29 research outputs found
ChemInform Abstract: Keto-Enol Tautomerism in β-Tricarbonyl Compounds (I): Infrared Spectroscopy, Molecular Mechanics and Semiempirical (AM1) Molecular Orbital Calculations.
No full textCompact beam position monitor using a segmented toroidal coil
No full textAn inductive compact beam position monitor based on a segmented toroidal coil surrounding the charged particle beam has been investigated. It makes use of the induced voltages in the windings instead of the induced charge imbalance on capacitor plates in the popular beam position monitors. We theoretically investigate the response of the coils to the bunched particle beam based on a lumped-element model and compare it to the measurements in the laboratory and in the storage ring COSY in terms of beam displacement. As to the frequency response of the coils, we find a resonant behavior, which may be exploited to further increase the sensitivity of the device. The resolution presently achieved is about 5 μm in a 1 s time interval for a beam current of 0.5 mA
Compact beam position monitor using a segmented toroidal coil
No full textAn inductive compact beam position monitor based on a segmented toroidal coil surrounding the charged particle beam has been investigated. It makes use of the induced voltages in the windings instead of the induced charge imbalance on capacitor plates in the popular beam position monitors. We theoretically investigate the response of the coils to the bunched particle beam based on a lumped-element model and compare it to the measurements in the laboratory and in the storage ring COSY in terms of beam displacement. As to the frequency response of the coils, we find a resonant behavior, which may be exploited to further increase the sensitivity of the device. The resolution presently achieved is about 5 μm in a 1 s time interval for a beam current of 0.5 mA
Desenvolvimento de um protótipo de sistema especialista para projeto de unidades de potência hidráulica
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia MecânicaEste trabalho trata do desenvolvimento de um protótipo de sistema baseado no conhecimento voltado ao projeto de unidades de potência hidráulica de sistemas industriais. O objetivo da pesquisa é sistematizar e disponibilizar computacionalmente parte do conhecimento deste domínio específico, por meio de um sistema especialista criado a partir de regras definidas para o projeto de unidades de potência hidráulica. Além da potencial aplicação operacional do sistema, também é proposta uma aplicação para ensino na área de conhecimento do sistema, discutindo-se como um programa pode ser desenvolvido para fins educacionais e quais as características relevantes de um sistema para tal finalidade. A criação de um sistema baseado no conhecimento é feita através das seguintes etapas: escolha da ferramenta de desenvolvimento, aquisição e representação do conhecimento, implementação, verificação e validação computacional. Tais etapas são detalhadas ao longo do texto. As dificuldades encontradas no desenvolvimento do protótipo, principalmente a aquisição de conhecimento sobre projetos de unidades de potência hidráulica, também são discutidas em detalhes. Por fim, são apresentados os resultados deste trabalho de mestrado, destacando-se a sistematização de projeto elaborada e o estágio atual de desenvolvimento do protótipo, que permite a seleção de uma UPH em quatro disponíveis, bem como a classe e o princípio de deslocamento da bomba hidrostática. São mostradas ainda as limitações inerentes às dificuldades encontradas durante a criação do protótipo e as possibilidades de aprimoramento e outros usos (sugestões para futuros trabalhos) de um sistema especialista para projeto de unidades de potência hidráulica. This study presents the development of a knowledge-based system prototype directed towards the design of hydraulic power units on industrial systems. The aim of this research is to systematize and make computationally available part of the knowledge about this specific domain, through an expert system created from rules defined for hydraulic power units design. Besides the potential operational application of the expert system, it is also proposed a tutoring application on the knowledge area of this system, discussing how a computer program can be developed for educational use and what are the relevant features of a system for this purpose. The creation of a knowledge-based system is made by the following stages: selection of a development tool, knowledge acquisition and representation, implementation, computational verification and validation. Those stages are shown through this text. The difficulties found on this expert system prototype development, mainly the knowledge acquisition of hydraulic power units design, are also discussed in details. Finally, this text presents the results of this MSc project: the organized HPU design systematization and the current stage of the expert system prototype development, which can select one of a four available HPUs and the class and working principle of the employed hydrostatic pump. In addition, the thesis shows inherent limitations on the difficulties found throughout its development and some possibilities of improvement and other uses, as suggestions for future researches, of an expert system directed towards hydraulic power units design
Connection between zero chromaticity and long in-plane polarization lifetime in a magnetic storage ring
No full textIn this paper, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97-GeV/c deuteron beam. The IPP magnitude was measured by continuously monitoring the down-up scattering asymmetry (sensitive to sideways polarization) in an in-beam, carbon-target polarimeter and unfolding the precession of the IPP due to the magnetic anomaly of the deuteron. The optimum operating conditions for a long IPP lifetime were made by scanning the field of the storage ring sextupole magnet families while observing the rate of IPP loss during storage of the beam. The beam was bunched and electron cooled. The IPP losses appear to arise from the change of the orbit circumference, and consequently the particle speed and spin tune, due to the transverse betatron oscillations of individual particles in the beam. The effects of these changes are canceled by an appropriate sextupole field setting
Sistematização do projeto de circuitos hidráulicos para o emprego de fluidos biodegradáveis
No full textTese (doutorado)- Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Mecânica, Florianópolis, 2013.A presente tese trata da sistematização do processo de projeto pa-ra sistemas hidráulicos com o uso de fluidos biodegradáveis. Atualmen-te a tendência de aumento de potência nos sistemas hidráulicos é alcan-çada por meio do emprego de maiores pressões de operação e conse-quentemente, utilizando componentes menores. Altas pressões implicam em maior possibilidade de vazamentos e, por conseguinte, derramamen-to de fluido. Esses acidentes podem trazer sérios prejuízos ao meio am-biente como, por exemplo, no setor de geração de energia elétrica, e em especial nas Pequenas Centrais Hidrelétricas (PCH´s), cujos volumes de fluido hidráulico mineral são da ordem de centenas de litros e que usu-almente operam desassistidas e monitoradas a distância, de forma que não é possível agir rapidamente para evitar que eventuais vazamentos contaminem os recursos hídricos. Outra perspectiva deste problema refere-se aos derrames existentes em sistemas hidráulicos móveis como, por exemplo, máquinas agrícolas, onde estudos indicam que são derra-mados anualmente no solo de cultivos milhares de litros de óleo mineral conseqüente de falhas e vazamentos nestes sistemas hidráulicos. Neste contexto e com o intuito de evitar ou mitigar a questão do risco ambien-tal, identifica-se no Brasil e no mundo um caminho de incentivos a pro-cura de desenvolvimento de sistemas e/ou produtos ecologicamente corretos, tal como o uso crescente de fluidos biodegradáveis nos siste-mas hidráulicos de potência, substituindo o atualmente usado fluido mineral. Sendo assim, no presente trabalho apresenta-se uma solução para o projeto de sistemas hidráulicos que possam empregar fluidos biodegradáveis, a qual foca-se na sistematização de procedimentos para especificação e análise dos requisitos de sistemas hidráulicos, com o fim de adequar e otimizar o desempenho e a vida útil dos componentes as-sim como do próprio fluido. Com estratégias adequadas de projeto, em-pregando-se conceitos de sistemas hidráulicos, análise de fluidos, moni-toração e tecnologia ambiental, a sistematização de projeto garante a minimização dos problemas intrínsecos na utilização de fluidos biode-gradáveis nos sistemas hidráulicos apresentando ao mesmo tempo, uma solução no âmbito ecológico e de projeto para o desenvolvimento de novas tecnologias para os sistemas hidráulicos, seja na área industrial ou móbil. A estruturação da sistematização é orientada por meio do desen-volvimento de um protótipo de sistema computacional inteligente, utili-zando a técnica de sistema baseado no conhecimento (SBC). Baseando-se nos requisitos de projeto, o protótipo incorpora critérios para análise e tomada de decisão, o qual resulta na seleção (especificação) de um ou vários fluidos biodegradáveis, a seleção dos principais componentes do circuito hidráulico, assim como a definição de diretrizes de monitoração do sistema hidráulico. Finalmente, a sistematização sintetizada no protó-tipo SBC é verificada e validada por meio de avaliações de especialistas de diferentes domínios de conhecimento. Abstract : This thesis deals with the systematization of design process for hydraulic systems using biodegradable fluids. Nowadays, the trend in power increase in hydraulic systems is achieved through of the use of high operating pressures and therefore, using small components. High pressures require a greater chance of leakage and as result, spilling of fluid. These accidents can cause serious damage to the environment, for example, in the electric power generation sector, especially in the Small Hydro Power (SHP), whose volume of mineral hydraulic fluid is the order of hundreds of liters and usually operate unattended and moni-tored from a distance, so that it is not possible to act quickly to prevent contamination of water resources due to any incidental leaks. Another perspective to this problem relate to leakage existing in hydraulic mo-bile systems, for example, agricultural machines, where studies indicate that are annually poured on farmland thousands of liters of mineral oil, resulting from failures and leakages in these hydraulic systems. In this context and in order to avoid or mitigate the issue of environmental risk is identified in Brazil and the world a way of incentives in search of systems development and / or environmentally friendly products, such as the increasing use of biodegradable fluids in hydraulic systems, re-placing currently used mineral fluid. Therefore, in this work a solution for the design of hydraulic systems that may employ biodegradable fluids is proposed, which focuses on the systematization of procedures for specifying and analyzing the requirements of hydraulic systems in order to adapt and optimize the performance and component life, as well as the fluid itself. With appropriate strategies of design, using concepts of hydraulic systems, fluid analysis, monitoring, and environmental technology, the systematization guarantees the minimization of the problems inherent in the use of biodegradable fluids in hydraulic sys-tems, where is presented at the same time a solution within ecological and design scopes for the development of new technologies for hydrau-lic systems, whether in industrial or mobile sector. The structuring of the systematization is oriented through the development of a computational intelligent system prototype, using the technique of the knowledge-based system (SBC). Based on the design requirements, the prototype incorporates criteria to analysis and decision making, which results in the selection (specification) of one or various biodegradable fluids, the selection of the main components of the hydraulic circuit, well as defini-tion of guidelines monitoring of the hydraulic system. Finally, the sys-tematization which is encapsulated in the prototype is verified and vali-dated by expert reviews of different knowledge domains
Phase Locking the Spin Precession in a Storage Ring
No full textThis Letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV/c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (≈121 kHz) and the phase of the horizontal polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to manipulate the polarization. In particular, the rotation rate shows a sinusoidal function of the horizontal polarization phase (relative to the rf solenoid), which was controlled to within a 1 standard deviation range of σ=0.21 rad. The minimum possible adjustment was 3.7 mHz out of a revolution frequency of 753 kHz, which changes the precession rate by 26 mrad/s. Such a capability meets a requirement for the use of storage rings to look for an intrinsic electric dipole moment of charged particles
Phase measurement for driven spin oscillations in a storage ring
No full textThis paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. The experiments were performed at the Cooler Synchrotron COSY in Jülich using a vector polarized, bunched 0.97 GeV/c deuteron beam. Using the new spin feedback system, we set the initial phase difference between the solenoid field and the precession of the polarization vector to a predefined value. The feedback system was then switched off, allowing the phase difference to change over time, and the solenoid was switched on to rotate the polarization vector. We observed an oscillation of the vertical polarization component and the phase difference. The oscillations can be described using an analytical model. The results of this experiment also apply to other rf devices with horizontal magnetic fields, such as Wien filters. The precise manipulation of particle spins in storage rings is a prerequisite for measuring the electric dipole moment (EDM) of charged particles
