Fatigue crack propagation in aluminum-base copper alloys

Fatigue crack propagation ratesda/dN in binary Al alloys with 3.6 wt pct Cu and 6.3 wt pct Cu and commercial 2024 aged at 21°C were compared with 99.95⁺ wt pct aluminum. Omitting an anomalous region at lowΔK, the extrapolated rates for “pure” aluminum are more than 100 times greater than those in the three alloys at the same ΔK. The data for the alloys fit into a single scatter band of a factor of three. It was suggested thatda/dN varies inversely with the square of the strength of the alloy but that another parameter related to the fatigue crack propagation energy per unit area is also important. Theda/dN vs ΔK curves were determined for 3.6 wt pct Cu single crystals aged seven days at 21°C which containGP zones and two and seven days at 160°C which contain mixtures ofθ′ andθ′’. No systematic variation of (da/dN _Δ with crystallographic orientation was discerned, but the naturally aged specimen had a strong orientation dependence on crack initiation. At low ΔK 21°C aged specimens gave the lowestda/dN while at high ΔK the warm aged specimens gave the lower values ofda/dN. Measurement ofda/dN vs ΔK curves were conducted on specimens of 3.6 wt pct Cu with 1 mm equiaxed grains aged for various times at 130°C, 160°C, and 190°C. All warm aged specimens experienced brittle intergranular fracture at sufficiently high ΔK. The transition ΔK where intergranular fracture first appears is inversely proportional to the aging temperature. The change of fracture mode from intra to intergranular occurs gradually over a broad range of ΔK which shifts to lower ΔK with increase in aging temperature.     

Designing a manufacturing strategy

A manufacturing strategy is a critical component of the firm's corporate and business strategies, comprising a set of well-coordinated objectives and action programs aimed at securing a long-term, sustainable advantage over the firm's competitors. A manufacturing strategy should be consistent with the firm's corporate and business strategies, as well as with the other managerial functional strategies. We present a process and a structured methodology for designing such a manufacturing strategy. This methodology has been successfully tested in actual manufacturing environments.     

亚稳态惰性原子与SOCl_2传能反应产物SO(A)的发射光谱和强度分析

本文在流动余辉装置上,利用亚稳态惰性气体原子[He(2~3S)、Ne(~3P_(0,2))、Ar(~3P_(0,2))]与SOCl_2的专能反应,在(230-430nm)波段观察到了产物的发射谱,光谱归属为自由基SO(A~3∏_(2,1,0)→X~3∑~-)的跃迁。对光谱强度分析表明:SO(A→X)的偶极跃迁矩Re随核间距明显地变化。通过拟合,找出了这一变化的关系。另外,本文还计算了SO(A~3∏_0→X~3∑~-)跃迁的Franck-Condon因子。     

Integrating psychology and philosophy in teaching a graduate course in ethics.

Recent surveys of doctoral and master's programs in clinical psychology suggest that there are major gaps in the frequency and quality of ethical training. After describing a model of the ethical decision-making process, we present a thorough and formal course in ethical issues that integrates the perspectives of psychology and philosophy. The course was team taught by a philosopher and a psychologist to 10 second-year master's-level students in clinical psychology. The first section of the class addressed underlying philosophical issues, including ethical frameworks and principles; the second portion focused on a series of issues that had important value dimensions, including "health and disease," virtue, and several key ethical principles; and the final section focused on applications of these basic concepts to situations typically encountered by psychologists. A follow-up survey of those students engaged in clinical practice 3 months after the completion of the course revealed that they perceived the course to have had a positive impact both attitudinally and behaviorally. Suggestions for others planning to teach such courses are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fatigue crack initiation and microcrack propagation in X7091 type aluminum P/M alloys

Fatigu crack initiation in extruded X7091 RSP-P/M aluminum type alloys o°Curs at grain boundaries at both low and high stresses. By a process of elimination this grain boundary embrittlement was attributed to Al₂O₃ particles formed mainly during atomization and segregated to some grain boundaries. It is not due to the small grain size, to Co₂Al₉, to η precipitates at grain boundaries, nor to a precipitate free zone. Thermomechanical processing after extrusion of X7091 with 0.8 pct Co was done by Alcoa to produce large recrystallized grains. This resulted in initiation of fatigue cracks at slip bands, and the resistance to initiation of fatigue cracks at low stresses was much greater. Microcrack growth is, however, much faster in the thermomechanically treated samples, as well as in ingot alloys, than in extruded and aged X7091.     

The effect of exposure to an extreme stimulus on judgments of some stimulus-related words.

"The study was designed to test the hypothesis that subjects' ratings of cold-toned words would shift away from the cold end of a warm-cold ordinal scale as a consequence of exposing the subjects to extremely cold temperatures. Three groups of subjects were exposed respectively to extremely cold, moderately cold, and warm ambient conditions. Before and after exposure, all subjects rated 13 words describing various degrees of warmth or coldness on a 16-point warm-cold ordinal scale. The results verified the hypothesis; ratings of the 'cold' words for the group exposed to the extreme cold shifted away from the cold end of the scale. The results are consistent with previous research on end-anchoring effects. Implications for the researcher using ordinal scales in situations where subjects are exposed to extreme stimuli with which they have had little experience are discussed." From Psyc Abstracts 36:02:2BB41F. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Welsh's internalization ratio as a behavioral index.

In the use of the MMPI, how does Welsh's Internalization Ratio (IR), derived by relating the "mood" scales to the "behavior" scales, differentiate between soldiers rated as satisfactory and those rated unsatisfactory? In one study it showed a difference between 13 men honorably discharged and 15 reassigned because of being considered unsatisfactory. In another study, ratings of 5 civilians ranked 17 Ss who were on a 6-week exercise in a subartic region as "satisfactory" and "unsatisfactory" and this agreed with the IRs. "Furthermore, the .87 cut off point again significantly discriminated between satisfactory and unsatisfactory individuals." From Psyc Abstracts 36:01:3LD17F. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The value of baseline chest radiograph reports in the care of elderly patients in an emergency department

The authors used a before/after research design to determine the impact of written reports of baseline chest radiographs (CXRs) on the care of elderly patients during 48 emergency department visits. Internal medicine housestaff completed questionnaires that included inquiries about their treatment plans for the patients both before and after they reviewed reports of baseline CXR results. The investigators compared these answers to determine the proportion of patients for whom baseline CXR reports changed patient management. In addition, three faculty reviewers used the nominal group process, a consensus analysis approach, to measure treatment changes and to estimate benefit to the patients from the alterations in management. The housestaff indicated that written baseline CXR reports caused them to change treatment plans during only 2 (4%) of the 48 visits. In both cases, they provided aggressive treatment for congestive heart failure because of baseline CXR results. The faculty reviewers could find only one case in which baseline CXR findings might have changed their management plans. Moreover, they were not convinced that the treatment changes indicated by the housestaff actually benefitted the patients. These results suggest that written reports of baseline CXRs do not improve the care of acutely ill patients in an emergency department setting.     

Critique of Miller's "Chance, choice, and the future of reproduction."

Discusses W. B. Miller's (see record 1984-17604-001) argument that the decision of whether to have a child involves a psychological process in which an individual freely chooses from among many alternatives. It is asserted that the political context of today, in which women's reproductive rights are an issue of great controversy, constrains such ideologically based freedom. Political, legal, and social conditions that limit women's reproductive control are described. Miller's support of progenics, which favors a particular type of offspring in evolutionary terms, is questioned. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)