Microstructure and mechanical properties of Pb-free solder alloys for low-cost electronic assembly: A review

Lead-free solders, including Sn-58Bi, Sn-52In, and Sn-3.5Ag, are potential replacements for Sn-37Pb solder in low-cost electronic assembly. This paper reviews the literature on the microstructure and mechanical properties of these alloys. Because of the processing and testing conditions, many of the data are not predictive for electronic assembly applications. However, eutectic Sn-Bi seems to have properties approaching those of eutectic Sn-Pb under most conditions, while eutectic Sn-In seems far inferior in most respects. Eutectic Sn-Ag has many promising characteristics, but its relatively high melting temperature may preclude its use for this type of application.     

The School as an Instrument in Planning

The school today plays a peculiarly dynamic role in neighborhood change, for its quality-real or as perceived by parents-strongly affects the decisions of upper-income families as to where to live. If the school reflects the changing social composition of its immediate neighborhood, it tends to speed up the transition from upper-income to lower-income occupancy and to encourage social homogeneity and segregation. If it maintains special standards and a special approach toward education, independent of changes in the population of the surrounding area, it serves as a brake on population change and tends to encourage heterogeneous neighborhoods. It is suggested this principle may help in achieving stable and heterogeneous neighborhoods.     

Instrumental conditioning of hippocampal theta and subsequent response persistence.

Following bar-press shaping of 24 male albino rats to a discrete-trial fixed-ratio (FR) 5 schedule of reinforcement; 16 were trained to produce either hippocampal theta (7.5-8.5 Hz) or nontheta (4-5 Hz) activity, while 8 served as a matched interreinforcement time control (yoked to the theta group). All Ss then returned to the FR-5 schedule on the lever response for 15 days, followed by 12 days of extinction. Results indicate that hippocampal theta production was learned more slowly than nontheta production but resulted in increased resistance to extinction of the subsequently performed lever response. These data are viewed as supporting the hippocampal theta-frustration hypothesis proposed by H. Glazer in 1972. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Task control and cognitive abilities of self and spouse in collaboration in middle-aged and older couples": Erratum.

Reports an error in "Task control and cognitive abilities of self and spouse in collaboration in middle-aged and older couples" by Cynthia A. Berg, Timothy W. Smith, Kelly J. Ko, Nancy J. M. Henry, Paul Florsheim, Gale Pearce, Bert N. Uchino, Michelle A. Skinner, Ryan M. Beveridge, Nathan Story and Kelly Glazer (Psychology and Aging, 2007[Sep], Vol 22[3], 420-427). Due to an editing mistake, the order of authorship was incorrect. The correct order is as follows: Berg, Smith, Ko, Beveridge, Story, Henry, Florsheim, Pearce, Uchino, Skinner, & Glazer. (The following abstract of the original article appeared in record 2007-13103-002.) Collaborative problem solving may be used by older couples to optimize cognitive functioning, with some suggestion that older couples exhibit greater collaborative expertise. The study explored age differences in 2 aspects of collaborative expertise: spouses' knowledge of their own and their spouse's cognitive abilities and the ability to fit task control to these cognitive abilities. The participants were 300 middle-aged and older couples who completed a hypothetical errand task. The interactions were coded for control asserted by husbands and wives. Fluid intelligence was assessed, and spouses rated their own and their spouse's cognitive abilities. The results revealed no age differences in couple expertise, either in the ability to predict their own and their spouse's cognitive abilities or in the ability to fit task control to abilities. However, gender differences were found. Women fit task control to their own and their spouse's cognitive abilities; men only fit task control to their spouse's cognitive abilities. For women only, the fit between control and abilities was associated with better performance. The results indicate no age differences in couple expertise but point to gender as a factor in optimal collaboration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

From the editor.

Introduces this special issue of the International Journal of Play Therapy, which is divided into three sections. The first presents a view of the future of play therapy; that is, what the profession of play therapy will become in the next century. The second section is intended to provide a context for the research award article. The third section is the 1998 Student Research Award. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of organizational commitment in occupational stress models.

This study examined affective organizational commitment (AOC) and continuance organizational commitment (COC) as moderators of the relationship between job-related anxiety and intention to leave among 506 Israeli nurses who completed self-administered surveys. Prior research examining organizational commitment as a moderator between stress-related variables has shown inconsistent results, most probably because organizational commitment was tested as a moderator of stressor-strain relationships. Both AOC and COC buffered the relationship between job-related anxiety and intention to leave the hospital (i.e., the positive relationship was not as strong with high levels of commitment). There was no buffering effect on the relationship between role stressors and intention to leave. Further, the relationship between job-related anxiety and intention to leave increased more strongly for low levels (vs. high levels) of COC. Implications for the role of organizational commitment in stress models and implications for hospital administrators are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Positive and negative symptoms in chronic psychiatric outpatients: Reliability, stability, and factor structure.

This study evaluates 2 instruments measuring positive and negative symptoms, the Scale for the Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms, for their reliability, internal consistency, and temporal stability. The interrelationships and course of specific symptoms are examined to ask whether they represent 1, 2, or more separate pathological processes. Symptoms were assessed in 399 outpatients followed for the long-term effects of antipsychotic medications; a subset (n?=?229) was given the instruments twice, approximately 24 months apart. Results suggest four distinct types of symptoms in severe mental disorders. Two correspond to general definitions of positive and negative symptoms. Attentional Impairment, Formal Thought Disorder, and possibly Bizarreness and Avolition-Apathy emerge as separate categories of symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Charging apparatus with a revolving distributor: Five years of successful operation on blast furnace No. 3 at the Bhilai Metallurgical Plant

A rotary charging apparatus (RCA) has been in use on 1033-m³ at the Bhilai Metallurgical Plant (in India) since 1998. The RCA is a new type of charging apparatus in which the main working element is a five-vane revolving charge distributor that provides for multi-flow, multi-layered distribution of the charge materials in the top of the furnace. The revolving distributor makes it possible to flexibly and efficiently regulate the distribution of the materials over the entire radius of the top by changing the speed and direction of rotation of the rotor. The operational and design features of the RCA ensure a higher quality distribution of the materials in the top, which in turn leads to a significant savings of coke and an increase in furnace productivity. The total cost of maintaining and repairing the RCA is proving to be substantially lower than the corresponding costs for standard double-bell-and-hopper and chute-type charging apparatuses. The investment in the RCA is recovered in six months or less.