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  • 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

An inquiry into the possible causes of Standard 10 examination malpractices : a socio-pedagogic perspective

Sibisi, Lindiwe Pamela January 1989 (has links)
Submitted in partial fulfilment of the requirements for the degree of MASTER OF EDUCATION in the department of EDUCATIONAL PlANNING AND ADMINISTRATION at the UNIVERSITY OF ZULULAND, 1989. / The aim of the study was to find out what the causes of standard 10 examination malpractices were. Standard 10 pupils, teachers, and principals were consulted and interviewed for this purpose. In this study two research methods were used; namely literature review and an empirical investigation. Literature was reviewed on the researched problem. Ndlovu (1983) maintains that some teachers are not in class during their teaching periods because they are in the staffroom or are not at school. Thus pupils involve themselves in examination malpractices in order to pass. The findings of this study were further backed up by Thembela (1982) who is of the opinion that copying is not prevented in some of the centres. In fact in some cases invigilators allow and encourage pupils to copy. There were three distinct samples to which questionnaires were administered. The questionnaire consisted of structured as well as the unstructured items for validity and reliability. The research was conducted among 300 pupils, 90 teachers and 11 principals. The researcher has preferred to use the questionnaire because it is more convenient and economical. By using a questionnaire one can have a lot of respondents without a lot of expense in time and effort. It covers a lot of people within a short space of time. The bigger the number of respondents the greater is the validity in the results. Each respondent receives the same set of questions which are phrased in the same way. The questionnaires are supposed to give a more comparable data. It took the researcher about 1 hour to get pupils, teachers and principals to complete the questionnaire. The researcher analysed data manually. Percentages were mainly used to analyse the pupils1, teachers1 and principals* responses. From the results it was found that standard 10 examination malpractices were caused by absenteeism of both teachers and pupils, lack of teaching equipment, laziness of both teachers and pupils, incompletion . of the syllabus, ^-.■stayg.ways.,-"; teachers-who are engaged in extra mural studies "-lack of prescribed books, and teachers who are not dedicated to their work. The following, hypotheses were formulated: (1) Stayaways, laziness and irresponsibility affect serious teaching and learning at school, leading in turn to the buying of stolen examination papers. (2) Tight security in the department prevents leakage. (3) If malpractices are suspected the department withholds results. (4) Some irresponsible members of^ the community sell stolen examination papers to pupils. The above hypotheses were proved valid in the analysis and interpretation of data. The findings of this study are recommended for further research.
2

Analysis of cellular mechanisms involved in scatter factor/hepatocyte growth factor-induced changes in cultured epithelial cells

Williams, Matthew John January 2002 (has links)
No description available.
3

Statistical modelling of the relationship between learner support intervention and matric pass rates in Letlhabile area, North-West Province of South Africa

Matshego, Joseph Nkashe January 2013 (has links)
Thesis (MSc(Statistics)) -- University of Limpopo (Medunsa Campus), 2012. / This study used statistical methods to determine the relationship between matric pass rates and interventions in the schools in the Letlhabile area. Nine schools were identified in this area. Five years (2007 to 2011) were looked at. Regressions methods were tried in which various forms of relationships were compared. The methods were linear, curvilinear (quadratic to polynomial of 4th power), exponential and power regressions were used in the tentative models investigated. The measures of bias and precision were used to compare the models. Multicollinearity was also investigated where it was possible. Time series analysis was used to illustrate the trend patterns of the pass rates in the various schools as well as the pattern of the numbers of interventions. In most of these schools the numbers of interventions increased over the five years and in only a few schools the number of interventions decreased over these years. . A highlight of this study is that more interventions enhanced the matric pass rates. It was also evident that in the years in which the interventions decreased, the pass rates also de.creased. The regression methods investigated were all showing to be applicable in the prediction of pass rates from the numbers of interventions. This was concluded from realising that thelneasures of bias, precision and quality all ratified them. The methods were compared in order to select the best one based on the measures. The linear regression in which the pass rates.areregressed on the number of interventions came out as the leading model in terms of all the criteria used.
4

The investigation of some socio-educational factors contributing to high failure rate in matric in KwaZulu

Khathi, Lamulani Joseph January 1990 (has links)
Submitted in partial fulfilment of the requirements for the degree of Master of Education in the Department of Planning and Administration in the University of Zululand, 1990. / This study looks into the problem of failure in Matric in Black schools in KwaZulu. Some researchers have focused on causes for academic failure before. Some of these researchers are: Souper, (1976); Bryant, (1978); Havinghurst, (1979); Donald, (1980); Simons, (1980). Failure is rarely, if ever, attributable to one simple cause. There are likely to be a multiplicity of interrelated causes. Some' of these causes are : family disorganisation; family size and education; poor study facilities at home and teacher-pupil ratio. Failure at school may imply that one may fail in life. Society believes that school subjects are the means of i equipping pupils with the knowledge of understanding certain socio-economic and political demands. School subjects, it is believed, reveal the r, ealities that they should know in their society. It is through these school subjects that the child will know how to live comfortable with other people (Social Studies); how to look after his/her body, (Physiology and Hygiene); how other organisms are important in her/his life, (Biology/ Ecology; (Geography) .
5

The role of liver matrix degradation in the development of hepatic fibrosis in genetic haemochromatosis

George, David Keith January 1999 (has links)
No description available.
6

Optical Waveguide Interconnects in Optoelectronic Matrix Switches

Ersoni, Michael 12 1900 (has links)
The speed and simplicity of the metal-semiconductor-metal (MSM) detector has made it a prime candidate for use in integrated optoelectronic circuits. While in most applications the optical input is coupled in through the top surface of the device, it is also possible to distribute the optical signal by means of transparent waveguides that are located below the absorbing detector layer. By controlling the degree of coupling between the waveguide and detector layers the detectors can be made to act as optical taps. The optical signal can thus be shared among a series of detectors as required in optoelectronic switching applications. We have made a series of simple ridge waveguides, each with a number of MSM structures designed for the characterization of absorption, responsivity and frequency response. A 4x4 optoelectronic switch was also fabricated and analyzed. We show that balancing the switch is accomplished by tailoring the absorption coefficient in the detector region so that all detectors absorb equal amounts of optical power. / Thesis / Master of Engineering (ME)
7

The Relationship Between Matric Water and Related Psychological Properties

Al-Saadi, Hussain Ali 01 May 1972 (has links)
Matric water was measured as the water retained by plant material on a pressure membrane or ultra filter after equilibration under 20 bars nitrogen gas pressure and the removal of free water. At increasing pressures lesser amounts of water are held by matric or colloidal surface forces. Twenty bars pressure, supplied by cylinder nitrogen for 48 hours, was used in this study. Matric water was expressed as a percent of either (a) the dry weight or (b) the original water content. Plant material was oven dried, ground, and then saturated with water prior to the determination. The matric water values of different aged leaves from a number of local species were studied. The highest values of matric water were found in the younger leaves. Both matric water and original moisture content were higher for spring than for fall or midwinter values. The linear relationship between matric water and original moisture content was established for all trees studied. Another linear relation was found between either the matric water or the water content of the tree leaves and the inverse of their age in months. Petioles had a higher matric water value as well as a water content than leaf blades in all the species studied. Roots and old stems had the lowest values of matric water. The matric water values increased during the cold hardening of Cabbage leaves. No appreciable differences in the matric water values for Sunflower leaves grown under different temperatures were found. The crude protein and cell wall materials were isolated and their matric water values studied. Crude proteins had a higher value of matric water than cell wall materials alone. The matric water values of several biocolloidal materials were determined also. Agar had the highest value of matric water, fibrous cellulose the lowest, and the proteins had intermediate values.
8

Investigating the impact of an intervention programme in a Grade 11 mathematics class : a case study

Mnqwazi, Xabiso Priceless January 2015 (has links)
Magister Educationis - MEd / The general performance of learners in mathematics in most secondary schools in South Africa is not encouraging. Statistics reveal that there is a general poor performance in mathematics and related science subjects especially in those schools located in previously disadvantaged communities. There is just a need for appropriate interventions of the significance of mathematics in present society which is now characterised by high information and technology thrust. The objective of the study was to investigate the impact of the tutorial intervention programme on the performance of a grade eleven mathematics class with a view to improving the mathematics performance of these grade 11 learners. The selection of the action research based method was premised on the idea that it would help the researcher to improve his tutoring practice as well as contributing to better learner performance. Data was collected through the use of qualitative research methods. These involved observation, the utilisation of focus group discussions of learners, and in-depth interviews with randomly selected learners and other mathematics colleagues. A careful mix of learners of different learning abilities was made so that high performers would assist those whose performance was lower. In each group of five at least two high performers were included. Findings of the study point to the effectiveness of the tutorial process, justifying its adoption on a long term basis. In general, it can be concluded that the tutoring strategies used by the researcher had a positive effect on the knowledge retention of the learners. This conclusion was arrived at from an observation of improved test results over time, the learners‟ views in the questionnaires as well as those of peer observers.
9

Interpretation of Load Transfer Mechanism for Piles in Unsaturated Expansive Soils

Liu, Yunlong 07 February 2019 (has links)
Water infiltration associated with natural precipitation events or other artificial activities such as pipe leaks in expansive soils significantly influence the engineering properties; namely, coefficient of permeability, shear strength and volume change behavior. For this reason, it is challenging to design or construct geotechnical infrastructure within or with expansive soils. Several billions of dollars losses, world-wide, can be attributed to the repairing, redesigning and retrofitting of infrastructure constructed with or within expansive soils, annually. Piles are widely used as foundations in expansive soils extending conventional design procedures based on the principles of saturated soil mechanics. However, the behavior of piles in unsaturated expansive soils is significantly different from conventional non-expansive saturated soils. Three significant changes arise as water infiltrates into expansive soil around the pile. Firstly, soil volume expansion contributes to ground heave in vertical direction. Secondly, volume expansion restriction leads to development of the lateral swelling pressure resulting in an increment in the lateral earth pressure in the horizontal direction. Thirdly, pile-soil interface shear strength properties change due to variations in water content (matric suction) of the surrounding soil. These three changes are closely related to matric suction variations that arise during the water infiltration process. For this reason, a rational methodology is necessary for the pile load transfer mechanism analysis based on the mechanics of unsaturated soils. Studies presented in this thesis are directed towards developing simple methods to predict the load transfer mechanism changes of piles in expansive soils upon infiltration. More emphasis is directed towards the prediction of the pile mechanical behavior which includes the pile head load-displacement relationship, the pile axial force (shaft friction) distribution and the pile base resistance using unsaturated mechanical as a tool. The function of matric suction as an independent stress state variable on the mechanical behavior pile is highlighted. More specifically, following studies were conducted: (i) Previous studies on various factors influencing the load transfer mechanisms of piles in unsaturated expansive soils are summarized and discussed to give a background of current research. More specifically, state-of-the-art reviews are summarized on the application of piles in expansive soils, mobilization of lateral swelling pressure, mobilization of unsaturated pile-soil interface shear strength and methods available for the load transfer analysis of piles in expansive soils. (ii) Employing unsaturated soil mechanics as a tool, theoretical methods are proposed for estimating the lateral earth pressure variations considering the mobilization of lateral swelling pressure. The proposed methods are verified using two large-scale laboratory studies and two field studies from published literatures. (iii) The shear displacement method and load transfer curve methods used traditionally for pile load transfer mechanisms analysis for saturated soils were modified to extend their applications for unsaturated expansive soils. The influence of volume change characteristics and unsaturated soil properties on unsaturated expansive soils are considered in these methods. The validation of the modified shear displacement method and modified load transfer curve method were established using a large-scale model test performed in the geotechnical engineering lab of University of Ottawa and a field case study results from the published literature. (iv) A large-scale model pile infiltration test conducted in a typical expansive soil from Regina in Canada in the geotechnical lab of University of Ottawa is presented and interpreted using the experimental data of volumetric water content suction measurements and shear strength data. The results of the comprehensive experiment studies are also used to validate the proposed modified shear displacement method and modified load transfer curve method achieving reasonable good comparisons. The proposed modified shear displacement method and modified load transfer curve method are simple and require limited number soil properties including the soil water characteristic curve (SWCC), matric suction profile upon wetting and drying and some soil physical properties. Due to these advantages, they can be easily and conveniently applied in engineering practice for prediction of the mechanical behavior of piles in unsaturated expansive soils, which facilitate practicing engineers to produce sound design of pile foundation in unsaturated expansive soils in a simplistic manner.
10

Avaliação funcional de instrumentos de medição do potencial matricial da água do solo seco / Functional evaluation of instruments for measuring the water status of dry soil

Rodrigues, Thaís Tokashiki Tavares 31 July 2017 (has links)
Estudos sobre a dinâmica da água no solo não-saturado passam pela medição, estimativa e/ou previsão do potencial matricial ou do teor de água. Diante disso, o objetivo da presente proposta foi realizar testes e avaliações de três instrumentos com características distintas, capazes de medir o potencial matricial da água no solo seco, sendo eles: um medidor baseado no ponto de orvalho (WP4), um instrumento baseado na pressão (tensiômetro de polímero-PoT) e um instrumento baseado na capacitância elétrica (FDR EC-5). A análise foi realizada em três partes: 1. Avaliação do WP4 com amostras com potencial equilibrado na câmara de Richards ou secas ao ar; 2. Avaliação dos PoT e 3. Experimento comparativo entre instrumentos em colunas de solo. Nesses experimentos foram utilizados materiais de solos com texturas diferentes (um de textura argilosa, um de textura média e um de textura arenosa). Os experimentos foram conduzidos no Laboratório de Física de Solo do CENA/USP em Piracicaba-SP. Os resultados mostram que o FDR EC-5 apresentou bons resultados em relação ao método que foi definido como padrão (método gravimétrico), por mais que possua erros associados à curva de retenção. O WP4, que possui uma ampla faixa de leitura de 0 a -30000 m, não se apresentou muito preciso para solos úmidos (h > -70 m) devido ao seu procedimento de leitura. Para solos muito secos, no entanto, ele se apresenta como uma boa opção. O tensiômetro de polímero mede a pressão diretamente na faixa entre 0 a -150 m. Esse instrumento requer cuidados com o coeficiente de calibração, a verificação do limite individual de funcionamento e o contato entre a cápsula porosa do tensiômetro e o solo / Studies about unsaturated soil water dynamics involve the measurement or prediction of matric potential and/or soil water content. In this study, the objective was to test and evaluate three measurement devices able to measure matric potential in dry soil: a dew point based instrument (WP4), a pressure based instrument (polymer tensiometer - PoT) and an electromagnetic capacitance based instrument (FDR EC-5). The analysis was performed in three steps: 1. Evaluation of WP4 using soil samples in equilibrium with a pressure chamber or with surrounding air; 2. Evaluation of PoT and 3. Experiments to compare devices in soil columns. In these experiments three soil textures were used (clay texture, silt texture and sand texture). The experiments were conducted in the soil physics lab at CENA/Universidade de São Paulo, Piracicaba, Brazil. Results show that the FDR EC-5 performed well when compared to the (standard) gravimetric method, even though it includes errors associated with the retention curve. The WP4 device has a wide reading range of 0 to -30000 m, but is not accurate for saturated or moist soils (h > -70 m) due to its working principle. For very dry soils, however, it is a good option. The polymer tensiometers measure pressure directly and perform in a range between 0 to -150 m. This equipment showed to require special care regarding its calibration coefficient, verification of individual reading limit and the porous cap-soil contact

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