104 resultados para Winch
Resumo:
For efficient functioning of a trawl winch it is essential that all component parts should be designed carefully taking into consideration all the relevant factors such as quantum and type of load each component is subjected to, amount of maintenance it will receive during actual operation, type of drive for the winch etc. Based on the practices adopted at the Central Institute of Fisheries Technology certain guidelines are proposed in this paper for designing of trawl winches.
Resumo:
Emission of europium(II) and europium(III) have been observed in SrMgF4 xEu, yTb phosphors winch are synthesized in Ar flow. The valence state of En is influenced by terbium, It is noted that the intensities of the ESR peaks corresponding to Eu2+ are increased when terbium ion is codopech this can be explained by electron transfer mechanism which is Eu3++Tb3+-->Eu2++Tb4+. And its equilibrium constant is calculated.
Resumo:
There is a need to obtain the hydrologic data including ocean current, wave, temperature and so on in the South China Sea. A new profiling instrument which does not suffer from the damage due to nature forces or incidents caused by passing ships, is under development to acquire data from this area. This device is based on a taut single point mid-water mooring system. It incorporates a small, instrumented vertically profiling float attached via an electromechanical cable to a winch integral with the main subsurface flotation. On a pre-set schedule, the instrument float with sensors is winched up to the surface if there is no strip passing by, which is defined by an on-board miniature sonar. And it can be immediately winched down to a certain depth if the sonar sensor finds something is coming. Since, because Of logistics, the area can only be visited once for a long time and a minimum of 10 times per day profiles are desired, energy demands are severe. To respond to these concerns, the system has been designed to conserve a substantial portion of the potential energy lost during the ascent phase of each profile and subsequently use this energy to pull the instrument down. Compared with the previous single-point layered measuring mode, it is advanced and economical. At last the paper introduces the test in the South China Sea.
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对水下机器人铠缆收放绞车进行主动升沉补偿控制,可以提高水下机器人作业和收放的安全性能。该文建立了液压绞车的主动升沉补偿控制模型,通过测量母船升沉运动进行主动升沉补偿控制,并采用了前馈控制器以提高液压绞车的响应速度。试验表明,液压绞车主动升沉补偿前馈控制可以得到较高的水下机器人升沉补偿效率。
Resumo:
针对母船的升沉运动影响有缆水下机器人的释放与回收的工程实际需求,提出了利用液压绞车降低中继器的升沉速度来实现水下机器人主动升沉补偿控制的方法,来提高水下机器人释放与回收的安全性能。建立液压绞车的数学模型并设计主动升沉补偿前馈控制器。水下机器人主动升沉补偿实验表明液压系统的非线性降低了液压绞车主动升沉补偿前馈控制的升沉补偿效率。针对液压绞车的非线性特性,设计了液压绞车主动升沉补偿预测控制算法,仿真实验表明基于液压系统参数辨识的液压绞车主动升沉补偿预测控制可以得到较高的升沉补偿效率。
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介绍一种基于水下机器人常规液压收放绞车的主动升沉补偿系统,利用加速度传感器获得母船的升沉运动信号,控制绞车的运转来降低母船的升沉运动对水下机器人的影响。通过理论计算建立主动升沉补偿系统的数学模型,仿真分析绞车运动对水下机器人升沉运动的补偿效果,并利用主动升沉补偿系统实验台验证基于常规液压收放绞车的主动升沉补偿方案的可行性。
Resumo:
在潜水器收放过程中,要求收放绞车具有恒张力控制功能,减小由于波浪起伏对潜水器的冲击。本文根据液压系统的流量连续性方程,建立恒张力收放绞车泵控液压马达系统的数学模型,并对该系统进行了仿真分析,仿真结果表明:该系统能够满足实际的作业工况,且具有良好的动态和稳态工作性能。仿真结果为收放系统的设计提供了依据。
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深海ROV是一种可以在深海进行观察和作业的水下机器人。其研究和开发,对海洋环境的调查,海洋资源的钻探以及军事应用方面都具有重要的意义。深海ROV收放在深海区域收放作业时,作业环境复杂,作业深度大,如果铠缆绞车采用单卷筒结构会存在驱动装置功率过大,卷筒的转动惯量过大,载体出水的瞬间铠缆外层压入内层等问题。另外,海面的海况条件比较恶劣,支持母船受风、浪、涌、流影响而产生较大幅度的升沉运动对有缆水下机器人正常作业和收放操作有较大的影响,ROV中继器的升沉运动甚至可以造成系缆的损害而使机器人本体丢失。为了提高ROV在恶劣海况下的安全性能,保护中继器与载体之间的系缆不受损坏,需要配备升沉补偿装置。所以深海ROV铠缆绞车及其升沉补偿装置的研究与设计,对实现深海ROV的收放及保障系统安全及各项关键技术的进一步研究具有重要的意义。 本文在863计划“基于母船升沉预测的深海装备主动升沉补偿测控单元的研究开发”资助下,结合7000m ROV收放操作和升沉补偿的要求,开展深海ROV铠缆绞车及其主动升沉补偿装置的设计研究。针对深海ROV收放作业时,ROV铠缆绞车需要具有ROV快速收放能力及升沉补偿能力,设计适合于深海ROV收放作业的铠缆绞车。本文重点研究适合于深海ROV铠缆绞车的双绞车结构形式;研究双绞车的受力分析,驱动装置的选型;设计深海ROV铠缆绞车的储存绞车和牵引绞车;设计用于深海ROV铠缆绞车的主动升沉补偿装置。本文的主要内容如下: (1)研究深海ROV铠缆绞车的结构形式。分析了如果深海ROV铠缆绞车采用单卷筒结构存在转动惯量过大,驱动装置功率过大,在出水的瞬间铠缆外层缆压入内层等问题,提出了双绞车结构。分析了双绞车的组成,布置及其作用原理,各部件的组成及作用原理。 (2)研究深海ROV铠缆绞车的受力及所需要的功率。利用微元分析,求解出深海ROV牵引绞车每个绞盘提供的摩擦力,从而求出各绞车驱动装置需提供的最大驱动力矩和功率,作为驱动装置的选型依据。 (3)设计深海ROV铠缆绞车。通过类比以前的绞车系统,理论计算,初步选定储存绞车及牵引绞车各个部件参数。采用SolidWorks进行三维建模后,采用ANSYS进行有限元分析,通过计算机仿真技术克服理论计算的缺陷,对各个部件进行强度校核及结构优化。 (4)设计主动升沉补偿装置。根据升沉补偿装置的技术指标,通过理论计算确定升沉补偿装置各个部分结构形式和参数,并进行了三维建模、通过有限元分析对各个部件进行强度校核,最后分析了超长缆释放时自身的张力对绞车定位的影响。 通过以上研究,设计出符合7000m ROV收放作业要求的深海ROV铠缆绞车及其升沉补偿装置,为7000m ROV的实现和收放技术的研究奠定了良好的基础。
Resumo:
El presente ensayo explora un concepto de ‘nosotros’ que sin rechazar el uso gramatical de la enunciación se enfoca en la pragmática que le subyace, desde la cual las condiciones de colectividad y exclusividad del enunciado se confrontan con su alteridad ontológica fundamental. A la luz de la tesis sobre la antropología postestructural del etnólogo brasilero Eduardo Viveiros de Castro, se examinan, de un lado, la necesidad de enunciar al ‘nosotros’ en su calidad de radical diferenciador y, de otro, la imposibilidad de constituirlo sustancialmente en tanto remite inexorablemente a la otredad. En la primera parte, se expone que las teorías socioculturales no triviales de la antropología son realmente una coproducción entre el antropólogo y la comunidad estudiada. En segunda instancia, se presenta el modo por el cual el ‘nosotros’ da lugar a una diferencia irreductible no sólo previa al Mismo, sino esencial y afirmativa. En tercer lugar, se plantea una colectividad inmanente caracterizada por la multiplicidad que permanece por debajo de cualquier enunciación organizativa del ‘nosotros’ y compuesta por la alteridad maquínica. A modo de conclusión, el ensayo afirma al ‘nosotros’ en su devenir en cuanto un-otro-por-venir, el cual funciona como acto político existencial.
Resumo:
Este artículo explora un tema central en la filosofía de la religión actual: la relación entre la razón y la fe, a partir de la controversia que genera la defensa de Norman Malcolm del argumento ontológico de San Anselmo. Dado que Malcolm es conocido por su postura fideísta, surge la cuestión de cómo es posible que defienda al mismo tiempo dos posiciones que parecen contrarias: por un lado, que las demostraciones racionales son irrelevantes para producir la fe y, por el otro, que haya un argumento a favor de la existencia de Dios que pueda ser considerado válido. Esta posición se puede entender a partir de la tesis propuesta en este trabajo que consiste en sostener que si bien la fe religiosa no se obtiene por argumentos, la argumentación racional tiene un lugar dentro de la fe, el cual consiste en ayudar a comprender por la razón aquello que se cree. Este trabajo intenta mostrar que la postura de Malcolm no es contradictoria en tanto que implica la diferencia entre la creencia "que Dios existe", la cual sería el objeto de los argumentos racionales y no supone ninguna práctica o devoción religiosa, y la creencia "en Dios", la cual a la vez que presupone que Dios existe, constituye el tipo de creencia propiamente religiosa que se entiende en términos de confianza, fe y devoción.
Resumo:
The objective with this study has been to build general models of the mechanics in tree felling with chain-saw and to compare felling torque for different tools. The theoretical models are completed and validated with a comparative study. The study includes a great number of felling tools of which some are used with different methods. Felling torque was measured using a naturally like measuring arrangement where a tree is cut at about 3.7 m height and then anchored with a dynamometer to a tree opposite to the felling direction. Notch and felling cut was made as ordinary with exception that the hinge was made extra thin to reduce bending resistance. The tree was consequently not felled during the trials and several combinations of felling tools and individuals could be used on the same tree.The results show big differences between tools, methods and persons. The differences were, however, not general, but could vary depending on conditions (first of all tree diameters). Tools and methods that push or pull on the stem are little affected by the size of the tree, while tools that press on the stump are very much dependent of a large stump-diameter. Hand force asserted on a simple pole is consequently a powerful tool on small trees. For trees of medium size there are several alternative methods with different sizes and brands of felling levers and wedges. Larger and more ungainly tools and methods like tree pusher, winch, etc. develop very high felling torque on all tree sizes. On large trees also the felling wedge and especially the use of several wedges together develop very high felling torque.
Resumo:
Grains and legume seeds are foods that form the basis of the diets of many cultures around the world, winch contritbute to the daily nutrient requirements of humans. Vicilins (7S globulin) are storage proteins found in legume seeds, and may have an additional function constitutive defense of the embryo against pests and pathogens. In this work the vicilin from Anadenanthera macrocarpa - AmV (red-angico), was purified and partially characterized, its effect on development and larval survival and adult emergence of Callosobruchus maculatus was evaluated by determination of LD50, WD50 and ED50 in system bioassay. Purification of vicilin was initiated by the chitin affinity chromatography and then gel filtration (Superdex 75 Tricorn 10x300 mm) FPLC system followed by reverse phase chromatography (C8 phenomenex) on HPLC system. Bioassays WD50 and LD50 for larvae were 0.32% and 0.33% (w:w) respectively, since the ED50 for adults was 0.096%. The probable mechanism of action was evaluated by testing digestibility of AmV in vitro, and observed for the involvement of two fragments vicilins immunoreactive against polyclonal Anti-vicilin from Erythrina velutina (Anti-EvV) about of 22 and 13 kDa chitin binding. The AmV in its native form has been recognized by the anti-EvV, indicating that there is a conserved region in the vicilin and is probably corresponding to the chitin binding domains. These results point to a new vicilin chitin binding that can subsequently be used as a possible biopesticide protein source, in order to control insect pest C. maculatus and confirm literature findings that demonstrate vicilin in the presence of different kinds of ligands to conserved regions chitin not yet characterized