Ergonomic evaluation of the musculoskeletal risks in a banana harvesting activity through qualitative and quantitative measures,with emphasis on motion capture (Xsens) and EMG

The objective of this study was to evaluate the risk of musculoskeletal injuries in a banana processing task. A sample of three workers were evaluated with the Nordic questionnaire as well as according to effort, discomfort and usability levels, hand grip dynamometry, inertial sensor motion capture (Xsens) and surface electromyography in the right arm. The workers had musculoskeletal complaints throughout the spine and hips, low effort and discomfort levels, and a satisfactory usability level. The hand grip strength values (dominant: 54.8 Kgf; non-dominant: 54.2 Kgf) were above the reference values for the Brazilian population. Regarding movement analysis, we identified risks related to cervical protrusion, forward and lateral trunk flexion, abduction and flexion in the shoulders, flexion, extension, radial and ulnar deviation in the wrists, as well as repetitive movements. Surface electromyography showed that the greatest demand during the task was on the extensor carpi radialis, although the trapezius and flexor carpi radialis showed a tendency toward fatigue. Thus, the set of evaluations showed that the tool used and worker adaptation to the position of the bunches, together with the repetitious movement, led to inadequate postures and musculoskeletal risks.Relevance to industryThe banana processing activity generates employment and income in several regions of the world and in Brazil. However, it is still rudimentary and may present risks to the worker's health. This study seeks to elucidate ergonomic risks through technological instrumentation in order to have a quantitative assessment of the ergonomic risks.     

Linear actuation in coextruded dielectric elastomer tubes

Cylindrical fibre actuators have been constructed by a coextrusion method using a thermoplastic polyurethane wall and a conductive grease filler. These actuators may be operated as single fibres or bundled together as actuating ropes. Key results include the validation of Carpi’s wall pressure model [F. Carpi, D.D. Rossi, Dielectric elastomer cylindrical actuators: electromechanical modelling and experimental evaluation, Mater. Sci. Eng. C-Biomimetic Supramol. Syst. 24 (2004) 555–562] and the proof-of-concept demonstration of a technique that can be used for producing inexpensive dielectric elastomer actuators on an industrial scale.     

基于蒙特卡罗法的FC-AE-ASM网络可靠性研究

对于FC-AE-ASM网络的可靠性问题,从FC-AE-ASM网络的基本模型出发,介绍了两种FC-AE-ASM网络冗余结构;提出了基于蒙特卡罗仿真法的网络可靠性分析方法,给出了FC-AE-ASM网络全端可靠度计算方法,给出了仿真结果的误差分析公式;结合由多个FC交换机组成的复杂FC-AE-ASM网络模型实例,分析链路冗余结构、链路可靠概率和节点可靠概率对FC-AE-ASM网络可靠性的影响。     

基于存储区域网络的数据备份技术研究

从数据备份系统结构的角度,研究了传统数据备份技术的优缺点,针对现有备份技术的存在的问题,通过在存储区域网络中引入网络数据管理协议,使得存储区域网络环境下的数据备份极大减轻了网络负载量,同时业务服务器最大限度地从数据备份过程中解脱出来,从而提高了整个备份系统的性能;同时对基于存储区域网络数据备份技术研究的特点、存在的问题、研究热点和应用情况等进行了分析。     

基于Fibre Chanel组播的远程数据备份体系结构

数据备份是容灾的基础.本文提出了一种基于FC组播服务的远程数据备份方法,对其工作原理和所涉及到的粗波分复用和流量控制等关键技术进行了研究,对基于FC组播的数据备份系统的性能和所属的容灾层次等内容进行了分析.     

基于IP的存储网络技术

介绍了存储局域网(SAN)和附网存储(NAS)特点,讨论了网络存储的发展趋势———基于IP的存储网络技术,并与光纤通道(FC)协议的存储局域网作比较,分析其优势,另外讨论了基于IP的存储网络的关键技术,并给出了有关实现方案。     

一种用于信令寻径高速光纤交换网的信令降频方法

针对高速光纤交换网络高质量的交换服务需求,提出了一种适用于信令寻径式高速光纤通道交换机的信令降频方法.该方法采用一套特殊的序列码对信令帧内容进行编码后传输,以达到信令帧信号频率成倍降低的目的,使交换机无需借助串并转换器对高频信令帧进行降频,就能够直接识别信令帧内容.试验结果显示,采用信令降频方法后,交换机的结构显著简化,可靠性得到很大提高,并且硬件成本大大降低.     

丝素蛋白腈纶结构性能及其混纺针织纱的开发

通过对丝素蛋白接枝腈 性能及原理的讨论，提出了素蛋白腈纶纤维与天然纤维混纺针织纱及最终产品开发中的技术要点，为丝素蛋白接接腈纶的产品提供了途径。     

Mechanics of three-dimensional braided structures for composite materials – part I: fabric structure and fibre volume fraction

This paper is the first part of a series on the mechanics of three-dimensional braided structures for composite materials which include fabric structure and fibre volume fraction models, prediction of mechanical properties, finite element analysis and simulation of deformations. In the present paper, the normalized pitch length is introduced as a key parameter of three-dimensional braided structures. It is demonstrated that the braiding angles and fibre volume fractions can be represented as functions of this key parameter. The structures of three-dimensional braids were simulated and the braided fabrics and preforms were designed and produced. Fibre volume fraction models were established. The predictions from the fibre volume fraction models are supported by experimental results.     

Nachträgliche Verstärkung gemauerter Tragwerke mit Faserverbundwerkstoffen

Gemauerte Konstruktionen lassen sich sehr effektiv mit Faserverbundwerkstoffen nachträglich verstärken. Dabei ist es sinnvoll, den Faserverbundwerkstoff direkt auf der Mauerwerksoberfläche durch das Einlegen von Fasergelegen in eine Klebstoffmatrix herzustellen. Anwendungsgebiete dieses Verfahrens sind die Umschnürung gemauerter Pfeiler, die Verstärkung von Wänden unter Scheibenbeanspruchung und die zugfeste Bewehrung biegebeanspruchter Bauteile. Die wichtigsten Ergebnisse umfangreicher experimenteller Untersuchungen, die an der Universität Kassel in den vergangenen Jahren durchgeführt wurden, werden vorgestellt und erläutert. Post‐strengthening of masonry structures with fibre reinforced polymers. Fiber reinforced polymeres can be used effectively for post‐strengthening of masonry structures. In this context it is reasonable to manufacture the FRP material by wet‐lay‐up directly on the surface of the masonry structure. Possible applications of the method are the confinement of columns as well as post‐strengthening of in‐plane and out‐of‐plane loaded structures. The main results of experimental research carried out at the University of Kassel during the last years will be presented.