Comment on “Liquid 4He: Contributions to First Principles Theory. II. Quantized Vortices and the Lambda Transition”

A comment on the paper “Liquid ⁴He: Contributions to First Principles Theory. II. Quantized Vortices and the Lambda Transition” by H.W. Jackson (J. Low Temp. Phys. 155:1, 2009).     

Effect of microscopic damage events on static and ballistic impact strength of triaxial braid composites

The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Methods to characterize the material properties used in the analytical models from a systematically obtained set of test data are also lacking. A macroscopic finite element based analytical model to analyze the impact response of these materials has been developed. The stiffness and strength properties utilized in the material model are obtained from a set of quasi-static in-plane tension, compression and shear coupon level tests. Full-field optical strain measurement techniques are applied in the testing, and the results are used to help in characterizing the model. The unit cell of the braided composite is modeled as a series of shell elements, where each element is modeled as a laminated composite. The braided architecture can thus be approximated within the analytical model. The transient dynamic finite element code LS-DYNA is utilized to conduct the finite element simulations, and an internal LS-DYNA constitutive model is utilized in the analysis. Methods to obtain the stiffness and strength properties required by the constitutive model from the available test data are developed. Simulations of quasi-static coupon tests and impact tests of a represented braided composite are conducted. Overall, the developed method shows promise, but improvements that are needed in test and analysis methods for better predictive capability are examined.     

Mid-Pliocene sea level and continental ice volume based on coupled benthic Mg/Ca palaeotemperatures and oxygen isotopes

Ostracode magnesium/calcium (Mg/Ca)-based bottom-water temperatures were combined with benthic foraminiferal oxygen isotopes in order to quantify the oxygen isotopic composition of seawater, and estimate continental ice volume and sea-level variability during the Mid-Pliocene warm period, ca 3.3-3.0Ma. Results indicate that, following a low stand of approximately 65m below present at marine isotope stage (MIS) M2 (ca 3.3Ma), sea level generally fluctuated by 20-30m above and below a mean value similar to present-day sea level. In addition to the low-stand event at MIS M2, significant low stands occurred at MIS KM2 (-40 m), G22 (-40m) and G16 (-60m). Six high stands of +10m or more above present day were also observed; four events (+10, +25,+15 and +30 m) from MIS M1 to KM3, a high stand of +15m at MIS K1, and a high stand of +25m at MIS G17. These results indicate that continental ice volume varied significantly during the Mid-Pliocene warm period and that at times there were considerable reductions of Antarctic ice.     

Stochastic Modeling for Pavement Warranty Cost Estimation

This paper presents a cost estimation model for long-term pavement warranties with multiple distress indicators. One application area for such warranties involves performance-based specifications (PBSs). In contrast to traditional approaches, PBS gives contractors the flexibility to select construction methods, materials, and even design. However, the contractors then must warrant the performance of their work for a specified period of time. Therefore, an accurate estimation of the risks associated with the warranty is a significant cost issue for any contractor to cover potential risks while still being competitive in bidding. Quantitative evaluation of the cost of risk incurred by the warranty has several difficulties. The deterioration of a highway project is a complex process, which is affected by pavement structure, material, traffic load, and weather conditions. Based on a probabilistic risk analysis of failures of performance indicators, the resulting model can estimate the warranty cost at a detailed level. The application of the model has been demonstrated via a numerical case study using long-term pavement performance data.     

Early career psychologists: Understanding, engaging, and mentoring tomorrow’s leaders.

This article on mentoring describes demographic characteristics and challenges faced by early career psychologists (ECPs) and how mentoring can significantly shape the development of ECPs’ professional and personal identity. ECPs have a significant impact on how psychology will evolve and be recognized in the marketplace. Mentors have the opportunity to significantly shape the development of this early career professional and thus assure the dynamic future of psychology. The characteristics of a mentor, the mentoring process of an ECP, diversity issues, and strategies for effective mentoring are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decarburization as a tool to explore parallels between solid-solid and liquid-solid transformations: Fe-C-Mn-Si steels

The study of single-interface transformations under controlled conditions offers insights into the similarities and distinctions between solidification and solid-solid transformations. In this contribution, we consider some parallels between the formation of a layer of ferrite on an originally austenitic steel bar and the growth of the columnar zone in the solidification of an alloy ingot. The necessary conditions for solid-solid interfacial breakdown of a decarburization front are explored and the evidence to date reviewed. The response of some Fe-C-Mn-Si steels to controlled decarburization is considered, and we present a first report of the morphological instability of a ferrite/austenite decarburization interface, and compare it with the interfacial breakdown in the solid-liquid interface. The instability is tentatively ascribed to the effects of grain-boundary nucleation and/or grain-boundary diffusion of alloying elements in austenite. Other similarities (and differences) between the growth of a ferrite layer on an alloy steel and the development of the columnar zone of an ingot are discussed.     

Construct validity of the Wechsler Abbreviated Scale of Intelligence and Wide Range Intelligence Test: Convergent and structural validity.

The Wechsler Abbreviated Scale of Intelligence (WASI; Psychological Corporation, 1999) and the Wide Range Intelligence Test (WRIT; Glutting, Adams, & Sheslow, 2000) are two well-normed brief measures of general intelligence with subtests purportedly assessing verbal–crystallized abilities and nonverbal–fluid–visual abilities. With a sample of 152 children, adolescents, and adults, the present study reports meaningful convergent validity coefficients and a latent factor structure consistent with the theoretical intellectual models both tests were constructed to reflect. Consideration of the hierarchical model of intelligence tests and issues regarding test interpretation are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The working alliance and employment outcomes for people with severe mental illness enrolled in vocational programs.

Purpose: The purpose of this study was to determine the relationship between the working alliance and employment outcomes in persons with severe mental illness receiving vocational services. Another purpose of this study was to determine whether working alliance differences exist between clients receiving evidence-based supported employment services and those receiving traditional stepwise vocational services. Design: This study was a secondary analysis of a 2-year randomized controlled trial comparing two employment programs providing services to people with severe mental illness. Results: Contrary to expectations, no overall relationship was found between the working alliance and employment outcomes. As predicted, supported employment participants each assigned to a single vocational worker had more positive working alliances than participants served by a team of vocational workers in the traditional vocational program. Conclusions/Implications: The lack of an association between the working alliance and employment outcomes is inconsistent with previous literature. Further research is needed using standardized working alliance measures and larger samples that include both working and nonworking clients. Evidence-based supported employment, which employs individual caseloads, seems to foster better relationships than a team-based vocational approach, although future research is needed to replicate this finding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thinking about Antarctic Heritage: kaleidoscopes and filters

The preliminary results of a project that is currently investigating the nature and range of meanings of Antarctic heritage are explored. The project involves two visits to Scott Base, and the subjects of the qualitative research are the members of the New Zealand Antarctic community. Work so far suggests that different meanings do exist, and a four-fold typology of meanings is suggested which needs to be considered in decisions affecting the future of Antarctica.     

Hydrogenation of vegetable oils using mixtures of supercritical carbon dioxide and hydrogen

Hydrogenation of vegetable oils under supercritical conditions can involve a homogeneous one-phase system, or alternatively two supercritical components in the presence of a condensed phase consisting of oil and a solid catalyst. The former operation is usually conducted in flow reactors while the latter mode is more amenable to stirred, batch-reactor technology. Although many advantages have been cited for the one-phase hydrogenation of oils or oleochemicals using supercritical carbon dioxide or propane, its ultimate productivity is limited by the oil solubility in the supercritical fluid phase as well as unconventional conditions that affect the hydrogenation. In this study, a dead-end reactor has been utilized in conjunction with a head-space consisting of either a binary fluid phase consisting of varying amounts of carbon dioxide mixed with hydrogen or neat hydrogen for comparison purposes. Reaction pressures up to 2000 psi and temperatures in the range of 120–140°C have been utilized with a conventional nickel catalyst to hydrogenate soybean oil. Depending on the chosen reaction conditions, a wide variety of end products can be produced having different iodine values, percentage trans fatty acid content, and dropping points or solid fat indices. Although addition of carbon dioxide to the fluid phase containing hydrogen retards the overall reaction rate in most of the studied cases, the majority of products have low trans fatty acid content, consistent with a nonselective mode of hydrogenation.