Complex Impedance Measuring Instruments (CIMI’s) are non-nuclear devices that calculate the dry unit weight and moisture content of soil by means of electromagnetic wave propagation theory. Unlike nuclear based test devices, these devices do not require certification or elaborate maintenance to own and operate. CIMI operation requires a soil specific calibration process where soil moisture and unit weight are correlated to electrical parameters. A new, smaller acrylic mold was developed as an alternative calibration tool to the manufacturer’s recommended mold. Calibrated soil models were generated using manufacturer recommended procedures as well as new procedures involving an acrylic mold. Models were then tested for accuracy. The new procedure outperformed the manufacturer’s procedure. Another small, acrylic mold was used to investigate the relationship between CIMI readings and soil parameters. Using several samples from four soils, the relationship between moisture, unit weight, and some electrical parameters was characterized. This characterization was then used to create a new, accurate calibration procedure.

The aim of this study was to determine the knowledge of critical care nurses regarding ventilator waveforms in order to develop an educational programme on this topic. A quantitative, descriptive, contextual research design was used, and convenience sampling implemented. A survey, using a questionnaire as measuring instrument, was conducted among critical care nurses in selected private hospitals in Gauteng. The response rate was 69%. Cronbach’s alpha indicated that the questionnaire was fairly reliable. The total average percentage achieved by the group of 111 respondents was 40,28%, which is 19.72% below the set competency indicator of 60%. Only 15 respondents achieved a percentage of or above the competency indicator. Results proved that the respondents required intensive training on the topic. A user-friendly education programme in the format of a PowerPoint presentation was developed to address knowledge deficiencies in critical care nurses’ interpretation of ventilator graphics. / Dissertation (MCur (Clinical))--University of Pretoria, 2007. / Nursing Science / MCur / unrestricted

The objektive of this thesis is acquaint with ways of speed sensing and torque noment sensing in automated systems and apply to chosen instruments to the real laboratory work, witch sould by instrumental for education in laboratory of drives.

Customer service has recently become an important subject with significant consequences for academic institutions. However, there is a lack of research in this area and relevant, scientifically justifiable studies should assist in determining what is required for the provision of good quality service to students. The purpose of this study was to determine the difference between the expectations of service and the perceptions of actual service provided by the Human Resources Department at the University of Pretoria. The respondent group included students from a variety of disciplines who chose Industrial and Organisational Psychology as subject. Based on the survey method a questionnaire was used to gather the relevant information. The literature study identified five important dimensions of customer service namely tangibles, reliability, responsibility, security and empathy. The expectations and perceptions of the students (n=255) of actual service in terms of the above dimensions were determined and weighed against each other. The results of this study showed that although there is room for improvement, the level of customer service provided by the department was proven to be satisfactory. The following conclusions were made regarding the perceptions of the research group in terms of current and expected levels of service. Aspects that appeared to be most satisfactory, were appearance of employees, reliability of lecturers, safety of interaction, time spent with students and keeping of accurate records. There is room for improvement in the following areas: spending time with individuals, current working and consulting hours, efficiency of available facilities and attention given to students' needs. Field of study, age, language, residence, academic and historical year did not have any effect worth mentioning on the perceptions of current levels of service. Biographical variables did have an impact on the expectations of levels of service. / Dissertation (MCom)--University of Pretoria, 2001. / Human Resource Management / unrestricted

The De Witte (2000) Job Insecurity Scale (JIS) claims to measure the cognitive and affective dimensionalities of job insecurity. However, there is a concern as to whether this is in fact a true reflection of the individual, owing to the possibility that the JIS may rather measure the negative and positive dimensionalities of job insecurity instead. This research article aims to investigate whether a revised version of the JIS measures the cognitive and affective dimensionalities of job insecurity, or alternatively, other dimensionalities of the revised JIS after additional items have been added to the scale. Furthermore, it is aimed at determining whether the constructs of the revised JIS prove to be invariant across gender, age and educational level, and to determine whether the psychometric properties of a revised version of the JIS is a valid and reliable instrument. Furthermore, this research article aims at determining if the revised version of the JIS is a more accurate indicator of job insecurity and its relation with organisational outcomes (job satisfaction and organisational commitment), as well as its equivalence across various demographic variables (i.e. gender, age and educational level). A quantitative research approach was used. This approach was utilised to statistically reflect the psychometric properties of the revised version of the JIS, using large amounts of data relating to job insecurity. A cross-sectional design was used for the purpose of this study. The sample consisted of employees working in the mining sector (n = 262) and manufacturing industries (n = 208), constituting a total sample of 470 (n = 470). Non-probability quota sampling was used to adequately divide the population according to its sector in the economy, and further according to the industry. The results showed that the revised JIS consists of a two-factor model, namely job security and job insecurity. Furthermore, it was found that the revised JIS is valid in providing relationships with organisational outcomes (job satisfaction and organisational commitment). The study indicated that job insecurity has a negative relationship with job satisfaction, as well as a predictive positive relationship with organisational commitment. The revised JIS proved to have discriminant validity in that it does not relate to an unrelated construct (physical tiredness during work). Lastly, the revised JIS can be deemed valid across different demographic groups (gender, age and educational level). Recommendations are made to be applied in practice, as well as for future research. / MA (Industrial Psychology), North-West University, Potchefstroom Campus, 2015

The De Witte (2000) Job Insecurity Scale (JIS) claims to measure the cognitive and affective dimensionalities of job insecurity. However, there is a concern as to whether this is in fact a true reflection of the individual, owing to the possibility that the JIS may rather measure the negative and positive dimensionalities of job insecurity instead. This research article aims to investigate whether a revised version of the JIS measures the cognitive and affective dimensionalities of job insecurity, or alternatively, other dimensionalities of the revised JIS after additional items have been added to the scale. Furthermore, it is aimed at determining whether the constructs of the revised JIS prove to be invariant across gender, age and educational level, and to determine whether the psychometric properties of a revised version of the JIS is a valid and reliable instrument. Furthermore, this research article aims at determining if the revised version of the JIS is a more accurate indicator of job insecurity and its relation with organisational outcomes (job satisfaction and organisational commitment), as well as its equivalence across various demographic variables (i.e. gender, age and educational level). A quantitative research approach was used. This approach was utilised to statistically reflect the psychometric properties of the revised version of the JIS, using large amounts of data relating to job insecurity. A cross-sectional design was used for the purpose of this study. The sample consisted of employees working in the mining sector (n = 262) and manufacturing industries (n = 208), constituting a total sample of 470 (n = 470). Non-probability quota sampling was used to adequately divide the population according to its sector in the economy, and further according to the industry. The results showed that the revised JIS consists of a two-factor model, namely job security and job insecurity. Furthermore, it was found that the revised JIS is valid in providing relationships with organisational outcomes (job satisfaction and organisational commitment). The study indicated that job insecurity has a negative relationship with job satisfaction, as well as a predictive positive relationship with organisational commitment. The revised JIS proved to have discriminant validity in that it does not relate to an unrelated construct (physical tiredness during work). Lastly, the revised JIS can be deemed valid across different demographic groups (gender, age and educational level). Recommendations are made to be applied in practice, as well as for future research. / MA (Industrial Psychology), North-West University, Potchefstroom Campus, 2015

Academics encounter problems with the selection, evaluation, testing and implementation of e-assessment software tools. The researcher experienced these problems while adopting e-assessment at the university where she is employed. Hence she undertook this study, which is situated in schools and departments in Computing-related disciplines, namely Computer Science, Information Systems and Information Technology at South African Higher Education Institutions. The literature suggests that further research is required in this domain. Furthermore, preliminary empirical studies indicated similar disabling factors at other South African tertiary institutions, which were barriers to long-term implementation of e-assessment. Despite this, academics who are adopters of e-assessment indicate satisfaction, particularly when conducting assessments with large classes. Questions of the multiple choice genre can be assessed automatically, leading to increased productivity and more frequent assessments. The purpose of this research is to develop an evaluation framework to assist academics in determining which e-assessment tool to adopt, enabling them to make more informed decisions. Such a framework would also support evaluation of existing e-assessment systems. The underlying research design is action research, which supported an iterative series of studies for developing, evaluating, applying, refining, and validating the SEAT (Selecting and Evaluating an e-Assessment Tool) Evaluation Framework and subsequently an interactive electronic version, e-SEAT. Phase 1 of the action research comprised Studies 1 to 3, which established the nature, context and extent of adoption of e-assessment. This set the foundation for development of SEAT in Phase 2. During Studies 4 to 6 in Phase 2, a rigorous sequence of evaluation and application facilitated the transition from the manual SEAT Framework to the electronic evaluation instrument, e-SEAT, and its further evolution. This research resulted in both a theoretical contribution (SEAT) and a practical contribution (e-SEAT). The findings of the action research contributed, along with the literature, to the categories and criteria in the framework, which in turn, contributed to the bodies of knowledge on MCQs and e-assessment. The final e-SEAT version, the ultimate product of this action research, is presented in Appendix J1. For easier reference, the Appendices are included on a CD, attached to the back cover of this Thesis.. / Computing / PhD. (Information Systems)

As variáveis climáticas como temperatura do ar, umidade relativa do ar e radiação solar exercem grande influência sobre a produção agrícola, sendo capazes de ocasionar perdas durante o processo produtivo, acarretando em um aumento considerável no preço do produto final. Desse modo, a presente pesquisa teve por objetivo, desenvolver um sistema automatizado de baixo custo, tendo como base o microcontrolador Basic Step 1, o qual gerenciou um circuito eletrônico capaz de coletar e armazenar dados das respectivas variáveis climáticas, em um dispositivo de memória flash com conexão USB (pen drive). Além disso, o equipamento conta com o Data Basic - Software, o qual foi elaborado de modo a permitir ao usuário a análise dos dados coletados, com fácil visualização, devido à sua interface gráfica, bem como seu manuseio pelo fato de estabelecer uma conexão com planilha eletrônica (EXCEL). Os resultados mostraram a viabilidade do uso do sistema automatizado (Data-Basic) o qual funcionou com regularidade e precisão ao coletar e armazenar o sinal de tensão contínua enviado pelos 3 sensores. Assim, os dados coletados pelos sensores de umidade relativa do ar e temperatura, HIH 4000 e LM35, respectivamente demonstraram-se confiáveis, evidenciando a viabilidade do uso do equipamento, embora o sensor de radiação solar tenha demonstrado fragilidade e necessidade de uma pré-calibração antes de sua instalação. O custo de montagem do equipamento foi cerca de 50% menor em relação aos data loggers portáteis e apresentou fácil manutenção, pois permite a troca de placas como a do Basic Step1 ou do módulo de gravação PenBS, sem contar que os sensores são externos o que facilita também sua substituição caso seja necessário. Desse modo, pôde-se concluir a viabilidade de utilização deste instrumento mediante o seu baixo custo de produção, porém para longos períodos de coleta, recomenda-se a utilização de uma bateria externa a fim de se evitar a perda de dados pela falta de energia da rede elétrica, além disso, durante o processo de instalação, devem ser tomadas precauções no sentido de evitar a oxidação dos sensores e erros de medida, que podem afetar diretamente a qualidade dos dados coletados. / Climate variables such as air temperature, air humidity and solar radiation have a significant impact on agricultural yield. These variables affect the production process, and have a considerable influence on final product prices. The objective of this research, therefore, was to develop a low-cost, automated system, based on the Basic Step 1 microcontroller, to collect and store climate data in a flash memory device with USB connection (pen drive). In addition, the system includes the Data Basic Software, developed to enable the user to visualize the data in a graphical user interface and to manipulate the data in a spreadsheet (EXCEL). The results demonstrated the viability of the automated system (Data-Basic), which worked with regularity and precision in measuring and storing continuous voltage signals from 3 sensors. The measured data from the air humidity and temperature sensors, HIH4000 and LM35, were reliable, showing the viability of the system, while the radiation sensor was fragile and required pre calibration before installation. The cost of mounting the equipment was approximately 50% of that of a portable data logger. The system is easy to maintain, allows for the replacement of elements such as the microcontroller (Basic Step 1) or the storage module (PenBS), and has external sensors which can be replaced if necessary. It is feasibility to use this tool because of its low production cost. However, for extended periods of data collection, it is recommended that an external battery be added to prevent data loss during power outages. During the installation process, precautions should be taken to prevent the oxidation of the sensors, which would result in measurement errors, directly affect the quality of data collected.

[pt] O para-raios é o principal equipamento de proteção dos transformadores e linhas de transmissão de energia, que estão presentes em todo território nacional, protegendo-os de descargas atmosféricas e sobretensão, evitando grandes perdas de equipamentos e um custo relativamente alto para as concessionárias de energia. O para-raios precisa obter conformidade e certificação em relação à qualidade do material e a suas características de proteção, e um dos ensaios de verificação de desempenho baseia-se na resposta ao impulso de corrente. Contudo, para a realização destes ensaios de desempenho é necessário que haja um sistema de medição acreditado, apto a realizá-los com precisão e rastreabilidade aos padrões de transdutores, ou seja, com níveis de incerteza dentro dos limites aceitáveis, segundo a norma IEC 62475:2010. O Inmetro, que é o Instituto Nacional de Metrologia do Brasil, ainda não possui um Sistema de Medição de Referência (SMR) que possa ser empregado na fiscalização e acreditação de laboratórios que venham a exercer a função de Sistema de Medição Aprovado (SMA), levando a rastreabilidade e conformidade aos padrões de transdutores de corrente elétrica, de modo a produzir equipamentos com confiabilidade e segurança. Assim, essa dissertação faz um levantamento dos níveis de rastreabilidade e um estudo normativo e estrutural de ensaios de impulso de corrente, à luz da norma IEC 62475:2010. / [en] The surge arrester is the main protection equipment of the power transformers and power transmission lines, which are present throughout the country, protecting them from lightnings and overvoltage, avoiding large equipment failures and a relatively high cost for the power companies. The arrester must obtain conformity and certification regarding the quality of the material and its safety features, and one of the performance verification tests is based on the response to current impulses. However, to realize these performance tests it is necessary to have a measurement system accredited to perform this type of test, with accuracy and traceability of the standard transducers, that is, uncertainty levels within acceptable limits according to IEC 62475:2010. The Brazilian National Institute of Metrology ( INMETRO) does not have a Reference Measuring System (RMS) that can be used in the inspection and accreditation of laboratories that will perform as a Approved Measuring System, giving traceability and conformity to the electrical current transducers standards (Shunts or CTs), so as to produce reliable and safe equipments. Thus, this dissertation surveys the traceability levels and the normative and structural landscape regadring current impulse tests based on IEC 62475:2010.

As variáveis climáticas como temperatura do ar, umidade relativa do ar e radiação solar exercem grande influência sobre a produção agrícola, sendo capazes de ocasionar perdas durante o processo produtivo, acarretando em um aumento considerável no preço do produto final. Desse modo, a presente pesquisa teve por objetivo, desenvolver um sistema automatizado de baixo custo, tendo como base o microcontrolador Basic Step 1, o qual gerenciou um circuito eletrônico capaz de coletar e armazenar dados das respectivas variáveis climáticas, em um dispositivo de memória flash com conexão USB (pen drive). Além disso, o equipamento conta com o Data Basic - Software, o qual foi elaborado de modo a permitir ao usuário a análise dos dados coletados, com fácil visualização, devido à sua interface gráfica, bem como seu manuseio pelo fato de estabelecer uma conexão com planilha eletrônica (EXCEL). Os resultados mostraram a viabilidade do uso do sistema automatizado (Data-Basic) o qual funcionou com regularidade e precisão ao coletar e armazenar o sinal de tensão contínua enviado pelos 3 sensores. Assim, os dados coletados pelos sensores de umidade relativa do ar e temperatura, HIH 4000 e LM35, respectivamente demonstraram-se confiáveis, evidenciando a viabilidade do uso do equipamento, embora o sensor de radiação solar tenha demonstrado fragilidade e necessidade de uma pré-calibração antes de sua instalação. O custo de montagem do equipamento foi cerca de 50% menor em relação aos data loggers portáteis e apresentou fácil manutenção, pois permite a troca de placas como a do Basic Step1 ou do módulo de gravação PenBS, sem contar que os sensores são externos o que facilita também sua substituição caso seja necessário. Desse modo, pôde-se concluir a viabilidade de utilização deste instrumento mediante o seu baixo custo de produção, porém para longos períodos de coleta, recomenda-se a utilização de uma bateria externa a fim de se evitar a perda de dados pela falta de energia da rede elétrica, além disso, durante o processo de instalação, devem ser tomadas precauções no sentido de evitar a oxidação dos sensores e erros de medida, que podem afetar diretamente a qualidade dos dados coletados. / Climate variables such as air temperature, air humidity and solar radiation have a significant impact on agricultural yield. These variables affect the production process, and have a considerable influence on final product prices. The objective of this research, therefore, was to develop a low-cost, automated system, based on the Basic Step 1 microcontroller, to collect and store climate data in a flash memory device with USB connection (pen drive). In addition, the system includes the Data Basic Software, developed to enable the user to visualize the data in a graphical user interface and to manipulate the data in a spreadsheet (EXCEL). The results demonstrated the viability of the automated system (Data-Basic), which worked with regularity and precision in measuring and storing continuous voltage signals from 3 sensors. The measured data from the air humidity and temperature sensors, HIH4000 and LM35, were reliable, showing the viability of the system, while the radiation sensor was fragile and required pre calibration before installation. The cost of mounting the equipment was approximately 50% of that of a portable data logger. The system is easy to maintain, allows for the replacement of elements such as the microcontroller (Basic Step 1) or the storage module (PenBS), and has external sensors which can be replaced if necessary. It is feasibility to use this tool because of its low production cost. However, for extended periods of data collection, it is recommended that an external battery be added to prevent data loss during power outages. During the installation process, precautions should be taken to prevent the oxidation of the sensors, which would result in measurement errors, directly affect the quality of data collected.