在這個對可再生能源需求不斷增加的新時代,聚合物太陽能電池成為其中一個最熱門的研究題目。在過去十年,聚合物太陽能電池的研究大多集中在液體處理的塊材異質接面結構。與傳統的‘雙層’結構比較,塊材異質接面結構提供一個更大的給體-受體界面面積讓電荷分離及減少電荷重組,從而帶來更高的能量轉換效率。目前使用塊材異質接面結構的聚合物太陽能電池最高能量轉換效率約為8 %。最近在文獻中公佈的一篇文章中,聲稱‘雙層’器件也可以達到與塊材異質接面器件媲美的高效率。這類‘雙層’器件採用相連沉積的給體層P3HT 和以二氯甲烷作溶劑的受體層PCBM 製作。然而,也有報告指在熱退火處理下PCBM 會擴散進入P3HT 的非晶區從而堤高能量轉換效率。我的工作是研究這類所謂的‘雙層’系統。藉運用紫外-可見光光譜儀和掠角X 光繞射,對埰用不同處理手法的純P3HT 薄膜的聚集和結晶性能進行研究。結果發現P3HT 的聚集和結晶性能可能沒有直接的相關性。同時也發現通過縮短底層P3HT 溶劑的揮發時間,這類液體鑄型‘雙層’器件的能量轉換效率得以提高。通過加熱P3HT 薄膜來加快變乾的速度,可以造具較低聚集度和較高結晶密度的P3HT 層。比起常規P3HT 薄膜可以提高能量轉換效率大約15 %。同時也對重量比為1:1 的複合P3HT:PCBM 薄膜的聚集和結晶性能進行了研究。實驗結果進一步表明P3HT 的聚集和結晶性能可能沒有直接的相關性。雖然實驗未有充分運用所有其他可能的處理方法和物理参數對器件進行全面優化,但這項研究卻為液體鑄型雙層聚合物太陽能電池開闢一條新的優化路線。 / In this new age with increasing demand of renewable energy sources, organic solar cell (OSC) has become one of the most intense research topics. The major attention of research in OSC was given to the solution-processed bulk heterojunction (BHJ) architecture during the past ten years. Compared to traditional ‘bilayer’ architecture, the BHJ structure provides a greater donor-accepter interface area for charge separation and reduced recombination, which leads to a higher power conversion efficiency (PCE). The highest PCE reported using BHJ was about 8 %. In a recent article published in the literature, it was claimed that ‘bilayer’ devices can also achieve a high efficiency comparable to that for BHJ devices. Such ‘bilayer’ devices were fabricated by sequential deposition of the donor P3HT and acceptor PCBM layers using dichlormethane as the solvent of PCBM. However, it was also reported that the PCBM could diffuse into the amorphous regions of P3HT during thermal annealing to cause the efficiency enhancement. My work is to study such so-called ‘bilayer’ system. By using UV-Visible spectrophotometer and grazing incidence XRD, the aggregation and crystallization properties of the pure P3HT films fabricated using different processing methods were studied. It was found that the P3HT aggregation may not have direct correlations with crystallinity. It is also discovered that the PCE of such solution-cast bilayer devices are increased by shortening the evaporation time of the underlying P3HT layer from a solution. By heating the P3HT film to accelerate its drying, a less aggregated P3HT layer with a higher density of crystallites could be obtained. The PCE could be enhanced by about 15 % over that using a regular P3HT film. The aggregation and crystallization properties of the composite P3HT:PCBM films with a ratio of 1:1 by weight were also studied. The experimental results further indicate that the P3HT aggregation may not have direct correlations with crystallinity. Although the devices have not been fully optimized by exhausting all the other possible processing and physical parameters, this study opens up a new route to optimize solution-cast bilayer polymer solar cells. / Detailed summary in vernacular field only. / Wong, Man Kwong = 聚合物太陽能電池研究 / 王文廣. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / Wong, Man Kwong = Ju he wu tai yang neng dian chi yan jiu / Wang Wenguang. / Abstract --- p.I / 摘要 --- p.III / Acknowledgement --- p.VI / Chapter Chapter 1 --- Introduction to Organic Solar Cells --- p.1 / Chapter 1-1 --- The history of the development of solar cells --- p.1 / Chapter 1-2 --- Motivation of developing polymer solar cells --- p.2 / Chapter 1-3 --- The materials used in polymer solar cells --- p.4 / Chapter 1-4 --- Basic working principles of the polymer solar cells --- p.6 / Chapter 1-5 --- Definition of some important parameters of solar cells --- p.8 / Chapter 1-5-1 --- Short circuit current density (J[subscript Ssubscript C]) --- p.8 / Chapter 1-5-2 --- Open circuit voltage (V[subscript Osubscript C]) --- p.9 / Chapter 1-5-3 --- Fill factor (FF) --- p.10 / Chapter 1-5-4 --- Power conversion efficiency (PCE) --- p.11 / Chapter 1-6 --- An outline of this thesis --- p.12 / Chapter Chapter 2 --- Experimental Procedures --- p.13 / Chapter 2-1 --- Common preparation procedures in all the experiments --- p.13 / Chapter 2-1-1 --- The cleaning of the glass and indium tin oxide (ITO) substrates --- p.13 / Chapter 2-1-2 --- The preparation of different donor and accepter solution --- p.13 / Chapter 2-1-3 --- The coating of PEDOT:PSS on the glass and ITO substrates --- p.14 / Chapter 2-1-4 --- The thermal vapor deposition of the cathode layer for solar cell devices --- p.14 / Chapter 2-2 --- The detailed experimental procedures of the active layers in different chapters --- p.15 / Chapter 2-2-1 --- Fabrication of the active layers in chapter 3 --- p.15 / Chapter 2-2-2 --- Fabrication of the active layers in chapter 4 --- p.17 / Chapter 2-2-3 --- Fabrication of the active layers in chapter 5 --- p.18 / Chapter 2-3 --- Measurement of the properties of the film samples and the performance of the solar cells --- p.19 / Chapter 2-4 --- Experimental errors --- p.20 / Chapter Chapter 3 --- A Survey on Polymer Solar Cells and Some Preliminary Works --- p.21 / Chapter 3-1 --- Traditional bilayer polymer solar cells --- p.21 / Chapter 3-2 --- Bulk heterojunction polymer solar cells --- p.22 / Chapter 3-3 --- Studies of thermal annealing effects --- p.26 / Chapter 3-4 --- Studies of solvent annealing effects --- p.28 / Chapter 3-5 --- Studies of the relationship between the thickness and the optical density of the films --- p.34 / Chapter 3-6 --- Solution-cast bilayer polymer solar cells --- p.35 / Chapter 3-7 --- Previous studies on solution-cast bilayer polymer solar cells --- p.39 / Chapter Chapter 4 --- Studies on Solution-Cast Bilayer Polymer Solar Cells --- p.42 / Chapter 4-1 --- Motivation and the basic ideas of my research work --- p.42 / Chapter 4-2 --- Higher PCE through the use of a low pressure environment of film formation --- p.43 / Chapter 4-3 --- Higher J[subscript Ssubscript C] through the use of chloroform as the P3HT solvent --- p.46 / Chapter 4-4 --- Higher PCE through the use of a pre-dried heating process --- p.52 / Chapter 4-5 --- Dependence of the device performances on the pre-dried heating temperature --- p.55 / Chapter 4-6 --- Effect of a small amount of PCBM in the underlying P3HT layer --- p.59 / Chapter 4-7 --- Short summaries --- p.62 / Chapter Chapter 5 --- Studies on P3HT:PCBM Blend Layers --- p.64 / Chapter 5-1 --- Motivation --- p.64 / Chapter 5-2 --- Effects on the P3HT aggregation and crystallization of the P3HT:PCBM blend layers due to different treatments --- p.64 / Chapter 5-3 --- Studies of the effects of the removal of PCBM on the P3HT aggregation and crystallization in P3HT:PCBM blend layers --- p.67 / Chapter 5-4 --- Short summaries --- p.70 / Chapter Chapter 6 --- Conclusion --- p.71 / Chapter 6-1 --- Summaries of the research work --- p.71 / Chapter 6-2 --- Ideas for future studies --- p.72 / Bibliography --- p.74

Free radical and aldehydic breakdown product content were determined, by EPR and UV / visible spectroscopy, primarily in intermediate (desiccation tolerant) seeds of <i>Carica papaya</i> L. (Papaya) and recalcitrant (desiccation intolerant) seeds of <i>Aesculus hippocastanum</i> L. (Horse chestnut), but also in other species covering a range of desiccation tolerances, with a view to determining the role of oxidative stress as a diagnostic marker for desiccation tolerance. Axes of non-senescent highly viable recalcitrant seeds of horse chestnut were metabolically active, contained products of lipid peroxidation, displayed low levels of enzymatic protection against activated oxygen and peroxides, and a two-peak free radical EPR signal. During fully hydrated storage at 16 °C for up to 18 months, seeds exhibited, sequentially, an increase in germination rate, a transient increase in intensities of both the low field and high field EPR peaks, a significant increase in membrane leakage and decrease in seed viability, germination rate, and SOD and peroxidase activities. Drying 'unstored' seeds below and embryonic axis moisture content of 40 to 50 % initiated viability loss. At < 25 % moisture content all axes were inviable and displayed a 2- to 4-fold increase in solute leakage, lipid peroxidation products and the low field EPR signal. Seed desiccation sensitivity increased with hydrated storage. The accumulation of lipid peroxidation products and free radicals on drying generally occurred to a greater extent, or at a higher moisture content, than observed with unstored seeds. The results indicate a mediating role for oxidative stress in recalcitrant seed viability loss which is differentially expressed during hydrated, 'natural' ageing and desiccation. Similar trends were seen in other recalcitrant species with the increase in lipid peroxidation products occurring around the point of viability loss. However the study of a more orthodox species (papaya) revealed no such trends.

Cassava ranks seventh in terms of worldwide crop production, providing a staple for over half a billion people. The production of cassava is limited by several factors, with post-harvest physiological deterioration (PPD) of storage roots a major constraint. PPD is a process initiated on harvesting and mediated by reactive oxygen species (ROS) that ultimately renders storage roots unpalatable and unmarketable. It is similar to a conventional plant wound response, but crucially lacks efficient wound repair and down-regulation of stress signalling. Therefore, the strategy utilised here to modulate PPD focussed on increasing the ROS scavenging ability of storage root tissue through a biotechnological approach. Three expression plasmids were produced, harbouring cassava genes encoding the antioxidant enzymes APX, CAT and SOD under the control of the storage rootspecific StPAT promoter. In addition, a reporter expression plasmid was created, with StPAT driving the expression of GusP. Transgenic Arabidopsis plants containing the StPAT::GusP cassette demonstrated root-specific GusP staining. Non-root tissue also showed wound-inducible GusP activity conferred by the StPAT promoter. This novel activity was detected almost immediately after wounding and occurred independently of ethylene, MeJa and ROS. The 3’ 261 bp of the StPAT promoter was sufficient to confer wound-inducible expression and contained putative wound responsive cis regulatory motifs. Analysis of PATATIN function indicated a role during early responses to wounding in the liberation of free fatty acids from cell membranes. Over-expression of the target genes in the model plant Arabidopsis increased the antioxidant enzyme activity in the roots of selected lines. Transgenic plants generally exhibited similar levels of oxidative stress resistance to wild-type plants, a result due in part to the efficient nature of the oxidative stress response of Arabidopsis – the APX activity of wild-type plants increased to transgenic levels under H2O2 stress. However, PPD in cassava is at least partially the result of a poor antioxidant response to harvesting, and so transformation of cassava with the expression plasmids remained a viable strategy. Transgenic cassava plants harbouring the expression cassettes are being generated and will soon be assessed for PPD resistance.

Synthetic fiber reinforced concrete sample sets were exposed to two different environments. One set, of six samples, was exposed to filtered seawater in the lab with wet and dry cycles, while the other set of samples was exposed, on a barge, to the marine environment, in the intracoastal waterways, at SeaTech. The samples were exposed for 8 months, and then removed for experimental and mechanical testing. Upon removal, the barge samples were photographed to observe surface organisms that were attached to each sample. The barge samples, after cleaning, were then exposed to UV light to observe surface bacteria. The barge samples were also taken to Harbor Branch facility for DNA testing, and then sent in for sequencing. This sequencing was used to identify the organisms that were present inside the concrete samples. An Indirect Tensile Strength Test, IDT, was performed on both sets of samples to observe the first crack, max load, and fracture toughness of each sample. The Barge samples had a lower first crack, max load, and fracture toughness, which means that it took less force to break these samples, than the Seawater samples. As the fiber content increased, the Seawater samples grew stronger, while the Barge samples grew weaker. Also, as the fiber content increased, the biodiversity found on the surface of the Barge samples increased as well. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

Bibliography: leaves 137-156. / xiv, 166 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--Dept. of Horticulture, Viticulture and Oenology, University of Adelaide, 1993

Bibliography: leaves 137-156.

No description available.

Infrastructure deterioration models are an integral part of asset management. Deterioration models are used to predict future asset condition and to estimate funding requirements. The purpose of this research is to develop a framework to create infrastructure deterioration models. An overview of the various types of deterioration models is included, presenting the advantages and disadvantages of each type. Existing deterioration model frameworks are also considered. A deterioration modelling framework is then proposed. The selection of the model type, calibration and validation is presented. The framework is then applied to two case studies. The first case study involves a comparison of three pavement deterioration models, created for the City of Oshawa for use in their asset management system. The second case study involves modelling sewer deterioration. This model has been developed to explore the relationship between age, material and deterioration in trunk sewers.

Infrastructure deterioration models are an integral part of asset management. Deterioration models are used to predict future asset condition and to estimate funding requirements. The purpose of this research is to develop a framework to create infrastructure deterioration models. An overview of the various types of deterioration models is included, presenting the advantages and disadvantages of each type. Existing deterioration model frameworks are also considered. A deterioration modelling framework is then proposed. The selection of the model type, calibration and validation is presented. The framework is then applied to two case studies. The first case study involves a comparison of three pavement deterioration models, created for the City of Oshawa for use in their asset management system. The second case study involves modelling sewer deterioration. This model has been developed to explore the relationship between age, material and deterioration in trunk sewers.

Corrosion of the reinforcing steel is a primary deterioration mechanism for reinforced concrete bridges. Heavy use of de-icing salts is believed to be a major contributor in Ontario to severe girder soffit spalling in certain cases. This thesis develops an assessment methodology to evaluate spalled bridges based on ultimate limit states. Specifically, a deterministic program is developed for assessment. It is subsequently compared to laboratory test results and used as a basis for a probabilistic reliability study. A modified area concept is proposed in this thesis to consider the effects of exposing reinforcement at various locations along the girder length. A multipoint analysis program, BEST (Bridge Evaluation Strength Tool), is developed that employs this concept, along with graphical spalling surveys and structural drawings, to evaluate reinforced concrete bridge girders. The program is adapted for a full bridge analysis and to consider the other effects of corrosion, such as bar section loss and bond deterioration. A case study bridge is evaluated to show that the BEST program offers a viable tool for the rapid assessment of spalled bridge girders and to facilitate the prioritization of rehabilitation projects. This evaluation indicates that the spatial distribution of the spalling along a girder, relative to bar splices and laps, has the most significant influence on structural capacity. Single girders show strength deficiencies in flexure and shear due to spalling. In general, the consideration of system effects improves the predicted bridge condition, while considering section loss and bond deterioration has the opposite effect. Laboratory work is used to validate the proposed model and identify a number of areas for future research. The laboratory test results also suggest that the current repair methods are effective in restoring bond and strength. In order to further explore potential uses for the BEST program, modifications are made so that it can be used to perform reliability analyses using Monte-Carlo simulation techniques. A simplified approach for estimating the reliability index as a function of the deterministic resistance ratio is proposed based on the reliability analysis results.