• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • 1
  • Tagged with
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efficacy of a synthetic zeolite against five species of stored-grain insects on concrete and wheat

Yao, Kouame January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Bhadriraju Subramanyam / A synthetic zeolite (Odor-Z-Way, sodium aluminum silicate) used for odor adsorption was tested for its ability to control adults of stored-grain insects on wheat and on concrete petri dishes used to simulate floors of empty bins. Insect species tested included unsexed adults of the lesser grain borer, Rhyzopertha dominica (F.); rice weevil, Sitophilus oryzae (L.); maize weevil, Sitophilus zeamais (Motschuslky); red flour beetle, Tribolium castaneum (Herbst), and sawtoothed grain beetle, Oryzaephilus surinamensis (L.). Two formulations were evaluated under laboratory conditions (28±1⁰C and 65±1% r.h.): coarse zeolite (with 90% of particles having a mean diameter at or below 155 µm) and fine zeolite (with 90% of particles having a mean diameter at or below 47.0 µm). On concrete, arenas in 9-cm diameter Petri dishes were sprinkled with the synthetic zeolite to provide deposits of 0 (control), 5 and 10 g/m[superscript]2. Mortality was assessed at times ranging from 10 minutes to 24 hours followed by 48 hours recovery on wheat. Mortality in adults of the five species increased as the rate of application and the duration of exposure increased. Concrete Petri dishes sprinkled with the fine zeolite yielded percent mortality greater or equal to that observed with the coarse zeolite- sprinkled Petri dishes. Bioassays on wheat were conducted using two dosage rates: 0.1 to 3.0 g/kg for R. dominica and 0.05 to 1.0 g/kg for the other insect species. Mortality was assessed 7 days post- infestation. A concentration of 0.75 g/kg of fine or coarse zeolite achieved 100% mortality in adults of S. zeamais, T. castaneum, and O. surinamensis. All adults of S. oryzae were killed using 0.50 g/kg of coarse or fine zeolite. Adults of R. dominica were the least susceptible: 2.50 g/kg of fine zeolite and 3.0 g/kg of coarse zeolite were required for 100% mortality. Mortality generally increased with the concentration of zeolite applied on wheat. Efficacy was not related to particle size. This is the first study showing the efficacy of a synthetic zeolite against adults of five species of stored-product insects on concrete and wheat. Synthetic zeolites can be a suitable alternative to currently used pesticides for treatment of empty bin floors and stored wheat for insect control.
2

Avaliação da eficácia de medidas de recuperação ambiental em mineração de calcário para cimento. / Assessment of effectiveness rehabilitation measures in limestone mines.

Neri, Ana Claudia 12 November 2007 (has links)
A gestão do processo de recuperação de uma área degradada pela mineração consiste em três etapas principais: planejamento; implementação das medidas de correção ou prevenção e implementação de gestão. Neste trabalho, foi desenvolvido um instrumento de avaliação que pode ser usado por órgãos públicos ou por empresas de mineração para auxiliar no controle e melhoria das práticas de recuperação ambiental. A avaliação é feita por meio da aplicação de um roteiro, fundamentado nas boas práticas internacionais e nacionais relacionadas à recuperação ambiental de minas. Para fins de teste e calibração, os roteiros foram aplicados em três minas de calcário, nas quais se verificou que as evidências - visuais, documentais e verbais (obtidas por meio de entrevistas) - coletadas devem ser interpretadas dentro de um contexto que envolva o entendimento das características ambientais e operacionais particulares de cada mina. As categorias de classificação da avaliação da eficácia de medidas de recuperação ambiental foram definidas em: eficaz, parcialmente eficaz, não eficaz e não se aplica. Ante aos resultados, foi possível identificar um \"cenário atual\" das práticas de recuperação ambiental empregadas em cada mina inspecionada e consequentemente recomendar ações visando a melhoria das práticas atuais e a redução de um futuro passivo ambiental. Diante destes resultados, conclui-se que o procedimento de avaliação da eficácia de medidas de recuperação ambiental desenvolvido nesta pesquisa é adequado, mas sua aplicação somente pode ser feita por um profissional que detenha alguma experiência no assunto, fator primordial para o julgamento e contextualização das evidências coletadas. O roteiro proposto nesta pesquisa ainda pode ser aplicado em outras minas de diferentes minerais e pedreiras. / The reclamation process management of an area degraded by mining activity consists of three main steps: planning. application of correction or prevention measures and monitoring. In this work, an assessment tool to be used by public bodies or by mining companies in order to support the control and improvement of environmental reclamation practices was developed. The assessment has been carried out with a script based on the national and international good practices regarding environmental reclamation in mines. For testing and calibration purposes, the scripts were applied in three limestone mines. The conclusion is that the evidences - visual, documental and verbal (interview) - must be analyzed in a context which involves the understanding of the environmental and operational characteristics in each mine. The categories for classification of the efficacy assessment of environmental reclamation measures have been defined as: efficacious, partially efficacious, non-efficacious and not applicable. Considering the results, it was possible to identify a \"current scenario\" of the environmental reclamation practices used in each inspected mine and consequently recommend actions to improve the current practices and reduce a future environmental liability. It was concluded that the procedure of the efficacy assessment of the environmental reclamation practices developed in this research is appropriate, but its application can only be made by a professional that presents some experience in the subject. It is a decisive factor for the evaluation and contextualization of the collected evidences. The proposed script for this research can still be applied in other mines with different minerals and quarries.
3

Avaliação da eficácia de medidas de recuperação ambiental em mineração de calcário para cimento. / Assessment of effectiveness rehabilitation measures in limestone mines.

Ana Claudia Neri 12 November 2007 (has links)
A gestão do processo de recuperação de uma área degradada pela mineração consiste em três etapas principais: planejamento; implementação das medidas de correção ou prevenção e implementação de gestão. Neste trabalho, foi desenvolvido um instrumento de avaliação que pode ser usado por órgãos públicos ou por empresas de mineração para auxiliar no controle e melhoria das práticas de recuperação ambiental. A avaliação é feita por meio da aplicação de um roteiro, fundamentado nas boas práticas internacionais e nacionais relacionadas à recuperação ambiental de minas. Para fins de teste e calibração, os roteiros foram aplicados em três minas de calcário, nas quais se verificou que as evidências - visuais, documentais e verbais (obtidas por meio de entrevistas) - coletadas devem ser interpretadas dentro de um contexto que envolva o entendimento das características ambientais e operacionais particulares de cada mina. As categorias de classificação da avaliação da eficácia de medidas de recuperação ambiental foram definidas em: eficaz, parcialmente eficaz, não eficaz e não se aplica. Ante aos resultados, foi possível identificar um \"cenário atual\" das práticas de recuperação ambiental empregadas em cada mina inspecionada e consequentemente recomendar ações visando a melhoria das práticas atuais e a redução de um futuro passivo ambiental. Diante destes resultados, conclui-se que o procedimento de avaliação da eficácia de medidas de recuperação ambiental desenvolvido nesta pesquisa é adequado, mas sua aplicação somente pode ser feita por um profissional que detenha alguma experiência no assunto, fator primordial para o julgamento e contextualização das evidências coletadas. O roteiro proposto nesta pesquisa ainda pode ser aplicado em outras minas de diferentes minerais e pedreiras. / The reclamation process management of an area degraded by mining activity consists of three main steps: planning. application of correction or prevention measures and monitoring. In this work, an assessment tool to be used by public bodies or by mining companies in order to support the control and improvement of environmental reclamation practices was developed. The assessment has been carried out with a script based on the national and international good practices regarding environmental reclamation in mines. For testing and calibration purposes, the scripts were applied in three limestone mines. The conclusion is that the evidences - visual, documental and verbal (interview) - must be analyzed in a context which involves the understanding of the environmental and operational characteristics in each mine. The categories for classification of the efficacy assessment of environmental reclamation measures have been defined as: efficacious, partially efficacious, non-efficacious and not applicable. Considering the results, it was possible to identify a \"current scenario\" of the environmental reclamation practices used in each inspected mine and consequently recommend actions to improve the current practices and reduce a future environmental liability. It was concluded that the procedure of the efficacy assessment of the environmental reclamation practices developed in this research is appropriate, but its application can only be made by a professional that presents some experience in the subject. It is a decisive factor for the evaluation and contextualization of the collected evidences. The proposed script for this research can still be applied in other mines with different minerals and quarries.
4

An ethnographic case study in a British primary (elementary) school classroom of academic self-efficacy

Iliff, Kelly 01 May 2011 (has links)
An ethnographic case study of a Year 6 (5th grade) classroom in Southwest England was conducted in order to explore factors that contribute to academic self-efficacy in British education, specifically in this classroom. Data was collected through qualitative observations, a teacher interview, and student questionnaires to determine the level of academic self-efficacy in the classroom. The class consisted of 14 female students and 9 male students, ranging from ten to eleven years old. Of the total number of students, parental consent was received to allow 9 boys and 7 girls to complete questionnaires. Data was analyzed by examining critical issues and comparing anecdotal records to a teacher interview and student questionnaires. Recurrent themes that materialized were: bullying, uniforms, discipline, competition, assessment, and exceptional students. Results showed that these core issues contributed to positive academic self-efficacy among students in this classroom in the context of the British educational system.

Page generated in 0.1067 seconds