Significant improvements in power conversion efficiency (>10%) of emerging thin-film photovoltaics have been achieved in the last 5 years. High efficiencies would not be possible without the development of new selective interfacial layers. However, a complete understanding of how interfacial layers function to improve the selectivity of charge extracting contacts in thin-film photovoltaics is still being sought. The goal of this work is to contribute to the understanding of the operation of selective interfacial layers based on the study of ionically functionalized fullerenes. Just as other ionically functionalized materials have shown promise as electron-selective interfacial layers in organic photovoltaics and mixed organic-inorganic halide perovskites, Chapter II demonstrates the utility of ionically functionalized fullerenes. High performing solar cells necessitate the use of conductive interfacial layers; anomalously high conductivity in ionically functionalized materials, which have been used as interfacial layers, has been ascribed to self-doping. This work demonstrates that less than 1% of an ionically functionalized fullerene is reduced in its highly conductive pristine state and is concurrent with the presence of distinct chemical species. These studies describe how the chemical origin of the high conductivity of ionically functionalized fullerenes does not require the invocation of direct anion reduction or significant chemical transformations such as Hofmann-like elimination reactions occurring to a stoichiometric degree. This work also addresses the question of how the selectivity of a charge extracting contact is improved by the presence of an interfacial layer. The quantification of energy barrier reduction, which is often discussed in terms of work function modification or energy-level alignment, is demonstrated using metal|semiconductor junctions modified with an ionically functionalized fullerene. The barrier height of high work function electrodes was reduced significantly, by as much as 0.45 V, and was correlated to thin (2–5 nm) portions of the film rather than fullerene aggregates. The studies that comprise this work form a coherent model for understanding the key factors that have resulted in the continued use of ionically functionalized interfacial layers, their high conductivity, and energy barrier modification of the charge extracting electrodes. This dissertation contains coauthored, previously published, and unpublished work. / 10000-01-01

<p>When discussing matters of usability, focus is usually kept on functionality whilst other aspects, such as aesthetics, are neglected. Discussions of aesthetics are on the other hand traditionally kept within the area of fine arts. Considering that both usability and aesthetics are of big importance in people’s lives, it is astonishing to find that their relationship has not been fully explored. Therefore, the purpose of this study was to, with interfaces of a Volvo Logistics environmental calculation tool, explore whether aesthetics (in the form of visual beauty) would affect the perceived usability of a system. Hence, the question of research has been whether a visually attractive user interface will be perceived as more usable than a less attractive one when usability/functionality is kept constant? (Or in more general terms; is beautiful more usable?)</p><p>To achieve this, two interfaces with the same functionality but with different levels of visual beauty were designed and used in an experiment where participants rated perceived usability and appearance. The results of the experiment were expected; participants perceived the better looking interface as more usable whereas actual usability appears to have been constant.</p>

Ever since the internet technology was developed in 90's, like radio, television andnews paper, it has become one of the most influencial medias. Comparing withtraditional media, internet performs significantly better on on-time information providing, communication, geography limitation and globalization. Not only the cost of seting it up is low, but also the speed of its information transmitting is fast. Therefore lots of firms set up their corporate websites and use its functionalaities to help their marketing and customer service. The most important factor that decides the quality of a corporate website is the website functionalities. The definition of "website functionalities" is wide. It contains many kinds of abilities that a website has. To help corporates/firms build corporate websites that can help their sales and services the best, this research intends to find out the relationship between companies' stock prices and their corporate website functionalities, and finally find out the website functionalities that can help firms' business performance and rank the website functionalities from the most important one to the least important one. This research takes stock information from the "Taiwan Stock Exchange Market Observation System" website. The information taken are the stock price, capital size and industry category. The size of the sample is 150 companies. This research developes a grading system that evaluates companies' performances on functionalities that were defined by Liu (1997)'s research on "Corporate Website Content" and Ghose& Dou(1998)'s research on "Corporate Website's Interactive Functionalities". This grading system gives a score to each of the 150 companies, and then analyzes the relationships between each company¡¦s score and its stock price/capital size/industry category. This research has a result showing that for the website functionalities that are related to a corporate's stock price, from the most significant related to least significant related can be ranked as "Customer Surpporting Functionality", "Website Information Functioanlity", "Advertising/Exhibiting/Broadcasting Functionality" and "Personalization Functionality". Considering industry category, companies in "Finance/Insurance" and "Transpotation industry" have highest scores on website functionalities. Companies in "high-tech industry" are the second. Companies in "conventional industries" score the lowest. Considering capital size, companies with capital size of "more than 5 billion NTD" have the highest score on website functionalities. Companies which have capital sizes of "2 ~ 5 billion" and "less than 2billion" have lower scores.

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Mechanically separated turkey meat (MSTM) is one of the cheapest sources of protein; however its use for production of further-processed poultry products is limited due to undesirable composition. pH-shifting extraction was applied to overcome the problems associated with MSTM. In the first study the effect of acid pH-shifting extraction with the aid of citric acid and calcium ions on lipids and heme pigments removal from MSTM was investigated. The maximum removal of total, neutral and polar lipids was achieved with addition of 4, 6 and 2 mmol/L of citric acid, respectively. Addition of 6 or 8 mmol/L of citric acid was the most efficient for total heme pigments removal. In the second and third studies chemical, functional and rheological properties of proteins isolated from MSTM were investigated as influenced by different (2.5, 3.5, 10.5 and 11.5) extraction pH. Gel-forming ability was found the highest for pH 3.5 extracted protein. / Food Science and Technology

The overarching goal of this research was to investigate the effect of cultivar and environment on the physicochemical and functional properties of pea protein isolates using a structure-function approach. Six pea cultivars (Agassiz, CDC Golden, CDC Dakota, CDC Striker, CDC Tetris, Cooper) were collected from two years (2011, 2012) over two locations in Saskatchewan (Saskatoon and Rosthern) from two field replicates. Pea protein isolates were prepared from defatted flours by alkaline extraction (pH 9.0) followed by isoelectric precipitation (pH 4.5), and then neutralized to pH 7.0 prior to freeze-drying. Samples were evaluated for composition (amino acid profile, legumin/vicilin ratio), surface characteristics (zeta potential, surface hydrophobicity), and functional properties (nitrogen solubility, oil holding capacity, foaming capacity, foam stability, emulsion stability). In addition, samples were assessed for seed weight and colour, and compared against the functional characteristics of six commercially produced protein isolates (whey, wheat, egg, pea, and two soy ingredients). The extracted pea protein isolates had protein contents of ~91% (d.b.), as well as isolate and protein yields of ~18% and ~72%, respectively. Although cultivars exhibited a range of legumin/vicilin ratios from 0.36 (Agassiz) to 0.79 (CDC Golden), such differences were not reflected in their amino acid profiles. Differences amongst cultivars, as well as significant cultivar × environment interactions, were found for only surface hydrophobicity (195-267 a.u.), solubility (63-75%), and foaming capacity (167-244%). No differences in either cultivar or environment were observed in other surface (zeta potential = ~-24 mV) or functional (oil holding capacity = ~3.2 g/g; foam stability = ~75%; emulsion stability = ~96%) properties. All functional properties were significantly correlated with legumin/vicilin ratio and/or surface hydrophobicity. However, such relationships were weak (r = -0.19 to -0.20, and r = 0.17 to 0.32). The strongest correlation was observed between the legumin/vicilin ratio and surface hydrophobicity at r = 0.63 for the pea protein isolates. Meanwhile, zeta potential did not display a significant correlation to any property tested. In comparison to commercial protein isolates, the pea protein isolates behaved most similarly to soy except for solubility. Whey and egg were superior in solubility and the foaming properties, whereas wheat and the commercial pea protein product underperformed in almost all functionality tests. These findings suggest that while inherent protein material source may be important to functional behaviours, the method of extraction could pose even greater effects. This was observed between the laboratory- and commercially-prepared pea protein isolates, which at minimum differed in processing (defatting) and method of drying (freeze- vs. spray-dried). Coupled with the weak correlations between physicochemical and functional properties, findings overall indicate that method of protein isolate production play a more significant role in protein functional characteristics than cultivar, environment, or composition. Findings also suggest that secondary processors may not need to specify either cultivar or environment of their raw materials, thus creating advantages in their feedstock sourcing.

Whilst working on a Masters degree on alternative solvents and extractants for the sorghum prolamin protein, kafirin, the author serendipitously found an ethanol-free method of making kafirin microparticles in dilute organic acid. Further, on drying a suspension of kafirin microparticles in dilute organic acid, a clear, transparent film was found to be formed. Microparticles from zein, the maize prolamin protein, have shown potential for food and pharmaceutical applications. Kafirin is more hydrophobic and less digestible than zein so it was hypothesised that it may form microparticles with superior properties. However, the structural and functional characteristics of kafirin microparticles and films made from them needed to be known before any potential applications could be exploited. Kafirin microparticles were made by dissolution of kafirin in glacial acetic acid followed by precipitation on addition of water. They were characterized by Light microscopy (LM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) and were found to be mainly spherical, porous and between 1-10 ìm in diameter. The kafirin microparticles had very large internal surface area due to the presence of many smooth walled holes or vacuoles of variable sizes, probably caused by entrapment of air during microparticle formation. Increasing the final acetic acid concentration resulted in kafirin microparticles of increased size, with an increasing number of internal holes. At 40% acetic acid the spherical microparticle structures completely disappeared and were replaced by an open matrix which resembled an expanded foam. The kafirin microparticles were found to form very thin (<15 ìm) free standing films and coatings. A minimum concentration of organic acid (10.8 percent) is required to form a cohesive kafirin microparticle film relative to the concentration of protein (1 percent for acetic acid). Some functional properties, e.g. smooth film surface properties, low water vapour permeability (WVP) and low protein digestibility of these films are superior to those of similar conventionally cast kafirin films. With the aim of exploiting the porous nature of kafirin microparticles for encapsulation of nutrient additives, several factors were examined for their influence on retarding protein digestibility. Retardation of digestibility of kafirin microparticles would allow controlled release of the encapsulated agent in the stomach and gastrointestinal tract. The importance of disulphide cross-linking and sorghum condensed tannin protein interactions were confirmed as major causal factors of the poor protein digestibility of sorghum. Gamma-kafirin was found to bind the most condensed tannins compared to the a-and b- kafirins, probably due to its high proline content. As expected, the protein digestibility of kafirin-tannin complexes was much lower than unbound kafirins. This seems to slow the biodegradation of kafirin films made with bound tannins. The antioxidants, catechin and sorghum condensed tannins were encapsulated within kafirin microparticles and the antioxidant release profiles investigated under simulated gastric conditions. Over a period of four hours, catechin and condensed tannin encapsulated kafirin microparticles showed virtually no protein digestion but released approximately 70% and 50% respectively total antioxidant activity. The mechanism for the formation of kafirin microparticles and films formed from them seems to involve controlled aggregation of kafirin molecules. Models for the formation of both were proposed based on an analogy with protein body formation and the potential ability of -kafirin to undergo a structural inversion exposing either hydrophilic or hydrophobic ends depending on the prevailing conditions. Research into cross-linking by physical or chemical agents is needed before practical applications can be exploited. However, encapsulation of catechin and sorghum condensed tannins within kafirin microparticles seems to be an effective way to use the binding properties of polyphenols with protein to enhance potential health benefits by controlled release of antioxidant activity within the stomach and gastrointestinal tract. Copyright / Thesis (PhD)--University of Pretoria, 2009. / Food Science / unrestricted

Bambara groundnut (Vigna subterranean L.) is considered a good source of protein in some parts of sub Saharan African countries. Long cooking time of about three hours contributed to its limited consumption and utilisation. Micronisation is an infrared heating process. It can reduce the cooking time of pre-moisture conditioned legume small seeds size such as cowpea and lentil, but mostly tempering of seeds has been used as the pre-conditioning techniques. The resulting flour from the pre-conditioned micronised cowpea can reduce pasting viscosity and has potentials in food systems as an instant product. This study aimed at (1) determining the effects of micronisation of pre-soaked whole and dehulled bambara groundnut seeds on their cooking characteristics, (2) determining the effects of micronisation and dehulling treatment of pre-soaked bambara groundnut on physicochemical, microstructure and functional properties of the resulting flours and (3) determining the effects of micronisation of pre-soaked whole and dehulled bambara groundnut seeds on the viscosity, nutritional and health benefits of the cooked samples in order to produce a quick cooked bambara groundnut with functional, nutritional and health benefits. Micronisation (130 ºC) at a different time (0, 5, 10 and 15 min) was used to optimise the process for pre-soaked (53% moisture) bambara groundnuts. Micronisation (130 ºC) reduced cooking time of pre-soaked (53% moisture) bambara groundnut (whole and dehulled) following cooking. Micronisation reduced the 162 min cooking of raw bambara groundnut to 109, 83, 75 and 62 min when micronized for 0, 5, 10 and 15 min. Micronisation (53% moisture, 130 ºC) caused molecular changes such as solubilisation of pectin which was responsible for the disruption of the middle lamella and separation of parenchyma cell observed by light microscopy and scanning electron microscopy (SEM). It also caused disruption in the structure of starch granule, protein matrix in the cotyledon. These changes in seeds structure and molecular properties of starch, protein and pectin, facilitate water hydration rate and cell separation during cooking, leading to the shorter cooking time of the bambara groundnuts. Micronisation of pre-soaked (53% moisture) bambara groundnuts caused molecular changes such as partial starch gelatinisation and reduced protein solubility in the resulting flours. The changes in the starch and proteins modified the resulting flours functional properties such asincrease swelling of the resulting flours, while reducing the water solubility. The pasting viscosities of resulting flours of pre-soaked bambara groundnut reduced following micronisation due to the denatured protein matrix preventing embedded starch hydration, dispersibility and molecular entanglement during pasting.This was evident by light and confocal laser scanning microscopy (CLSM) that showed the aggregates of denatured protein matrix surrounding embedded pre-gelatinised starch granules increase with micronisation in the resulting flours and cooked soft porridge of bambara groundnut. Micronisation has an effect on the apparent viscosity, nutritional, bioactive compound such as phenolics and hence the antioxidant properties of cooked soft porridge of bambara groundnut. All cooked soft porridge of bambara groundnut exhibited a shear thinning behavior and micronised bambara groundnut had lower viscosity increased in the starch and protein digestibility of cooked soft porridge of bambara groundnut. It also increased the phenolic content and antioxidant properties of cooked soft porridge of whole bambara groundnut, but these were reduced in cooked soft porridge of dehulled bambara groundnut due to seed coat absence. Thus, micronisation of pre-soaked bambara groundnut (whole and dehulled) would contribute towards increased utilisation of bambara groundnut as well as improving house hold nutrition and health promoting properties.Micronisation of bambara groundnut has potential to produce a quick paste with low viscosity which depend on the pre-soaking and micronisation time of the bambara groundnut. Flours from micronised bambara groundnut can therefore be used as instant flour ingredient in food products. / Thesis (PhD)--University of Pretoria, 2016. / National Research Foundation (NRF) of South Africa / Food Science / PhD (Food Science) / Unrestricted

Yes / For the development of applications and novel uses for peptide nanostructures, robust routes for their surface functionalization, that ideally do not interfere with their self‐assembly properties, are required. Many existing methods rely on covalent functionalization, where building blocks are appended with functional groups, either pre‐ or post‐assembly. A facile supramolecular approach is demonstrated for the formation of functionalized nanofibers by combining the advantages of biocatalytic self‐assembly and surfactant/gelator co‐assembly. This is achieved by enzymatically triggered reconfiguration of free flowing micellar aggregates of pre‐gelators and functional surfactants to form nanofibers that incorporate and display the surfactants’ functionality at the surface. Furthermore, by varying enzyme concentration, the gel stiffness and supramolecular organization of building blocks can be varied. / FP7 Marie Curie Actions of the European Commission. Grant Number: 289723; EPSRC; HFSP; ERC; Leverhulme Trust

USDA Select bovine Biceps femoris (BF) samples were divided into four sections and randomly assigned to three hydrodynamic shock wave (HSW) treatments and a control. Different amounts of explosive (105 g, H1; 200 g, H2; 305 g, H3) were suspended in the center of the hemishell tank, 26.7 cm above the vacuum packaged beef placed on the bottom center of that water-filled tank and detonated, representing three HSW treatments. In addition, BF steaks (2.54-cm thick) from a different and limited common source (2 muscles) were packaged with each HSW designated BF section. These served as internal refernce steaks (IRS) for the six replications to determine if the HSW treatments physically altered the structural integrity of the meat. H1 and H3 decreased (P<0.05) Warner-Bratzler shear values of the IRS from 3.86 and 3.99 kg (controls) to 3.01 and 3.02 kg (HSW), respectively. H2 shear values, 3.86 (control) to 3.46 kg (HSW) were not different (P> 0.05). HSW and control BF sections were analyzed for protein solubility and then used to manufacture frankfurters formulated with 2.0% NaCl, 0.5 % sodium tripolyphosphate, 156 ppm sodium nitrite, 0.42 % sodium erythorbate, 2.0 % sucrose, and 25 % water. Frankfurters (cooked to 71 C) were evaluated for cooking yield, CIE L*a*b*, nitrosylhemochrome, Texture Profile Analysis (hardness, cohesiveness), and stress and strain (torsion testing). Compared to the control samples, the HSW did not affect (P>0.05) myofibrillar or sarcoplasmic protein solubility, cooking yield, or color. Textural properties and gel strength of the frankfurters were not affected (P>0.05) by the HSW. These results indicate that beef trim obtained from HSW processed meat can be used interchangeably with normal meat trim in the production of further processed meats since the functionality of meat protein is not affected significantly by the HSW process. / Master of Science