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1
Bothner, Rose. "An optimization model for selecting the economical cutting parameters in an external forward turning operation /." Online version of thesis, 1990. http://hdl.handle.net/1850/10592.
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Oen, Richard James. "Measuring cutting forces on a metal cutting lathe." Ohio : Ohio University, 1989. http://www.ohiolink.edu/etd/view.cgi?ohiou1182447008.
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Cullen, Paul. "The place-names of the Lathes of St Augustine and Shipway, Kent." Thesis, University of Sussex, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263152.
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Moore, Robert Keith. "Computer aided programming of a CNC lathe." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25123.
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A software package and associated hardware have been developed which gives users of the ORAC CNC Training Lathe an easier and faster method of manufacturing on the lathe. The package, entitled ORACAP, uses the computing power of a mini-mainframe computer, a VAX 11/750, to assist in part design, program generation, program optimization, and program proving for the ORAC Lathe. The package is designed for users unfamiliar with computers such as students in an educational institute or workers in a production facility and uses command procedures to simplify the preparation and execution of the modules of the package. In addition to providing users with a valuable tool for manufacturing, ORACAP also gives users insight into the Computer Aided Design and Computer Aided Manufacturing methods used in industry, that is, it demonstrates the methods which allow production of a part from a very concise description of its geometry. Finally, ORACAP demonstrates the production advantages of a CAD/CAM system over conventional manufacturing methods for small to medium size batch production.Applied Science, Faculty of
Mechanical Engineering, Department of
Graduate
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Ковальчук, Р. І. "Ефективність регулювання і стабілізації характеристик затискних механізмів токарних верстатів." Thesis, Вид-во СумДУ, 2005. http://essuir.sumdu.edu.ua/handle/123456789/19986.
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Юрчишин, О. Я. "Дослідження характеристик широкодіапазонних цангових патронів з одинарною мультиплікацією для токарно-револьверних верстатів з ЧПК." Thesis, Вид-во СумДУ, 2005. http://essuir.sumdu.edu.ua/handle/123456789/20168.
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Donovan, Alan. "On-line tool wear identification by tribo emf signal analysis." Thesis, Queensland University of Technology, 1993. https://eprints.qut.edu.au/107080/1/T%28BE%26E%29%20545%20On-line%20tool%20wear%20indentification%20by%20tribo%20emf%20signal%20analysis.pdf.
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The acoustic air-borne signal, the cutting tool vibration, and the stochastic component of the tribo emf signal produced by single point continuous turning operations have been analysed using statistical techniques. The correlation between variation in their statistical function values and the degree of cutting tool flank wear has been considered to determine to what extent they may be applied to "in-process" tool wear identification. The test program used a range of cutting parameters typical for the cutting of mild steel and high tensile cast iron using high speed steel and carbide
cutting tools. The acoustic sound and the tool vibration have been shown to have limited potential as a means of accurate tool wear identification. The tribo emf signal showed a greater dependence on the tool condition,
and accurate assessment was carried out using high tensile cast iron workpieces. The statistical variations of the tribo emf signal obtained for cutting mild steel were highlighted using pseudo random binary sequence slotted test workpieces. The method was developed, using a comparable sequence defined as a quasi random binary sequence, to investigate the response characteristics of the tribo emf by means of correlation analysis, and also to highlight the dynamic response of the lathe through spectral
analysis of vibration measured at the toolpost. A mathematical model of the contact conditions at the tool workpiece interface was proposed and tested; showing good correlation with monitored spectral variation of the
tribo emf for the cutting of cast iron.
Finally, conclusions have been made concerning the potential of the various stochastic signals for the purpose of in-process tool wear identification.
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Заболоцький, В. Ю. "Особливості формоутворення мікрорельєфу поверхні обертання на багатошпиндельних токарних автоматах." Thesis, Вид-во СумДУ, 2005. http://essuir.sumdu.edu.ua/handle/123456789/19979.
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Leclerc, Michael Edward. "Characterization of a vertical two axis lathe." Thesis, Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-03172005-141805/.
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Зінченко, Руслан Миколайович, Руслан Николаевич Зинченко, Ruslan Mykolaiovych Zinchenko, and Ю. Ю. Купрацевич. "ЗD модель процесса обработки деталей на кулачковых автоматах продольного точения." Thesis, Издательство СумГУ, 2007. http://essuir.sumdu.edu.ua/handle/123456789/19257.
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Micaroni, Ricardo. "Influencia do fluido de corte sob pressão no torneamento do aço ABNT 1045." [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265586.
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Orientador: Anselmo Eduardo DinizTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: Na usinagem dos metais, a aplicação do fluido de corte otimizada é um recurso que pode aumentar a taxa de remoção de material. Dentre os beneficios pode-se citar a redução da temperatura da ferramenta e melhor formação dos cavacos. Na primeira fase deste trabalho foi estudada a viabilização do corte a seco, da aplicação do fluido de corte em fluxo abundante ou convencional e em alta pressão em diferentes direções no torneamento do aço ABNT 1045, empregando-se ferramentas de metal duro em operação de acabamento. Para isso, foi montado um sistema composto por uma bomba de alta pressão e injetores direcionados para a superficie de saída, para a superficie de folga e simultaneamente para estas duas direções. As variáveis de saída foram: desgaste e vida da ferramenta, rugosidade da peça, potência e temperatura de corte. Na segunda fase será estudada a influência do uso ou não do fluido de corte na dilatação térmica de corpos de parede fina. Foi observado que a redução da vazão e o aumento da pressão do fluido de corte aumentaram a vida da ferramenta em relação às outras condições de refrigeração e, que a redução da vazão não alterou significativamente a temperatura de corte da ferramenta. Por outro lado, nos ensaios de dilatação térmica ficou constatado que a ausência do fluido de corte influenciou significativamente a variação diametral dos corpos de prova de parede fina
Abstract: In machining, the suitable use of cutting fluid is a resource that can increase the rate of material removal. Among the benefits it is possible to mention the tool temperature decrease and better chip formation. In the first stage of this work, several cooling/lubrication conditions were compared in finish turning operations of ABNT 1045 steel. These conditions were: dry cutting, the application of a abundant flow of cutting fluid in a conventional way (high flow rate and small pressure) and application of high pressure fluid in different directions. With this purpose, it was assembled a system containing a high pressure pump and injectors directed. to rake face, flank face and simultaneously in both directions. The output parameters were: tool wear an tool life, workpiece surface roughness, cutting power and temperature. In the second phase will be study the influence of the cutting fluid in the thermal expansion of worpieces with thin wall. The flow reduction and cutting fluid pressure increase the lifetime of the tool compared to other cooling conditions and that the flow reduction did not significant1y affected the tool temperature. On the other hand, the diameter variation of the workpiece with thin walls was larger in the absence of the cutting fluid
Doutorado
Materiais e Processos de Fabricação
Doutor em Engenharia Mecânica
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Заєць, С. С., and В. В. Шевченко. "Система діагностування процесу фрезерної обробки на багатофункціональних верстатах." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/11382.
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Holub, Michal. "VLIV GEOMETRICKÉ PŘESNOSTI VYBRANÝCH OBRÁBĚCÍCH CENTER NA POŽADOVANÉ VLASTNOSTI VÝROBKŮ." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-233989.
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The main subject of this doctoral thesis is the influence of the geometrical accuracy of large CNC machine tools on desired features of produced work pieces. Doe to globalized market environment and competition producers of machine tools have changed their strategy for delivery of their products to customers. The main issue is not only to deliver a machine tool as such; supporting instructions related to the technology of the cutting process on the machine tool are of great importance. When taking delivery, the customer can see a new machine tool that will produce by him specified work piece with a desired accuracy. In the proposed thesis, a development of a novel methodology of measuring vertical lathes for prediction of chosen geometrical parameters of work pieces is introduced. The main goal of this work has been to determine the influence of the geometrical accuracy of selected design groups of a vertical lath on the future geometric accuracy of the work piece. The proposed methodology has been developed and verified on a selected vertical lath SKIQ30 produced by TOSHULIN, a.s. For identification of chosen parameters of the vertical lath a measuring system using latest measuring technologies has been applied. The basic tool for measured data processing has been a set of statistic methods for prediction of behaviour of measured design groups of the machine. The foundation for statistical processing has been calculation of geometrical deviations obtained from algorithms designed for proposed measurement methodology. The proposed measurement methodology for vertical lathes has been divided into two parts. In the first part, the methodology of measurement and evaluation of linear axes is solved, where a measuring system Laser Track has been used. The employment of the system Laser Track turned out to be very suitable. Conclusions related to the accuracy of the measuring device have been drawn in the thesis. The second part of the proposed methodology is represented by observation and description of the rotating disk, where non-contact position transducers have been used. In the course of the doctoral dissertation it has been observed that the studied (with respect to the geometry) behaviour of the machine is significantly affected by the cutting conditions. To these belong the loading of the rotating disc by the mass of the work piece, angular velocity of the rotating disc and the operating time of the machine. Based on these observations it can be stated that for prediction of work piece features it is essential to know the behaviour of the machine tool in the whole range of the operating speeds and loading of the rotating disc. A part of the proposed methodology for measuring vertical lathes seems to be very suitable for a design of a diagnostic system that could be applied on large rotating disc. Furthermore, it is recommended to extend the doctoral thesis in order to develop a unit for compensation of geometrical errors on rotating discs of vertical lathes.
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Павлюк, Тарас Романович, and Taras Pavliuk. "Дослідження кінематичних та силових параметрів допоміжних механізмів для обробки деталей на важких токарних верстатах." Master's thesis, Тернопільський національний технічний університет імені Івана Пулюя, 2018. http://elartu.tntu.edu.ua/handle/lib/24266.
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Павлюк Т.Р. Дослідження кінематичних та силових параметрів допоміжних механізмів для обробки деталей на важких токарних верстатах. 133 – Галузеве машинобудування. – Тернопільський національний технічний університет імені Івана Пулюя. – Тернопіль, 2018.Pavliuk T. Investigation of kinematic and force characteristics of auxiliary mechanisms for parts machining on heavy lathes.. – Ternopil Ivan Pul’uj National Technical University. – Ternopil, 2018.
В дипломній роботі проведено пошукове конструювання та розрахунок основних виконавчих вузлів важкого токарного верстата та досліджено основні кінематичні та силові характеристики та параметри його допоміжних механізмів.
The dissertation has carried out a search design and calculation of the main executive units of heavy lathes and investigated the main kinematic and force characteristics and parameters of its auxiliary mechanisms.
Вступ, Загальний розділ, Оптимізація схеми формоутворення та компонувальних схем верстата, Технологічний розділ, Науково-дослідний розділ, Конструкторський розділ, Обґрунтування економічної ефективності, Охорона праці та безпека в надзвичайних ситуаціях, Екологія, Спеціальна частина. САПР. Висновки
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Сукова, Т. О., and Я. В. Васильченко. "Розробка інформаційної системи прогнозування параметрів важких верстатів як засобу підвищення ефективності автоматизованого виробництва." Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/38169.
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В даний час все більш актуальним стає питання створення важких багатоцільових верстатів, які зможуть замінити цілий комплекс важких верстатів. На важких токарних верстатах з числовим програмним управлінням проводиться обробка більшості деталей, які входять до складу сучасних важких машин: прокатні валки, ротори турбін і вітрогенераторів, колісні пари залізничного та гірничого транспорту, корабельні гребні вали і т.д. Розширення технологічних можливостей є актуальним завданням для забезпечення конкурентоспроможності випущеної машинобудівної продукції.
В даний час існує велика безліч конструкторських рішень всередині кожної групи і навіть виду верстатів, для яких постійно підвищуються технічні та технологічні вимоги, що в свою чергу ускладнює конструкції верстатів. Спостерігається розрив в наступності поколінь конструкторів через стан, в якому знаходяться багато наших верстатобудівних підприємств, що обумовлює нестачу висококваліфікованих фахівців в області конструювання.
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Заблоцький, В. Ю. "Вдосконалення технології оброблення кілець підшипників на токарному автоматі моделі 1Б265П-6К." Thesis, Видавництво СумДУ, 2010. http://essuir.sumdu.edu.ua/handle/123456789/11316.
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Використовуючи нову методику оброблення
кілець підшипників на токарному автоматі якість
оброблення робочих поверхонь значно покращується за
рахунок використання однієї заготовки, що дозволяє
уникнути ряду похибок форми деталі. Змінивши
технологічний процес виготовлення кілець підшипника
з’явилась можливість економії робочого часу в зв’язку із
зникненням операції чистового точіння, що дає досить
високий економічний ефект.
При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/11316
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Березовская, И. К., and В. Д. Ковалев. "Повышение эффективности тяжелых токарных станков за счет оптимального управления посредством PLC модулей." Thesis, Сумский государственный университет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/38090.
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Целью работы является разработка и реализация законов управления режимами обработки на тяжелом токарном станке, а именно управление скоростью резания для достижения оптимальной температуры и управление подачей для регулирования силы резания посредством PLC модулей.
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Santos, Deivis Hamilton DAmbros dos. "Análise de risco ergonômico em postos de tornearia de uma indústria metalúrgica." Universidade de Taubaté, 2011. http://www.bdtd.unitau.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=247.
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O presente trabalho teve como objetivo estudar a comparação entre o protocolo de Couto e o protocolo Strain Index, de Moore e Garg, para Análise Ergonômica do Trabalho, em dois postos de tornearia do setor de usinagem de uma indústria de médio porte, do setor metalúrgico. Para tanto, realizou-se uma fundamentação teórica, para apresentação dos métodos, cujos protocolos não são equivalentes (embora sejam aplicados como tal). Foi uma pesquisa aplicada, cujos resultados foram submetidos à análise quantitativa, buscando verificar os mecanismos de lesão a que estão sujeitos os operadores de tornos, neste caso específico, de uma indústria metalúrgica que possui dois postos de tornearia, sendo um para peças maiores que necessitam do uso de dispositivos de içamento e o outro posto dedicado a peças menores, capazes de serem manuseadas pelo operador. Concluiu-se que a relação entre o trabalho e a saúde requer a implantação e implementação, por parte das organizações e de políticas de prevenção, construindo uma cultura organizacional, em que seja propícia a realização da missão da organização com a garantia da qualidade de vida e realização das pessoas.This study aimed to study the comparison between the protocol and the protocol Couto Strain Index, Moore and Garg, for ergonomic work analysis in two positions in the industry turning the machining of a medium-sized industry, metallurgical industry. To this end, we carried out a theoretical basis for presentation of methods, protocols are not equivalent (although they are applied as such). It was an applied research, whose results were submitted to quantitative analysis, in order to understand the mechanisms of injury that are subject to the operators of lathes in this particular case, a metal industry, which has two turning stations, one for larger parts that need the use of lifting devices and other station dedicated to smaller parts, capable of being handled by the operator. It was concluded that the relationship between work and health requires the establishment and implementation by organizations and prevention policies, building an organizational culture that is conducive to achieving the mission of the organization with the guarantee of quality of life and fulfillment of people.
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Parkhill, Brian. "Lather, Rinse, Repeat." Thesis, California State University, Long Beach, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1569588.
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Lather, Rinse, Repeat was an exhibition that culminated in my Graduate Thesis exhibition. This exhibition consisted of a set of four artworks that explore issues of authorship in relation to my own graduate art practice. This paper serves its purpose to offer reflection, insight and a brief description of the four artworks exhibited. Though Lather, Rinse, Repeat had humble beginnings, these artworks are the result of how I view relationships in my life, and how those relationships shape the aspects of self, authorship and authority. Lather, Rinse, Repeat's four artworks vary in production method but all stem from my experiences in and out of the classroom, and in the graduate school community. My hope is that these artworks and this paper provide a glimpse into how one artists brains struggles with the many roles it fulfills daily.
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Pereira, Hugo Daniel Isaías. "Maquinagem sustentada de latões ecológicos." Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/9936.
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Mestrado em Engenharia MecânicaUltimamente o estudo da maquinabilidade de latões ecológicos tem apresentado um grande interesse por parte das indústrias dos latões no âmbito da manufatura sustentada. Neste trabalho pretende-se avaliar a maquinabilidade de alguns latões ecológicos, em operações de fresagem e furação utilizando a mínima quantidade de lubrificante (MQL). A presente dissertação tem como objetivos avaliar a fiabilidade da maquinagem de latões ecológicos, aliada à utilização da MQL com lubrificante biodegradável, para que estes possam substituir a maquinagem de latões convencionais com Lubrificação Abundante (LA). Os resultados foram avaliados tendo em consideração o acabamento de superfície, a presença ou não de rebarbas, a classificação das aparas obtidas e a temperatura atingida na peça. Conclui-se que a MQL traz benefícios para a maquinagem de latões, principalmente os ecológicos, com um melhor acabamento superficial e uma melhor limpeza da zona de maquinagem, para além dos benefícios ambientais. Conclui-se também que o bismuto é um bom substituto para o chumbo uma vez que os latões com adição deste elemento obtêm valores de Ra quase sempre inferiores aos dos latões convencionais.
Lately the study of the machinability of ecological brasses has shown a great interest by the brass industries under the sustainable manufacture. In this paper we intend to evaluate the machinability of some ecological brasses, in milling and drilling operations, using the minimum quantity of lubricant (MQL). This thesis aims to evaluate the reliability of ecological brasses machining allied to the MQL use with biodegradable lubricant, so they can replace the machining of conventional lead brasses with Abundant Lubrication (AL). The results were evaluated considering the surface finishing, the presence or absence of burrs, the classification of the obtained chips and the temperature reached in the piece. It was concluded that the MQL benefits the brass machining, especially the ecological, with improvements in surface finish and in the machining zone cleaning, furthermore the environmental benefits. It was also concluded that the bismuth is a good substitute for the lead since the brasses with addiction of this element achieved Ra values almost always lower than in conventional brasses.
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Guerra, Marcelo Del. "Desenvolvimento de apalpador de contato elétrico (\"touch trigger probe\") para atuação no processo de torneamento." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/18/18135/tde-12022016-174015/.
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A utilização dos apalpadores acoplados a máquinas CNC se tornou uma realidade muito comum no mundo atual, principalmente devido à diminuição do tempo de preparação e possibilidades de realização de medições na própria máquina-ferramenta. Porém, ainda existem algumas barreiras a se transpor, como por exemplo, a dificuldade de programação, custo relativamente elevado e pouca literatura que trata exclusivamente a respeito da utilização dos apalpadores para medição nas máquinas-ferramentas. Nesse trabalho é realizada uma revisão bibliográfica sobre o uso dos apalpadores em ambiente industrial, discutindo-se as tecnologias utilizadas na geração do sinal de \"trigger\" e é proposto um novo modelo de apalpador de contato elétrico, de baixo custo, desenvolvido especialmente para atender as necessidades de medições em tornos CNC. Os testes em laboratório revelaram que a repetibilidade do protótipo construído foi de 0,003 mm dentro de uma confiabilidade de mais ou menos 3 \'sigma\' ou 99,73%. Concluiu-se que tais características são altamente compatíveis com os requisitos necessários para a maioria dos processos de torneamento.The use of touch trigger probes attached to CNC machines has become a world standard, especially due the reduction of setup time and the ability to promote work piece measurements on machine. However, some barriers like measurement routines programming difficulties, high costs of these equipments and the low number of technical literature about this subject, still need to be transposed. This work presents a review on the applications of touch trigger probes on companies shop floor, discussing the nowadays technologies used to generate the trigger signal. A new touch trigger probe model based on a simple electrical contact is specially developed to provide the measuring characteristics required for Lathes, with the needed characteristics and low cost. The tests of the probe developed in the laboratory shown a repeatability of 0,003 mm (more and less 3 \'sigma\' or 99,73%). Those characteristics are high compatible with the most needs of the industry.
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Seth, Vikram. "Exploiting level sensitive latches in wire pipelining." Thesis, Texas A&M University, 2004. http://hdl.handle.net/1969.1/1433.
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The present research presents procedures for exploitation of level sensitive latches in wire pipelining. The user gives a Steiner tree, having a signal source and set of destination or sinks, and the location in rectangular plane, capacitive load and required arrival time at each of the destinations. The user also defines a library of non-clocked (buffer) elements and clocked elements (flip-flop and latch), also known as synchronous elements. The first procedure performs concurrent repeater and synchronous element insertion in a bottom-up manner to find the minimum latency that may be achieved between the source and the destinations. The second procedure takes additional input (required latency) for each destination, derived from previous procedure, and finds the repeater and synchronous element assignments for all internal nodes of the Steiner tree, which minimize overall area used. These procedures utilize the latency and area advantages of latch based pipelining over flip-flop based pipelining. The second procedure suggests two methods to tackle the challenges that exist in a latch based design. The deferred delay padding technique is introduced, which removes the short path violations for latches with minimal extra cost.
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Bernard, Jérôme. "Dynamique des perturbations d'un exemple de lattes." Paris 11, 1994. http://www.theses.fr/1994PA112216.
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Dans cette these, on etudie la dynamique d'une famille de fractions rationnelles de degre deux parametree par deux nombres complexes. Ces fractions rationnelles sont les perturbations d'un exemple de lattes. On demontre que l'ensemble des parametres pour lesquels la fraction rationnelle admet une mesure invariante absolument continue et un exposant de lyapounov strictement positif possede un point de densite. La methode employee repose sur l'utilisation de suites de partitions emboitees obtenues en decoupant la sphere de riemann selon les preimages d'un systeme stable de trois courbes de jordan. Pour qu'un couple de parametres donne lieu au type de dynamique recherchee, il est suffisant, grace a un argument base sur les applications de markov complexes, que les partitions satisfassent des conditions de nature purement combinatoire. Cette approche presente l'avantage d'offrir une description combinatoire et geometrique de l'espace des parametres. Un ensemble de parametres convenables est ainsi obtenu comme intersection decroissante d'ouverts geometriquement simples: unions disjointes d'ouverts homeomorphes a un bidisque et feuilletes par deux familles transverses de surfaces de riemann
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Griffiths, Neil R. "Gill disease in barramundi (Lates calcarifer)." Thesis, Griffiths, Neil R. (2009) Gill disease in barramundi (Lates calcarifer). Masters by Research thesis, Murdoch University, 2009. https://researchrepository.murdoch.edu.au/id/eprint/2434/.
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Disease is a major impediment to world aquaculture, amplified by the increase of the intensity of aquaculture relieving pressure from over depleted wild stocks, but with intensity brings disease and particularly disease of the fragile gill organ, exposed directly to the water environment. There is little literature on barramundi biology and the various forms of culture impacting on health, particularly the gill and much research is required in gaining a further understanding of this popular eating fish.
The light microscope is a pivotal tool with cytology and histology mandatory in assessing gill health. The gill biopsy should be considered part of a clinical examination as the water medium surrounding the gill and on the gill contains often fragile organisms that would otherwise be lost in fixation for histology alone, but easily viewed with cytology. Barramundi are easily anaesthetised and recovered like many terrestrials and gill re-growth is rapid, healing within days. Biopsies should be viewed unstained with and without phase contrast and then stained and reviewed, recognizing some ectoparasites maybe lost with anaesthetic agents and stains. The sacrificing of the fish after a live gill biopsy is necessary with histology and microbiology our major tools for diagnostics, with no other non invasive methods readily available as for terrestrials. Every year many new water organisms related to aquaculture are described in the literature and the finding of novel and new organisms makes the veterinary examination of the live fish exciting yet imperative.
A major concern is the gill pathogens found in wild barramundi were similar to those found in culture. For example the prevalence of the parasite Henneguya a Myxosporidean was 90% in sea cages 60 km offshore from Darwin in the Bathurst Island river system and 66% for ponded fish with water drawn from the Darwin Elizabeth river, compared to 33% infected in the wild habitat of the Mary river system close to Darwin by road. However the bacterial disease Epitheliocystis had a prevalence of 66% in the sea cages and 18% of similarly sized fish in the Mary river system, yet nil found in the pond farm, but in this case sample numbers were restricted. Consequently the surveillance for new fish pathogens and monitoring for existing pathogens in the wild ecosystems and aquaculture facilities is necessary and must include the macro and micro flora and fauna surrounding such facilities as they are potentially affected from aquaculture waste streams. The sustainability of aquaculture in open water culture must be considered with great concern for many reasons, but disease by its nature could overwhelm a species and other aquatic life quickly disseminated in a dynamic water medium.
Freshwater culture of barramundi has problems with off flavour and disease, particularly recirculating aquaculture systems due to undercapitalization and possibly at this stage with existing type farms not suited for the culture of barramundi with one farm having all fish sampled diagnosed with systemic bacteraemia and gill Epitheliocystis. Commonly fish sampled from freshwater culture had suffered pathological changes to the gill, particularly hyperplasia indicating the fish are continually affected by issues of water quality and disease.
Pond culture appeared to control gill disease issues by affording lower stocking rates, high water exchanges from a river within metres, fallow and the flavour of the fish similar to wild catch or sea cage culture, when purged in brackish water. The decreased environmental and ecosystem risks, coupled with the pond farmer reporting good profits with a simple form of culture, also suitable for intensification is a success story for barramundi production for today and the future.
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Holtzapffel, Thierry. "Minéraux argileux lattes : les smectites du domaine atlantique." Angers, 1986. http://www.theses.fr/1986ANGE0006.
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Les smectites des sédiments atlantiques du jurassique supérieur à l'actuel ; on distingue des particules floconneuses mixtes et lattées. Les premières, d'origine détritique probable, n'ont subi aucune modification post-sédimentaire ; les dernières résultent du réajustement diagenétique précoce des premières. L'intensité de ce réajustement, qui a lieu à bilans chimique et minéralogique pratiquement constants, a été quantifiée puis comparée à de nombreux paramètres sédimentaires. Trois facteurs importants : microperméabilité initiale du sédiment, temps de contact entre particules et fluides interstitiels et la composition de ces fluides.
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Gangadhar, Sreenivas. "Delay fault coverage for circuits with embedded latches /." Available to subscribers only, 2007. http://proquest.umi.com/pqdweb?did=1453188931&sid=7&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Holtzapffel, Thierry. "Minéraux argileux lattes, les smectites du domaine atlantique." Grenoble 2 : ANRT, 1986. http://catalogue.bnf.fr/ark:/12148/cb375983522.
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Lopez, Marcus S. B. Massachusetts Institute of Technology. "Design of a tabletop lathe educational kit." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43018.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references.
The purpose of this research is to create and characterize an educational kit for the mechanical engineering courses, 2.75: Precision Machine Design and 2.72: Elements of Machine Design. This kit is intended to provide instructors with a means to create a positive learning experience by (1) providing an opportunity for students to be innovative, (2) allowing students to better understand the limitations and strengths of their designs, and (3) optimizing the benefit of the learning experience. Engaging students with a project that motivates and inspires them ultimately produces a more capable engineer. The redesign and analysis of a table-top lathe is covered in this thesis. The efforts entailed herein revolve around the design of modular lathe that best suits the needs of students and instructors in 2.75 and 2. 72. Additionally, this thesis reviews the fabrication and testing of a prototype used to identify any problems with the manufacturing and assembly.
by Marcus Lopez.
S.B.
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Kutlu, Asim. "Design and development of a lathe spindle." Thesis, KTH, Maskinkonstruktion (Inst.), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187477.
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Verktygsmaskiner möjliggör tillverkning av materiekroppar med olika form. Svarvar är de vanligaste maskinerna för att bearbeta runda detaljer. Man kan säga att en svarvspindeln möjliggör hela skärprocessen och att den därför är den viktigaste komponenten i en svarv. En svarvaxel, eller en spindel, bearbetar det roterande ämnet med ett stationärt skärverktyg, och materialet tas bort vid skärverktygets kontakt med ämnet.Det här arbetet syftar till att konstruera en spindel som uppfyller en given kravspecifikation. Specifikationen innehåller prestandakrav, som rotationshastighet och kraft, geometri och dimensionskrav, som storlek och håldiameter, samt vilka komponenttyper som ska användas, som t.ex. motorn.I enlighet medprestandakravet definieras maximalt lastscenario. Med givna svarvningsparametrar beräknas skärkraften på materialet vid dess kontakt med skärverktyget. En inbyggd motor som är tillräckligt kraftfull och uppfyller hastighets- och effektkraven väljs och en preliminär konstruktion skapas med valda lager, lagerordningar och axelmaterial.Beteendet av den preliminära spindelkonstruktionen, under påverkan av skärkrafter och rotation analyseras statiskt och dynamiskt med hjälp av FEM och analytiska modeller. Inom ett givet område optimeras avståndet mellan lagren, vilka utgör spindelns stöd.Genom verifikation och optimering av den preliminära konstruktionen skapas den slutliga detaljkonstruktionen. Slutkonstruktionen innefattar alla nödvändiga detaljer och viktiga krav beaktas och balanseras, som att vara tillverkningsbar och monterbar, tätningssystem, ett system för hastighetsmätning och lägesmätning, kabelvägar och andra nödvändiga punkter. I slutänden konstrueras en spindel som uppfyller den definierade kravspecifikationen.Machine tools enable the industry to shape almost any material by a variety of methods. Lathes are one of the most common machines to cut circular parts with precision and accuracy. And the spindle of a lathe can be entitled as the most critical mechanical component which makes the cutting process possible. A lathe spindle rotates the workpiece to be cut against a stationary rigid cutting tool, therefore removing material through the contact edge. In this thesis, a spindle is aimed to be designed which complies with a set of specifications defined. These specifications consists of performance requirements such as speed and power, dimensional constraints for space and bore diameter, and component types which must be used, such as for the motor.Based on the performance requirements, a maximum loading case with cutting parameters is defined. With these cutting parameters, cutting forces acting to the material from at the contact point with the cutting tool are calculated. A built-in motor with sufficient power and speed specifications is selected based on the maximum cutting forces and speed requirements. A preliminary design is made up by selecting bearings, bearing arrangements and shaft material.With static and dynamic analysis conducted on the preliminary design through analytical models and FEM, the behavior of the spindle is investigated separately under the cutting forces and during the rotation. Within an allowable range, optimization is made on the bearing span distances which are the support locations for the spindle.Following the verification and optimization of the preliminary design, the final detail design of the spindle is made. The final design includes the design of all the necessary parts, by taking the manufacturability, assemblability, sealing design, a system for speed and position measurements, cable paths and more necessary points into account. Ultimately, a spindle which meets the requirements and specifications successfully is designed as the expected outcome of this thesis.
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Bas, Serkan. "Synthesis of Hybrid Latexes and Polymerization Kinetics of Functional Latexes." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1248366840.
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Bonifacio, Ailton Sergio. "Ontologias e consulta semântica : uma aplicação ao caso Lattes." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2002. http://hdl.handle.net/10183/7082.
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A quantidade e diversidade dos dados disponíveis na Web aumentam constantemente. Os motores de busca disponíveis, que usam palavras-chave, fornecem ao usuário resultados inexatos. Atualmente, os sistemas convencionais de consultas utilizam técnicas de base sintática. As pesquisas voltam-se para o estudo de abordagens de consultas através de conceitos, permitindo a recuperação semântica. Neste sentido, algumas propostas envolvem a criação de metadados que seguem modelos de ontologias.O propósito deste trabalho é apresentar, avaliar e permitir uma melhor compreensão de um conjunto de conceitos, linguagens e ferramentas que são usadas na Web Semântica. Dentre elas, linguagens para construção de ontologias e linguagens para consultas; além das ferramentas associadas que objetivam o armazenamento, manutenção e anotação em ontologias. Para atingir este propósito, estas linguagens e ferramentas são aplicadas a um caso de dimensão e complexidade realistas, o Currículo Lattes. O trabalho apresenta um modelo de metadados com semântica para o Currículo Lattes. Este modelo é baseado numa ontologia especificada na linguagem DAML+OIL. Além disso, é apresentada uma avaliação dos métodos de instanciação desta ontologia. Uma avaliação dos métodos e/ou linguagens de consulta mais adequadas para a consulta semântica das informações também é apresentada.
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Wilson, Andrew Kirk 1977. "Design of an automated on-car brake lathe." Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/8550.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references (p. 91-92).
An on-car brake lathe resurfaces disk-brake rotors by rotating them "in place" and making a light cut along the surface of the disk. The primary goal of this thesis is to develop an automated cutting head for an on-car brake lathe. The new cutting head must produce a surface finish that matches or exceeds that of the current (manual) cutting head. Pro-Cut International, a leading manufacturer of on-car brake lathes, developed functional requirements and cost constraints for the automated cutting head. Technical challenges include design and fabrication of low-cost precision linear bearings and actuators with dynamic stiffness sufficient to suppress chatter. During this thesis, two prototype cutting heads were designed, manufactured, and tested. The first prototype employed modular linear bearings, and produced unacceptable surface finish due to chatter. Cutting-tip vibration measurements combined with modal testing showed that chatter was caused by low structural stiffness of the modular bearing rails. A second prototype employing a unitary ground bearing system produced an acceptable surface finish of 70 [mu] -inch at 0.015" depth of cut per side. The key components of this design can be extruded and sliced to form the assembly, thereby meeting cost constraints.
by Andrew Kirk Wilson.
S.M.
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Oen, Jr Richard James. "Measuring cutting forces on a metal cutting lathe." Ohio University / OhioLINK, 1989. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1182447008.
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Medrano, Cornejo Humberto Félix, Rojo Luis Alberto Durán, and de Castilla Ponce Francisco Javier Ruiz. "Seminar: "Latest Tax Modifications"." Derecho & Sociedad, 2015. http://repositorio.pucp.edu.pe/index/handle/123456789/117547.
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The present seminar deals about the last modifications occurred in the Peruvian normativity on tax matter. This analysis focuses on the last modifications occurred on Income Tax, Tax Code, Tax Drawdown regime and Municipal Taxation.El presente seminario versa sobre las últimas modificaciones ocurridas en la normatividad peruana en materia tributaria. Dicho análisis se centrará en las últimas modificaciones ocurridas en materia de Impuesto a la Renta, a nivel del Código Tributario, en el Régimen de Detracciones de Impuestos y en materia de Tributación Municipal.
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Cividanes, Filipe de Simone. "CollectLattes : sistema para extração do conhecimento sobre a plataforma Lattes." Instituto Tecnológico de Aeronáutica, 2010. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=1075.
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Recentemente, há uma preocupação cada vez maior por parte do governo brasileiro em obter um conjunto de indicadores acadêmicos que permita visualizar o grau de maturidade da pesquisa científica no país, de forma a tomar ações mais eficazes de fomento à pesquisa científica. O foco deste trabalho é obter métricas de desempenho dos programas de pós-graduação que estejam relacionadas à avaliação trienal da CAPES por intermédio de um sistema computacional para extração de conhecimento a partir de dados públicos da Plataforma Lattes. São utilizadas técnicas de extração de informação e algoritmos de similaridade para classificação e tratamento dos dados científicos extraídos. Além disso, as informações acadêmicas de domínio público são extraídas automaticamente a partir da Internet. Ao final, desenvolve-se um eficiente banco de dados com informações que podem ser potencialmente úteis à Gestão em Ciência & Tecnologia. Uma das contribuições deste trabalho é fornecer uma visão panorâmica sobre os programas de pós-graduação, permitindo um levantamento de indicadores de desempenho dos programas, que pode ser utilizado, por exemplo, como apoio à tomada de decisão por coordenadores e gestores das instituições.
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Inglis, Anthony Ian. "'Burning matches, lifting latches' : sociology, popular culture and the Beatles." Thesis, Online version, 2003. http://ethos.bl.uk/OrderDetails.do?did=1&uin=uk.bl.ethos.490588.
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Gibson-Kueh, Susan. "Diseases of Asian seabass (or barramundi), Lates calcarifer Bloch." Thesis, Gibson-Kueh, Susan (2012) Diseases of Asian seabass (or barramundi), Lates calcarifer Bloch. PhD thesis, Murdoch University, 2012. https://researchrepository.murdoch.edu.au/id/eprint/14817/.
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Other than the study by Griffiths (2009) on gill diseases, there has been no comprehensive study and report on the major diseases of Asian seabass (or barramundi) Lates calcarifer Bloch. It is a food fish species of growing importance in Asia and Australia. This study investigates some of the major diseases encountered in the various stages of the culture of L. calcarifer, at the histopathological, ultrastructural and molecular levels. Culture practices can have significant impacts on fish health. Disease outbreaks are influenced by factors involving the host, environment and pathogen. Current knowledge on diseases of L. calcarifer, and these factors which may influence disease outbreaks are discussed in Chapter 1.
This is the first report of an intestinal Eimeria infection in L. calcarifer. The Eimeria infection was associated with severe pathology and significant mortality in the absence of other pathogens. It was detected in diseased L. calcarifer in all five nurseries in Ca Mau, Vietnam. Although these were small scale nurseries which stocked an average of 3000 to 5000 fish at any one time, a mortality rate of up to 30% was reported and is the cause of significant economic losses for these nurseries. Moderate to heavy Eimeria infestation were observed in greater than 80% of diseased fish examined. This high rate of Eimeria infestation is suspected to be linked to the low daily water exchange rates practised in these nurseries. However, the examination of only diseased fish does not allow the determination of prevalence. A systemic iridovirus infection was concurrently observed in some of the fishes but was not consistently present when compared to the Eimeria infection. Molecular analysis showed that the Eimeria of L. calcarifer from Vietnam formed clades with the Eimeria detected in L. calcarifer cultured in Australia, but clustered separately from other known Eimeria species. Although Cryptosporidium was detected in these L. calcarifer tissues, it could not be demonstrated histologically or ultrastructurally, suggesting a low grade infestation or perhaps an environmental contaminant in fish tissues tested. In situ hybridization using labeled PCR products showed that labeled DNA probes generated from 18S PCR products could not be used to distinguish between closely related genera such as Cryptosporidium and Eimeria. Future investigation to determine the origin, transmission and risk factors associated with this Eimeria infestation in L. calcarifer are needed.
‘Scale drop syndrome’ is a novel disease first reported in L. calcarifer in Penang, Malaysia in 1992. Cases with similar gross and clinical presentations were observed in Singapore in 2002, 2006 and 2009. Affected fish have loose scales, which dropped off easily when handled. The disease was initially observed in 100-300g fish, and later in larger fish up to 5kg bodyweight. Cumulative mortalities of 40 to 50% were reported by farms, posing significant economic losses of larger more valuable fish. This investigation forms the first pathological description of ‘scale drop syndrome’ (SDS) in L. calcarifer. To aid recognition of new cases for study, a case definition was developed for ‘scale drop syndrome’ in L. calcarifer as a systemic vasculitis associated with tissue necrosis in all major organs including the skin, with apparent targeting of cells of epithelial origin. Attempts to isolate or detect the causative agent(s) by cell culture, PCR and immunohistochemistry have proven unsuccessful. Further studies to elucidate the definitive aetiology, isolate the causal agent(s) and reproduce the disease will help better understanding and control of SDS.
Although systemic iridoviral disease has been previously reported in many freshwater and marine fish species, this study forms the first report of this disease in L. calcarifer. Systemic iridoviral disease was observed in 5 to 20g L. calcarifer usually 2 to 3 weeks post-transfer into sea cages at two farms. Inclusion bodies suggestive of a systemic iridovirus infection were observed in clinically healthy L. calcarifer from the land-based nursery of one of these two farm; the presence of an iridovirus infection was supported by positive PCR results using Red Sea bream iridovirus (RSIV) primer 1. The presence of inclusions was not accompanied by any tissue necrosis in these clinically healthy fish. This finding suggested that the systemic iridovirus infection occurred before stocking at sea, and did not originate from wild fish or older fish in adjacent sea cages as initially suspected by this farm. Immunohistochemistry on tissues of clinical cases of systemic iridovirus gave positive results using the Red Sea bream iridovirus monoclonal antibody (RSIV M10), although intensity varied between tissues, possibly related to varying exposure of different tissues to fixation chemicals. Inclusion bodies in clinically healthy fish from the same farm did not show positive reaction with RSIV M10. This may be due to a lack of antigenic expression by the viral infected cells at this early stage of infection.
Viral nervous necrosis (VNN) is a serious disease of hatchery reared L. calcarifer fry in this study. Mortalities of 50 to 100% were reported in 3wo fry. VNN can be difficult to diagnose in older fry, where it can be associated with few vacuolations or an absence of viral inclusions
‘Pot belly disease’ (PBD) was previously reported in L. calcarifer fry less than 1g, in association with an intracellular coccobacillus infection and mortalities of 80 to 100%. In this study, PBD was observed in 120g L. calcarifer at two sea cage farms, in association with significant granulomatous enteritis. The extent of the granulomatous enteritis is likely to have an effect on affected fish. It was observed concurrently with systemic iridoviral disease at one farm and nocardiosis at another farm. Diagnosis by histopathology and the lack of other confirmatory tests for PBD may result in underdiagnosis of this disease. The epidemiology of PBD needs further study to establish origin and modes of transmission, to facilitate better disease control.
Diseases associated with infections by ubiquitous bacteria such as Vibrio, Tenacibaculum were commonly observed in L. calcarifer post-handling. Tenacibaculosis and vibriosis often occurred concurrently with other diseases such as streptococcosis, systemic iridviral disease or PBD. Streptococcosis can affect fish up to 3kg bodyweight, resulting in significant mortalities greater than 40 to 50%. Like SDS, because streptococcosis can affect up to market size fish, they can cause considerable economic losses. Although vaccines against Streptococcosis are available, conflicting views are held on the efficacy of Streptococcus vaccines by various research groups. Overall, the South-east Asian L. calcarifer farms which practiced vaccination against Streptococcus iniae reported a reduction of mortality, especially in fish greater than 1 to 1.5kg bodyweight.
Nocardiosis has been reported as an emerging disease in marine food fish species caused by acid fast filamentous branching bacterium. Although nocardiosis was observed histopathologically in L. calcarifer at two sea cage farms, the numbers of samples examined were small and no other tests were attempted due to lack of suitable samples. More intensive and extensive study is needed to determine the significance of nocardiosis in L. calcarifer. Chronic granulomatous enteritis was not uncommon in the cases submitted to the Fish Health Laboratory in Perth. Although the peritonitis was associated with heavy bacteria infection, it is unclear if these are secondary invaders. Schipps, Bosmans & Humphreys (2009) reported that Vibrio harveyi and Photobacterium damsela damsela vaccinations appeared to be not efficacious, suggesting that these bacteria were not the primary cause of the disease.
It is well recognized that disease outbreaks in farmed fish are influenced by the interaction between host, the environment and pathogens. While serious diseases are often reported in association with specific aquatic pathogens, not much is known about the risk factors which trigger fish disease outbreaks. Disease outbreaks often occur after stressful events such as net transfers, recent handling or poor water quality. In fact, diseases are often caused by ubiquitous pathogens that are commonly present in the culture environment. Although further research is necessary to gather more information to improve diagnosis and management of specific diseases, general health management strategies can be applied at the various stages in the culture of L. calcarifer to minimize disease outbreaks. This is discussed for L. calcarifer in Chapter 6.
Observations of types of disease agents may be influenced by site conditions or the types of tests or materials examined. For example, some parasites may be more prevalent in certain sites where intermediate hosts abound, or loosely attached ectoparasites may be lost unless wet mount microscopic examinations of fresh tissues were carried out. The study of emerging diseases such as scale drop syndrome (SDS) or pot belly disease (PBD) in L. calcarifer has been hampered by lack of confirmatory diagnostic tools and inadequate knowledge on critical epidemiological factors such as mode of transmission or potential reservoirs. While ideally identification and isolation of the causal agent will help fulfil Koch’s postulates, it may be possible to improve the understanding of disease via cohabitation or infectivity trials using tissue homogenates from diseased fish when pure isolates are not available. There is a need to conduct research to not only establish a definitive aetiology, but also to identify risk factors to facilitate successful disease control. The successful management of disease in aquaculture does not lie in any one strategy but an integrated management of all risks encountered during the culture cycle against disease occurrence or incursions.
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Wright, Christopher. "Carbon : Desktop Vinyl Lathe Recapturing Value In Recorded Music." Thesis, Umeå universitet, Designhögskolan vid Umeå universitet, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-110700.
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Vinyl records have re-emerged as the preferred format for music fans and artists alike. The problem is that producing vinyl records is slow and expensive; this makes it difficult for up-and-coming artists to release their music on vinyl. What if you could make your own records at home?
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Shah, Ziarat 1978. "Efeito de tensoativos na polimerização em emulsão." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/250318.
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Orientador: Fernando GalembeckTese (doutorado) - Universidade Estadual de Campinas, Instituto de Química
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Resumo: Neste trabalho foram sintetizados latexes do poli[estireno-co-(acrilato de butila)-co-(acido acrilico)], com a mesma composicao monomérica, sob as mesmas condições experimentais, mas utilizando diferentes tensoativos. Foram utilizados tensoativos não-iônicos, derivados etoxilados (EO) do nonilfenol (NP), álcool laurílico e do álcool oleico, apresentando numeros de grupos EO por molecula igual a: 4 e 100, 23 e 20, respectivamente. Foi também empregado o tensoativo aniônico, dodecilsulfato de sódio (SDS). Os polímeros foram sintetizados através do método da pré-emulsão, a 75ºC, sob atmosfera de nitrogênio e usando persulfato de sódio, como iniciador. Os latexes obtidos foram caracterizados através das seguintes técnicas: espectroscopia vibracional na região do infravermelho (FTIR), espectroscopia por correlação de fótons (PCS), calorimetria de varredura diferencial (DSC), analise termogravimétrica (TGA), centrifugação zonal em gradiente de densidade, ensaio de adesão, microscopia de força atômica (AFM), microscopia eletrônica de varredura (SEM) e microscopia eletrônica de transmissão (TEM). Os espectros FTIR são similares, mas apresentam diferenças nítidas em algumas regiões espectrais. Os resultados obtidos das análises térmicas indicam que uma maior quantidade de água não congelável ligada está presente no latex sintetizado a partir da mistura de tensoativos não iônico NP(EO)40 e aniônico SDS, sendo que a fração de massa de água livre é quase igual em todos os latexes. Os resultados de TGA mostram que a degradação dos latexes ocorre em etapas diferentes, sendo que a diferença na faixa de temperatura de decomposição dos diferentes latexes não é muito significativa, exceto no caso da amostra sintetizada usando a mistura de NP(EO)40 e SDS. Os resultados dos estudos microscópicos mostram uma grande variabilidade nas particulas formadas, na rugosidade e nos padrões de distribuição da viscoelasticidade nas superfícies dos filmes. Esta tese demonstra que é possivel obter latexes muito diferentes com os mesmos monômeros e mesmo procedimento de polimerização, mas mudando simplesmente o tensoativo
Abstract: In this work six different latexes of poly[styrene-co-(butyl acrylate)-co-(acrylic acid)], were synthesized under similar experimental conditions and monomer composition by changing the surfactants only. The surfactants used were ethoxylated nonylphenol NP(EO)n, lauryl alcohol and oleic alcohol, with (EO) chain lengths equal to 4, 100, 23 and 20, respectively. The anionic surfactant sodium dodecyl sulfate (SDS) was also used. The polymers were synthesized by the semi-batch emulsion polymerization method at 7ºC under nitrogen atmosphere using sodium persulfate, as a free-radical initiator. The latexes were characterized using Fourier transform infrared spectroscopy (FTIR), photon correlation spectroscopy (PCS), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), zonal density gradient centrifugation, film adhesion, atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The FTIR spectra are similar but also show differences in some spectral regions. The DSC results present that a significant fraction of non-freezing bound water was found in the latex stabilized with a mixture of NP(EO)40 with (SDS), and the percentage of free water was almost equal in all samples. TGA results show that the complete thermal degradation of latexes occurs at different temperature and difference in the decomposition temperature was not very significant, except for the sample synthesized with a mixture of SDS and NP(EO)40 surfactants. The results of microscopy studies show a great variability in the particles formed, surface roughness and in the distribution pattern of viscoelasticity on the film surfaces. This thesis demonstrates that that it is possible to obtain very different latices with the same monomers and the same polymerization procedure but simply changing the surfactant
Doutorado
Físico-Química
Doutor em Ciências
40
Nunes, Patrícia dos Santos. "Alfabetização científica-tecnológica-digital e a plataforma Lattes: quais as possibilidades?" Universidade do Vale do Rio do Sinos, 2006. http://www.repositorio.jesuita.org.br/handle/UNISINOS/1888.
Full textAbstract:
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Esta dissertação tem como objetivo problematizar a experiência pedagógica que envolveu alunos e alunas de uma Escola de Ensino Médio da rede pública estadual do Rio Grande do Sul, realizada durante o segundo semestre de 2006. A experiência teve como lócus o laboratório de Informática. O objetivo principal foi envolver os estudantes em atividades que utilizaram como recurso a Internet, mais especificamente, a Plataforma Lattes do CNPq, com vistas ao processo de alfabetização científica-tecnológica-digital dos mesmos, esta entendida como a possibilidade de realizar uma melhor leitura de mundo, através da linguagem da Ciência, aliada à capacidade de lidar com os artefatos tecnológicos, em especial a Informática, o que permite uma apropriação crítica dos códigos digitais. Apoiada em tal concepção, são analisados os enunciados dos alunos, dando o sentido da pesquisadora para os sentidos dados pelos mesmos à experiência pedagógica vivida. Para tanto, fez-se necessário investigar o universo que permeia a inter-rela
41
Galego, Eduardo Ferreira. "Extração e consulta de informações do Currículo Lattes baseada em ontologias." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/45/45134/tde-18122013-080644/.
Full textAbstract:
A Plataforma Lattes é uma excelente base de dados de pesquisadores para a sociedade brasileira, adotada pela maioria das instituições de fomento, universidades e institutos de pesquisa do País. Entretanto, é limitada quanto à exibição de dados sumarizados de um grupos de pessoas, como por exemplo um departamento de pesquisa ou os orientandos de um ou mais professores. Diversos projetos já foram desenvolvidos propondo soluções para este problema, alguns inclusive desenvolvendo ontologias a partir do domínio de pesquisa. Este trabalho tem por objetivo integrar todas as funcionalidades destas ferramentas em uma única solução, a SOS Lattes. Serão apresentados os resultados obtidos no desenvolvimento desta solução e como o uso de ontologias auxilia nas atividades de identificação de inconsistências de dados, consultas para construção de relatórios consolidados e regras de inferência para correlacionar múltiplas bases de dados. Além disto, procura-se por meio deste trabalho contribuir com a expansão e disseminação da área de Web Semântica, por meio da criação de uma ferramenta capaz de extrair dados de páginas Web e disponibilizar sua estrutura semântica. Os conhecimentos adquiridos durante a pesquisa poderão ser úteis ao desenvolvimento de novas ferramentas atuando em diferentes ambientes.The Lattes Platform is an excellent database of researchers for the Brazilian society , adopted by most Brazilian funding agencies, universities and research institutes. However, it is limited as to displaying summarized data from a group of people, such as a research department or students supervised by one or more professor. Several projects have already been developed which propose solutions to this problem, including some developing ontologies from the research domain. This work aims to integrate all the functionality of these tools in a single solution, SOS Lattes. The results obtained in the development of this solution are presented as well as the use of ontologies to help identifying inconsistencies in the data, queries for building consolidated reports and rules of inference for correlating multiple databases. Also, this work intends to contribute to the expansion and dissemination of the Semantic Web, by creating a tool that can extract data from Web pages and provide their semantic structure. The knowledge gained during the study may be useful for the development of new tools operating in different environments.
42
Menezes, Júnior Aurélio Andrade de. "Um método para busca de competências a partir de currículos lattes." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/2891.
Full textAbstract:
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Previous issue date: 2012-08-22Large databases have been very common nowadays. These databases allow access to a huge amount of information. However, this scenario leads the task of finding a specific information among such a large amount of information, become very difficult. Systems of Information Retrieval (IR) have been widely used to sole this kind of problem. Among the many problems caused by the large amount of information available on databases, there is the problem related to competence searching. This problem occurs in the following context, given a profile, described as a set of competencies, one looks for finding researchers with similar profiles. In this work, we describe an IR method which provides support to find researchers taking into account competence information retrieved from a database a desired competency profile, the proposed method provides the curriculums more similar to the desired profile. The experiments were conducted using three proposed strategies: Sum of Similarities, Production and Borda Count. The results achieved show that the proposed successfully accomplishes its objective
Grandes bases de dados tem sido muito comum hoje em dia e tem permitido o acesso a uma grande quantidade de informação. Por outro lado, esse cenário torna dificil a tarefa de encontrar uma informação específica no meio de uma grande quantidade de informação. Sistemas de Recuperação de Informação (RI) têm sido largamente empregados para a solucionar este tipo de problema. Dentre os problemas ocasionados pela grande quantidade de informação disponível em bases de dados, existe o problema da busca de competências. Este problema ocorre no seguinte contexto, dado um perfil, descrito na forma de um conjunto de competências, procura-se descobrir pesquisadores com perfis similares. Este trabalho descreve um método de RI que fornece apoio à busca de pesquisadores a partir de informações sobre competências extraídas de uma base de currículos Lattes. Assim, dada uma consulta especificando um perfil de competência desejada, são selecionados os currículos com maior grau de similaridade com este perfil. Após a execução de experimentos em três estratégias propostas: Soma de Similaridades, Produção e Contagem de Borda, os resultados indicam o sucesso do método proposto
43
AraÃjo, Eduardo Barbosa. "Scientific Collaboration Networks from Lattes Database: Topology, Dynamics and Gender Statistics." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=17184.
Full textAbstract:
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoCompreender a dinÃmica de produÃÃo e colaboraÃÃo em pesquisa pode revelar melhores estratÃgias para carreiras cientÃficas, instituiÃÃes acadÃmicas e agÃncias de fomento. Neste trabalho nÃs propomos o uso de uma grande e multidisciplinar base de currÃculos cientÃficos brasileira, a Plataforma Lattes, para o estudo de padrÃes em pesquisa cientÃfica e colaboraÃÃes. Esta base de dados inclui informaÃÃes detalhadas acerca de publicaÃÃes e pesquisadores. CurrÃculos individuais sÃo enviados pelos prÃprios pesquisadores de forma que a identificaÃÃo de coautoria nÃo à ambÃgua. Pesquisadores podem ser classificados por produÃÃo cientÃfica, localizaÃÃo geogrÃfica e Ãreas de pesquisa. Nossos resultados mostram que a rede de colaboraÃÃes cientÃficas tem crescido exponencialmente nas Ãltimas trÃs dÃcadas, com a distribuiÃÃo do nÃmero de colaboradores por pesquisador se aproximando de uma lei de potÃncia à medida que a rede evolui. AlÃm disso, ambas a distribuiÃÃo do nÃmero de colaboradores e a produÃÃo por pesquisador seguem o comportamento de leis de potÃncia, independentemente da regiÃo ou Ãreas, sugerindo que um mesmo mecanismo universal pode ser responsÃvel pelo crescimento da rede e pela produtividade dos pesquisadores. TambÃm mostramos que as redes de colaboraÃÃo investigadas apresentam um tÃpico comportamento assortativo, no qual pesquisadores de alto nÃvel (com muitos colaboradores) tendem a colaborador com outros semelhantes. Em seguida, mostramos que homens preferem colaborar com outros homens enquanto mulheres sÃo mais igualitÃrias ao estabelecer suas colaboraÃÃes. Isso à consistentemente observado em todas as Ãreas e à essencialmente independente do nÃmero de colaboraÃÃes do pesquisador. A Ãnica exceÃÃo sendo a Ãrea de Engenharia, na qual este viÃs à claramente menos pronunciado para pesquisadores com muitas colaboraÃÃes. TambÃm mostramos que o nÃmero de colaboraÃÃes segue o comportamento de leis de potÃncia, com um cutoff dependente do gÃnero. Isso se reflete no fato de que em mÃdia mulheres produzem menos artigos e tÃm menos colaboraÃÃes que homens. TambÃm mostramos que ambos os gÃneros exibem a mesma tendÃncia quanto a colaboraÃÃes interdisciplinares, exceto em CiÃncias Exatas e da Terra, nas quais mulheres tendo mais colaboradores sÃo mais propensas a pesquisas interdisciplinares.
Understanding the dynamics of research production and collaboration may reveal better strategies for scientific careers, academic institutions and funding agencies. Here we propose the use of a large and multidisciplinary database of scientific curricula in Brazil, namely, the Lattes Platform, to study patterns of scientific production and collaboration. Detailed information about publications and researchers is available in this database. Individual curricula are submitted by the researchers themselves so that co-authorship is unambiguous. Researchers can be evaluated by scientific productivity, geographical location and field of expertise. Our results show that the collaboration network is growing exponentially for the last three decades, with a distribution of number of collaborators per researcher that approaches a power-law as the network gets older. Moreover, both the distributions of number of collaborators and production per researcher obey power-law behaviors, regardless of the geographical location or field, suggesting that the same universal mechanism might be responsible for network growth and productivity. We also show that the collaboration network under investigation displays a typical assortative mixing behavior, where teeming researchers (i.e., with high degree) tend to collaborate with others alike. Moreover, we discover that on average men prefer collaborating with other men than with women, while women are more egalitarian. This is consistently observed over all fields and essentially independent on the number of collaborators of the researcher. The solely exception is for engineering, where clearly this gender bias is less pronounced, when the number of collaborators increases. We also find that the distribution of number of collaborators follows a power-law, with a cut-off that is gender dependent. This reflects the fact that on average men produce more papers andhave more collaborators than women. We also find that both genders display the same tendency towards interdisciplinary collaborations, except for Exact and Earth Sciences, where women having many collaborators are more open to interdisciplinary research.
44
Araújo, Eduardo Barbosa. "Scientific Collaboration Networks from Lattes Database: Topology, Dynamics and Gender Statistics." reponame:Repositório Institucional da UFC, 2016. http://www.repositorio.ufc.br/handle/riufc/18489.
Full textAbstract:
ARAÚJO, Eduardo Barbosa. Scientific Collaboration Networks from Lattes Database: Topology, Dynamics and Gender Statistics. 2016. 88 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2016.Submitted by Edvander Pires (edvanderpires@gmail.com) on 2016-07-19T15:58:54Z No. of bitstreams: 1 2016_tese_ebaraujo.pdf: 3600069 bytes, checksum: a78e83ffda97c499e589b405da4da3c8 (MD5)
Approved for entry into archive by Edvander Pires (edvanderpires@gmail.com) on 2016-07-19T15:59:07Z (GMT) No. of bitstreams: 1 2016_tese_ebaraujo.pdf: 3600069 bytes, checksum: a78e83ffda97c499e589b405da4da3c8 (MD5)
Made available in DSpace on 2016-07-19T15:59:07Z (GMT). No. of bitstreams: 1 2016_tese_ebaraujo.pdf: 3600069 bytes, checksum: a78e83ffda97c499e589b405da4da3c8 (MD5) Previous issue date: 2016
Understanding the dynamics of research production and collaboration may reveal better strategies for scientific careers, academic institutions and funding agencies. Here we propose the use of a large and multidisciplinary database of scientific curricula in Brazil, namely, the Lattes Platform, to study patterns of scientific production and collaboration. Detailed information about publications and researchers is available in this database. Individual curricula are submitted by the researchers themselves so that co-authorship is unambiguous. Researchers can be evaluated by scientific productivity, geographical location and field of expertise. Our results show that the collaboration network is growing exponentially for the last three decades, with a distribution of number of collaborators per researcher that approaches a power-law as the network gets older. Moreover, both the distributions of number of collaborators and production per researcher obey power-law behaviors, regardless of the geographical location or field, suggesting that the same universal mechanism might be responsible for network growth and productivity. We also show that the collaboration network under investigation displays a typical assortative mixing behavior, where teeming researchers (i.e., with high degree) tend to collaborate with others alike. Moreover, we discover that on average men prefer collaborating with other men than with women, while women are more egalitarian. This is consistently observed over all fields and essentially independent on the number of collaborators of the researcher. The solely exception is for engineering, where clearly this gender bias is less pronounced, when the number of collaborators increases. We also find that the distribution of number of collaborators follows a power-law, with a cut-off that is gender dependent. This reflects the fact that on average men produce more papers andhave more collaborators than women. We also find that both genders display the same tendency towards interdisciplinary collaborations, except for Exact and Earth Sciences, where women having many collaborators are more open to interdisciplinary research.
Compreender a dinâmica de produção e colaboração em pesquisa pode revelar melhores estratégias para carreiras científicas, instituições acadêmicas e agências de fomento. Neste trabalho nós propomos o uso de uma grande e multidisciplinar base de currículos científicos brasileira, a Plataforma Lattes, para o estudo de padrões em pesquisa científica e colaborações. Esta base de dados inclui informações detalhadas acerca de publicações e pesquisadores. Currículos individuais são enviados pelos próprios pesquisadores de forma que a identificação de coautoria não é ambígua. Pesquisadores podem ser classificados por produção científica, localização geográfica e áreas de pesquisa. Nossos resultados mostram que a rede de colaborações científicas tem crescido exponencialmente nas últimas três décadas, com a distribuição do número de colaboradores por pesquisador se aproximando de uma lei de potência à medida que a rede evolui. Além disso, ambas a distribuição do número de colaboradores e a produção por pesquisador seguem o comportamento de leis de potência, independentemente da região ou áreas, sugerindo que um mesmo mecanismo universal pode ser responsável pelo crescimento da rede e pela produtividade dos pesquisadores. Também mostramos que as redes de colaboração investigadas apresentam um típico comportamento assortativo, no qual pesquisadores de alto nível (com muitos colaboradores) tendem a colaborador com outros semelhantes. Em seguida, mostramos que homens preferem colaborar com outros homens enquanto mulheres são mais igualitárias ao estabelecer suas colaborações. Isso é consistentemente observado em todas as áreas e é essencialmente independente do número de colaborações do pesquisador. A única exceção sendo a área de Engenharia, na qual este viés é claramente menos pronunciado para pesquisadores com muitas colaborações. Também mostramos que o número de colaborações segue o comportamento de leis de potência, com um cutoff dependente do gênero. Isso se reflete no fato de que em média mulheres produzem menos artigos e têm menos colaborações que homens. Também mostramos que ambos os gêneros exibem a mesma tendência quanto a colaborações interdisciplinares, exceto em Ciências Exatas e da Terra, nas quais mulheres tendo mais colaboradores são mais propensas a pesquisas interdisciplinares.
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com, cmarshall@tobob, and Carina Rynn Ecremen Marshall. "Evolutionary Genetics of Barramundi (Lates Calcarifer)in the Australian Region." Murdoch University, 2005. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20050421.134447.
Full textAbstract:
Barramundi (Lates calcarifer) is a centropomid teleost with a wide distribution across the
Indo Pacific. In Australia, barramundi are native to the tropical zone from Exmouth Gulf
in Western Australia, across the northern part of the continent, to the Mary River in
Queensland. Barramundi are protandrous hermaphrodites, and are euryhaline, with a
catadromous life history. Barramundi are a valuable Australian resource, with important
commercial and recreational fisheries and aquaculture production to the value of $11
million dollars per year. Recent declines in the availability of the fish in some rivers has led
to an interest in the possibility of restocking rivers with barramundi from other areas.
Determining the genetic structure of barramundi populations in Australia is important for
understanding biogeographic history, and appropriate management practices for both
aquaculture and recreational and commercial fishing. Previous studies have concentrated
on the east coast of Australia, and have largely ignored the western populations. In this
study, I obtained DNA data from barramundi populations across the Australian range of
the species, as well as populations from Papua New Guinea and Indonesia. The aims of
this study were to use the genetic data to determine: 1. if populations in Western Australia
show genetic differences between geographic regions 2. if these populations show an
ancestral split from populations in the east of Australia and 3. the ancestral origins of
Australian barramundi.
Previous studies of DNA data from barramundi have discovered an east/west split
occurring at the Torres Strait that was assumed to be caused by the closing of the strait
during lowered sea levels. However, these studies suffered from a bias in sampling area,
concentrating either on the eastern half of the range of barramundi, or on the western tip
of the range. Data from these studies were combined and reanalyzed. Two major clades
were discovered, with considerable biogeographic structuring, but their geographic
locations did not coincide with the reported vicariance event at the Torres Strait. Instead,
historical divisions among freshwater drainage systems appeared to have driven the
evolutionary history of barramundi in Australia.
In order to investigate these historical divisions further, a 290 bp section of the
mitochondrial DNA control region was sequenced in 284 barramundi from seven
populations across the Australian geographic range of the species and from one population
in Papua New Guinea and one population in Indonesia. Analyses of molecular variance
within and among populations showed significant geographic structuring, based on
biogeographical provinces and drainage divisions. Nested clade analyses indicated that
these geographical associations were the result of restricted gene flow, range expansion,
and past fragmentation events. I hypothesise that the Ord River area in the west of the
continent was the ancestral source population for the rest of the species range across
Australia, with Indonesia being the most likely origin of this source. Populations of
barramundi from the Pilbara region are genetically distinct and geographically isolated, with
strong evidence of an ancestral divide along geographical barriers to dispersal. There is a
strong association between Papua New Guinea and Australia, although further investigations using the cytochrome b region of mitochondrial DNA indicated a more
ancestral divide between the two than is currently evident, which could reflect an ancient
geographical divide between the two, or could be evidence of a secondary migration route
to Australia.
For a more detailed study of evolutionary processes acting on populations of barramundi in
Western Australia, allelic diversity was examined at five microsatellite loci. All loci were
polymorphic and genotypic frequencies conformed to Hardy-Weinberg expectations, with
no significant linkage between loci evident in any population. Measures of within
population diversity were significantly related to latitude, suggesting southerly migration
from a northern source population. The Ord River was the most genetically diverse
population, and the most likely ancestral migration source to the area, with diversity
decreasing down the west coast. Although there were significant differences among
populations, the nuclear microsatellite data do not indicate the same degree of genetic
structuring as is evident in the mitochondrial data. This may be a consequence of rapid
evolutionary change at microsatellite loci, with past separations or population differences
masked by recombination and back mutation of the microsatellite alleles. However, the
nature of nuclear and mitochondrial inheritance may also indicate life history differences
between the sexes, where significant genetic contribution to gene flow by males and limited
female gene flow may lead to preservation of maternally inherited population substructure.
The principal findings from this study are:
There is no genetic evidence for an east/west division of barramundi populations
in Australia, as suggested by previous research.
Despite barramundis catadromous life history, and ability to disperse through
marine waters, the present genetic structure indicates a division principally among
river drainages. From a population genetic viewpoint, the species can be regarded
as freshwater, rather than marine.
The most likely origin of barramundi in Australia is the Ord River region, with
Indonesia as the route of migration.
Differences in the population structure demonstrated by nuclear and mitochondrial
data indicate possible life history differences between the sexes.
Barramundi populations in different biogeographical provinces may have been
substantially isolated over a long period of time, and may therefore represent
independently evolving populations. This has important implications for fishery
management and translocation issues for restocking rivers.
46
Portofée, Clemens. "Untersuchungen zur Gewinnung von Viktoriabarsch (Lates niloticus) - Filets in Uganda /." Hannover : [s.n.], 2000. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009435974&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Full text
47
Marshall, Carina Rynn Ecremen. "Evolutionary genetics of barramundi (Lates calcarifer) in the Australian region." Thesis, Marshall, Carina Rynn Ecremen (2005) Evolutionary genetics of barramundi (Lates calcarifer) in the Australian region. PhD thesis, Murdoch University, 2005. https://researchrepository.murdoch.edu.au/id/eprint/181/.
Full textAbstract:
Barramundi (Lates calcarifer) is a centropomid teleost with a wide distribution across the Indo Pacific. In Australia, barramundi are native to the tropical zone from Exmouth Gulf in Western Australia, across the northern part of the continent, to the Mary River in Queensland. Barramundi are protandrous hermaphrodites, and are euryhaline, with a catadromous life history. Barramundi are a valuable Australian resource, with important commercial and recreational fisheries and aquaculture production to the value of $11 million dollars per year. Recent declines in the availability of the fish in some rivers has led to an interest in the possibility of restocking rivers with barramundi from other areas.
Determining the genetic structure of barramundi populations in Australia is important for understanding biogeographic history, and appropriate management practices for both aquaculture and recreational and commercial fishing. Previous studies have concentrated on the east coast of Australia, and have largely ignored the western populations. In this study, I obtained DNA data from barramundi populations across the Australian range of the species, as well as populations from Papua New Guinea and Indonesia. The aims of this study were to use the genetic data to determine: 1. if populations in Western Australia show genetic differences between geographic regions 2. if these populations show an ancestral split from populations in the east of Australia and 3. the ancestral origins of Australian barramundi.
Previous studies of DNA data from barramundi have discovered an east/west split occurring at the Torres Strait that was assumed to be caused by the closing of the strait during lowered sea levels. However, these studies suffered from a bias in sampling area, concentrating either on the eastern half of the range of barramundi, or on the western tip of the range. Data from these studies were combined and reanalyzed. Two major clades were discovered, with considerable biogeographic structuring, but their geographic locations did not coincide with the reported vicariance event at the Torres Strait. Instead,historical divisions among freshwater drainage systems appeared to have driven the evolutionary history of barramundi in Australia.
In order to investigate these historical divisions further, a 290 bp section of the mitochondrial DNA control region was sequenced in 284 barramundi from seven populations across the Australian geographic range of the species and from one population in Papua New Guinea and one population in Indonesia. Analyses of molecular variance within and among populations showed significant geographic structuring, based on biogeographical provinces and drainage divisions. Nested clade analyses indicated that these geographical associations were the result of restricted gene flow, range expansion, and past fragmentation events. I hypothesise that the Ord River area in the west of the continent was the ancestral source population for the rest of the species' range across Australia, with Indonesia being the most likely origin of this source. Populations of barramundi from the Pilbara region are genetically distinct and geographically isolated, with strong evidence of an ancestral divide along geographical barriers to dispersal. There is a strong association between Papua New Guinea and Australia, although further investigations using the cytochrome b region of mitochondrial DNA indicated a more ancestral divide between the two than is currently evident, which could reflect an ancient geographical divide between the two, or could be evidence of a secondary migration route to Australia.
For a more detailed study of evolutionary processes acting on populations of barramundi in Western Australia, allelic diversity was examined at five microsatellite loci. All loci were polymorphic and genotypic frequencies conformed to Hardy-Weinberg expectations, with no significant linkage between loci evident in any population. Measures of within population diversity were significantly related to latitude, suggesting southerly migration from a northern source population. The Ord River was the most genetically diverse population, and the most likely ancestral migration source to the area, with diversity decreasing down the west coast. Although there were significant differences among populations, the nuclear microsatellite data do not indicate the same degree of genetic structuring as is evident in the mitochondrial data. This may be a consequence of rapid evolutionary change at microsatellite loci, with past separations or population differences masked by recombination and back mutation of the microsatellite alleles. However, the nature of nuclear and mitochondrial inheritance may also indicate life history differences between the sexes, where significant genetic contribution to gene flow by males and limited female gene flow may lead to preservation of maternally inherited population substructure.
The principal findings from this study are:
* There is no genetic evidence for an east/west division of barramundi populations in Australia, as suggested by previous research.
* Despite barramundi's catadromous life history, and ability to disperse through marine waters, the present genetic structure indicates a division principally among river drainages. From a population genetic viewpoint, the species can be regarded as freshwater, rather than marine.
* The most likely origin of barramundi in Australia is the Ord River region, with Indonesia as the route of migration.
* Differences in the population structure demonstrated by nuclear and mitochondrial data indicate possible life history differences between the sexes.
* Barramundi populations in different biogeographical provinces may have been substantially isolated over a long period of time, and may therefore represent independently evolving populations. This has important implications for fishery management and translocation issues for restocking rivers.
48
Marshall, Carina Rynn Ecremen. "Evolutionary genetics of barramundi (Lates calcarifer) in the Australian region." Marshall, Carina Rynn Ecremen (2005) Evolutionary genetics of barramundi (Lates calcarifer) in the Australian region. PhD thesis, Murdoch University, 2005. http://researchrepository.murdoch.edu.au/181/.
Full textAbstract:
Barramundi (Lates calcarifer) is a centropomid teleost with a wide distribution across the Indo Pacific. In Australia, barramundi are native to the tropical zone from Exmouth Gulf in Western Australia, across the northern part of the continent, to the Mary River in Queensland. Barramundi are protandrous hermaphrodites, and are euryhaline, with a catadromous life history. Barramundi are a valuable Australian resource, with important commercial and recreational fisheries and aquaculture production to the value of $11 million dollars per year. Recent declines in the availability of the fish in some rivers has led to an interest in the possibility of restocking rivers with barramundi from other areas.
Determining the genetic structure of barramundi populations in Australia is important for understanding biogeographic history, and appropriate management practices for both aquaculture and recreational and commercial fishing. Previous studies have concentrated on the east coast of Australia, and have largely ignored the western populations. In this study, I obtained DNA data from barramundi populations across the Australian range of the species, as well as populations from Papua New Guinea and Indonesia. The aims of this study were to use the genetic data to determine: 1. if populations in Western Australia show genetic differences between geographic regions 2. if these populations show an ancestral split from populations in the east of Australia and 3. the ancestral origins of Australian barramundi.
Previous studies of DNA data from barramundi have discovered an east/west split occurring at the Torres Strait that was assumed to be caused by the closing of the strait during lowered sea levels. However, these studies suffered from a bias in sampling area, concentrating either on the eastern half of the range of barramundi, or on the western tip of the range. Data from these studies were combined and reanalyzed. Two major clades were discovered, with considerable biogeographic structuring, but their geographic locations did not coincide with the reported vicariance event at the Torres Strait. Instead,historical divisions among freshwater drainage systems appeared to have driven the evolutionary history of barramundi in Australia.
In order to investigate these historical divisions further, a 290 bp section of the mitochondrial DNA control region was sequenced in 284 barramundi from seven populations across the Australian geographic range of the species and from one population in Papua New Guinea and one population in Indonesia. Analyses of molecular variance within and among populations showed significant geographic structuring, based on biogeographical provinces and drainage divisions. Nested clade analyses indicated that these geographical associations were the result of restricted gene flow, range expansion, and past fragmentation events. I hypothesise that the Ord River area in the west of the continent was the ancestral source population for the rest of the species' range across Australia, with Indonesia being the most likely origin of this source. Populations of barramundi from the Pilbara region are genetically distinct and geographically isolated, with strong evidence of an ancestral divide along geographical barriers to dispersal. There is a strong association between Papua New Guinea and Australia, although further investigations using the cytochrome b region of mitochondrial DNA indicated a more ancestral divide between the two than is currently evident, which could reflect an ancient geographical divide between the two, or could be evidence of a secondary migration route to Australia.
For a more detailed study of evolutionary processes acting on populations of barramundi in Western Australia, allelic diversity was examined at five microsatellite loci. All loci were polymorphic and genotypic frequencies conformed to Hardy-Weinberg expectations, with no significant linkage between loci evident in any population. Measures of within population diversity were significantly related to latitude, suggesting southerly migration from a northern source population. The Ord River was the most genetically diverse population, and the most likely ancestral migration source to the area, with diversity decreasing down the west coast. Although there were significant differences among populations, the nuclear microsatellite data do not indicate the same degree of genetic structuring as is evident in the mitochondrial data. This may be a consequence of rapid evolutionary change at microsatellite loci, with past separations or population differences masked by recombination and back mutation of the microsatellite alleles. However, the nature of nuclear and mitochondrial inheritance may also indicate life history differences between the sexes, where significant genetic contribution to gene flow by males and limited female gene flow may lead to preservation of maternally inherited population substructure.
The principal findings from this study are:
* There is no genetic evidence for an east/west division of barramundi populations in Australia, as suggested by previous research.
* Despite barramundi's catadromous life history, and ability to disperse through marine waters, the present genetic structure indicates a division principally among river drainages. From a population genetic viewpoint, the species can be regarded as freshwater, rather than marine.
* The most likely origin of barramundi in Australia is the Ord River region, with Indonesia as the route of migration.
* Differences in the population structure demonstrated by nuclear and mitochondrial data indicate possible life history differences between the sexes.
* Barramundi populations in different biogeographical provinces may have been substantially isolated over a long period of time, and may therefore represent independently evolving populations. This has important implications for fishery management and translocation issues for restocking rivers.
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Wei, Wei-jiunn, and 魏維俊. "Optimum Design of Headstocks of Precision Lathes." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/42188228557878101580.
Full textAbstract:
碩士國立中興大學
機械工程學系
85
This thesis deals with optimum design of headstocks with three different shapes. The design purpose is to minimize the deflection of workpieces at cutting point. Each kind of headstock is subjected to two load case. The first load case includes the cutting force and the second load case combines the cutting force and the thermal effects. Heat generation is due to friction which is resulted from bearing revolution. The quantity of heat generated is calculated by the formula given by bearing manufactures. Design variables are the shape of headstock, the size of headstock, the stiffnesses of bearings, locations of bearings,locations of fins,and the size of fins. These variables include integer and continuous varilables. Because genetic algorithm has the ability of global search and dealing with mixed-variable problems, it is chosen to be the solver. The finite element model used in this thesis is created by MSC/PATRN and alayzed by MSC/NASTRAN. Each example which represents one specific shape is solved twice by the two load cases mentioned previsously. The validity and difference of the results are checked and discussed. The optiimun results of the three different-shape headstocks are compared and the best one is determined.
50
Fang, Nan, and 方. 楠. "COMPARING CNC LATHES USING DATA ENVELOPMENT ANALYSIS." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/02063632936498418253.
Full textAbstract:
碩士國防管理學院
資源管理研究所
88
This study reports on an application of Data Envelopment Analysis (DEA) to compare products which vary in excellence along a number of dimensions, and for each of which there might be a number of associated ‘cost’. The DEA method is illustrated by comparing 21 CNC (Computer Numerical Control ) lathes for small-size shell production. Potential uses of a DEA analysis of products might be: to assist military buyers who may need to reconcile a diversity of present and future uses in one standardized purchase; in competitors analysis; in determining unexplored market niches; and as a normative model of product excellence against which product purchasing behavior could be compared.