The objective of this study was to determine how the rice plant responds to combinations of temperature and photoperiod. Both temperature and photoperiod are important for normal completion of the life cycle, but there has been little study of their combined effects in rice. Controlled temperature and photoperiod experiments were conducted in growth cabinets using 4 temperatures; 35/18, 35/26.5, 35/35 and 40.5/18°C day/night. There were 4 photoperiods of 8, 10, 12 and 14 hours. Light was provided by cool white fluorescent tubes. The day temperature periods corresponded to the photoperiods. Four varieties were selected: Kangni-27 and Dokribasmati from Dokri, Pakistan; Caloro from California, U.S.A.; and Bluebonnet-50 from Texas, U.S.A. Growth characteristics, net photosynthesis rates, and flowering were measured and chlorophyll a and b, carotenoid, carbohydrate and ash concentrations were determined. The effect of photoperiod on flowering was most pronounced at 35/26.5. The delays in flowering at 14 hours for this temperature were 30, 30, 21 and 63 days in Kangni, Caloro, Dokri and Bluebonnet compared to the optimum, photoperiod which varied among varieties. The delays observed at 35/18 were 23, 14, 6 and 2 days. At 35/26.5 all varieties showed a significant photoperiodic effect on flowering, but at 35/18, Dokri and Bluebonnet did not show a significant photoperiodic effect. 35/35 was most unsatisfactory for flowering. A similar but less serious effect was found at 40.5/18. Final dry matter production was high at 35/35 and 40.5/18; an increase of 3 to 8 g per pot was noted at these temperatures compared with 35/26.5 and 35/18. There was an increase of about 5 g per pot at maturity for each increase of 2 hours in photoperiod. Panicle characteristics were generally unaffected by temperature, but there were some photoperiod effects. At the 12-hour photoperiod panicles of all varieties were 2 to 4 cm longer than at other photoperiods and at 10-and 12-hour photoperiods there were 10 to 32 more spikelets per panicle than at 8 and 14 hours. Sterility was very high at 35/35 (95%) and 40.5/18 (69%). Average sterility at 35/18 and 35/26.5 was about 36%. There was 8 to 24% less sterility at 10- and 12-hour photoperiod compared with 8 or 14 hours. Hundred-grain weight was unaffected by photoperiod or temperature. High numbers of tillers were consistently observed at 40.5/18 and 35/18 and low numbers at 35/35. The differences varied with the stage of growth. Plants at 14-hour photoperiod had consistently more tillers than those at other photoperiods. Kangni and Dokri had higher numbers of tillers than Caloro and Bluebonnet. Leaf development was fastest at 40.5/18 and the 12-hour photoperiod. This was especially so at 6 and 8 weeks. Kangni and Dokri had faster development than Caloro and Bluebonnet. Plant height was 2 to 5 cm greater at 2 weeks at 35/26.5 and 35/35 but at 4, 6 and 8 weeks, plant height was greater at 35/18. The shortest plants were observed at 40.5/18. The rate of net photosynthesis on a leaf blade weight basis was highest at 2 weeks in all varieties at all photoperiods and temperatures. The rate generally declined with the aging of plants. The greatest decline at 8 weeks, compared to 2 weeks, was 71% in Dokri and least was 65% in Bluebonnet. Except at 2 weeks, the highest rate of photosynthesis was at 40.5/18 but at 6 and 8 weeks there were also high rates at 35/35. The rate was consistently higher in plants growing in the 8-hour photoperiod. The rate was higher in the 8-hour photoperiod compared to the 14-hour by 28 and 25% at 6 and 8 weeks respectively. Both Caloro and Bluebonnet had higher net photosynthetic rates than Kangni and Dokri. In all varieties chlorophyll and carotenoid content declined with age. Both chlorophyll and carotenoid were high at 40.5/18 at all stages. Chlorophyll concentration was also high at 35/18 at 2, 4 and 6 weeks. A definite correlation between chlorophyll content and photosynthesis was not shown, but there was a significant correlation between chlorophyll and fresh weight at all temperatures and photoperiods except at 2 weeks. Total water soluble carbohydrate and total ash content did not show definite trends according to stages of growth. No relationship could be shown between floral initiation and combined carbohydrate and ash content. / Land and Food Systems, Faculty of / Graduate

The mechanism and the history of retinal photocoagulation are reviewed. The eye and the light beam parameters are discussed as they affect the coagulation lesion, and optimum parameters are indicated. Some comparisons are made between photocoagulators of various types. A new reason which may account for the unpredictability of the lesion size for a given exposure, the variable focal length or lens-to-retina distance of the eye, is suggested and studied. The use of a television ophthalmoscope for studying retinal coagulation generally, and in carrying out special studies in this thesis, is reported. Some unique haemorrhages and blast effects obtained during coagulation experiments are reported. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

This thesis examines the optical properties of Christiansen filter systems.

The structural design, synthesis and characterization of luminogens with aggregation-induced emission (AIE) properties are studied in this thesis. The remarkable emission properties, thermal stability and biocompatibility of the AIE-active materials demonstrate the promising applications in bioimaging and organic light-emitting diodes (OLEDs).;Chapter 1 introduces the existence of aggregation-caused quenching (ACQ) effect in most conventional organic dyes as well as phosphorescent transitional metal complexes. Discovery of AIE and its mechanical study allow further exploration of usage in organic luminescent materials. This chapter also gives some examples and the applications these AIE-active compounds.;In Chapter 2, a series of cyanostilbenes with simple electron donor (D)-p-electron acceptor (A) structure are presented and synthesized. They exhibit remarkable AIE effect as well as deep red emission peak in 95 % water fraction in THF. These results indicate that attachment of these electron acceptors provides alternative strategy for designing highly emissive AIE-active materials.;In Chapter 3, strongly emissive cyanostilbenes with phenothiazine unit are designed and synthesized. This chapter also investigates the effect of substituents in phenothiazine and terminal cyanostilbene on the photophysical properties and AIE effect. The results suggest that they are AIE-active with different sizes in nano-aggregates. Furthermore, these dyes exhibit clear and strong fluorescence in live cell imaging with excellent biocompatibility.;In Chapter 4, a series of AIE-active phosphorescent Pt(II) complexes made up of C^N^C tridentate ligands are designed and synthesized. They exhibit different morphologies and emission properties upon aggregation in 90 % water in acetonitrile although similar tridentate ligands are applied. One of the complexes in this chapter show nano-rod formation with the highest quantum efficiency in aggregated state, suggesting that rapid self-assembly process occurs to prevent non-radiative decay and oxygen quenching.;In Chapter 5, a series of bis-cyanostyryl fluorophores are designed and synthesized. They are emissive in solid state with colour range from orange to NIR region. Furthermore, they are AIE-active and some of them may contain hybridized local and charge transfer (HLCT) excited state to achieve highly efficient emission upon solvatochromic investigation. Some bis-cyanostyryl thiophenes are fabricated in OLED devices show deep-red to NIR emission, indicative of a promising way to design solid-state NIR-emissive compounds using bis-cyanostyryl derivatives.;Finally, Chapter 6 and 7 present the concluding remarks and the experimental details of the work in Chapters 2 to 5, respectively.

Vitamin D is a fat-soluble vitamin that has proven to be extremely important for human health. Vitamin D has important functions that regulate calcium and phosphate absorption from the gastrointestinal tract. The regulation of calcium and phosphorus metabolism is extremely important for the maintenance of the structural integrity of the human skeleton, neuromuscular function and a wide variety of metabolic processes. A major source of vitamin D for most children and adults if exposure to sunlight. During sun exposure 7-dehydrocholesterol in the epidermis and dermis absorb solar ultraviolet B radiation with wavelengths of 290-315nm. This results in it being converted to previtamin D. Once formed, the thermodynamically unstable previtamin D is isomerized to vitamin D. Vitamin D is then hydroxylated in the liver and the kidneys to its active form before it can act as a homeostatic regulator of calcium and phosphorus metabolism. There are certain patients who do not respond well to vitamin D supplements because they suffer from fat malabsorption syndromes such as cystic fibrosis, Crohn’s disease and ulcerative colitis. In addition, gastric bypass patients have difficulty in absorbing dietary and supplemental vitamin D. One approach for treating vitamin D deficiency in these patients is to recommend that they be exposed to artificial UVB radiation either from a tanning bed or from a Sperti vitamin D producing lamp. Novel ultraviolet emitting light emitting diodes (LED) have emerged as a promising solution because of their size, efficiency, and ability to use narrow band UV radiation. A LED has been developed to emit narrowband UVB radiation with a peak wavelength of that 295nm. This thesis provides evidence that this novel UVB-LED is able to cause the photo-conversion of 7-deyhdrocholesterol to previtamin D3 in vitro, using 7-dehydrocholesterol containing borosilicate ampoules as positive controls, as well as produce vitamin D3 in surgically obtained type II human skin. Results from this study suggest that vitamin D producing LEDs can be developed for the treatment of vitamin D deficiency, especially in patients with fat malabsorption syndromes.

This thesis explores how natural light can be integrated with built form to create a “performance of light” in architecture. Lighting conditions from a contemporary dance piece, as well as other architectural precedents, were studied, and aspects adapted into the building’s design. In addition to designing theatrical effects of light, the classroom and administrative spaces were designed to take advantage of natural light. Daylight studies were used to inform glazing design and material selection to stay within illuminance thresholds in the spaces. This project is responding to the facility needs of the campus of UMass Amherst where the program of the dance, theater and music departments are stressed for space, are operating in below-average facilities, and are separated, making collaboration difficult. The programmatic concept driving this design purposely mixes offices, classrooms and rehearsal spaces, creating overlap and collaborative opportunities. The use of mass timber was also an important aspect of the buildings’ design. Wood brings along many benefits, such as lower embodied energy, carbon sequestration, better thermal properties, and an increase in the perceived quality of architectural spaces. The volume of wood used in the building’s structural system was run through a life-cycle analysis to determine the overall carbon footprint, in relation to the amount of steel and concrete used.

The purpose of this thesis is to explore the different aspects of therapeutic architecture through the design of a therapeutic community for refugees who suffer from PTSD. To understand a therapeutic space a depth of understanding of what space, atmosphere and stimulation of senses is explored through the effects of light, shadow, and color psychology. The methodology exploration studies different lighting strategies and massing models to understand the relationship and aura of the space being designed.

No description available.

>Magister Scientiae - MSc / Ethylene and propylene are greatly used for their importance as feedstocks for producing useful materials. Due to rise in prices and the demand of ethylene and propylene, the need to increase the selective production of these light olefins is necessary. To achieve this, zeolites, specifically ZSM-5 has been used to investigate catalytic cracking of several types of hydrocarbons for the production of these light olefins. This study focuses on developing hierarchical macro and/or mesoporous ZSM-5 zeolites with variable Si/Al ratios. The synthesized materials were then evaluated on their performance via catalytic cracking of hexane, dodecane and tyre derived oil [TDO] to produce light olefins, particularly ethylene and propylene.

This thesis is focused on the use of light and LEDs for communication between the light and the user. In the introduction, the principles of VLC, which Li-Fi is part of, are described. The work also contains issues on the topics of Li-Fi, such as methods of modulation of carrier signals for data transmission, comparisons between other wireless communications, individual elements of optical frontends, current versions of Li-Fi and other possible uses of this technology. The work also contains the designing of a system working on the principle of Li-Fi.