882 resultados para doses and efficiency of nitrogen use
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Abstract This study was undertaken to examine traditional forms of literacy and the newest form of literacy: technology. Students who have trouble reading traditional forms of literacy tend to have lower self-esteem. This research intended to explore if students with reading difficulties and, therefore, lower self-esteem, could use Social Networking Technologies including text messaging, Facebook, email, blogging, MySpace, or Twitter to help improve their self-esteem, in a field where spelling mistakes and grammatical errors are commonplace, if not encouraged. A collective case study was undertaken based on surveys, individual interviews, and gathered documents from 3 students 9-13 years old. The data collected in this study were analyzed and interpreted using qualitative methods. These cases were individually examined for themes, which were then analyzed across the cases to examine points of convergence and divergence in the data. The research found that students with reading difficulties do not necessarily have poor self-esteem, as prior research has suggested (Carr, Borkowski, & Maxwell, 1991; Feiler, & Logan, 2007; Meece, Wigfield, & Eccles, 1990; Pintirch & DeGroot, 1990; Pintrich & Garcia, 1991). All of the participants who had reading difficulties, were found both through interviews and the CFSEI-3 self-esteem test (Battle, 2002) to have average self-esteem, although their parents all stated that their child felt poorly about their academic abilities. The research also found that using Social Networking Technologies helped improve the self-esteem of the majority of the participants both socially and academically.
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Affiliation: Pierre Dagenais : Hôpital Maisonneuve-Rosemont, Faculté de médecine, Université de Montréal
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Le début de l’adolescence est une période de changements rapides où la détresse psychologique et l’expérimentation de la marijuana sont choses fréquentes. Certaines études longitudinales ont démontré que ces deux phénomènes ont tendance à se manifester conjointement tandis que d’autres n’ont pu observer de tel lien. Ces résultats divergents suggèrent que plusieurs questions persistent concernant la nature de cette relation. Cette thèse a pour objectif d’explorer la consommation de marijuana et la détresse psychologique en début d’adolescence afin de mieux saisir les changements à travers le temps, ainsi que d’examiner si ces deux problématiques évoluent conjointement et s’influencent réciproquement. Un échantillon de 448 adolescents garçons et filles fréquentant deux écoles secondaires de Montréal, ont été suivi de secondaire I à secondaire III. De 1999 à 2001, les participants ont complété un questionnaire à chaque année de l’étude incluant des mesures portant sur la consommation de marijuana et la détresse psychologique (IDPESQ-14). Un modèle de mixture semi-paramétrique (Nagin, 2005) a été utilisé afin d’identifier les trajectoires développementales de la consommation de marijuana et de détresse psychologique. Des analyses ont également été effectuées afin d’établir les liens d’appartenance entre chacune des trajectoires de consommation identifiées et la détresse psychologique lors de la première année de l`étude, ainsi qu’entre chacune des trajectoires de détresse psychologique et la consommation de marijuana en première année du secondaire. Finalement, des analyses de trajectoires jointes ont été effectuées afin de déterminer l’interrelation entre la consommation de marijuana et la détresse psychologique. Les résultats de notre étude suggèrent qu’il existe une grande hétérogénéité au niveau de la consommation de marijuana et la détresse psychologique. Trois trajectoires développementales ont été identifiées pour la consommation de marijuana: consommation légère, consommation grandissante et consommation élevée et stable. Trois trajectoires ont également été observées pour la détresse psychologique : basse, moyenne et élevée. Nos résultats démontrent la présence d’un lien entre la détresse psychologique rapportée lors de la première année de l’étude et les trajectoires de consommation problématiques. Ce lien a également été observé entre la consommation de marijuana rapportée lors de première année de l’étude et les trajectoires problématiques de détresse psychologique. Les analyses de trajectoires jointes démontrent la présence d’une concordance entre la consommation de marijuana et la détresse psychologique. Cette interrelation est toutefois complexe puisque les trajectoires de détresse psychologique élevée sont associées à un niveau de consommation de marijuana plus problématique mais l’inverse de cette association est moins probable. Notre étude met en lumière la nature asymétrique de la concordance entre la consommation de marijuana et la détresse psychologique.
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Contexte: Évaluer les déterminants de maladies évitables et leurs coûts est nécessaire dans le contexte d’assurance maladie universelle. Le moment d’évaluer les impacts des traumatismes crâniocérébraux (TCC) survenus lors d’accidents de vélo est idéal vu la popularité récente du cyclisme au Québec. Objectifs: Comparer les caractéristiques démographiques et médicales, ainsi que les coûts sociétaux qu’engendrent les TCC de cyclistes portant ou non un casque. Méthodologie: Étude rétrospective de 128 cyclistes avec TCC admis à l’Hôpital Général de Montréal entre 2007 et 2011. Les variables indépendantes sont sociodémographiques, cliniques et le port du casque. Les variables dépendantes sont la durée de séjour, l’échelle GOS-E, l’échelle ISS, l’orientation au congé, les décès et les coûts à la société. Résultats: Le groupe portant un casque était plus vieux, plus éduqué, retraité et marié; au niveau médical, ils avaient des TCCs moins sévères à l’imagerie, des hospitalisations aux soins intensifs plus courtes et moins de neurochirurgies. Les coûts médians à la société pour les TCC isolés de cyclistes avec casque étaient significativement moindres. Conclusion: Dans cette étude, le port du casque semblait prévenir certaines complications des TCC et permettait de faire économiser de l’argent à l’état. Le port de casque est recommandé.
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This thesis has been realised through a scholarship offered by the Government of Canada to the Government of the Republic of Mauritius under the Programme Canadien de Bourses de la Francophonie
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By the end of 2004, the Canadian swine population had experienced a severe 2 increase in the incidence of Porcine circovirus-associated disease (PCVAD), a problem that was 3 associated with the emergence of a new Porcine circovirus-2 genotype (PCV-2b), previously 4 unrecovered in North America. Thus it became important to develop a diagnostic tool that could 5 differentiate between the old and new circulating genotypes (PCV-2a and -2b, respectively). 6 Consequently, a multiplex real-time quantitative polymerase chain reaction (mrtqPCR) assay that 7 could sensitively and specifically identify and differentiate PCV-2 genotypes was developed. A 8 retrospective epidemiological survey that used the mrtqPCR assay was performed to determine if 9 cofactors could affect the risk of PCVAD. From 121 PCV-2–positive cases gathered for this 10 study, 4.13%, 92.56% and 3.31% were positive for PCV-2a, PCV-2b, and both genotypes, 11 respectively. In a data analysis using univariate logistic regressions, PCVAD compatible 12 (PCVAD/c) score was significantly associated with the presence of Porcine reproductive and 13 respiratory syndrome virus (PRRSV), PRRSV viral load, PCV-2 viral load, and PCV-2 14 immunohistochemistry (IHC) results. Polytomous logistic regression analysis revealed that 15 PCVAD/c score was affected by PCV-2 viral load (P = 0.0161) and IHC (P = 0.0128), but not by 16 the PRRSV variables (P > 0.9); suggesting that mrtqPCR in tissue is a reliable alternative to IHC. 17 Logistic regression analyses revealed that PCV-2 increased the odds ratio of isolating 2 major 18 swine pathogens of the respiratory tract, Actinobacillus pleuropneumoniae and Streptococcus 19 suis serotypes 1/2, 1, 2, 3, 4, and 7, which are serotypes commonly associated with clinical 20 diseases.
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How much, how often and how fast a drug reaches the brain determine the behavioural and neuroplastic changes associated with the addiction process. Despite the critical nature of these variables, the drug addiction field often ignores pharmacokinetic issues, which we argue can lead to false conclusions. First, we review the clinical data demonstrating the importance of the speed of drug onset and of intermittent patterns of drug intake in psychostimulant drug addiction. This is followed by a review of the preclinical literature demonstrating that pharmacokinetic variables play a decisive role in determining behavioural and neurobiological outcomes in animal models of addiction. This literature includes recent data highlighting the importance of intermittent, ‘spiking’ brain levels of drug in producing an increase in the motivation to take drug over time. Rapid drug onset and intermittent drug exposure both appear to push the addiction process forward most effectively. This has significant implications for refining animal models of addiction and for better understanding the neuroadaptations that are critical for the disorder.
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We consider two new approaches to nonparametric estimation of the leverage effect. The first approach uses stock prices alone. The second approach uses the data on stock prices as well as a certain volatility instrument, such as the CBOE volatility index (VIX) or the Black-Scholes implied volatility. The theoretical justification for the instrument-based estimator relies on a certain invariance property, which can be exploited when high frequency data is available. The price-only estimator is more robust since it is valid under weaker assumptions. However, in the presence of a valid volatility instrument, the price-only estimator is inefficient as the instrument-based estimator has a faster rate of convergence. We consider two empirical applications, in which we study the relationship between the leverage effect and the debt-to-equity ratio, credit risk, and illiquidity.
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Department of Applied Chemistry, Cochin University of Science and Technology
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Aim of the present work was to automate CSP process, to deposit and characterize CuInS2/In2S3 layers using this system and to fabricate devices using these films.An automated spray system for the deposition of compound semiconductor thin films was designed and developed so as to eliminate the manual labour involved in spraying and facilitate standardization of the method. The system was designed such that parameters like spray rate, movement of spray head, duration of spray, temperature of substrate, pressure of carrier gas and height of the spray head from the substrate could be varied. Using this system, binary, ternary as well as quaternary films could be successfully deposited.The second part of the work deal with deposition and characterization of CuInS2 and In2S3 layers respectively.In the case of CuInS2 absorbers, the effects of different preparation conditions and post deposition treatments on the optoelectronic, morphological and structural properties were investigated. It was observed that preparation conditions and post deposition treatments played crucial role in controlling the properties of the films. The studies in this direction were useful in understanding how the variation in spray parameters tailored the properties of the absorber layer. These results were subsequently made use of in device fabrication process.Effects of copper incorporation in In2S3 films were investigated to find how the diffusion of Cu from CuInS2 to In2S3 will affect the properties at the junction. It was noticed that there was a regular variation in the opto-electronic properties with increase in copper concentration.Devices were fabricated on ITO coated glass using CuInS2 as absorber and In2S3 as buffer layer with silver as the top electrode. Stable devices could be deposited over an area of 0.25 cm2, even though the efficiency obtained was not high. Using manual spray system, we could achieve devices of area 0.01 cm2 only. Thus automation helped in obtaining repeatable results over larger areas than those obtained while using the manual unit. Silver diffusion on the cells before coating the electrodes resulted in better collection of carriers.From this work it was seen CuInS2/In2S3 junction deposited through automated spray process has potential to achieve high efficiencies.
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Trawling, despite being heavily energy expensive, still continues to be the most energy expensive fishing method particularly so in View of the export oriented nature of the Indian seafood industry. This study therefore aims at analyzing the efficiency of trawls operation from Cochin, an important fishing center along the southwest coast of India. The analysis is made along two perspectives - economic and technological. Even though technological efficiency complement economic efficiency, in the fishing parlance, parameters like the size composition of the catch, selectivity factors, etc., will have a direct bearing on the technological qualities of the trawl, and which parameters will have a significant impact on the effective exploitation of a fishery stock. Whereas the technological analysis aims at improving the efficiency with regard to the effective utilization of fuel and fishery stocks, economic analysis ascertains the present status of the trawling operations from the commercial angle.
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The distribution of three important dissolved forms of nitrogen, viz. nitrate, nitrite and urea in the surface and bottom water samples collected from 27 selected hydrographic profiles, in the Arabian Sea, along the west coast of India is described. Of the three forms, nitrate concentrations were the highest and comparatively higher concentrations were observed in the bottom water. Decomposition of organic matter resulting in the release of the thermodynamically stable nitrogen species, i.e. nitrate, may be the major factor resulting in higher nitrate concentrations at these depths, where the water is also characterized by low values of dissolved oxygen and temperature. The significant positive correlation between A.O.U. and nitrate of the bottom water samples emphasizes the role of oxidative decomposition of organic matter which plays an active role in reducing the oxygen concentrations below the theoretical values since at this depth ( 200 m) the net production is taken to be zero. This is also evidenced by the negative correlation of nitrate with dissolved oxygen and temperature, for the bottom samples
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Cement industry ranks 2nd in energy consumption among the industries in India. It is one of the major emitter of CO2, due to combustion of fossil fuel and calcination process. As the huge amount of CO2 emissions cause severe environment problems, the efficient and effective utilization of energy is a major concern in Indian cement industry. The main objective of the research work is to assess the energy cosumption and energy conservation of the Indian cement industry and to predict future trends in cement production and reduction of CO2 emissions. In order to achieve this objective, a detailed energy and exergy analysis of a typical cement plant in Kerala was carried out. The data on fuel usage, electricity consumption, amount of clinker and cement production were also collected from a few selected cement industries in India for the period 2001 - 2010 and the CO2 emissions were estimated. A complete decomposition method was used for the analysis of change in CO2 emissions during the period 2001 - 2010 by categorising the cement industries according to the specific thermal energy consumption. A basic forecasting model for the cement production trend was developed by using the system dynamic approach and the model was validated with the data collected from the selected cement industries. The cement production and CO2 emissions from the industries were also predicted with the base year as 2010. The sensitivity analysis of the forecasting model was conducted and found satisfactory. The model was then modified for the total cement production in India to predict the cement production and CO2 emissions for the next 21 years under three different scenarios. The parmeters that influence CO2 emissions like population and GDP growth rate, demand of cement and its production, clinker consumption and energy utilization are incorporated in these scenarios. The existing growth rate of the population and cement production in the year 2010 were used in the baseline scenario. In the scenario-1 (S1) the growth rate of population was assumed to be gradually decreasing and finally reach zero by the year 2030, while in scenario-2 (S2) a faster decline in the growth rate was assumed such that zero growth rate is achieved in the year 2020. The mitigation strategiesfor the reduction of CO2 emissions from the cement production were identified and analyzed in the energy management scenarioThe energy and exergy analysis of the raw mill of the cement plant revealed that the exergy utilization was worse than energy utilization. The energy analysis of the kiln system showed that around 38% of heat energy is wasted through exhaust gases of the preheater and cooler of the kiln sysetm. This could be recovered by the waste heat recovery system. A secondary insulation shell was also recommended for the kiln in the plant in order to prevent heat loss and enhance the efficiency of the plant. The decomposition analysis of the change in CO2 emissions during 2001- 2010 showed that the activity effect was the main factor for CO2 emissions for the cement industries since it is directly dependent on economic growth of the country. The forecasting model showed that 15.22% and 29.44% of CO2 emissions reduction can be achieved by the year 2030 in scenario- (S1) and scenario-2 (S2) respectively. In analysing the energy management scenario, it was assumed that 25% of electrical energy supply to the cement plants is replaced by renewable energy. The analysis revealed that the recovery of waste heat and the use of renewable energy could lead to decline in CO2 emissions 7.1% for baseline scenario, 10.9 % in scenario-1 (S1) and 11.16% in scenario-2 (S2) in 2030. The combined scenario considering population stabilization by the year 2020, 25% of contribution from renewable energy sources of the cement industry and 38% thermal energy from the waste heat streams shows that CO2 emissions from Indian cement industry could be reduced by nearly 37% in the year 2030. This would reduce a substantial level of greenhouse gas load to the environment. The cement industry will remain one of the critical sectors for India to meet its CO2 emissions reduction target. India’s cement production will continue to grow in the near future due to its GDP growth. The control of population, improvement in plant efficiency and use of renewable energy are the important options for the mitigation of CO2 emissions from Indian cement industries