Comparisons of tibial accelerations when walking on a wood composite vs. a concrete mezzanine surface

Mezzanine surfaces can be made from concrete, bar grate, or composite materials. Anecdotal data indicate that mezzanines in distribution centers made from composite materials, due to their increased compliance, may be a more comfortable working surface. Prior research suggested that a measure of tibial shock, peak tibial acceleration, could potentially discriminate the biomechanical differences between these surfaces. The objective of this study was to quantify differences in tibial accelerations as 27 people walked on mezzanines constructed from concrete and a wood composite material. Accelerometers were attached bilaterally to the shins of volunteers, and data were collected as they walked 30.5 m on each surface at their normal walking speed, a faster-than-normal walking speed, and a slower-than-normal walking speed. Peak acceleration values obtained from the leg with the highest values were compared. On average, the peak acceleration values were 5% higher on the concrete mezzanine as compared with the wood composite mezzanine (p = .036). These findings suggest that individuals working on mezzanines in distribution centers constructed from composite surfaces would potentially experience less discomfort associated with long exposure periods on these surfaces.     

Purifying Bodies,Translating Race: The Lantern Slides of Sir Everard im Thurn

In 1893 the colonial administrator and anthropologist, Everard Ferdinand im Thurn, gave an illustrated lecture, entitled Anthropological Uses of the Camera, in which he used more than thirty lantern slides. Im Thurn argued that, in addition to photographing the measured physical body, ‘primitive folk’ as ‘living beings’ in their ‘natural conditions’ could also be captured on film for the advancement of anthropological science. Although this lecture has been seen as representing a humanistic turn in anthropological photography, little attention has been given to the ways in which lantern slide technology participated in and facilitated this shift. The present paper demonstrates that im Thurn used the lantern slide to re‐assert and re‐define the scope of anthropological inquiry, altering the connections between morality and race and culture and nature. Lantern slides not only permitted heightened public visibility of particular selections of the body but also normalized classifications of race, nature, and culture. By situating lantern slides as photographic translations that travel through various spaces, we can begin to understand how the lantern slide was enlisted by im Thurn to uphold anthropology as a science, to alter what constituted a proper anthropological subject for the photograph, and ultimately to legitimize himself as a scholar.     

Strength variability of single flax fibres

Due to the typical large variability in the measured mechanical properties of flax fibres, they are often employed only in low grade composite applications. The present study aims to investigate the reasons for the variability in tensile properties of flax fibres. It is found that an inaccuracy in the determination of the cross-sectional area of the fibres is one major reason for the variability in properties. By applying a typical circular fibre area assumption, a considerable error is introduced into the calculated mechanical properties. Experimental data, together with a simple analytical model, are presented to show that the error is increased when the aspect ratio of the fibre cross-sectional shape is increased. A variability in properties due to the flax fibres themselves is found to originate from the distribution of defects along the fibres. Two distinctive types of stress–strain behaviours (linear and nonlinear) of the fibres are found to be correlated with the amount of defects. The linear stress–strain curves tend to show a higher tensile strength, a higher Young’s modulus, and a lower strain to failure than the nonlinear curves. Finally, the fibres are found to fracture by a complex microscale failure mechanism. Large fracture zones are governed by both surface and internal defects; and these cause cracks to propagate in the transverse and longitudinal directions.     

The fate of Transparent Exopolymer Particles (TEP) in integrated membrane systems: Removal through pre-treatment processes and deposition on reverse osmosis membranes

The abundance of Transparent Exopolymer Particles (TEP) in surface waters has been unnoticed for many years until recently as a potential foulant in reverse osmosis systems. Recent studies indicate that TEP may cause organic and biological fouling and may enhance particulate/colloidal fouling in reverse osmosis membranes. The presence of TEP was measured in the raw water, the pre-treatment processes and reverse osmosis (RO) systems of 6 integrated membrane installations. A spectrophotometric method was used to measure TEP in the particulate size range (>0.40 μm) and was extended to measure TEP in the colloidal size range (0.05–0.40 μm). Ultrafiltration pre-treatment applied in 4 plants, totally removed particulate TEP while microfiltration systems (2 plants) and coagulation/sedimentation/rapid sand filtration systems (3 plants) partially removed this fraction. None of the pre-treatment systems investigated totally removed colloidal TEP. Biopolymer analysis using LC–OCD showed consistency between colloidal TEP and polysaccharide removal by UF pre-treatment and further verified the presence of TEP in the RO feedwater. TEP deposition in the RO system was determined after measuring total TEP concentrations in the RO feed and concentrate. The TEP deposition factors and specific deposition rates indicate that TEP accumulation had occurred in all plants investigated. This observation was verified by an autopsy of RO modules from two RO plants. Further improvement and verification of the (modified) TEP method, in particular the calibration, is necessary so that it can be employed to investigate the role of TEP in the fouling of RO systems.     

Prevention groups: Today and tomorrow.

This closing article for the special issue lists some of the challenges facing group psychologists as they seek to expand prevention group theory. The role of reading failure in early elementary is highlighted, as are the Spartan Mentor Program with high school students and the group model to promote prevention of HIV/AIDS with adolescents. To aid in workplace prevention, this article also describes the Coping with Work and Family Stress Project. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Being bicultural: A mixed-methods study of adolescents' implicitly and explicitly measured multiethnic identities.

Understanding how ethnic identities develop in adolescence is currently limited by a reliance on self-report paper-and-pencil measures. This mixed-methods study presents a novel response time measure, the Multiethnic Identities Processing Task (MIPT), to quantify bicultural adolescents' implicit identifications with ethnic and racial identity labels. Eighty-four adolescents (age 14–21 years) of diverse ethnic and racial backgrounds self-identified as bicultural or not bicultural and described their ethnic identities, pride, and ethnic centrality during a brief interview. Participants were assigned to complete either the interview (self-prime) or the MIPT (no prime) first. Results indicate that bicultural adolescents readily endorsed a variety of ethnic and racial labels in the MIPT, reflecting their multifaceted identities. Younger bicultural adolescents showed a large inhibited response to the label “White,” indicating some hesitation in deciding whether the label was “like me” or “not like me.” Heart rate monitoring and qualitative analyses of interviews provide some insight into this pattern of results. Findings are discussed with respect to developmental theory, and the strengths of using both implicit and explicit measures to understand multiethnic identity development in adolescence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of an advanced filial therapy model.

This article presents an advanced filial therapy model. This model was developed and implemented by the author in an effort to provide parents with ongoing support and skill development after the completion of a standardized filial model called Child–Parent Relationship Therapy. The advanced filial therapy model is described, including an exploration of how it was developed and how it compares with basic filial therapy models. Examples from the author's clinical experience are provided to illustrate various components of this approach. Finally, implications for research and practice are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A solution thermodynamic study of soybean oil/solvent systems by inverse gas chromatography

Inverse gas chromatography (IGC) has seen wide application in the characterization of molten polymers, fibrous materials, and natural products, such as proteins and carbohydrates, over the past fifteen years. This study describes a relatively simple IGC technique for evaluating solute-solvent interactions using a refined soybean oil as a solvent. Utilizing soybean columns that are 5–20% by weight of the inert support has allowed the determination of a number of thermodynamic solution parameters for 22 solute-solvent pairs in the temperature range of 55–125°C. Weight and mole fraction activity coefficients, along with Henry's Law constants at infinite dilution, are presented for six solute classes. In general, activity coefficients increase with carbon number for n-alkanes, alkyl-substituted benzenes, and n-alkanoic acids at all temperatures investigated, while the reverse is found for the n-alkanols. The activity coefficient data indicate that aromatic solutes, chlorinated hydrocarbons, ketones, and cyclohexane can readily dissolve soybean oil. Calculated heats of mixing for n-alkanols were found to be positive (to 2.84 kcal/mole) while recorded enthalpic interactions were weak for aromatic solutes, lower alkanes, and chlorinated hydrocarbons. The relevance of the above data to such problems as oil dissolution and solvent devolatilization are discussed. Presented at the American Oil Chemists' Society Annual Meeting in Phoenix, Arizona, in May 1988.     

国外电冰箱节能新进展

制冷工业过去的十年是新技术不断涌现的十年，一度是平稳发展的成熟的制冷工业已经变成了革新的温床。继解决了向使用对环境影响更小的制冷剂过渡所面临的种种技术难题之后，这个行业已经加强了在提高其产品能效方面的努力。 据估计，一台电冰箱消耗的电量约占家庭用电量的五分之一，假如以该产品预期寿命为１５至２０年来计算的话，在能效方面即使是些许改进，其整体收益都是很可观的。在关注制冷系统整体的热效率的同时，通过优化制冷系统主要零部件的性能，产品的设计开发生产商和为其定牌生产的制造商已经在节能方面取得了显著的进步。 …