Master of Science / Department of Grain Science / Rebecca Miller / Hard winter wheat flour is predominantly used for bread production. Optimal dough handling properties are critical in commercial bread production. Variation in flour water absorption tolerance dramatically affects dough handling. Understanding the factors which affect water absorption tolerance and the influences of genotype, environment, and their interaction on those factors will improve breeding efforts and production practices to improve the quality of bread wheat. A previous study found the γ-gliadin protein fraction correlated highly with water absorption tolerance. The objectives of this study were to confirm the effect of γ-gliadin and investigate the effects of genetics and environment on water absorption tolerance. Nineteen hard winter wheat cultivars consisting of released varieties and experimental breeding lines from the Pacific Northwest grown in 2011 in 2 locations in Oregon (Pendleton and Arlington) were obtained. Quality evaluations including flour yield, test weight, kernel weight, kernel diameter, and kernel hardness were conducted on the wheat kernels and water absorption tolerance, protein content, moisture content, ash content, Solvent Retention Capacity (SRC), starch damage, and protein composition analyses were preformed on the resulting flours. The mixograph water absorption tolerance behavior of each sample was ranked as high, medium or low. Farnum and OR2080156H grown at Arlington had the highest water absorption tolerance range (1.6mL) while Farnum, Eddy, Paladin and OR2080227H grown at Pendleton exhibited the lowest interval (0.4mL). No wheat or flour parameters measured showed high correlation with water absorption tolerance. Moderate correlation was observed between water absorption tolerance and kernel weight (r = 0.39), kernel diameter (r = 0.37), starch damage (r = 0.33), and the extractable and unextractable polymeric protein fractions (r = 0.32).

This research is for the implementation of non-intrusive measurement techniques in the study of high temperature pipe flow. A low pressure, laboratory scale hybrid rocket motor simulator was built to achieve high temperatures with various gases. A quartz test section was designed, built, and implemented into the existing test setup to accommodate the laser beam of the existing Tunable Diode Laser Absorption Spectrometer (TDLAS) system which was designed to observe water vapor. A super-heated water vapor injector was designed to obtain the desired water vapor concentrations. Flow characteristics were simultaneously recorded using the existing TDLAS system and the DAQ system for temperatures for later comparison. A numerical study using a commercial CFD package was used to predict the flow characteristics at certain locations for experimental comparison. Based on this study, it is concluded that the TDLAS can be used to make real time temperature measurements of heated internal gas flows.

In the first part of the work three polycarbazoles poly[N-((4-dimesitylboryl)-3,5-dimethylphenyl)-carbazole]-2,7-diyl P1, poly[N-((4-dimesitylboryl)-3,5-dimethylphenyl)-carbazole]-3,6-diyl P2 and poly[N-(4-(diphenylmethylene)-phenyl)- carbazole]-2,7-diyl P3 were synthesized by Yamamoto coupling reaction and their spectroscopic and electrochemical properties were investigated. Absorption and fluorescence characteristics of P1 and P3 were found to be similar to other 2,7-linked polycarbazoles, whereas P2 shows a CT absorption band arising from a shift of electron density from the nitrogen of the carbazole donor to the triarylborane acceptor. This causes a negative solvatochromic absorption and a positive solvatochromic fluorescence behaviour and is responsible for the significantly enlarged fluorescence quantum efficiency in solution and solid state compared to other 3,6-linked polycarbazoles. Thus the spectroscopic properties are governed by the connection pattern: the 2,7-linked polycarbazoles are not affected by the acceptor substituent due to the rigid poly-para-phenylene-like backbone structure, whereas the 3,6-linked polycarbazole P2 is dominated by the properties of the monomer unit due to its more flexible (less conjugated) structure. The oxidative processes of P1-P3 have been investigated in detail by cyclic voltammetry, which are similar to known 2,7- and 3,6-polycarbazoles. The reversible reduction found for P1 and P2, respectively, is attributed to the reduction of the triarylborane moiety. No reduction process referring to the carbazole moiety was observed. Due to its better solubility compared to P1 and P3 only P2 was used as active layer in an OLED device (ITO/P2/Al). The electroluminescence spectrum revealed CIE coordinates of (0.17, 0.21). In the second part of the work the low band gap polyradical poly{[((2,3,4,5,6-pentachlorophenyl)-bis(2,3,5,6-tetrachlorophenyl)methyl radical)-4,4’-diyl]-alt-4,4’-bis(vinylphenyl)-4-(2-ethylhexyloxy)phenylamin} P4 was synthesized by Horner-Emmons reaction. It shows an IV-CT band in the NIR, which arises from an ET from the triarylamine donor to the PCTM radical acceptor. This transition is confined to one monomer unit as deduced from comparison with the monomer spectra. HOMO and LUMO of P4 determined by cyclic voltammetry are at -5.5 and -4.5 eV, respectively. The smaller electrochemical band gap (1.0 eV) compared to the optical band gap (1.2 eV) is probably caused by ion pairing effects in the electrochemical experiments and indicates a low exciton binding energy. Femtosecond-pump-probe transient absorption spectroscopy revealed the spectral features of the oxidized triarylamine donor and the reduced PCTM acceptor similar to the spectra obtained separately for positive and negative potentials by spectroelectrochemistry. Thus the ET event causing the IV-CT absorption band could unambiguously be identified. The decay of the IV-CT state was found to be biexponential. The fast solvent dependent decay component is ascribed to the direct decay from the IV-CT state to the ground state, whereas the slow solvent independent decay component is tentatively attributed to an equilibrium formation of the IV-CT state and a completely charge separated state formed by charge migration along the polymer backbone. Well balanced ambipolar charge transport with hole and electron mobilities of ca. 3 × 10-5 cm2 V-1 s-1 was found in OFET devices (BG/TC structure) comprising an additional insulating organic PPcB layer. Polymer/polymer BHJ solar cell devices with the structure glass/ITO/PEDOT:PSS/(P3HT/P4)/Ca/Al yielded a power conversion efficiency of 3.1 × 10-3 %, VOC = 0.38 V, JSC = 2.8 × 10-2 mA cm-2 and FF = 0.29 for the 1:4 (P3HT/P4) blend ratio. The improper solid state morphology of P4 that causes the unsatisfying performance of OFET and solar cell devices renders P4 less suitable for these applications, whereas the hypothesis of charge migration in the excited state is worth to be investigated in more detail. / Im ersten Teil dieser Arbeit wurden die drei Polycarbazole Poly[N-((4-dimesitylboryl)-3,5-dimethylphenyl)-carbazol]-2,7-diyl P1, Poly[N-((4-dimesitylboryl)-3,5-dimethylphenyl)-carbazol]-3,6-diyl P2 und Poly[N-(4-(diphenylmethylen)-phenyl)-carbazol]-2,7-diyl P3 mittels Yamamoto Kupplung synthetisiert und ihre spektroskopischen und elektrochemischen Eigenschaften untersucht. Absorptions- und Fluoreszenzeigenschaften von P1 und P3 sind denen anderer 2,7-verknüpfter Polycarbazole ähnlich, wohingegen P2 eine CT Absorptionsbande zeigt, die durch die Verschiebung von Elektronendichte vom Stickstoff des Carbazoldonors zum Triarylboranakzeptor verursacht wird. Daraus ergeben sich negativ solvatochromes Absorptions- und positiv solvatochromes Fluoreszenzverhalten und eine deutlich erhöhte Fluoreszenzquantenausbeute in Lösung und im Festkörper verglichen mit anderen 3,6-verknüpften Polycarbazolen. Das bedeutet, dass die spektroskopischen Eigenschaften durch die Art der C-C-Verknüpfung gesteuert werden können: das 2,7-verknüpfte Polycarbazol P1 wird durch den Akzeptorsubstituenten aufgrund des starren Polymergerüsts, dem eine poly-para-phenylenartige und damit stärker delokalisierte Struktur zugrunde liegt, nicht beeinflusst. Im Gegensatz dazu treten beim 3,6-verknüpften Polycarbazol P2 die Eigenschaften der Monomereinheit aufgrund der flexibleren 1,4-diaminobiphenyl Struktur in den Vordergrund. Die Oxidationsprozesse von P1-P3 wurden im Detail mittels Cyclovoltammetrie untersucht. Die Ergebnisse stimmen mit Literaturwerten überein. Außerdem wurde bei den Messungen von P1 und P2 ein reversibler Reduktionsprozess, der am Boranzentrum stattfindet, beobachtet. Eine Reduktion der Carbazoleinheit konnte hingegen nicht gefunden werden. Mit der Herstellung von OLEDs der Struktur ITO/P2/Al konnte blaue Elektrolumineszenz mit den CIE Farbkoordinaten (0.17, 0.21) nachgewiesen werden. Im zweiten Teil der Arbeit wurde das low band gap Polyradikal Poly{[((2,3,4,5,6-pentachlorphenyl)-bis(2,3,5,6-tetrachlorphenyl)methyl radical)-4,4‘-diyl]-alt-4,4‘-bis(vinylphenyl)-4-(2-ethylhexyloxy)phenylamin} P4 mittels Horner-Emmons Reaktion synthetisiert. Im NIR beobachtet man eine IV-CT Absorptionsbande, die durch einen Elektronentransfer vom Triarylamindonor zum PCTM-Radikalakzeptor hervorgerufen wird. Dieser elektronische Übergang ist auf eine Monomereinheit begrenzt wie der Vergleich mit den Monomerabsorptionsspektren zeigt. HOMO und LUMO Energien von P4, die anhand der Cyclovoltammogramme bestimmt wurden, liegen bei -5.5 und -4.5 eV. Die im Vergleich zur optischen Energielücke (1.2 eV) kleinere elektrochemische Energielücke (1.9 eV) ist wahrscheinlich auf Ionenpaareffekte bei den elektrochemischen Messungen zurückzuführen, deutet aber auch auf eine geringe Excitonenbindungsenergie hin. Transiente Absorptionsspektren zeigen die spektralen Charakteristika von oxidiertem Triarylamindonor und reduziertem PCTM-Akzeptor vergleichbar mit den Spektren der spektroelektrochemischen Messungen, bei denen eine Lösung von P4 jeweils nacheinander reduziert und oxidiert wurde. Dadurch konnte der Elektronentransferprozess, der zur Ausbildung der IV-CT Bande führt, zweifelsfrei nachgewiesen werden. Der IV-CT Zustand zerfällt biexponentiell. Der schnelle, lösungsmittelabhängige Zerfall beschreibt den direkten Übergang vom IV-CT Zustand in den elektronischen Grundzustand. Dagegen wird der langsame, lösungsmittelunabhängige Zerfall einer Gleichgewichtseinstellung zwischen IV-CT Zustand und vollständig ladungsgetrenntem Zustand, der durch Ladungswanderung entlang der Polymerkette erreicht wird, zugeschrieben. In OFETs mit P4 als Halbleiter und einer zusätzlich isolierenden, organischen PPcB Schicht wurde ein ausgeglichener, ambipolarer Ladungstransport mit Loch- und Elektronenbeweglichkeiten von ca. 3 × 10-5 cm2 V-1 s-1 gefunden. Polymer/Polymer BHJ Solarzellenmodule mit der Struktur Glas/ITO/PEDOT:PSS/(P3HT/P4 1:4)/Ca/Al hatten einen Wirkungsgrad von 0.0031 % bei einer Leerlaufspannung VOC = 0.38 V, einem Kurzschlussstrom JSC = 0.028 mA cm-2 und einem Füllfaktor FF = 0.29. Die ungeeignete Morphologie der P4- und P3HT/P4-Schichten als Ursache für die unbefriedigende Performance von OFETs und Solarzellen lässt solche Anwendungen für P4 wenig sinnvoll erscheinen. Dagegen verdient die Hypothese der Ladungswanderung im angeregten Zustand eine vertiefte Untersuchung.

Abstract will not load on to DSpace

A Thesis presented for the degree of Doctor of Philosophy in the University of the Witwatersrand. Johannesburg, January, 1967. / Although reports of the medicinal use of iron date back to ancient times it was not until the present century that the many functions of iron in the body were studied. Once started, the investigation received impetus from the seriousness of iron deficiency anaemia, a major cause of ill health throughout the world. The introduction of radio-isotope tracer techniques in 1939 greatly facilitated investigation of absorption, excretion and the metabolic pathways of iron. The tremendous amount of work already carried out has led to a fairly comprehensive knowledge of the various aspects of iron metabolism. Nevertheless, there remain wide gaps in the overall picture. In / IT2018

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, October 2016. / The adsorption of molecules on a metal surface is core in heterogeneous catalysis. Surface sensitive techniques such as low energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS) and temperature programmed desorption (TPD) are key tools to study adsorption geometries and structures of molecules and atoms on a metal surface. As our first model system we investigated the dissociation of NO on Ir{100}. The LEED experimental results showed a p(2 X 2) diffraction pattern at 300 K using. In this study two options were explored: phase mixing where dissociated nitrogen and oxygen are on the same unit cell, as well as phase separation where both nitrogen and oxygen form their own separate unit cell which results in a p(2 x 2) unit cell. Calculations were done on atop, bridge and hollow sites, with only perpendicular parameters and vibrational amplitude being varied initially. Results for phase mixing calculations gave the lowest R-factor of 0.70 ± 0.11 for atop site. We further considered phase separation for hollow and bridge sites for nitrogen and oxygen respectively because these two sites were found to be the most stable sites using DFT from previous studies. The lowest R-factors were 0.37 ± 0.06 for nitrogen c(2x2) and 0.24 ± 0.13 for oxygen p(2 X 1) For oxygen significant row pairing of iridium atoms stabilized the structure as mentioned in previous studies. Therefore from our results it is evident that phase separation models the experimental data better than phase mixing. Nitrogen and oxygen form c(2 X 2) and p(2 X 1) overlayer structures respectively which in combination result in a p(2 X 2) pattern that is in agreement with experimental results. The second system involves enantio-selectivity and chiral resolution at the organic-inorganic interfaces. The d-serine molecule was adsorbed on the Cu{110} surface. Density functional theory (DFT) calculations were used as a benchmark for our CLEED calculations. LEED experiments showed a (- 1 + 2: 40) overlayer pattern for d-serine adsorbed on Cu{110} surface. Three structures from DFT calculations with the lowest energy were used for CLEED calculations. These structures differed by the way they bond to the surface and molecular interactions. Calculations were carried out on these three structures and the structure with intra-dimer bonding was the best structure. The searches for this structure were further optimized by introducing pairing of the atoms in the row reconstruction on the copper surface and angle search. The lowest value obtained was 0.37 ± 0.09, which suggests that further understanding of this system is needed. The ultra-high vacuum (UHV) chamber was fully commissioned and is now ready for TPD and XPS studies. / LG2017

The influence of voids on the moisture uptake of epoxy has been studied. Specimens with void contents from 0 to about 50% were prepared. Void geometry and content were analyzed using microscopy and density methods. Void containing dry samples were characterized by Differential Scanning Calorimetry and Dynamic-Mechanical Analysis which verified consistency of chemistry of the epoxy network. The moisture uptake of specimens immersed in distilled water at 40 °C was monitored. The rate of absorption and saturation moisture content increased with increasing void content. The moisture uptake of void-free and void containing specimens was non-Fickian. The Langmuir model provided good fits to the experimental results for specimens with low to medium void content, although the moisture uptake of the high void content specimens showed substantial deviations from the Langmuir diffusion model. The moisture diffusivity agreed reasonably with predications from the Maxwell inclusion model over a range of void contents from 0 to 50%. The state of sorbed water was examined using mass balance calculations and DSC analysis. Only 6-8% of the void volume is occupied by water at saturation. Absorbed water may be classified as free and bound water. For void-free specimens, only bound water was found. The medium and high void content specimens contained water in three states: free water, freezable bound water, and non-freezable bound water. The DSC results show that the proportions of free water and freezable bound water increase with increasing void content, while the content of non-freezable bound water decreased. Moisture induced swelling decreased with increasing void content. The swelling is attributed to the content of non-freezable bound water. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Thesis (MTech (Chemistry))--Cape Peninsula University of Technology, 2016. / Boron concentration analysis is an important and critical analysis performed by the Analytical Chemistry Laboratory at Koeberg Nuclear Power Station (KNPS), because boron controls reactivity and the concentration determination is a Technical Specification Parameter (safety parameter). Hence accurate, precise results for boron concentration produced by laboratories and on-line analysers are important because of their operational implications associated with reactivity control and also for nuclear safety. The project focused on comparing the quality of chemical analysis results of boron produced by analysis techniques/ methods used at Koeberg Nuclear Power Station namely; Potentiometric Titration, Atomic Absorption Spectrophotometry (Flame) and UV-VIS Azomethine-H method. The methods were described, optimised, evaluated and compared in terms of uncertainty of measurement, accuracy, precision, analysis range, limitations, appropriateness and applicability for boron analysis in 2500 mg B/kg concentration range. For Potentiometric Titration method, the measurement uncertainty = 2500 ±16 mg B/kg, accuracy= 0.2%, precision= 0.08% the range of analysis= 5-800 mg B/kg. For Atomic Absorption Spectrophotometry (Flame) the measurement uncertainty= 2500 ±51 mg B/kg, accuracy= 0.12%, precision= 0.44% the range of analysis= 0 -500 mg B/kg. For UV-VIS Azomethine-H the measurement uncertainty= 2500 ±72 mg B/kg, accuracy= 0.08%, precision= 0.44% the range of analysis= 0 -10 mg B/kg. The INPOs 95% accuracy and precision criteria for boron is ± 1%. So these techniques could be used for boron analysis in PWR. Based on the evaluation and assessments mentioned above; the Potentiometric Titration was found to be the most preferred method for boron analysis for Pressurised Water Reactors followed by Atomic Absorption Spectrophotometry (Flame) that can be of good use in determining boron especially in waste samples and samples with complex matrices. The UV-VIS Azomethine-H methods can only be used when it is really necessary to determine very low levels of boron between 0- 10mg B/kg of which it was never required before. Since it is specifically the B-10 isotope that is responsible for the ability to control reactivity, the implementation of isotopic boron analysis (by Inductively Coupled Plasma – Mass Spectrometry) at KNPS is explained and the advantage of the programme is illustrated. Although the current state of instrumental capabilities is adequate for 10B isotope determination, further work of optimising the methodology for even better results is recommended.

Chitin is known as an effective biosorbent, which is used to preconcentrate PCP for further treatment. In order to reuse and recover the biosorbent, magnetic separation is a cost-effective alternative to separate the PCP-adsorbed biosorbent (i.e. chitin) from the treated water. Therefore, chitin is immobilized by magnetite prior PCP adsorption. From the immobilization results, the solution pH, temperature, agitation rate do not show great effect on the immobilization of chitin and magnetite. Second, magnetite-immobilized chitin can be formed as quickly as 5 min. Moreover, the interaction of chitin and magnetite is very strong since it is not easy to separate by vigorous shaking, high temperature and changing pH. Although the underlying mechanism of magnetite and chitin is still obscure, the biosorbent is proved to have high stability and reusability. In addition, both Langmuir and Freundlich models indicate that immobilization of chitin by magnetite is favorable with the Langmuir model being the major one. / For PCP adsorption study, it is found that magnetite-immobilized chitin can retain the PCP adsorption ability as free chitin. In accordance with the results, the PCP adsorption of magnetite-immobilized chitin is influenced by altering the parameters of biosorbent concentration, solution pH, temperature, agitation rate, contact time and initial PCP concentration. In general, higher amount of biosorbent gives higher removal efficiency (RE) but lower removal capacity (RC) as more binding sites are available for PCP. The PCP removal is enhanced by lowering pH since uncharged PCP is favorable for adsorption. It is speculated that hydrophobic interaction, hydrogen bonding and electrostatic interaction are involved. In addition, the biosorption efficiency is impeded by high temperature. Evidence shows that the adsorption might be due to the exothermic force such as hydrogen bonding. The biosorption is described as biphasic mechanism with the fast initial phase followed by slow equilibrium phase. For the PCP (10 mg/L) adsorption, the optimized conditions are: 1,500 mg/L of magnetite-immobilized chitin, initial pH 6, 25°C, 200 rpm and 60 min. The RE is 57.9% and RC is 5.4 mg/g. However, the increase in the amount of immobilized chitin (24,000 mg/L) can increase the RE up to 98%. By considering the Langmuir and Freundlich isotherms, the adsorption might be heterogenous, as the correlation coefficient from Freundlich model is higher. / Pentachlorophenol (PCP), a highly chlorinated aromatic organic compound, was widely used as a biocide and is now restrictly used as a wood preservative. PCP is toxic and ubiquitous environmental pollutant. In the present study, integrated treatment of biosorption and photocatalytic oxidation (PCO) using magnetite-immobilized chitin is employed to completely degrade PCP. / To thoroughly remove PCP, PCO is also employed after the biosorption. One hundred % of PCP removal is achieved after 5 h irradiation time, in 100 mL solution at initial pH 9 with 20 mM of H2O2 and 200 mg/L of TiO2. The intermediates of PCP are identified as 2,3,5,6-tetrachlorohydroquinone (TeHQ) and 2,3,5,6-tetrachlorophenol (TeCP) by GC/MS analysis. In addition, the toxicity of sample is monitored by the solid-phase and aqueous-phase Microtox RTM tests, which the toxicity increases and then decreases along the irradiation time. The biosorbent shows no great changes on chitin content and functional groups after PCO. In addition, the results imply that magnetite-immobilized chitin has a good potential to be reused at least for four cycles with high RE and DE. Therefore, the combination of biosorption and PCO treatment was feasible for PCP removal and the system is economic and convenient for repeated use. / by Pang, King Man. / "Oct 2007." / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4636. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 186-212). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

by Siu-tai Tsim. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (leaves 382-403). / Statement --- p.4 / Acknowledgements --- p.5 / Abstract --- p.6 / Abbreviation --- p.8 / Chapter Chapter 1. --- General introduction --- p.10 / Chapter PART I. --- Biodegradation of Indigo carmine / Chapter Chapter 2. --- Introduction to indigo/indigo carmine --- p.29 / Chapter Chapter 3. --- Purification and characterization of crude indigo carmine degrading enzyme --- p.59 / Chapter Chapter 4. --- Characterization of indigo carmine degradation products --- p.181 / Chapter Chapter 5. --- Toxicity of indigo carmine and its degradation products --- p.219 / Chapter Chapter 6. --- A new method to determine the concentration of indigo dye --- p.301 / Chapter PART II. --- Biosorption of Sulfur black dye / Chapter Chapter 7. --- "An efficient method for removal of sulfur black dye, a contaminant in sodium thiosulfate, a side product of sulfur black production" --- p.319 / References --- p.382