electrolyte composition on the electrolyte diffusion limitation from the perspectives of cation additive options, cation concentration and solvent additives respectively. Based on a comprehensive analysis, suggestions have been made regarding lithium-ion-free and polymer-in-salt strategies, and also regarding cobalt complex degradation and the crucial role of Lewis base additives. The fundamental studies contribute to the understanding of DSSC chemistry and provide a guideline towards achieving efficient and stable DSSCs.QC 20160517
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Galindo, Lorente Sergi. "Studies on organic solar cells based on small-molecules : tetraphenyldibenzoperiflanthene and fullerene C70." Doctoral thesis, Universitat Politècnica de Catalunya, 2015. http://hdl.handle.net/10803/325421.
Повний текст джерелаАнотація:
This work deals with the research on organic solar cells based on small-molecules semiconductors. In particular, organic solar cells of this thesis have been used tetraphenyldibenzoperiflanthene as donor material and fullerene C70 as acceptor material.
In the first part of this thesis, we focus on the influence of the density of states of the donor layer on the characteristic parameters of solar cells. Further, organic solar cells with p-i-n structure are presented, where the intrinsic layer is obtained by coevaporation of donor and acceptor. The influence of the thickness of the intrinsic layer on the p-i-n solar cell characteristic is analysed.
In the second part, an equivalent circuit for organic solar cells is presented. A new term is added to the standard model representing recombination losses in the active layer of the device. The analysis of the characteristics of current - voltage measured at different illumination intensities allows the estimation of the term recombination. The model clearly separates technological issues (series and parallel resistance) from effects related to the physics of the device (recombination losses). It also allows obtaining an effective mobility-lifetime product in the active layer of the device to be determined, characterising its state of degradation.En aquesta tesi s’investiguen cèl·lules solars orgàniques basades en semiconductors de petita molècula. En particular, les cèl·lules solars orgàniques d’aquesta tesi han emprat tetraphenyldibenzoperiflanthene com material donador i ful·lerè C70 com material acceptador. En la primera part d'aquesta tesi, ens centrem en la influència de la densitat d'estats de la capa donadora en els paràmetres característics de les cèl·lules solars. Més endavant, es presenten cèl·lules solars orgàniques amb una estructura p-i-n, on la capa intrínseca s'obté per l'evaporació conjunta del donador i l’acceptador. S'analitza la influència del gruix de la capa intrínseca de la cèl·lula solar p-i-n en la característica de la cèl·lula solar. En la segona part, es presenta un circuit equivalent per a les cèl·lules solars orgàniques. S'afegeix un nou terme en el model estàndard que representa les pèrdues de recombinació a la capa activa del dispositiu. L’anàlisi de les característiques de corrent-tensió mesurades a diferents intensitats de llum permeten l'estimació del terme de recombinació. El model separa clarament les qüestions tecnològiques (resistències en sèrie i en paral·lel) dels efectes relacionats amb la física del dispositiu (pèrdues de recombinació). També permet l’obtenció d’un producte de la mobilitat - temps de vida efectiu a la capa activa del dispositiu a ser determinat, la caracterització del seu estat de degradació.
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Lee, Yi-Hsuan. "Studies on Degradation Behavior of Ni-based Cermet Anode for Solid Oxide Fuel Cells." 京都大学 (Kyoto University), 2013. http://hdl.handle.net/2433/180503.
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Dufton, Jesse T. R. "Computational studies of sulphide-based semiconductor materials for inorganic thin-film photovoltaics." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607142.
Повний текст джерелаАнотація:
New thin-film solar cell materials and a greater understanding of their properties are needed to meet the urgent demand for sustainable, lower-cost and scalable photovoltaics. Computational techniques have been used to investigate Cu2ZnSnS4, CuSbS2 and CuBiS2 , which are potential absorber layer materials in thin-film photovoltaics. Their low cost, low toxicity and their constituent’s relative abundance make them suitable replacements for current thin-film absorbers, which are CdTe or Cu(In, Ga)(S, Se)2 based systems. Firstly, we have used hybrid Density Functional Theory (DFT) calculations to study CuSbS2 and CuBiS2. We calculate band gaps of 1.69 eV and 1.55 eV respectively, placing CuBiS2 within the optimal range for a viable absorber material. The density of states for both these materials indicate that formation of electron hole charge carriers will occur in the Cu d10 band. Consequently, photoexcitation leads to the oxidation of Cu(I). Secondly, we have derived interatomic potentials which describe the complex structure of Cu2ZnSnS4 accurately. We find that the Cu/Zn antisite defect represents the lowest energy form of intrinsic defect disorder. For these antisite defects, we find a preference for small neutral defect clusters, which suggests a degree of self-passivation exists. Investigations of Cu-ion transport find VCu migration is possible via a vacancy hopping mechanism. There are pathways which can be connected to give 3D long-range diffusion. Investigations of the Cu/Zn site disorder in Cu2ZnSnS4 find that configurations which are kesterite-like will dominate synthetic samples. However, perfectly ordered kesterite will not be formed due to entropic effects. The simulations indicate the stannite and stannite-like polymorphs are less favourable, and can only account for ≈2.5% of a sample. Investigations of the surfaces of Cu2ZnSnS4, suggest that the vast majority of the low index surfaces are dipolar and that only the (1 1 2), (0 1 0) and (1 0 1) surfaces have low surface energies.
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Muroyama, Hiroki. "Studies on Composites Based on Sulfates and Phosphates for Electrolytes in Intermediate-Temperature Fuel Cells." 京都大学 (Kyoto University), 2009. http://hdl.handle.net/2433/124508.
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Liu, Hanxiao. "Studies of efficient and stable organic solar cells based on aluminum-doped zine oxide transparent electrode." HKBU Institutional Repository, 2014. https://repository.hkbu.edu.hk/etd_oa/34.
Повний текст джерелаАнотація:
Organic solar cells (OSCs) have attracted significant attention due to their potential of large area solution fabrication capability at low-cost. For bulk heterojunction (BHJ) OSCs, a thin film of transparent conducting indium tin oxide (ITO), coated on glass or flexible plastic substrate, is widely used as a front electrode. However, indium is not abundant on Earth. Its price has increased continuously over the past 10 years and will likely become an obstacle for the commercialization of OSCs at low cost. Aluminum-doped zinc oxide (AZO) is a promising ITO alternative due to its advantages of high electric conductivity, optical transparency, non-toxicity and low cost. However, reports on OSCs using AZO electrode are quite limited, due to the relatively lower power conversion efficiency (PCE) of AZO-based OCSs as compared to that of ITO-based OCSs. This work focused on studies of high performance AZO-based OSCs through AZO surface modification, absorption enhancement and process optimization. The optical and electronic properties of AZO film including transmittance, sheet resistance, surface morphology and surface work function were characterized. AZO-based OSCs with conventional and inverted structures were fabricated. It was found that AZO-based OSCs with inverted structure demonstrated superior performance than the ones with conventional structure. The inverted structure avoids the use of acidic PEDOT:PSS hole transporting layer, allows the improving of the absorbance of the OSCs and therefore its efficiency. An AZO front transparent cathode was used for application in high performance inverted BHJ OSCs. The photoactive layer consisted a blend of poly[[4,8-bis[(2- ethylhexyl)oxy] benzo [1,2-b:4,5-b'] dithiophene-2,6- diyl][3-fluoro- 2-[(2-ethylhexyl) carbonyl]thieno[3,4-b]thiophenediyl]](PTB7):3'H-Cyclopropa[8,25][5,6]fullerene- C70- D5h(6)-3'-butanoicacid, 3'-phenyl-, methyl ester (PC70BM). A structurally identical control OSC having an ITO front cathode was also fabricated for comparison studies. The structure of OSCs was optimized to achieving absorption enhancement in the active layer. AZO and ITO were modified with a 10 nm thick solution-processed ZnO interlayer to facilitate the efficient electron extraction. The results revealed that bilayer AZO/ZnO and the ITO/ZnO cathodes possess similar electron extraction property. AZO layer has a transparency cutoff at wavelength < 380 nm, results in a slight decrease in the short-circuit current density (JSC). However, the decrease in JSC is very small because the main energy of solar irradiation falls in the spectrum with wavelength > 380 nm. It shows that AZO-based OSCs have a promising PCE of 6.15%, which is slightly lower than that of a control ITO-based OSC (6.57%). AZO-based OSCs, however, demonstrate an obvious enhancement in the stability under an ultraviolet (UV)-assisted acceleration aging test. The significant enhancement in the stability of AZO-based OSCs arises from the tailored absorption of AZO electrode in wavelength < 380 nm, which serves as a UV filter to inhibit an inevitable degradation process in ITO-based OSCs due to the UV irradiation. In order to further investigate the degradation mechanism of OSCs under UV exposure, the change in charge collection characteristics of the OSCs made with ITO/ZnO and AZO/ZnO front cathode before and after UV exposure was examined. It was found that there was an obvious decrease in the charge extraction efficiency of ITO-based OSCs after UV exposure, while there was no observable change in the charge extraction efficiency of OSCs made with AZO/ZnO cathode under the same acceleration aging test. This work demonstrates that AZO is a suitable ITO alternative for application in OSCs, offering an improved device stability, comparable PCE and cell fabrication processes with an attractive commercial potential.
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Gadisa, Abay. "Studies of Charge Transport and Energy Level in Solar Cells Based on Polymer/Fullerene Bulk Heterojunction." Doctoral thesis, Linköping : LInköping University, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8047.
Повний текст джерела
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Aoki, Hiroyoshi. "Studies on Electronic and Local Structure of Pt based Cathode Catalysts for Polymer Electrolyte Fuel Cells." Kyoto University, 2011. http://hdl.handle.net/2433/142305.
Повний текст джерелаАнотація:
Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第16177号
人博第560号
新制||人||134(附属図書館)
22||人博||560(吉田南総合図書館)
28756
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 内本 喜晴, 教授 杉山 雅人, 教授 田部 勢津久, 准教授 福塚 友和
学位規則第4条第1項該当
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Söderlund, Stina. "Clinical and Immunological Studies in Chronic Myeloid Leukaemia." Doctoral thesis, Uppsala universitet, Hematologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-324272.
Повний текст джерелаАнотація:
Chronic myeloid leukaemia (CML) is characterised by the constitutively active tyrosine kinase BCR-ABL. Standard treatment with tyrosine kinase inhibitors (TKI) in the chronic phase (CP) of CML conveys excellent long-term prognosis but is associated with side effects and costs. Treatment free remission (TFR) is possible in a proportion of patients discontinuing treatment after obtaining deep treatment responses but it is not fully known how to select the right patients for stopping attempts. Treatment of accelerated phase (AP) and blast crisis (BC) is more complicated and the prognosis more dismal. In this thesis, we have studied factors of importance for outcome in CML patients with focus on immunological factors and clinical management. In a cohort of 32 newly diagnosed CP-CML patients, evidence of active immune escape mechanisms were found. These declined with the course of TKI treatment and at the same time, effector lymphocyte responses were elicited. These anti-leukaemia immune responses might help in the long-term control of CML. Multiple plasma protein markers were also measured with three multiplex platforms in a smaller cohort of patients (n=14). Inflammatory cytokines and other plasma proteins were affected by TKI treatment and multiplexing seems useful for finding potential biomarkers with biologic or prognostic significance in CML. Patients progressing to AP/BC were studied in a population-based material from the Swedish CML register. Approximately 4% of TKI-treated CP-CML patients transformed to AP/BC within 2 years of diagnosis. Monitoring of treatment responses was suboptimal in 1/3 of these patients and the median survival was 1.4 years after diagnosis of AP/BC. Thus, minimising the risk of disease progression through strict adherence to guidelines for monitoring and treatment is essential. In a cohort of patients (n=50) discontinuing TKI treatment within a large European trial, musculoskeletal pain was reported by 30% of patients, starting within 1- 6 weeks of TKI discontinuation and spontaneously resolving over time in most cases. Patients (n=56) were also evaluated with a multiplex platform with a total of 162 inflammation- and cancer-related plasma proteins. No predictive protein biomarkers for successful TKI discontinuation could be found. However, profound effects of TKI-treatment were seen and plasma proteomics could be useful for understanding effects of long-term TKI-treatment.