The relations of daily task accomplishment satisfaction with changes in affect: A multilevel study in nurses.

Focusing on a sample of nurses, this investigation examined the relationships of daily task accomplishment satisfaction (for direct and indirect care tasks) with changes in positive and negative affect from preshift to postshift. Not accomplishing tasks to one's satisfaction was conceptualized as a daily workplace stressor that should increase daily negative affect and decrease daily positive affect from preshift to postshift. Further, because of the greater centrality of direct care nursing tasks to nursing work role identities (relative to indirect care tasks), we expected that task accomplishment satisfaction (or lack thereof) for these tasks would have stronger effects on changes in affect than would task accomplishment satisfaction for indirect care tasks. We also examined 2 person-level resources, collegial nurse–physician relations and psychological resilience, as moderators of the relationships among these daily variables, with the expectation that these resources would buffer the harmful effects of low task accomplishment satisfaction on nurse affect. Results supported almost all of the proposed effects, though the cross-level interactions were observed only for the effects of indirect care task accomplishment satisfaction on affect and not for direct care task accomplishment satisfaction on affect. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Laminated beams subjected to transverse load

A simple elastic solution has been developed for predicting the shear stress distribution in a laminated beam subjected to a variety of transverse loading conditions. Photoelastic tests on composite models involving a single bonding layer have been used to validate the theory, and also to comment upon the significance of these results in interpreting the interlaminar shear strength and bending modulus of the simplest form of laminated strip.     

Spent nuclear fuel and residential property values: the influence of proximity, visual cues and public information

This article examines whether public knowledge of spent fuel storage at nuclear power plants, and any local adverse risk perceptions that may have occurred, affect the sale price of single-family residential properties. We present evidence from the Rancho Seco, California, plant on residential property values using an hedonic modeling framework. We include a large number of control variables, data with a high level of spatial detail and a number of public information variables in order to model property market effects within a fifteen mile radius of the plant. Our findings indicate that proximity and visual reminders of the plant have some influence on local property markets, and that there is a small media coverage effect on single-family home sale prices. Received: 6 May 1998 / Accepted: 26 May 1999     

Screening of phenylalanine ammonia lyase in plant tissues,and retention of activity during dehydration

BACKGROUND: Oral therapy with phenylalanine ammonia lyase (PAL), naturally encapsulated in plant cells, may provide a potential alternative treatment for hyperphenylalaninemic patients, including those with phenylketonuria. Therefore different sources of plant tissue were investigated for PAL activity. RESULTS: Enzyme activity was highest in grain seedlings, with maximal enzyme activity in 7‐day‐old red spring wheat (Triticum aestivum L.) seedlings. The PAL activities of leaves and roots/endosperm of wheat seedlings were 11.90 ± 2.64 and 6.48 ± 1.59 µmol h^?1 g^?1 dry weight respectively. Three PAL‐related polypeptides with molecular weights of 74, 83 and 103 kDa were identified in wheat seedling leaf tissues, while only the 74 kDa polypeptide was detected in root/endosperm tissues. Dehydration was investigated as a method of concentrating PAL in wheat seedlings. Freeze‐drying was found to retain the most PAL activity (>90% recovery on a dry weight basis) compared with air drying and vacuum microwave drying for both leaf and root/endosperm samples. CONCLUSION: This study has led to a better understanding of PAL activity and stability in plant tissues and provides the basis for developing a natural plant preparation as a dietary supplement for the treatment of hyperphenylalaninemia. Copyright © 2007 Society of Chemical Industry     

Feeling is Believing: Using a Force‐Feedback Joystick to Teach Dynamic Systems

As an innovative approach to providing physical demonstrations in the engineering classroom, we present the haptic paddle: a low‐cost, single‐axis force‐feedback joystick. Using the paddle in the laboratory component of an undergraduate course on dynamic systems, students not only learned to model and analyze dynamic systems, but they also felt the effects of phenomena such as viscous damping, stiffness, and inertia. By interacting with virtual environments using their sense of touch, students improved their understanding of dynamic systems, modeling and control. In addition, the paddles added entertainment and excitement to the course. In this paper, we describe the purpose and design of the haptic paddle, show examples of how the paddle was integrated into the course, and present the results of preliminary student evaluations.     

数字电源管理为价格敏感型应用提供可调速度控制

引言 许多厨房与车库电器、电动工具以及其他小家电中使用的传统通用电动机一般都不能精确地控制速度.电动机只能关或开.通过数字电源管理实现精确可调速度控制的方法具有显著优点,如耗电量降低、安全性提高、工具寿命延长、更易用和操作控制改善.这种方法还最大程度低减少了电器开关时产生的可导致电路断开的电涌.历史上,对于许多消费类电器而言,实现智能电机控制的主要障碍是成本.     

The effect of particle reinforcement on the creep behavior of single-phase aluminum

The effect of TiC particle reinforcement on the creep behavior of Al (99.8) and Al-1.5Mg is investigated in the temperature range of 150 °C to 250 °C. The dislocation structure developed during creep is characterized in these materials. The addition of TiC increases creep resistance in both alloys. In pure aluminum, the presence of 15 vol pct TiC leads to a factor of 400 to 40,000 increase in creep resistance. The creep strengthening observed in Al/TiC/15_p is substantially greater than the direct strengthening predicted by continuum models. Traditional methods for explaining creep strengthening in particle-reinforced materials(e.g., threshold stress, constant structure, and dislocation density) are unable to account for the increase in creep resistance. The creep hardening rate(h) is found to be 100 times higher in Al/TiC/15_p, than in unreinforced Al. When incorporated into a recovery creep model, this increase inh can explain the reduction in creep rate in Al/TiC/15_p. Particle reinforcement affects creep hardening, and thus creep rate, by altering the equilibrium dislocation substructure that forms during steady-state creep. The nonequilibrium structure generates internal stresses which lower the rate of dislocation glide. The strengthening observed by adding TiC to Al-1.5Mg is much smaller than that found in the pure aluminum materials and is consistent with the amount of strengthening predicted by continuum models. These results show that while both direct (continuum) and indirect strengthening occur in particle-reinforced aluminum alloys, the ratio of indirect to direct strengthening is strongly influenced by the operative matrix strengthening mechanisms. This article is based on a presentation made in the symposium entitled “Creep and Fatigue in Metal Matrix Composites” at the 1994 TMS/ASM Spring meeting, held February 28–March 3, 1994, in San Francisco, California, under the auspices of the Joint TMS-SMD/ASM-MSD Composite Materials Committee.     

Pervasive information — the key to ‘true’ mobility

Since Weiser’s vision in 1991 for ubiquitous (also called pervasive) computing there has been little tangible progress towards it. However, over time the communications industry has begun to erode many of the hardware barriers to this vision. Even so, the utopia of pervasive computing remains out of reach, primarily as a result of the continued fixation with devices and connectivity as a way to realise mobility. However, it could be argued that users ultimately require access to information or content irrespective of the devices and connectivity around them. Consequently, pervasive information is seen as the key to true user mobility. This paper will introduce a potential secure pervasive information architecture that fits Weiser’s vision, and position it with respect to a sub-set of current contenders for future systems from both academia and the telecommunications industry, and highlight their strengths and weaknesses.