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In this thesis, we design electrode shape of light emitter diode (LED) to help the current diffusing uniformly. The purpose of the uniform current is to avoid the waste heat from the devices and enhance the efficiency of active region. The LED samples adopted in this study are GaN base materials grown on sapphire. The P-N electrodes must be processed on the same side since the poor conductivity of sapphire. The same side P-N electrode will results in current crowding phenomena. We design special electrode shapes to make the current diffuse uniformly and reduce the current crowding phenomena. First, we use COMSOL simulation software to simulate the current spreading between the electrodes. We adopt the same parameters from the reference papers to confirm the reliabilities of the simulation. Then we simulate several electrode shapes with highly uniform current spreading. Second, we use the simulation results to fabricate electrode on chips. The first set is LED without transparent conductive layer. This set is to confirm whether the fabrication processes is feasible and adjust the simulation parameters at the same time. The second set is LED with transparent conductive layer. The experimental emission intensity has deviation from the simulation results. We deduce the emission intensities from smaller LED chip size will have great influence on illumination surface. The third set is electrodes fabricated on large size LED chip. The electrode patterns successfully enhance the uniformity of current spreading, and enhance the output light intensity of 21%. The current density distribution trend from simulation is matched with the illumination intensities.

We carried out a three year (2013-2015) observational campaign at the Danish 1.54-m Telescope at the ESO observatory at La Silla in Chile in which we obtained ~1000 astronomical images in the field of 11 Galactic globular clusters. The selection of these stellar systems was focused mainly on the visibility of the targets and their relevant physical properties available in the catalogues, among them were considered the density, variable stars known, colour-magnitude diagrams, and luminosity. The telescope was equipped with an electron-multiplying CCD (EMCCD) with the aim of taking very short exposure-time images. The camera was configured to take 10 frames per second. Due to this, the brighter stars observed were not affected by saturation, it helped to give higher signal to noise ratio to the fainter stars and, importantly, it minimised the effects of the atmospheric turbulence such as blending between stars in the crowded fields. To produce normal-exposure-time images (minutes) we implemented the shift-and-add technique that also enabled us to produce images with better angular resolution than previously achieved with conventional CCDs on ground-based telescopes, and even enabled us to produce images with angular resolution close to that obtained with space telescopes. The detection of the stars in each of the globular clusters and the photometry was performed via difference image analysis by using the DanDIA pipeline whose procedures and mathematical techniques have been demonstrated to produce high-precision time-series photometry of very crowded stellar regions. We produced time-series photometry for ~15000 stars in the fields observed which were statistically analysed in order to automatically extract variable stars. Our aim is to complete, or improve, the census of the variable star population in the globular clusters. In NGC 6715, we found light curves for 17 previously known variable stars near the edges of our reference image (16 RR Lyrae and 1 semi-regular) and we discovered 67 new variables (30 RR Lyrae, 21 long-period irregular, 3 semi-regular, 1 W Virginis, 1 eclipsing binary, and 11 unclassified). This cluster was particularly interesting because apart from the results obtained, it shows the benefits of using the EMCCD cameras and the shift-and-add technique. It is a cluster studied several times including data obtained with the OGLE survey and also with the Hubble Space Telescope and our discoveries were still new. Our new RR Lyrae star discoveries help confirm that NGC 6715 is of intermediate Oosterhoff type. In the other 10 globular clusters, we obtained light curves for 31 previously known variable stars (3 L, 2 SR, 20 RR Lyrae, 1 SX Phe, 3 cataclysmic variables, 1 EW and 1 NC) and we discovered 30 new variables (16 L, 7 SR, 4 RR Lyrae, 1 SX Phe and 2 NC). In NGC 6093, we analysed the famous case of the 1860 Nova, for which no observations of the Nova in outburst have been made until the present study. Ephemerides and photometric measurements for the variable stars are available in electronic form through the Strasbourg Astronomical Data Centre.

O objetivo deste trabalho é analisar as potencialidades econômicas do Distrito Eco Industrial de Palmas/TO, a partir da interação das dimensões de sustentabilidade ambiental e social. Trata-se de uma pesquisa bibliográfica, documental e estudo de caso. Para o estudo de caso, aplicou-se um questionário semiestruturado às empresas localizadas no Distrito Eco Industrial e Atacadista de Palmas/TO. O estudo abrangeu 24 de um total de 171 empresas, em atividades diversas no local, no período de setembro de 2015, para se obter a caracterização das empresas alocadas no distrito, identificando as redes internas de cooperação existentes e a observância dos aspectos ambientais, sociais e econômicos. Os resultados indicam que a cooperação entre as empresas é mínima, tendendo a ser nula. Percebeu-se que as empresas, apesar de estarem em uma tendência de redução do consumo dos recursos naturais, como matérias-primas, energia e água, não reúnem elementos suficientes para caracterizar que estão em um distrito eco industrial. Verificou-se que não há uma interação entre os agentes relacionados ao ambiente de negócios e ao meio ambiente que leve a uma simbiose industrial. Identificou-se, também, que há geração de resíduos passíveis de comercialização, entretanto as empresas não despertaram para a possibilidade se obter receita a partir desses resíduos, com sua venda para serem utilizados em outro processo produtivo. Dentre as principais possibilidades econômicas, voltadas à questão ambiental e social, destaca-se a probabilidade da comercialização de parte desse resíduo. / He objective is to analyze the economic potential of Eco Industrial District Palmas/TO from the interaction of the dimensions of environmental and social sustainability. It is a bibliographical research, document and case study. For the case study applied a semi-structured questionnaire to companies located in the District Eco Industrial and Wholesale Palmas/TO. The study covered 24 companies of 171 in various activities at the site in September 2015 to obtain the characterization of the companies allocated in the district, identifying the existing internal networks of cooperation and compliance with the environmental, social and economic aspects. The results indicate that the cooperation between companies is minimal tending to zero. It was noticed that companies, despite being on a downward trend in the consumption of natural resources such as raw materials, energy and water, do not gather sufficient information to characterize who are in an industrial eco district. It was found that that there is an interaction between the agents related to the business environment and the environment leading to an industrial symbiosis. It was identified, too, there is the generation of waste insusceptible marketing, entertaining, companies do not have woken up to the possibility to earn revenue from these waste by selling it for use in another production process. Among the main economic possibilities, focused on environmental and social issues, there is the likelihood of the commercialization of this waste.

Cooperative learning has emerged to be a preferred teaching-learning model in South Africa since the inception of Curriculum 2005 (C2005) emphasising Outcomes-based education (OBE). However, the documented success rate of cooperative learning in mathematics was experienced in small group sizes (emanating h m small class size) of about five learners. This study, therefore, aims at affording mathematics teachers and learners of crowded classes an opportunity to effectively use cooperative learning, namely the Hour-glass model in mathematics lessons. The prevalence of crowded classes in the majority of South African schools seems to inhibit the effectiveness of cooperative learning in mathematics. The big cooperative group size of about eight learners in South African context results in very complex lines of communication between learners. The teacher spends more time trying to manage off-task behaviour of learners instead of engaging them in active participation in the learning of mathematics. The combined quantitative and qualitative research methods were used. For the former, the study orientation in mathematics (SOM) questionnaire and the mathematics academic achievement test were used to collect data with regard to the influence of the Hour-glass model on the learners' learning skills in mathematics, and on the mathematics academic achievement respectively. A specific true experimental design, namely, the Solomon Four-group design, was used because of a large sample size (n > 500), and its credited ability to control the sources of threats to internal validity. For the latter the lesson observation and interviews were conducted to collect information about the influence of the Hour-glass model on learners' social skills during cooperative learning in mathematics. The groups that received the treatment (i.e. Hour-glass model) achieved higher scores of practical significance in mathematics academic achievement test than the groups that did not receive the treatment The Hour-glass model also yielded positive social skills among learners during mathematics learning. The teachers who applied the Hour-glass model revealed that they coped easier with crowded mathematics classes when using cooperative small groups. However, the Hour-glass model did not significantly influence learners' learning skills in mathematics. Certain logistical and administrative limitations emerged with regard to the implementation of the Hour-glass model in the usual school setting. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2004.

Cooperative learning has emerged to be a preferred teaching-learning model in South Africa since the inception of Curriculum 2005 (C2005) emphasising Outcomes-based education (OBE). However, the documented success rate of cooperative learning in mathematics was experienced in small group sizes (emanating h m small class size) of about five learners. This study, therefore, aims at affording mathematics teachers and learners of crowded classes an opportunity to effectively use cooperative learning, namely the Hour-glass model in mathematics lessons. The prevalence of crowded classes in the majority of South African schools seems to inhibit the effectiveness of cooperative learning in mathematics. The big cooperative group size of about eight learners in South African context results in very complex lines of communication between learners. The teacher spends more time trying to manage off-task behaviour of learners instead of engaging them in active participation in the learning of mathematics. The combined quantitative and qualitative research methods were used. For the former, the study orientation in mathematics (SOM) questionnaire and the mathematics academic achievement test were used to collect data with regard to the influence of the Hour-glass model on the learners' learning skills in mathematics, and on the mathematics academic achievement respectively. A specific true experimental design, namely, the Solomon Four-group design, was used because of a large sample size (n > 500), and its credited ability to control the sources of threats to internal validity. For the latter the lesson observation and interviews were conducted to collect information about the influence of the Hour-glass model on learners' social skills during cooperative learning in mathematics. The groups that received the treatment (i.e. Hour-glass model) achieved higher scores of practical significance in mathematics academic achievement test than the groups that did not receive the treatment The Hour-glass model also yielded positive social skills among learners during mathematics learning. The teachers who applied the Hour-glass model revealed that they coped easier with crowded mathematics classes when using cooperative small groups. However, the Hour-glass model did not significantly influence learners' learning skills in mathematics. Certain logistical and administrative limitations emerged with regard to the implementation of the Hour-glass model in the usual school setting. / Thesis (M.Ed.)--North-West University, Potchefstroom Campus, 2004.

Les polyélectrolytes sont des polymères avec des unités de répétition ionisables qui dans un solvant polaire, comme l’eau, se dissocient en libérant des contre-ions. Les polyélectrolytes, du fait leur présence dans de nombreuses formulations, de leur rôle dans les processus industriels, les milieux biologiques et environnementaux ont fait l’objet d’un grand nombre d’études. Pour mieux comprendre et exploiter les polyélectrolytes, leurs propriétés en présence d’autres composés doivent cependant être étudiées plus en détail. Dans cette optique, ce travail se concentre sur la modification des propriétés dynamiques de polyélectrolytes courts en présence de nanoparticules de silice. Dans ce but, nous avons conçu un système expérimental de diffuseurs dispersés au sein de suspensions d’obstacles chargés. Les diffuseurs sont des molécules de carboxylate de différentes tailles : des carboxylates simples jusqu’aux polyélectrolytes (polyacrylate de sodium, PAANa) courts. Les obstacles sont des nanoparticules de silice de différentes tailles et charges de surface. L’étude des carboxylates simples a été suggérée par la nécessité de réduire la complexité des diffuseurs. L’autodiffusion des molécules est étudiée principalement par diffusométrie RMN, technique qui permet d’étudier les mouvements browniens de molécules sur une échelle de temps de 10-1000 ms (10-100 μm en échelle spatiale). Ce travail examine également comment la présence de polyélectrolytes modifie les interactions entre particules de silice en utilisant la diffusion de neutrons aux petits angles. / Polyelectrolytes are a particular class of polymers with ionizable repetition units that dissociate in polar solvents (such as water) leading to macro-ions and counterions. Solutions and materials made of polyelectrolytes are extensively used in several formulations and in industrial, biological and environmental processes. For a better insight into these systems, the properties of polyelectrolytes in presence of other particles have to be studied in more detail. This work deals with the modification of the dynamics properties of short polyelectrolytes in presence of charged silica nanoparticles.To study this problem, we design an experimental system made of carboxylate molecules of various sizes, from simple carboxylate (propionate) up to short polyelectrolytes (sodium polyacrylate, PAANa), diffusing in aqueous dispersions of silica nanoparticles of different size and surface charge. Both polyelectrolytes and nanoparticles are negatively charged at high pH. Thanks to the use of simple carboxylates, it is possible to reduce the complexity of the diffusers. The self-diffusion of the molecules is investigated using NMR diffusion experiments, which monitors the Brownian motions of individual molecules on 10-1000 ms timescale (10-100 μm spatial scale). This work also investigates how the presence of polyelectrolytes modifies the phase behaviour of silica particles by using small angle neutron scattering.

Capturing protein dynamics in biological crowded environments is essential for under- standing cellular function. In this project, we have explored the dynamic properties of apoferritin in aqueous solutions under varying conditions, including different temper- ature, solvent viscosity and protein concentrations. Dynamic light scattering (DLS) was applied here at various scattering angles from 90 to 150 degrees and at temperatures 295 K and 263 K on three different samples, including one with 19.5 mg/ml apo- ferritin, 6 mg/ml NaCl and 50% glycerol in volume fraction, one with 20 mg/ml apoferritin and 6 mg/ml NaCl, and one with 196.7 mg/ml apoferritin, 6 mg/ml NaCl and 50% glycerol in volume fraction. With the intensity autocorrelation func- tions from DLS measurements, the corresponding diffusion coefficients, hydrodynamic radii and relaxation time constants for each sample under varying conditions were ex- tracted. By comparing with the previous studies, unexpectedly large hydrodynamic radii were noticed and were attributed to undissolved protein crystallites. Still, it can be indicated from our experiment that applying smaller momentum transfer, decreas- ing temperature, increasing solvent viscosity and increasing protein concentration in the solutions can slow down the diffusion dynamics of protein molecules and clusters. Especially by increasing protein concentration, the slowing down of dynamics may be due to crowding effects, as well as increased size of the crystallites. In addition, the data indicate that in all cases, larger solution viscosity can lead to slower diffusivity of proteins.

The purpose of this study was to determine the influence of dentofacial appearance on perceived social attributes of college-aged adult males and females as judged by their peers. Specifically, the objective was to determine if ideal smile esthetics positively influenced this age group’s perception of opposite-sex peers based on ratings of the following psychosocial characteristics: attractiveness, desire to spend time with, desire to date, and desire for a long-term relationship. Evaluators were shown digital photographs of subjects with ideal and nonideal smiles and asked to rate those 4 attributes using a visual analogue scale (VAS). The subjects’ photographs with ideal smile esthetics were consistently rated higher on average than the same subjects’ photographs with nonideal smile esthetics. The differences in ratings between ideal and nonideal smile images were significant for all 4 psychosocial judgments (P <.0001). These differences ranged in magnitude depending on the sex and race of the evaluator and subject.

One of my concerns has been how children behave in a crowded classroom with few available opportunities to interact and rehearse the lesson with their peers and teacher. This research paper allows me to explore how teacher`s directives/ manners  (verbal &amp; non-verbal communication) during the English lesson,  impact and fix children`s behaviours temporarily.  I have conducted this emprirical case study in a religious catholic, monolingual, Spanish school conformed only by girls aged 7-9, who are in the third level of its primary level.  As my interest was to analyze the talk of my purpose sampling (teacher-student) and the interactive behaviour in the natural occurring situation in this social setting, the method I chose was the analysis of social interaction, on Conversation Analysis. This allows me to unfold the talk-in-interaction and concentrate on micro-analytic situations using the standard convention to transcribe my selected analysis. Therefore, the contribution of this paper is to explore and demonstrate how disciplinary acts were deilvered by the teacher affecting the child`s subjectivity and performance in a crowded classroom.