FINITE ELEMENT ELASTIC-PLASTIC-CREEP AND CYCLIC LIFE ANALYSIS OF A COWL LIP

Results are presented of elastic, elastic-plastic and elastic-plastic-creep analyses of an actively cooled cowl lip. A cowl lip is part of the leading edge of an engine inlet of proposed hypersonic aircraft and is subject to severe thermal loadings and gradients during flight. Values of stresses calculated by elastic analysis are well above the yield strength of the cowl lip material. Such values are highly unrealistic, and thus elastic stress analyses are inappropriate. The inelastic (elastic-plastic and elastic-plastic-creep) analyses produce more reasonable and acceptable stress and strain distributions in the component. Finally, using the results from these analyses, predictions are made for the cyclic crack initiation life of a cowl lip. A comparison of predicted cyclic lives shows the cyclic life prediction from the elastic-plastic-creep analysis to be the lowest and, hence, most realistic.     

DNA looping by the Sfi I restriction endonuclease

The SfiI endonuclease has to interact with two copies of its recognition sequence before it can cleave DNA. To demonstrate that the reaction of SfiI on a DNA with two sites involves the formation of a DNA loop, and to characterise the looping interactions on supercoiled and linear DNA, a series of plasmids was constructed with lengths of DNA between two SfiI sites varying from 104 to 211 bp. Both supercoiled and linear forms of each DNA were tested as substrates for SfiI. The reactions were monitored from the rates of DNA cleavage and from the generation of partially cleaved products, the latter indicating loop disruption before cleavage of both sites. On both supercoiled and linear DNA, the stabilities of the complexes spanning two SfiI sites varied in sinusoidal fashion with the distance between the sites, in the manner characteristic of a process governed by the helical periodicity of DNA. In all cases, the looping interaction was stabilised by DNA supercoiling. The sinusoidal variation from SfiI reactions on supercoiled DNA at 50 degreesC yielded a helical repeat of about 11.5 base-pairs per turn.     

Couple communication and female problem drinking: A behavioral observation study.

Couples with alcohol and relationship problems often report poor communication, yet little is known about the communication of maritally distressed couples in which the woman abuses alcohol (MDWA couples). Compared with maritally distressed couples without alcohol problems (MDNA) and couples with neither problem (NDNA), MDWA couples showed a distinctive pattern of negative communication. Similar to MDNA men, MDWA men spoke negatively to their partners but listened positively to their partners much like NDNA men. MDWA women listened negatively, much as MDNA women did, but spoke positively, like NDNA women did. The interactions of MDWA couples can be characterized as a male-demand-female-withdraw pattern, which is a gender reversal of the female-demand-male-withdraw pattern often observed in MDNA couples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Can skills training prevent relationship problems in at-risk couples? Four-year effects of a behavioral relationship education program.

Eighty-three couples were stratified into groups at high and low risk for relationship distress and randomized to either the Self-Regulatory Prevention and Relationship Enhancement Program (Self-PREP) or a control condition. As predicted, there were differential effects of Self-PREP on high-risk and low-risk couples. Because of low statistical power, results must be interpreted cautiously, but at 1-year follow-up high-risk couples in Self-PREP showed trends toward better communication than control couples. However, there was no difference in the communication of Self-PREP and control low-risk couples. High-risk couples receiving Self-PREP exhibited higher relationship satisfaction at 4 years than control couples, but in low-risk couples relationship satisfaction was higher in the control condition. High-risk couples seemed to benefit from skills-based relationship education, but low-risk couples did not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological stress and blood glucose regulation in Type I diabetic patients.

Investigated whether psychological stress (PS) predicted blood glucose levels (BGLs), independent of self-management, in 15 Type I diabetic patients. Ss self-monitored daily mean BGLs, PS, diet, exercise, and insulin injections for 8 wks. Considerable individual variability in findings was evident, with PS predicting BGLs in a statistically significant manner in 7 Ss. PS had a significant effect on BGLs independent of the effects of diet, exercise, and insulin administration for the 7 Ss. Discussion focuses on the problems of measuring the key self-management behaviors influencing BGLs and on the possibility that a subgroup of diabetic patients may be BGL stress responders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Couple relationship education at home: Does skill training enhance relationship assessment and feedback?

To evaluate the effective components of couple relationship education, 59 newlywed couples were randomly assigned to one of two couple relationship programs (CRE): (1) RELATE, which involved receiving feedback on their relationship based on the on-line RELATE assessment; or (2) RELATE + Couple CARE, which was RELATE plus completing the 6 unit Couple CARE relationship skill training program. Relative to RELATE, RELATE + Couple CARE produced more improvement in couple communication, and high relationship satisfaction across the next 12 months in women. Men sustained high and similar relationship satisfaction in either condition. Skill training CRE has additional benefits for couples beyond assessment and feedback. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Re-examination of cumulative fatigue damage analysis—an engineering perspective

A method which has evolved in our laboratories for the past 20 years is re-examined with the intent of improving its accuracy and simplicity of application to engineering problems. Several modifications are introduced both to the analytical formulation of the damage curve approach, and to the procedure for modifying this approach to achieve a double-linear damage rule formulation which immensely simplifies the calculation. Improvements are also introduced in the treatment of mean stress for determining fatigue life of the individual events that enter into a complex loading history. While the procedure is completely consistent with the results of numerous two-level tests that have been conducted on many materials, it is still necessary to verify applicability to complex loading histories. Caution is expressed that certain phenomena can also influence the applicability-for example, unusual deformation and fracture modes inherent in complex loading—especially if stresses are multiaxial. Residual stresses at crack tips and metallurgical factors are also important in creating departures from the cumulative damage theories; examples of departures are provided.     

The ongoing evolution of behavioral couples therapy: retrospect and prospect

Behavioral couples therapy (BCT) was first described thirty years ago, and the conceptual basis of the approach has been evolving ever since. Whilst BCT in its current form is a well established treatment for relationship problems, there are significant limitations to its efficacy, and there are a number of new developments intended to enhance the efficacy of the approach. Currently BCT primarily is a skills training therapy, targeting change in couple's interactions to promote greater relationship satisfaction. Current developments focus on broadening this traditional emphasis on changing couple interactions to greater attention to reducing negative emotional responses to partner behaviors (increasing acceptance), and increasing self-directed personal change efforts. Future developments of BCT are likely to pay greater attention to different types of couple interaction which are associated with sustained relationship satisfaction, the individual vulnerabilities partners bring to relationships, and the environmental stresses impinging upon the couple.