Advanced material handling systems' impact on flexible manufacturing systems (FMS) have increased the efficiency and work rate over conventional manufacturing assemblies. The interaction of automated guided vehicles (AGVs), roller conveyors and conveyor belts with robots and machine tools forms highly sophisticated assembly operations. Whilst material handling in FMS today is conventionally used to transport assembly units from one work station to another, it does not take an active role in the manufacturing process. With manufacturers implementing more advanced manufacturing principles to perform agile manufacturing, there is a growing need to implement "smarter" material handling systems that would perform essential, integral roles in the assembly process. This research outlines the development of a cordless linear synchronous motor (CLSM) material handling system. The CLSM incorporates a permanent magnet courier that moves without tether restrictions on an integrated reverse air bearing system which eliminates friction. The CLSM provides a material handling system with enhanced travel, flexibility and accuracy. The CLSM material handling system is designed to integrate with overhead manipulators and part feeders to form a comprehensive flexible manufacturing system. This research covers the 2-D finite element modeling (FEM) used to determine the CLSM's optimal parameters. The development of the motor windings design and construction, together with the control system for the CLSM, is also covered. The CLSM novel air bearing system is outlined and compared to other conventional linear bearing systems. The possible impact of the CLSM on current manufacturing systems is explored to determine the validity of the research project and possible further research opportunities. / Thesis (M.Sc.Eng)-University of Natal, Durban, 2000.

"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft." / Doctor of Philosophy

"Back injuries have consistently been the most common types of injuries suffered by people at work. They have been a significant worker injury problem in most, if not all, industrialised countries for many years and manual handling has long been established as a significant task related back injury causal factor.[...] This research project established that the manufacturers of the jet airlines used by the airlines in this study had not previously been acquainted with the issue of baggage handler back injuries.[...] This study also canvassed the opinion of airline safety professionals and airline baggage handlers concerning baggage handling tasks and working environment related causal factors. [...] A major focus of this research project was also to measure the effect of ACE and Sliding Carpet, two commercially available retro-fit baggage systems, on the risk of back injuries to baggage handlers stacking baggage within Boeing B737 narrow-body aircraft." / Doctor of Philosophy

Im Projekt wurde die Substitution von Metallen durch Holzwerkstoffe in drei ausgewählten Anwendungsfällen untersucht. Es wurde ein Arbeitstisch mit Nutenplatte, ein Schlitten für einen Rollenprüfstand und ein Vertikalförderer in Metallbauweise subsituiert. Die resultierenden drei Holzbauweisen wurden als Prototyp realisiert. Ein Vergleich der Bauweisen zeigt technische, ökonomische und ökologische Vorteile sowie Grenzen der Holzbauweisen. Förderkennzeichen: 22023611 bzw. 11NR236 / The substitution of three applications made from metals using wooden materials was the objective of the project. A workbench with a slotted table top, a sliding carriage for a roller test bench and a vertical conveying system have been substituted. As a result, three wood constructions were realized as prototypes. A comparison of the constructions shows technical, economical and ecological advantages as well as limits of the wood design itself.

This research identifies the attributes to be considered in the selection of an automated guided vehicle (AGV). A distinction is made between automated guided vehicles (AGVs) and an automated guided vehicle system (AGVS). This research is concerned only with the selection of automated guided vehicles (AGVs). A selection model is developed which forces the user to evaluate attributes. his requirements and preferences for AGV The first step of the model allows the user to enter his specifications for AGV attributes which are applicable to his production environment. The second step in the selection model is for the user to determine 8-15 attributes to use as selection criteria. In the third phase, the user inputs his preferences and priorities with respect to the attributes chosen as selection criteria in the second step. model ranks the Based on this information, the selection AGV models in the feasible set. A description of the model and a numerical example are included. Steps 1 and 2, described above, are implemented using an R:BASE™ program. The BASIC computer language was used to perform the interrogation of the user with respect to his priorities and preferences among attributes in Step 3. The IBM PC™ is the hardware chosen for running the selection model. / M.S.

Es wurde ein plattenförmiges Qualitätshalbzeug aus Spezialholzwerkstoffen für den konstruktiven Einsatz im Maschinebau, mit dem Schwerpunkt Fördertechnik entwickelt. Mit diesem Halbzeug sind ökologisch vorteilhafte Konstruktionen möglich. Entwicklungsschwerpunkte waren: einstellbare, hohe absolute und spezifische mechanische Eigenschaften mit kleinen Streuungen. Die Entwicklung wurde durch verschiedene Werkstoffprüfungen von Labor- und Industriewerkstoffen begleitet und deren Ergebnisse mittels speziell erarbeitetet Bewertungskriterien evaluiert. Weiterhin wurde das Werkstoffverhalten von diversen Holzwerkstoffen unter dynamischer Belastung klassifiziert. / A panel-shaped high quality semi-finished product made of special wood-based materials for structural applications in mechanical engineering, with a focus on materials handling technology, was developed. With said semi-finished product ecologically advantageous constructions are possible. Development priorities were: adjustable, high absolute and specific mechanical properties with little variation. The development was accompanied by various materials tests of laboratory and industrially manufactured materials, and their results were evaluated by specially developed evaluation criteria. Furthermore, the material behaviour of various woodbased materials under dynamic loading was classified.

In order to investigate the etiology of and evaluate interventions for work-related back injuries, researchers need efficient, accurate occupational exposure assessment methods suitable for large samples. The chapters in this thesis examine critical decisions using electromyography (EMG): How should exposure be measured? For what duration? Who should be measured, and how many times? Low-back EMG, or muscle activity data, was collected during 138 full-shift field measurements over 30 different job titles at 50 different worksites in 5 heavy industries: forestry, transportation, wood products, construction, and warehousing. Observations and self-reports of posture, manual materials handling (MMH), and driving exposures were collected concurrently. 1) Variability of EMG calibration measurements was investigated on right/left sides, multiple trials, 4 positions, and pre/post-shift. Position accounts for the majority of explained variability; there is little to gain by measuring multiple trials or pre- and post-shift, but measuring both sides and multiple positions is worthwhile. 2) Observation and self-report data were easier to collect and cheaper than the EMG direct measure. Costs and successful field performance need to be weighed against the added data detail when making choices about exposure assessment techniques for epidemiological studies. 3) Observed and self-reported exposures were used to predict EMG exposure metrics using mixed multiple linear regression models. Regression models using observed variables predicted 43-50% of the variability in the EMG metrics, while self-reported variables predicted 21%-36%. The observation exposure model provides a low-cost alternative to direct measurement. The self-reported exposure model should be considered with more caution. 4) Full-shift EMG data was resampled for 4, 2, and 1 hour, and for 10 and 2 minute durations to determine the optimal sampling duration. Bias was consistently low, but shorter durations had higher absolute error, percentage error, and limits of agreement. Durations of 4 and 2 hours may be acceptable but those less than 1 hour had large errors. 5) Components of EMG variance were calculated between- and within-subject, and between- industry, company, job, and post hoc grouping. Resolution, contrast, and exposure-response relationship attenuation were calculated for each grouping scheme. The post hoc scheme had the highest contrast and lowest resolution.

In order to investigate the etiology of and evaluate interventions for work-related back injuries, researchers need efficient, accurate occupational exposure assessment methods suitable for large samples. The chapters in this thesis examine critical decisions using electromyography (EMG): How should exposure be measured? For what duration? Who should be measured, and how many times? Low-back EMG, or muscle activity data, was collected during 138 full-shift field measurements over 30 different job titles at 50 different worksites in 5 heavy industries: forestry, transportation, wood products, construction, and warehousing. Observations and self-reports of posture, manual materials handling (MMH), and driving exposures were collected concurrently. 1) Variability of EMG calibration measurements was investigated on right/left sides, multiple trials, 4 positions, and pre/post-shift. Position accounts for the majority of explained variability; there is little to gain by measuring multiple trials or pre- and post-shift, but measuring both sides and multiple positions is worthwhile. 2) Observation and self-report data were easier to collect and cheaper than the EMG direct measure. Costs and successful field performance need to be weighed against the added data detail when making choices about exposure assessment techniques for epidemiological studies. 3) Observed and self-reported exposures were used to predict EMG exposure metrics using mixed multiple linear regression models. Regression models using observed variables predicted 43-50% of the variability in the EMG metrics, while self-reported variables predicted 21%-36%. The observation exposure model provides a low-cost alternative to direct measurement. The self-reported exposure model should be considered with more caution. 4) Full-shift EMG data was resampled for 4, 2, and 1 hour, and for 10 and 2 minute durations to determine the optimal sampling duration. Bias was consistently low, but shorter durations had higher absolute error, percentage error, and limits of agreement. Durations of 4 and 2 hours may be acceptable but those less than 1 hour had large errors. 5) Components of EMG variance were calculated between- and within-subject, and between- industry, company, job, and post hoc grouping. Resolution, contrast, and exposure-response relationship attenuation were calculated for each grouping scheme. The post hoc scheme had the highest contrast and lowest resolution.

Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2016-12-21T18:14:50Z No. of bitstreams: 0 / Made available in DSpace on 2016-12-21T18:14:50Z (GMT). No. of bitstreams: 0 / Com a alta taxa de desertificação dos solos e a necessidade de irrigação constante dos plantios, existe a necessidade da criação de um polímero superabsorvente (SAP) com a característica de ser biodegradável. Observando o estágio tecnológico relacionado às atividades de pesquisa e desenvolvimento de SAPs no Brasil, foi utilizado o poli (álcool vinílico)/PVA e o amido de mandioca para a formação de hidrogéis a partir de blendas poliméricas. Assim, soluções aquosas desses polímeros foram reticuladas quimicamente, usando o glutaraldeído como agente reticulante e comparadas com amostras reticuladas por radiação gama, irradiadas a uma dose de 25 kgy. Os hidrogéis resultantes foram caracterizados por diversas técnicas analíticas como a fração gel, o intumescimento em água destilada, a espectroscopia de infravermelho com refletância total atenuada ATR (FT-IR), a termogravimetria (TG/DTG), a calorimetria exploratória diferencial (DSC) e a microscopia eletrônica de varredura (MEV). Observou-se uma maior reticulação nos hidrogéis reticulados com o glutaraldeído e em consequência um menor grau de intumescimento quando comparadas com as amostras que foram irradiadas. Com vias a produzir hidrogéis em uma escala industrial, misturas de PVA e amido foram processadas por extrusão reativa, mudando assim o processo de preparação de solução aquosa para misturas secas. Foram extrudadas amostras de PVA com diferentes pesos moleculares tais como o PVA 26-88, o PVA 40-88, o PVA 110-99 e o poli (ácido glioxílico vinílico)/PVGA, este último sintetizado a partir da modificação do PVA 110-99. Foi adicionado na mistura o ácido glioxílico no desenvolvimento do SAP por reticulação química nas amostras do PVA, por ter grupos carboxílicos que podem aumentar o intumescimento e também servir como agente reticulante. Também foram feitas formulações de extrusão sem o ácido glioxílico para serem usados como brancos. Adicionou-se nas misturas diversos agentes plastificantes como a glicerina e o polietilenoglicol (PEG 400) e as propriedades mecânicas foram estudadas. Foram desenvolvidas duas análises fatoriais de 23 para analisar as mudanças na reticulação das formulações. Os pellets foram caracterizados com as mesmas técnicas analíticas que os hidrogéis feitos em solução, adicionando-se análises de intumescimento e reversibilidade de intumescimento em diversos solventes como a água pura, a água da chuva, as soluções tampão de pH 3, pH 7 e pH 10, além de soro fisiológico, visando a aplicação em diferentes solos com diferentes pH e salinidades. Os testes de intumescimento em diferentes sais demonstraram a ter menor retenção de água quando comparada com água pura. Os testes de reversibilidade de intumescimento dos pellets mostraram que a maioria das formulações perde a sua capacidade de intumescimento máximo aos seis primeiros ciclos. Foi feita a compressão dos pellets para observar a flexibilidade dos mesmos, visando aplicações debaixo do solo. Realizou-se um estudo de biodegradação em terra ao longo de 120 dias, e estudou-se a relação direta com os valores da fração gel. Os resultados mostraram que os pellets menos reticulados intumesceram mais, enquanto as microscopias mostraram que essas amostras tinham uma morfologia mais porosa, o que contribuiu na melhora na retenção do líquido. Além disso, eram mais flexíveis e biodegradaram mais rápido, sendo extremamente viáveis para a aplicação na agricultura. Foi verificado que o PVA 40-88 apresentou os melhores valores de intumescimento em diferentes sais. Com o SAP obtido, foi constatado que a extrusão reativa é um método viável para a produção dos SAPs. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Submitted by Pedro Silva Filho (pfsilva@ipen.br) on 2017-11-23T11:10:00Z No. of bitstreams: 0 / Made available in DSpace on 2017-11-23T11:10:00Z (GMT). No. of bitstreams: 0 / O processamento por radiação gama para beneficiamento de produtos tem se tornado uma tecnologia aceita mundialmente. Tem como aplicações a esterilização de produtos médicos, a irradiação de alimentos e produtos agrícolas, a modificação de materiais poliméricos e biomateriais, a preservação de objetos de patrimônio cultural, a esterilização de tecidos humanos para transplante, a mudança de cor em gemas, dentre outros. Desde 2004, o Irradiador Multipropósito de Cobalto-60 do Centro de Tecnologia das Radiações do IPEN tem sido utilizado no estudo e aperfeiçoamento dessas aplicações com objetivos de pesquisa e no estabelecimento de aplicações rotineiras. Este, embora concebido para trabalhar no modo contínuo de irradiação, é utilizado no modo estacionário mais indicado para irradiações de materiais delicados ou de pesquisa. Neste trabalho foram validadas e verificadas experimentalmente as adequações dos métodos à irradiação estacionária; bem como as interrupções para medição de doses em dosímetros de polimetilmetacrilato em processos fracionados, onde seu uso se mostrou adequado para taxas de dose maiores que 2kGy·h-1. A descrição do processo de carga das fontes mostra a importância do seu planejamento e seu impacto na distribuição de taxas de dose. Os mapeamentos das doses e taxas de dose permitiram localizar regiões de valores homogêneos e máximos. Foi estabelecido um procedimento de irradiação de tecidos para aloenxertia utilizando monitoração dosimétrica externa. Foram levantados os custos e despesas de irradiação, aplicáveis a instalações governamentais. O balanço energético da piscina de armazenamento das fontes permitiu calcular o fluxo de calor do sistema e definir as condições máximas de operação sem trocador de calor. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP