Symmetric Equations for Evaluating Maximum Torsion Stress of Rectangular Beams in Compliant Mechanisms

There are several design equations available for calculating the torsional compliance and the maximum torsion stress of a rectangular cross-section beam, but most depend on the relative magnitude of the two dimensions of the crosssection(i.e., the thickness and the width). After reviewing the available equations, two thickness-to-width ratio Independent equations that are symmetric with respect to the two dimensions are obtained for evaluating the maximum torsion stress of rectangular cross-section beams. Based on the resulting equations, outside lamina emergent torsional joints are analyzed and some useful design Insights are obtained. These equations, together with the previous work on symmetric equations for calculating torsional compliance, provide a convenient and effective way for designing and optimizing torsional beams in compliant mechanisms.     

Compliant high-precision E-quintet ratcheting (CHEQR) mechanism for safety and arming devices

Ratchet and pawl mechanisms are used in safety applications to provide mechanical isolation between inputs and an output to insure that extreme environmental conditions do not inadvertently allow an unexpected output. These devices have become smaller and are approaching a size regime where traditional precision components, such as precision bearings and springs, are not available. This paper introduces the compliant high-precision E-quintet ratcheting (CHEQR) mechanism as a means of exploiting the advantages of compliant mechanisms to create safety devices that eliminate the need for bearings and springs. The pseudo-rigid-body model was used to design a mechanism with the desired force-deflection characteristics, and the result is a radical departure from traditional ratchet and pawl mechanisms. Large-scale proof-of-concept prototypes were followed by micro-wire EDM fabrication of precipitation hardened stainless steel devices with flexible segment widths of 50 μm. The device was integrated with a 6 mm ratchet wheel and rotary solenoid actuator.     

在科学研究和生物制药学系统中实现可追踪的气体流量监测与控制

科学和制药进展方面越来越多的研究都依赖于对细胞生长和复杂生化反应的了解和控制。在以上过程中实现气体精确和可追踪的监测和控制很有必要。对诸如二氧化碳、氮气、空气等气体的测定与控制已经可以通过一个简单的可变截面流量计成功实现。但可变截面流量计在精确度、可追踪性和最大允许压力等方面仍然具有明显的局限性。本文所介绍的热式质量流量计和控制系统为流量测定和控制提供了更高的准确度和直接的可追溯性,且此准确度和追溯性几乎不受压力和温度变化的影响。     

The in-line inspection of carbon anodes for aluminum production

In this paper, methods for measuring the quality of carbon anodes consumed in the commercial production of aluminum are discussed. The electrical and mechanical qualities of these anodes are important for the economic operation of the aluminum plant. While the investigation is ongoing, results from tests made at an aluminum reduction plant are included. The methods reviewed include direct resistivity measurement using core samples, ultrasonic measurement, the hammer method, analysis of the Hall effect, the four-probe method, and use of magnetic coils (various arrangements).     

Bioceramics

Ceramics used for the repair and reconstruction of diseased or damaged parts of the musculo-skeletal system, termed bioceramics, may be bioinert (e.g., alumina and zirconia), resorbable (e.g., tricalcium phosphate), bioactive (e.g., hydroxyapatite, bioactive glasses, and glass-ceramics), or porous for tissue ingrowth (e.g., hydroxyapatite-coated metals). Applications include replacements for hips, knees, teeth, tendons, and ligaments and repair for periodontal disease, maxillofacial reconstruction, augmentation and stabilization of the jaw bone, spinal fusion, and bone repair after tumor surgery. Pyrolytic carbon coatings are thromboresistant and are used for prosthetic heart valves. The mechanisms of tissue bonding to bioactive ceramics have resulted in the molecular design of bioceramics for interfacial bonding with hard and soft tissue. Bioactive composites are being developed with high toughness and elastic modulus that match with bone. Therapeutic treatment of cancer has been achieved by localized delivery of radioactive isotopes via glass beads. Clinical success of bioceramics has led to a remarkable advance in the quality of life for millions of people.     

Mechanism of corona treatment on polyolefin films

This paper reviews recent studies on the mechanism of corona treatment of polyolefin films, specifically the chemical and physical changes of this process and the self-adhesion mechanism. Corona discharge of polymeric films introduces polar groups into the surfaces, which increases the surface energy and, as a consequence, improves substrate wettability and adhesion. The main chemical mechanism of corona treatment is oxidation. In addition, corona treatment can crosslink surface regions and increase the film cohesive strength.     

Samuel Guttenplan,ed., A Companion to the Philosophy of Mind

Minds and Machines -     

Ironic effects of repetition: Measuring age-related differences in memory.

Four experiments examined ironic effects of repetition, effects opposite to those desired (cf, D. M. Wegner, 1994). For an exclusion task, participants were to respond "yes" to words heard earlier but "no" to words that were read earlier. Results from young adults given adequate time to respond showed that false alarms to earlier-read words decreased with their repetition. An opposite, ironic effect of repetition was found for elderly adults—false alarms to earlier-read words increased with repetition. Younger adults forced to respond quickly or to perform a secondary task while reading words showed the same ironic effect of repetition as did elderly adults. The process-dissociation procedure (L. L. Jacoby, 1991, 1998) was used to show that factors that produce ironic effects do so by reducing recollection while leaving effects of repetition on familiarity unchanged. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Beyond parallel play: Science befriending the art of method acting to advance healing relationships.

Research underscores the central role of factors in healing that appear to relate to the therapeutic relationship. These nonspecific or common factors and placebo effects are often overshadowed by an emphasis in the field on particular empirically supported therapies. Yet relationship variables account for a greater proportion of the variance in treatment outcomes than the technical intervention employed, representing a notable blind spot in our science and, by extension, our practice. As a consequence, clinical instruction in psychology and in the health professions more broadly generally lacks adequate specificity with respect to how to cultivate a healing relationship. Through the elaboration of several techniques derived from theatrical traditions, the authors propose that method acting and similar schools of drama provide a method for honing clinical skills in these areas that is amenable to empirical scrutiny. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

在线检测与分析 快速发现不可见的电学缺陷

在Fab里，在经过特别设计的短流程测试晶圆上进行的快速电学测试和自动FIB／SEM缺陷分析可以将不可见缺陷探测与分析的时间降低一个数量级，并且对不同的设计参数非常敏感，因而有足够的样本来做重要的统计评估。