An in-vitro investigation into the cement pressurization achieved during insertion of four different femoral stems

Adequate cement pressurization during stem insertion improves the interdigitation of cement into bone. This increases the strength of the cement-bone interface, thus contributing to the reduction of the incidence of aseptic loosening, the commonest cause of revision surgery. This in-vitro study compared the cement pressurization achieved during insertion of four different stems of equivalent sizes: the Elite Plus (DePuy, UK), C-Stem (DePuy, UK), Exeter (Stryker, USA), and CPS-Plus (Plus Orthopedics, Switzerland). The maximum pressures attained at the time of stem insertion were recorded at proximal, mid and distal stem levels. The Elite Plus generated significantly higher distal pressures than the other stems. The CPS-Plus generated significantly greater proximal cement pressures than the Elite Plus, C-Stem, and Exeter prostheses. The triple taper of the C-Stem increased the cement pressurization medial to the stem. The stem shape and the presence or absence of a proximal stem centralizer affect cement pressurization. The presence of a proximal stem centralizer, a large stem volume, and a lateral-medial taper are all factors associated with increased cement pressurization during stem insertion.     

现场检测质谱膜进样技术研究进展

在简单阐述了膜进样质谱的基本原理后,重点介绍了近年来现场检测质谱膜进样技术的研究进展,包括膜材料、膜结构及应用领域的进展。针对化学毒剂和有毒工业化学物质对现场检测质谱仪的要求,提出了设计膜进样系统时需要解决的问题。     

ZYG气液增压缸的原理及其应用

通过分析ZYG气液增压缸的结构和工作系统图分析了其工作原理,介绍其主要技术参数及应用场合。     

The effect of the Rim Cutter on cement pressurization and penetration on cemented acetabular fixation in total hip arthroplasty: an in vitro study

The Rim Cutter (Stryker Orthopedics, Mahwah, New Jersey) is a tool designed to cut a ledge inside the rim of the acetabulum, onto which a precisely trimmed, cemented, flanged cup can be fitted. The aim was to investigate the effect of the Rim Cutter on the intra-acetabular cement mantle pressure and the depth of cement penetration during cup insertion. The study had two parts. In the first part, hemi-pelvis models were fitted with pressure sensors. Pressure in the acetabulum was measured on insertion of a conventional cemented flanged cup with and without the use of a Rim Cutter to prepare the rim of the acetabulum. The second part assessed cement penetration when the same cups were inserted into a foam shell model. The shell was mounted in a jig and had holes drilled in it; the distance that cement penetrated into the holes was measured. A significant increase in cement pressure at the apex (p = 0.04) and the rim (p = 0.004) is seen when the Rim Cutter is used. Cement penetration in the Rim Cutter group was significantly increased at the rim of the acetabulum (p = 0.003). Insertion of a flanged cup after the acetabulum is prepared with the Rim Cutter leads to a significant increase in cement pressure and penetration during cup insertion in vitro when compared with conventional flanged cups.     

Assessment of techniques for estimating oil-film bearing coefficients

In recent years methods have been developed for estimating oil-film stiffness and damping coefficients based upon techniques drawn from the field of control engineering. The stage has been reached where these new methods need to be evaluated, in relation to more traditional approaches as a prelude to future developments. That is the purpose of this paper.Experiments performed on a squeeze-film bearing rig are used to explain the new methods. Some current trends are described; in particular, an approach is outlined for estimating oil-film coefficients from operational data without introducing a test signal.     

Three-dimensional flow characteristics of propeller-propulsion WIG effect vehicle with direct underside pressurization

Numerical investigations for a 3-dimensional WIG effect vehicle with DUP (direct underside pressurization) have been performed. The purpose of this study is to analyze the aerodynamic characteristics and static height stability of DUP using computational fluid dynamics (CFD). When a WIG effect vehicle accelerates to take off on water, increased pressure under the fuselage by DUP (propeller and air chamber) can considerably reduce the take-off speed and thus minimize the effect of the hump drag which is one of the technical difficulties of a WIG effect vehicle. The accelerated air by the propeller enters the air chamber through a channel in the middle of the fuselage resulting in an augmentation of the lift by changing the air pressure from dynamic to static. However, the DUP is not favorable for both stability and aerodynamic performance of the WIG effect vehicle because the accelerated air produces an excessive drag, negative pitching moment and 3-dimensional effects (that is, yawing and rolling moments). The result shows that the effect of yawing and rolling moments is not serious.     

基于单铰运动链的内力加压装置及其创新设计

内力加压自适应装置在实践中被广泛使用,它以力的传递为主要工作目的.通过对内力加压装置的结构与自由度特征的分析,总结出进行内力加压自适应装置综合创新的一般方法.     

Assessment of precipitates of isothermal aged austenitic stainless steel using measurement techniques of ultrasonic attenuation

AISI 316L stainless steel is widely used as a structural material of high temperature thermoelectric power plants, since austenitic stainless steel has excellent mechanical properties. However, creep damage is generated in these components, which are operated under a high temperature and high pressure environment. Several researches have been done on how microstructural changes of precipitates affect to the macroscopic mechanical properties. And they investigate the relation between ultrasonic parameters and metallurgical results. But, these studies are limited by experiment results only. In this paper, attenuations of ultrasonic with isothermal damaged AISI 316L stainless steel were measured. Also, simulation of ultrasonic attenuation with variation of area fraction and size of precipitates were performed. And, from the measured attenuations, metallographic data and simulation results, we investigate the relations between the ultrasonic attenuations and the material properties which is area fraction of precipitates for the isothermal damaged austenitic stainless steel specimens. And, we studied parametric study for investigation of the relation between ultrasonic parameters and metallurgical results of the isothermal damaged AISI 316L stainless steel specimens using numerical methods.     

60t增压型钢筋挤压机液压系统的设计

钢筋挤压连接技术是一种粗钢筋连接的新技术新方法.增压型钢筋挤压连接系统代替原来的超高压系统,其突出优点是减少了挤压设备的重量、减小了劳动强度和加快了施工速度.     

Multipurpose high-pressure high-temperature diamond-anvil cell with a novel high-precision guiding system and a dual-mode pressurization device

A novel diamond-anvil cell (DAC) design has been constructed and tested for in situ applications at high-pressure (HP) operations and has proved to be suitable even for HP sample environments at non-ambient temperature conditions. The innovative high-precision guiding mechanism, comparable to a dog clutch, consists of perpendicular planar sliding-plane elements and is integrated directly into the base body of the cylindrically shaped DAC. The combination of two force-generating devices, i.e., mechanical screws and an inflatable gas membrane, allows the user to choose independently between, and to apply individually, two different forcing mechanisms for pressure generation. Both mechanisms are basically independent of each other, but can also be operated simultaneously. The modularity of the DAC design allows for an easy exchange of functional core-element groups optimized not only for various analytical in situ methods but also for HP operation with or without high-temperature (HT) application. For HP-HT experiments a liquid cooling circuit inside the specific inner modular groups has been implemented to obtain a controlled and limited heat distribution within the outer DAC body.     

Assessment of cleaning effectiveness for new ecological systems on ancient tempera icon by complementary microscopy techniques

The study presents an old icon painted in egg tempera on lime wood, with a poor conservation condition and clogged dirt deposits. The icon is attributed to an anonymous painter of XIXth century and to the neo‐classical style of painting. The painting layer was done with only a hand full of pigments, earth colors that were often used in painting the icons from XVIIth to XIXth century in Eastern Europe, that have Byzantine influences. Taking into consideration the nature and the structure of the materials from the upper layers of the painting, affected by deposits of dirt over time, a series of cleaning recipes were studied, using the so called cleaning tests with compatible mixtures of different juices and infusion from indigenes plants, that were freshly done and odorless. A low alkaline 95% ethyl alcohol solution, combined with a few drops of ammoniac 25%, was used as a reference system, due to its compatibility with the greasy deposits found on the polychrome layer and on the wood. The cleaning capacity of the new systems used, in comparison with the standard solution, was analyzed through modern analytical methods of evaluating the degree of cleaning, more exactly by means of visible and UV reflectography, CIE L*a*b* colorimetry by reflection assisted by SEM‐EDX and IR spectroscopy. Microsc. Res. Tech. 77:1060–1070, 2014. © 2014 Wiley Periodicals, Inc.     

JSP技术简介及发展前景

JSP是基于JAVA的技术,它具备了JAVA语言所有的优点,同时拥有强大的服务器端动态网页技术功能,目前是在中国,乃至全球最流行、应用最广泛的软件开发技术之一.     

GFTC-4000数控激光加工技术简介

一、数控激光加工机床概述 GFTC-4000数控激光加工机床,此机床采用最新激光技术适用于对各种轴类、盘类、矩形零件、异形零件、以及齿轮齿面的表面淬火、熔凝、熔覆、及合金化工作.     

CIMT2011展品介绍

中国机床工具工业协会主办的CIMT2011于2011年4月11-16日在北京中国国际展览中心隆重举行.作为国内最大、最先进的机床展,本次展会展出了国内最先进、最优质的产品和国外厂商推向中国市场的最先进的产品.本刊分主机、数控系统、测量、刀具、传动、特种加工几个部分来介绍展品,其中主机部分由于展品众多,我们挑选了五轴和复合加工机床展品分国内和国外两个部分进行了重点报道.本届展会展示的重点之一就是国家科技重大专项(以下简称重大专项)的成果,展会上展出了其中的一些产品,本刊在报道中标注出涉及的部分,但本刊无法报道出所有的产品,还请见谅.希望我们的报道能够给您提供有价值的信息.     

浅谈概念车造型与品牌形象

概念车作为具有前瞻性的车型,承载着塑造未来造型趋势,探索汽车前沿科技发展方向的意义。同时概念车作为一个展示平台,可以展现出企业强大的研发能力及利用先进科学技术的能力,极大地提高企业品牌形象,提高产品的认知度。通过分析概念车设计对品牌形象及家族化造型风格的影响,并结合国际主流厂商概念车发展的状况,阐述了概念车造型设计的的重要性。     

在线分析工程技术导论

在线分析工程技术取得"数量"发展之后,正迎来历史性新机遇,进入新的发展时期,而传统的技术观念和技术思维却是本专业健康发展的严重障碍.发展在线分析工程技术,迫切需要大趋势理念.本文在全方位深入分析探讨在线分析工程技术时,重新定义"样气处理系统"‘在线分析系统"、"在线分析工程技术",倡导在线分析工程技术新专业的理论初创.将"样气处理系统"提升到了"在线分析工程技术的核心和关键技术"的新高度,以样气处理系统取代使用数十年的"取样预处理系统"具有颠覆性的重要意义.仪器仪表是信息工业的源头.作为精密仪器的科学仪器(核心是分析仪器)更不待言,在线分析系统堪称科学仪器皇冠上的明珠,在开发资源、节约能源和防治环境污染等重要领域为人类社会不断创造出新的生产力,持续地推进人类社会的发展.任何技术的快速发展,都必须以理论创新为导向.以21世纪前沿技术的独特视角,去探寻考量此前未被深入触及的领域及疑难问题,试图领悟和探索进而把握住在线分析工程技术理论初创和质量发展的契机.     

胶接接头设计及检验方法

介绍了胶接接头的设计原则,对胶接前零件的表面及涂胶处理作了说明,同时介绍了初步的胶接工艺流程与检验方法．扼要对胶接技术与传统的连接方式进行了比较。     

水泥销售系统的研发设计

本文介绍了水泥销售管理信息系统设计的设计过程,通过严格按照生命周期法进行开发,完成了水泥销售管理信息系统的开发,实现客户管理、销售管理、报表管理、车辆管理、人事管理、发货管理六大部分的管理信息化,重点分析解决了关于客户信用等级的评价指标体系和算法.最后进行系统实现和系统测试.