Thermally Activated Deformation of Gold Single Crystals

A study of the thermally activated tensile deformation of gold single crystals has been conducted between 4.2 and 473 K. The activation energy in terms of a single process analysis, AG₀, at zero effective stress was found to be 1.5 eV and was sensitive to the effective stress. From the strain dependence of the zero temperature effective stress it was concluded that the barriers giving rise to the thermally activated deformation process increase in density during deformation and are probably the forest dislocations. ROBERT B. HERRING, Formerly of the Department of Materials Science, Northwestern University, Evanston, Illinois     

"Exemplary Efforts in Psychology to Recruit and Retain Graduate Students of Color": Correction.

Reports an error in the original article by Margaret R. Rogers and Ludwin E. Molina (American Psychologist, 2006, Vol.61, No. 2, pp.143-156). Two corrections should be made to Tables 1, 2, and 3. First, Southern Illinois University at Carbondale was incorrectly referred to as "University of Southern Illinois at Carbondale". Second, there are two clinical psychology programs at the University of Virginia. The program included in the sample for the study was the one located in the Department of Psychology at the University of Virginia. (The following abstract of this article originally appeared in record 2006-01690-004). Many psychology departments are striving for a greater representation of students of color within their graduate preparation programs with the aim of producing a more diverse pool of psychological service providers, scientists, and educators. To help improve the minority pipeline in psychology, the authors identify and describe recruitment and retention strategies used at 11 departments and programs considered to be making exemplary efforts to attract and retain minority students of color. The strategies most consistently used included engaging current minority faculty and students in recruitment activities, offering attractive financial aid packages, having faculty members make personal contacts with prospective students, creating linkages with historical institutions of color, having (or approached having) a critical mass of faculty and students of color, offering a diversity issues course, and engaging students in diversity issues research. Despite the similarities, the programs and departments were each distinctive and innovative in their overall approaches to student recruitment and retention. Highlighting the strategies used at successful institutions may help others develop plans for improving the minority pipeline within their own departments and programs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-shared control systems: Promises and problems.

Describes a time-shared system used to control and service multiple facilities in the Psychology Department at Illinois State University. Two Data General Nova 820 computers, one with a small memory (8K) and the other with a large one (32K), are coordinated into a single system which uses INTERACT, a commercial interface/software system marketed by a psychological equipment firm. Types of experiments in which the system has been used are listed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simplified AASHTO Load and Resistance Factor Design Girder Live Load Distribution in Illinois

Illinois began full transition to the American Association of State Highway and Transportation Officials load and resistance factor design (LRFD) bridge design specifications from the traditional load factor design code or standard specifications in 2002. To facilitate implementation of the new specification, engineers from the Illinois Department of Transportation undertook a series of investigations. The studies focused on interpretation of LRFD for the design of typical bridges in Illinois and the simplification of its procedures for determination of live load lane distributions to primary superstructure girders. Some important presented results from the conducted investigations are believed not only relevant to bridge design in Illinois, but to other states and jurisdictions which employ or will employ LRFD in the near future. The initial simplifications and interpretations focused on concrete deck-on-steel girder bridges and were subsequently expanded to include concrete deck-on-prestressed concrete girder structures. These types of structures comprise a large portion of Illinois’ inventory. Illinois Department of Transportation engineers continue to build on the studies described in the paper such that policies and procedures for other types of typical bridges can be formulated.     

Microstructure of laser clad Ni- Cr- Al- Hf alloy on a γ′ strengthened ni- base superalloy

Alloys and coatings for alloys for improved high temperature service life under aggressive atmo-spheres are of great contemporary interest. There is a general consensus that the addition of rare earths such as Hf will provide many beneficial effects for such alloys. The laser cladding technique was used to produce Ni-Cr-AI-Hf alloys with extended solid solution of Hf. A 10 kW CO₂ laser with mixed powder feed was used for laser cladding. Optical, scanning electron (SEM) and scanning transmission electron (STEM) microscopy were employed to characterize the microstructure of alloys produced during laser cladding processes. Microstructural studies revealed grain refinement, considerable in-crease in solubility of Hf in the matrix, Hf-rich precipitates, and new metastable phases. The size and morphology of γ′ (Ni₃Al) phase were discussed in relation to its microchemistry and the laser processing conditions. This paper will report the microstructural development in this laser clad Ni-Cr-AI-Hf alloy. Formerly Visiting Assistant Professor, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign.     

Evaluation of Performance of Bridge Deck Expansion Joints

The bridge deck expansion joint is an important element in the functioning of bridge structures. When joints fail to function properly, they can create problems out of proportion to their size. Selection of a good joint for use can create fewer bridge maintenance problems. The purpose of the study was to evaluate the performance of several types of joints currently in use on Indiana highway bridges. The types of joints investigated are compression seal, strip seal, integral abutment, poured silicone, and polymer modified asphalt. The research was accomplished through questionnaire surveys, analysis of Indiana Department of Transportation roadway management data, and expert interviews. The questionnaire survey identified the problems and their causes and the merits and potential improvements of each type of joint. The analysis of Indiana roadway management data ranked the performance of different types of joints based on the deterioration rates estimated by the regression coefficients. The expert interviews investigated the practices of Indiana and its surrounding states regarding the selection and maintenance of joints. Based on the research results, several suggestions were proposed to ensure the longer service life of expansion joints.     

Orientation relationships in graphitic cast irons

Ferrite/graphite and martensite/graphite interfaces in three commercial cast irons have been analyzed using transmission electron microscopy. Two recurring orientation relationships have been found to account for over 60 pct of the ferrite/graphite interfaces analyzed. A similar pair of relationships discovered in martensitic material strongly suggests that the prior austenite/graphite interface was also ordered. The same relationships were prominent in gray and ductile irons. One of the relationships observed can be transformed through the Kurdjumov-Sachs relationship to a previously-reported austenite/graphite relationship. Formerly with the Department of Metallurgy and Mining Engineering, University of Illinois, Urbana, IL. Formerly with the Department of Metallurgy and Mining Engineering, University of Illinois, Urbana, IL.     

Mental health service utilization among African American and Caucasian mothers and fathers.

Mental health services have been routinely underutilized. This study investigated the influence of parents' gender, race, and psychopathology on perceived barriers and attitudes toward mental health utilization for themselves and for their children. A unique contribution of this study is the examination of father, mother, and child factors influencing service utilization from the parents' perspective. A total of 194 African American and Caucasian parents were recruited from the community to participate. Parents completed measures on barriers and attitudes toward treatment for themselves and for their children, history of mental health service utilization for themselves and for their children, and their own current psychological symptoms. Results indicated that 36.3% and 19.4% of parents and children, respectively, had used mental health services during their lifetime. Parents perceived fewer barriers and had more positive attitudes toward seeking services for their children than for themselves. Race and gender differences were found in parents' perceptions of barriers and attitudes toward treatment. Furthermore, barriers, attitudes, and psychopathology predicted parents' plans for future utilization of mental health services. The clinical implications of this study and directions for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developing a Decision Support Tool for Nighttime Construction in Highway Projects

This paper presents a decision support tool that is intended to help highway agencies in evaluating the suitability of nighttime construction for highway projects. This tool was developed as part of a research project sponsored by the Illinois Department of Transportation. The tool is a simple software package that was developed using a Microsoft Excel spreadsheet and Visual Basic for Applications. The proposed tool utilizes the cost-effectiveness analysis as a basis for comparison between daytime and nighttime operations. The proposed tool is mainly used whenever night shift is thought of as an alternative to the conventional daytime shift. Nonetheless, the tool is also generic in the sense that it can be used to compare different alternative plans such as different lane closure strategies or scheduling alternatives.     

Research barriers in psychopharmacology

The author discusses barriers to psychopahrmacological research, including attacks by vocal human rights groups, regulation by local review boards, and Department of Health, Education, and Welfare restrictions. He suggests that those patients least able to give informed consent are most in need of the benefits of research on new drugs.     

The interactive role of inclusions and SiC reinforcement on the high-cycle fatigue resistance of particle reinforced metal matrix composites

The effect of intermetallic inclusions on the fatigue crack initiation and growth in 2080 Al alloy and 2080/SiC _p composites was investigated. Using surface replication, it was determined that, in the high-cycle fatigue region, life is dominated by the initiation process. It was also determined that the majority of initiation sites were associated with intermetallic inclusions. While 2080/SiC/20 _p showed a definitive relationship between inclusion size and fatigue life, i.e., a higher inclusion size resulted in lower fatigue life, there was no correlation in 2080/SiC/30 _p . This was attributed to more of the load being shared by the higher volume fraction of SiC particles and smaller average inclusion sizes in the latter composite. A conceptual model is proposed that accounts for these observations and qualitatively shows the effect of reinforcement on stress enhancement in near-surface inclusions. N. CHAWLA, formerly Research Fellow, Department of Materials Science and Engineering, University of Michigan C. ANDES is former Research Fellow, Department of Materials Science and Engineering, University of Michigan. This article is based on a presentation made in the Symposium “Mechanisms and Mechanics of Composites Fracture” held October 11–15, 1998, at the TMS Fall Meeting in Rosemont, Illinois, under the auspices of the TMS-SMD/ASM-MSCTS Composite Materials Committee.     

Precipitate effects on the mechanical behavior of aluminum copper alloys: Part I. Experiments

This article focuses on understanding the mechanical behavior of precipitation-hardened alloys by studying single and polycrystalline deformation behavior with various heat treatments. Aluminumcopper alloys are the focus in this work and their changing stress-strain behavior is demonstrated resulting from the different hardening mechanisms brought about by the various precipitates. Extensive transmission electron microscopy investigations facilitated the interpretation of the stress-strain behavior and the work hardening characteristics. The use of both single and polycrystals proved valuable in understanding the role of anisotropy due to crystal orientation vs precipitate-induced anisotropy. The experiments show that precipitation-induced anisotropy could offset the crystal orientation anisotropy depending on the orientation. This is clearly demonstrated with similar [111] and [123] behaviors under 190 °C and 260 °C aging temperatures. Experiments on pure aluminum crystals are also provided for comparison and understanding the crystal anisotropy in the absence of precipitates. Part I of this article will focus on experiments, and part II will describe the modeling of the effect of different metastable phases in the matrix acting as barriers to dislocation motion. FOGLESONG for-merly with the Department of Mechanical and Industrial Engineering, University of Illinois, Urbana, IL 61801     

Inhomogeneous deformation in INCONEL 718 during monotonic and cyclic loadings

The deformation microstructures produced by room-temperature monotonie tensile and uniaxial low-cycle fatigue tests in aged (precipitate-hardened) INCONEL 718 were examined by transmission electron microscopy (TEM). Regularly spaced arrays of deformation bands on {111} slip planes were observed. Under monotonie loading, the dislocation structure within a deformation band formed an inverse pileup at a grain boundary, indicating that the boundary was the probable dislocation source. Under fatigue loading, the bands contained a high density of dislocations in a complex arrangement, which was attained after relatively few cycles. Samples of homogenized (precipitate-free) material were deformed monotonically in tension for comparison with the aged material. Early in the deformation, there was only one deformation band per grain and little evidence of work hardening; that is, there was a region of constant flow stress. With increased deformation, work hardening began, more bands nucleated, and their spacing became similar to that in the aged material. This result demonstrates that the degree of coarseness of inhomogeneous deformation in this material was not necessarily a result of a softening process within the bands because of precipitate shearing, but rather, it was primarily a function of the amount of work hardening within the bands. The regularity of the bands and the dislocation structure can be rationalized in terms of a periodic resistance to glide of the dislocations due to the presence of the precipitates and a distribution of dislocation sources along the grain boundaries. D.W. WORTHEM, formerly Graduate Student, Department of Theoretical and Applied Mechanics and Materials Research Laboratory, University of Illinois F.A. LECKIE, formerly Professor, Department of Theoretical and Applied Mechanics and Materials Research Laboratory, University of Illinois     

Spinodal decomposition of a Co-Ti-Nb alloy

The microstructural evolution on aging a Co-3 wt pct Ti-2 wt pct Nb alloy has been followed by transmission electron microscopy and diffraction to show that the solid solution decomposed by the spinodal mode. The strengthening observed has been correlated with the differences in lattice parameters of the coexisting phases. The several stages of coarsening have been documented to yield information about their kinetics and morphological changes. Formerly Visiting Assistant Professor, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana-Champaign, 1206 West Green Street, Urbana, IL 61801, is with .     

Powerlessness regarding health-service barriers: construction of an instrument

PURPOSE: The purpose of the study was to develop a scale to calculate college students' powerlessness regarding health service barriers (PHSB). METHODS: Scale items were generated to represent two domains of interest: powerlessness and college students' powerlessness regarding health service barriers. The final 20-item instrument was subjected to multiple measures of validity with college students and panels of nurse experts in the area of nursing diagnosis. Reliability was assessed by two samples (n = 92 and n = 33) of college-age students. A final administration was conducted with 197 college students. FINDINGS: The PHSB scale was determined to be an accurate and consistent measure. CONCLUSIONS: This instrument will provide a reliable and valid measure to conduct research.     

Veterans Administration psychology: Six decades of public service (1946-2006).

Psychologists in the Veterans Administration (VA), now the Department of Veterans Affairs, have contributed 60 years of public service to the treatment of our nation's veterans, enhanced by their involvement in clinical research supporting that care. From the development of new mental health care programs following World War II to their role in today's polytrauma centers caring for severely wounded veterans, VA psychologists have not only provided distinguished service to veterans but also provided insights for the entire profession in the care of veterans. This article highlights some of their contributions to practice and research as VA psychology and its training program celebrate their 60th anniversary. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies of the orientations of fracture surfaces produced in austenitic stainless steels by stress-corrosion cracking and hydrogen embrittlement

Orientation studies have been made on several different austenitic stainless steels, using photogrammetric and electron channeling techniques. The fracture facets produced by SCC in boiling aqueous MgCl₂ (155 °C) were large and relatively flat in the case of type 310 steels, and the fracture plane was found to be at or near {100}. The transgranular stress-corrosion fractures in type 304 steels were more complex, and there was considerably more scatter in the orientation determinations. However, the orientations of the fracture facets in these steels were clearly not {100}, but fell into two distributions, one near {211} and the other near {110}. Electron diffraction studies from the fracture surfaces indicated the presence of α′ and martensites in the type 304 but not in the type 310 cases; the possibility that this was responsible for the differences in fracture planes is discussed. Studies were also made of a type 304 specimen which had failed by SCC at 289 °C. No martensitic phases were detected at the fracture surfaces in this case, and the fracture facets were large and flat, similar to those for type 310. Cleavage-like fracture surfaces were also produced in type 304 steels by hydrogen embrittlement, using both gaseous hydrogen and cathodic charging, but the facets were too small for precise orientation determination. Formerly with the Department of Metallurgy, University of Illinois at Urbana-Champaign. Formerly with the Department of Metallurgy, University of Illinois at Urbana-Champaign. Formerly Professor of Metallurgy, University of Illinois.     

Psychotherapy, Classism, and the Poor: Conspicuous by Their Absence.

Four decades of research have delineated the need for improved psychotherapeutic opportunities for poor clients, yet psychotherapists remain contradictory in their stance regarding service to the poor. Despite periodic calls within the field to address the needs of poor people, evidence from the psychotherapeutic literature suggests that the poor are still largely absent from consideration. What barriers prevent psychotherapists from enacting their professional principles more consistently on behalf of poor clients? The author suggests that unexamined classist assumptions constitute a significant obstacle for practitioners and presents the experience of confronting her own classism to illustrate the operation of these attitudinal barriers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptions of care access: the experience of rural and urban women following brain injury

To examine care access among women with brain injuries, a qualitative, phenomenological study was conducted. Twenty-one women with acquired brain injuries were recruited for the inquiry, representing rural and urban regions of Colorado. The phenomenological approach allowed the investigators to examine the shared experiences of women with brain injuries as they sought rehabilitative supports and services, and attempted to re-enter their lives and communities. Each woman was interviewed one or two times, the interviews were transcribed and then coded and analysed by both authors separately. Thematic analysis of the data revealed two major emergent themes: issues surrounding diagnosis and barriers to accessing care. A total of 10 women interviewed experienced difficulty obtaining a diagnosis of brain injury and experienced serious personal and professional consequences as a result. All the women experienced barriers to accessing care, including problems with service providers and service systems, financial challenges, travelling for services, lack of information or services in their area, lack of care coordination and funneling. Some of the barriers cannot be changed secondary to cost, efficiency and logistics. Other barriers, could be changed through education, training and policy making.