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Thesis (MScAgric)--Stellenbosch University, 2014. / ABSTRACT ENGLISH: Canola is increasingly becoming an important economic field crop in South Africa, because it can be used to produce high quality cooking oil and margarine, animal feed, biofuel and in crop rotation systems to break the disease cycle and improve weed management. Effect of temperature on phenological responses with respect to required number of days, growing degree days, photothermal units to specific growth stages, growth rate, as well as vegetative and reproductive growth of canola were studied under controlled conditions. Seven canola cultivars selected from early and mid-maturing groups of canola cultivars, presently planted in the Western Cape canola production area, were grown in 3 litre plastic bags filled with a mixture of sand and compost at ratio of 1:1 and irrigated with fully balanced nutrient solution at EC=2.0 in two glasshouses at night/day temperature regimes of 10/15oC and 15/20oC. Number of days, growing degree days (GDD) and photothermal units (PTU) from planting to seedling emergence, first true leaf appearance, visible flower buds, first flower opening, seed ripening and seed physiological maturity were recorded. Plant heights were measured at 14 day intervals from 28 to 84 days after planting (DAP). Plants were sampled for leaf area (LA) and above ground dry mass (DM) at budding, flowering and seed physiological maturity. Plant growth rates (PGR) from planting to budding, from budding to flowering and from flowering to physiological maturity were calculated. Relative growth rates (RGR) and net assimilation rates (NAR) from budding to flowering and from flowering to physiological maturity were also calculated. Days after planting, GDD and PTU at budding, flowering and physiological maturity were correlated with leaf area, dry mass, number of pods plant-1 and pod dry mass plant-1 at budding, flowering and physiological maturity to determine whether there were relationships between the variables. The study showed that by increasing night/day temperature from 10/15⁰C to 15/20⁰C plant height, number of leaves plant-1 at budding stage, leaf area at budding , plant growth rate (PGR) from planting to budding stage and relative growth rate (RGR) from budding to flowering stage were increased. However, PGR from budding to physiological maturity, RGR from flowering to physiological maturity, net assimilation rate (NAR) from budding to flowering stage, leaf area at flowering and physiological maturity stages , as well as number of flower stems, number of pods plant-1, above ground total dry mass at flowering and physiological maturity stages were decreased. Pod dry mass at physiological maturity decreased by 22.24% to 40.35% for different cultivars which clearly demonstrated the sensitivity of canola cultivars to increasing night/day temperatures. By increasing the mean daily mean temperature from 12.5⁰C (10/15⁰C night/day) to 17.5⁰C (15/20 ⁰C night/day) the duration of the period from planting to seedling emergence as well as the vegetative and reproductive growth stages were decreased. With the exception of the vegetative growth stage, GDD and PTU requirements to reach specific growth stages increased with an increase in temperature. Plant growth parameters such as dry mass, leaf area, number of pods plant-1 and pod dry mass plant-1 at specific growth stages showed a positive correlation with the number of days needed to reach that growth stage, but not with GDD or PTU requirements. Although the responses of cultivars to increasing temperatures did differ for most parameters measured, responses did not always correlate with the maturity grouping of cultivars, suggesting that responses to temperature may to a large extent be determined by the genetic make-up (breeding company) of cultivars. These results indicate that number of days, GDD and PTU requirements to reach physiological maturity may be used to describe the cultivar maturity groupings, but because of the effect of temperature and day length, GDD and PTU should be more accurate. / AFRIKAANSE OPSOMMING: Canola se waarde as ekonomies belangrike akkerbou-gewas in Suid-Afrika het die afgelope aantal jare skerp toegeneem, omdat dit gebruik kan word om hoë kwaliteit kook-olie en margariene asook bio-brandstowwe en dierevoere, te vervaardig. In wisselboustelsels kan dit gebruik word om die siekte-ketting te breek en onkruidbeheer te vergemaklik. In hierdie studie is die invloed van temperatuur op die fenologiese reaksies van canola in terme van die aantal dae, gewasgroeidae en fototermiese eenhede, benodig om spesifieke groeistadiums te bereik, asook die invloed op groeitempo, vegetatiewe- en reproduktiewe groei onder gekontroleerde toestande nagevors. Sewe canola cultivars vanuit die kort en mid-groeiseisoen volwassenheidsgroepe wat tans in die Weskaap verbou word is geplant in 3-liter plastiek houers gevul met „n 1:1 sand: kompos mengsel as groeimedium en besproei met „n volledig gebalanseerde voedingsoplossing met EC=2.0. Twee glashuise met nag/dag temperature van onderskeidelik 10/15oC en 15/20oC is vir hierdie doel gebruik. Die aantal dae, gewasgroeidae (GGD) en fototermiese eenhede (FTE) wat vanaf plant tot saailingverskyning; eerste volwasse blaarverskyning; eerste blomknop verskyning; eerste blom; saad verkleuring en fisiologies volwasse stadiums vereis word, is bepaal. Plant lengte is gemeet met 14-daagse tussenposes vanaf 28 tot 84 dae na plant. Plante is gemonster is tydens die eerste blomknopverskyning asook blom- en fisiologies volwasse stadiums om blaaroppervlakte (BO) en droëmassa (DM) te bepaal. Plant groeitempos (PGT) vanaf plant tot blomknopverskyning; blomknopverskyning tot blom en vanaf blom tot fisiologiese volwasse stadium is bereken. Relatiewe groeitempos (RGT) en netto-assimilasietempos (NAT), is bereken vanaf blomknopverskyning tot blom en vanaf blom tot fisiologiese volwasse stadium. Die aantal dae vanaf plant, asook GGD en FTE benodig om blomknopstadium, blomverskyning en fisiologies volwasse stadiums te bereik, is gekorreleer met BO en DM plant-1 asook die aantal peule en peulmassa plant-1 tydens genoemde groeistadia om moontlike verwantskappe te bepaal. Die studie het getoon dat deur die nag/dag temperatuur te verhoog vanaf 10/15⁰C tot 15/20⁰C, plant lengte, aantal blare en BO plant-1 tydens blomknopverskyning, asook PGT vanaf plant tot blomknopverskyning en RGT van blomknopverskyning tot blomstadium, toeneem. Daarteenoor het PGT van blomknopverskyning tot fisiologies volwassenheid, RGT van blom tot fisiologies volwassenheid, asook NAT van blomknopverskyning tot blomstadium en BO tydens blom en fisiologies volwasse stadium, afgeneem. Reproduktiewe ontwikkeling soos gemeet aan die aantal bloeistele, peule plant-1 en peulmassa plant-1 is ook benadeel deur genoemde verhoging in temperatuur. Die afname in peulmassa het gewissel tussen 22.24% en 40.35% vir verskilende cultivars en is „n duidelike aanduiding van die verskillende canola cultivars se gevoeligheid teenoor toenemende nag/dag temperature. Die toename in gemiddelde nag/dag temperatuur vanaf 12.5⁰C (10/15⁰C) tot 17.5⁰C (15/20 ⁰C) het die aantal dae vanaf plant tot saailing verskyning asook die vegetatiewe en reproduktiewe groei fases verkort. Met die uitsondering van die vegetatiewe groei fase, het die GGD and FTE vereistes om spesifieke groeistadiums te bereik toegeneem met „n toename in temperatuur. Plant komponente soos DM, BO, aantal peule plant-1 en peulmassa plant-1 tydens spesifieke groeistadia het „n positiewe verwantskap getoon met die aantal dae wat benodig is om spesifieke groeistadiums te bereik, maar sodanige verwantskap is nie bevestig met GGD en FTE vereistes. Hoewel die reaksie van verskillende cultivars teenoor „n toename in temperatuur vir die meeste gemete plantkomponente verskil het, het die reaksie nie altyd verband gehou met die volwassenheidsgroepering van die cultivars. Dit wil dus voorkom asof die reaksie teenoor temperatuur tot „n groot mate ook verband hou met die genetiese samestelling van die cultivar soos bepaal deur die telingsmaatskappy. Hierdie resultate toon dat die aantal dae, GGD en FTE wat vereis word om fisiologiese volwassenheid te bereik gebruik kan word om die cultivar se volwassenheidsgroepering te beskryf maar dat GDD en FTE waarskynlik meer akuraat sal wees weens effek van temperatuur en daglengte op die ontwikkkeling van cultivars.

Thermoregulatory, analgesic and respiratory depressive responses as well as tolerance to morphine were investigated in young (3 to 5 months), mature (10 to 12 month) and senescent (26 to 28 month) male Fischer 344 rats. The thermoregulatory system of senescent rats was not able to maintain body temperature in hot and cold environments as well as the thermoregulatory system of young rats. Additionally, senescent rats had basal rectal temperatures which were approximately one degree lower than basal temperatures in young rats. Subcutaneous morphine caused biphasic effects on body temperature ie. hyperthermia at low doses and hypothermia at high doses. Senescent rats were less responsive to the hypothermic effects of subcutaneous morphine than young rats, but this was not due to decreased subcutaneous blood flow or inability to lose heat. Morphine injections intracerebroventricularly showed no age-related differences. A two site model for the actions of morphine on thermoregulation was proposed and it was suggested that the age-related differences are due to changes in a non periventricular site. Previously reported increased lethality of intravenous morphine in aged rodents was shown to be due to decreased respiratory reserve rather than increased sensitivity to respiratory depression. Senescent rats were also found to acquire tolerance to the thermic effects of morphine less readily than young rats regardless of the route of administration. Normal aging has been characterized as a decrease in adaptability, and it was suggested that senescent rats were less able to compensate for the thermic effects of morphine as well as young rats. In order to determine the mechanisms of decreased adaptability, neurotransmitters proposed to be involved in thermoregulation were injected intracerebroventricularly in morphine tolerant rats. The results suggested a shift from catecholaminergic to cholinergic transmitters with aging.

ABSTRACT AS4/PEEK (APC-2) is a thermoplastic composite materials consisting of polyether-ether-ketone (PEEK) reinforced with AS4 carbon fibers. APC-2 has been widely used in many weight critical applications because of high specific strength and stiffness, good corrosion resistance, good formability and high temperature durability. However, the susceptibility of composite materials to damage result from low-velocity impacts (for example, from dropped tools, runway stones or hailstones) is a major problem. Low-velocity impact induces internal damage in the composite laminate without any visible sign on the surface, but it is result in a loss of laminate strength. This paper is aimed to investigate the mechanism and mechanical performance of [0/90] and [0/+45/90/-45] laminates subjected to Drop-Weight Impact by a cylindro-conical, a cylindro-hemisphere and a cylindrical impactor tip at temperature of 25¢J, 75¢Jand 125¢J. The study of impact response and post impact strength of composite laminates subjected to low velocity impact shows that the failure mechanism is predominantly delamination and fiber breakage. Generalizing the results of experiment, we can conclude that an impactor with a small nose (cylindro-conical) induces a larger impact-induced damage than one with a large nose (cylindrical), as well as a greater degree of fiber breakage. But for the reduction of post-impact strength, the cylindro-hemisphere impcator induces the most reduction of strength than the cylindro-conical and the cylindrical impactors. The post-impact residual strength of [0/90] specimens is higher than [0/+45/90/-45] specimens. But, [0/+45/90/-45] specimens are better to resist the impact effect. As for the effect of elevated temperature, we found that when the temperature increases, the damage extent reduces slowly. Keywords: composite, low-velocity impact, temperature effect, young's modulus, ultimate strength

In this thesis, the aluminum nitride (AlN) thin film was selected as a sensing membrane for the H+ ion-sensitive field-effect transistor (ISFET). The AlN thin films were prepared by a rf sputtering technology on the reference electrode/electrolyte /AlN /SiO2/p-Si/Al structure. The capacitance-voltage (C-V) measurement was used to detect the H+ ion concentration and the C-V characteristic curves were obtained in the different pH buffer solutions. On the other hand, AlN thin films were also prepared on the double layer structure of AlN/SiO2 gate ISFET devices. After packaging, the current-voltage (I-V) measurement with a PID temperature controller was utilized to measure a series of the I-V characteristic curves. The threshold voltage can be obtained to evaluate the pH sensitivity in the different pH buffer solutions. Additionally, the effects of non-ideal factors, such as temperature effect, drift and hysteresis phenomenon on the characteristics of the ISFET are also measured, analyzed and compared with other sensing materials. According to the experimental results, it can be found that the ISFET based on aluminum nitride thin film has a superior high pH sensitivity of approximately 50~58 mV/pH at 25¢J. The drift and hysteresis are dependent on the H+ ion concentration in pH=1~11, in which the drift rate increases with the pH value increased and the hysteresis magnitude depends on the measuring time and route. It is found that the hysteresis widths measured in pH=7®3®7®11®7 cycle at 960s, 1920s and 3840s loop time are 1.0, 1.5 and 4.5 mV, respectively. When the temperature effect was considered, it was found that the ISFET could be operated at 5~65¢J, in which, the pH sensitivity increased as the ambient temperature increased with the temperature coefficient of sensitivity of about 0.13 mV/pH¢J. In addition, the output voltage of AlN pH-ISFET can be obtained by a constant current constant voltage (CCCV) read out circuit with a fairly linear response, stability and reproducibility in the pH measuring cycle. From the characteristics mentioned above, the AlN thin film can be as a sensing membrane for pH-ISFET applications.

Orientador: Débora Alves Nunes Leite Lima / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-23T00:08:03Z (GMT). No. of bitstreams: 1 D'Arce_MariaBeatrizFreitas_D.pdf: 1270067 bytes, checksum: 7681e880d0d8a3c1dc2b3f8cfa2af016 (MD5) Previous issue date: 2013 / Resumo: O objetivo deste estudo foi avaliar a mudança de cor do esmalte e dentina após clareamento com géis de alta e baixa concentração em diferentes temperaturas. Cinquenta fragmentos dentais bovinos foram pigmentados em uma solução de chá preto. As amostras foram distribuídas aleatoriamente em 10 grupos (n=5) de acordo com o protocolo de clareamento: peróxido de carbamida 10% (PC) 4h/dia por 21 dias; peróxido de hidrogênio 6% (PH) com cálcio 1:30h/dia por 21 dias; PH 20% com cálcio 50 min/sessão com intervalo de 7 dias (3 sessões); HP 35% Blue com cálcio 40 min/sessão com 7 dias de intervalo (3 sessões); HP 35% Maxx 3x15 min/sessão com intervalo de 7 dias (3 sessões), e da temperatura de 22ºC e 41ºC. As amostras foram armazenadas em saliva artificial durante o todo experimento. A mudança de cor foi avaliada por meio de um espectrofotômetro (Konica Minolta CM 700d, Japan) e os dados expressos nos valores do sistema CIE Lab. As leituras de cor do esmalte e dentina foram feitas após a pigmentação e após o final de cada semana de clareamento. Ainda, a superfície de esmalte de 3 amostras de cada grupo foram avaliadas por meio de Microscopia Eletrônica de Varredura (MEV). Para a coordenada L*, os dados foram analisados por medidas repetidas e teste de Tukey-Krammer (5% de nível de significância) e os valores de ?E foram submetidos ao teste ANOVA 2 way e teste de Tukey (5% de nível de significância). Não houve diferença estatística significante entre as temperaturas avaliadas de 22ºC e 41ºC. À 22ºC, o PH 20% com cálcio mostrou os menores médias de reflectância diferindo estatisticamente de PC 10% e PH 6% com cálcio nas superfícies de esmalte e dentina. À 41ºC, nenhuma diferença estatística entre os agentes clareadores foi observada após três semanas de tratamento. O peróxido de hidrogênio 20% com cálcio foi menos efetivo na temperatura ambiente no esmalte e na dentina. Entretanto, a temperatura de 41ºC melhorou a eficácia deste agente clareador. Foram observadas alterações morfológicas na superfície de esmalte após o uso dos agentes clareadores, sendo que as maiores alterações ocorreram nos grupos tratados com géis com baixo pH / Abstract: The aim of this study was to evaluate the enamel and dentin color changes after bleaching using low- and high-concentration gels at different temperatures. Fifty bovine teeth fragments were stained in a black tea solution. The samples were randomly placed in 10 groups (n=5) according to the bleaching protocol: 10% carbamide peroxide (CP) 4h/day for 21 days; 6% hydrogen peroxide (HP) with calcium 1.30h/day for 21 days; 20% HP with calcium 50 min/session with seven-day intervals (3 sessions); 35% HP Blue with calcium 40 min/session with seven-day intervals (3 sessions); 35% HP Maxx 3x15 min/session with seven-day intervals (3 sessions), and a gel temperature of 22ºC and 41ºC. The samples were stored in artificial saliva at all times during the experiment. Color change effectiveness was evaluated using a spectrophotometer (Konica Minolta CM 700d, Japan) and data was expressed in CIE Lab System values. The enamel and dentin color measurements were made after staining and at the end of each week of bleaching sessions. In addition, three enamel surface samples from each group were evaluated using a scanning electronic microscope (SEM). For the L* coordinate, data was analyzed by repeated-measures and Tukey-Krammer Test (5% significance level) and ?E values were submitted to ANOVA 2-ways and Tukey tests (5% significance level). There were no statistical differences between the evaluated temperatures 22ºC and 41ºC. At 22ºC, the 20% HP with calcium showed the lowest reflectance means differing statistically from 10% CP and 6% HP with calcium on the enamel and dentin surfaces. At 41ºC, no statistical difference among bleaching agents was observed after three weeks of treatment. The 20% hydrogen peroxide with calcium was less effective at room temperature on enamel and dentin. However, the temperature at 41ºC improved the efficacy of this bleaching agent. Morphology changes on enamel surface were observed after using the bleaching agents, being more pronounced in the groups treated with low pH gels and high-concentration agents / Doutorado / Dentística / Doutora em Clínica Odontológica

Regions with a cold winter, as in the Baltic countries, have a problem to meet the nitrogen requirement in the Urban Wastewater Treatment Directive 98/15/EC. Especially in the winter season, the temperature of the influent wastewater could arrive also below 10°C and this delays the biological processes that takes place in the wastewater treatment. With the decrease of the temperature, the efficiency of nitrogen removal in the system decreases and leads to a high nitrogen loading in the effluent. The ITEST (Increased Technology and Efficiency in Sewage Treatment) project situated in Hammarby Sjöstadsverk in Stockholm has as its main aim to enhance nitrogen removal, thereby increasing the temperature in the incoming wastewater. The pilot plant ITEST is comprised of two treatment lines, one works with natural temperature influent and the other works at the temperature of 20 °C. In order to warm the incoming water a heating system, using waste heat, is used, leading to save energy. The two test lines were compared analyzing different parameters from January to May 2013. Total nitrogen, nitrate-nitrogen and ammonium-nitrogen concentrations were measured in the incoming water and in the effluent from the two treatment lines. Hence, the efficiency of the nitrogen removal was compared between the reference and the temperature line. In the period where the system was well functioning, the results show a nitrogen efficiency with a maximum of 92 % of removal of total nitrogen for the temperature line compared to only 65 % for the reference line. In the period where the system did not have any troubles the total nitrogen is under 10 mg/l, which is the limit of total nitrogen discharges specified in the Directive. Instead, for the sludge volume and the suspended solids any particular difference can be noticed from the two lines of treatment. In conclusion, in the temperature line can be noticed a great efficiency in nitrogen removal compared to the reference line.

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Sorption isotherms and scanning data were obtained for three test materials at three different temperatures. These data resulted from further investigating the operating range of an existing experimental apparatus and procedure. During the course of the research, the operating range and control of the existing apparatus were extended, and its temperature range was tested for the first time. The apparatus is composed of a small test chamber, which is capable of containing from one to six test samples, and an external forced-air relative humidity and temperature conditioning system. The conditioning system maintains test chamber relative humidity and temperature, as directed by a GW-BASIC computer program. Sample moisture content is gravimetrically determined in situ. The system can maintain dry-bulb temperatures between 10 C and 70 C. At room temperature, the apparatus can maintain relative humidities between o and 90 per cent. Low temperature set points have a significantly lower maximum relative humidity range as a result of the formation of condensation in the concentric tube counterflow heat exchanger. High temperature set points are also severely limited, due to the formation of condensation in the test chamber during data collection. Sorption isotherms were measured for oriented strand board, fiber board sheathing, and exterior grade plywood over the relative humidity range limits at 12 C, 25 C, and 55 C. Scanning curves were measured from the 50 per cent relative humidity set points on the adsorption and desorption curves of the 25 C isotherms. / Master of Science

Master of Science / Department of Entomology / James R. Nechols / Temperature has an important indirect impact on pest populations. Direct effects occur, but also may result from temperature-induced changes in plant quality, including the expression of host plant resistance traits. Therefore, I examined both indirect and direct effects of temperature on biotype 1 soybean aphids (SBA), Aphis glycines, on a Rag1-resistant soybean variety and compared the effects with a susceptible variety to gain a better understanding of how temperature impacts SBA. Four aphid responses were evaluated: preimaginal development, survival to adulthood, number of progeny produced, and adult longevity. In the first experiment, I grew soybean seedlings to the V-0 stage at 25°C and then conditioned them for 0, 3 or 5 days at 20° or 30°C before infesting with a single first instar SBA at each of the two experimental temperatures. Based on previous literature for SBA, I hypothesized that conditioning plants at the lower temperature would cause resistance to break down and that longer exposure would exacerbate the effect. Results showed that conditioning soybeans to 20°C significantly reduced SBA survival, and the effect on survival increased with longer conditioning. Conditioning plants to 30°C had no significant effect on SBA survival. However, estimated population growth decreased as conditioning time increased at 30°C and this effect was also observed at 20°C. Thus, plant resistance may have increased at both temperatures. The second experiment compared SBA responses, including population growth, at four temperatures (15, 20, 25, and 30⁰C) on a Rag1-resistant and susceptible soybean variety. I predicted that SBA fitness would be lower at all temperatures on resistant soybeans, but the magnitude of differences between cultivars would not be uniform across temperatures. Results indicated that both temperature (highest and lowest) and plant resistance detrimentally affected SBA fitness. There was also a significant interaction between the two variables with respect to SBA survival. Survival was lower and development rates were slower on the resistant cultivar. SBA required more degree-days to develop on resistant soybeans compared to the susceptible cultivar. This information will aid soybean producers in implementing a cost-efficient IPM strategy involving Rag1 resistant soybeans to combat SBA under a range of temperatures.