A new source of X-ray line broadening: inhomogeneous strains induced by uniform homogeneous temperature conditions in polyphase or non-cubic materials

Thermal strains may contribute to X-ray diffraction line broadening in both single-phase non-cubic and in polyphase cubic polycrystalline materials even under uniform temperature conditions. A method is developed for calculating the magnitude of these thermally induced strains directly from the measured diffraction peak profiles. Corrections for particle-size effects can be made readily if particle-size broadening is significant, and the thermal diffuse scattering (TDS) contribution to the diffracted intensity can be taken into account experimentally. By this method, the strains in a Mg-5 wt% Si alloy were found to be increased by as much as 35% by a 190° C temperature change. Even in the case of this relatively low melting point alloy, the TDS effect causes only a maximum of 15% error in these measured strain effects. The interpretation of these isothermally induced strains in terms of crystal anisotropy, grain morphology and orientation and the relative sizes of phases and grains is discussed.     

Person, situational, and interactional influences on assertive behavior.

Explored the validity of the College Self-Expression Scale (CSES) in the context of 3 alternative models of behavior: personism, situationalism, and interactionalism. 72 high- and 72 low-assertive female college students role-played scenes requiring assertive behavior. The scenes varied on 3 situational dimensions: positive–negative assertion, male–female, and familiar–unfamiliar partner. The dependent measures were content, appropriateness of affect, and duration of reply. Results support the concurrent validity of the CSES and the role of both person and situational, but not interactional, influences on assertion. Implications for assertion training, for using the CSES, and for concept-utilizing assertive behavior are discussed. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Socialization, awareness, and electrodermal response to deception and self-disclosure.

Poorly socialized young adult males have been found to give smaller skin conductance responses (SCRs) to both physical and certain social (i.e., deception) stressors than their more highly socialized counterparts. This study with 30 male undergraduates examined whether these differences are dependent on S's awareness that his physiological responses are being recorded. 15 Ss attempted to deceive a polygraph examiner both before (unaware) and during (aware) a polygraph test. The 15 other Ss made truthful denials to the examiner's questions. All Ss were also asked biographical questions as part of an interview in the unaware condition. Under both aware and unaware conditions, high-socialization (Socialization scale of the California Psychological Inventory) Ss gave larger SCRs when deceiving than did low-socialization Ss. They also gave larger SCRs than low-socialization Ss when disclosing significant personal information but did not differ electrodermally when answering routine information questions. Awareness of physiological monitoring apparently does not mediate the finding that highly socialized Ss are markedly aroused and low socialization Ss little aroused by stress. (10 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The stress response of a semi-infinite micropolar granular material subject to a concentrated force normal to the boundary

We consider the problem of a two dimensional semi-infinite granular material subject to a concentrated or point force normal to the boundary. This boundary value problem was originally solved for a classical elastic material by Flamant in 1892 and, hence, is also known as the Flamant problem (Johnson [8]). In this paper, the granular material is considered as an elastic micropolar or Cosserat continuum and is represented by a particular form of the general constitutive law derived in Walsh and Tordesillas [29]. The stress distribution predicted by the model is in good agreement with experimental data for small strains. In particular, two important features that are captured by the proposed model are: (i) the presence of tensile stress response regions, and (ii) the dependence of the stresses on the microstructural properties, i.e. the particles normal, tangential and rotational stiffness constants. The proposed analysis utilizes two new stress functions, similar to Airys stress functions in classical elastic theory.The support of the US Army Research Office through a grant to AT (Grant No. DAAD19-02-1-0216) and the Melbourne Research and Development Grant scheme is gratefully acknowledged. We thank our reviewers for their useful suggestions and insightful comments.     

Changes in the body size of UK and US children over the past three decades

The major sources of published anthropometric data on children are now over two decades old. Due to concern being expressed regarding the continued validity of such data, changes in the body sizes of the UK child population over the past three decades have been considered. Comparisons were also made between the size of the current UK child population to the current US child population, and to the most comprehensive source of measured data on US children (but which are now over 20 years old). The growth of children in the UK and US over the past three decades was assessed for an indication of secular growth trends. Stature increases were found to have generally been less than body weight increases (as a percentage) at 5th percentile, mean and 95th percentile levels for UK children, and UK children were found to be closer in size to US children now than they were 30 years ago.     

Fate of carbon tetrachloride during phytoremediation with poplar under controlled field conditions

The fate of carbon tetrachloride (CT) during phytoremediation with poplar was assessed by examining the transpiration of CT from leaves, diffusion from soil, tree trunks, and surface roots, and accumulation of chloride ion in soil and plant tissues. Feedwater containing 12-15 mg/L CT was added to the field test beds planted with poplar, and over 99% of the CT was removed. No significant amount of CT was transpired or diffused into the air, and no significant amount of CT-chlorine accumulated in the tree tissues. Chloride ion accumulated in the soil accounted for all of the CT-chlorine removed. When soils from the root zones were compared to unvegetated soils, microbial mineralization of CT was not enhanced in soils from the root zones as compared to unvegetated soils. Thus, we conclude that uptake and dechlorination of CT by plant tissues is likely the primary mechanism for phytoremediation by poplar.     

Some consequences of different older driver licensing procedures in Australia

Given both the expected growth in the number of older drivers and their over-involvement in fatal and serious injury crashes, there has been a world-wide call for improved licensing procedures to manage older driver safety. In particular, licensing authorities have been urged to move from mandatory assessment of all older drivers to assessment practices targeting only those at higher crash risk. The current study examined older driver fatal and serious injury crash involvement rates across all Australian States to determine a possible association with the different licensing procedures. In particular, older driver crash involvement rates in Victoria (where there is no age-based assessment program) have been compared with rates in other jurisdictions with assessment programs. Crash involvement rates have been calculated using two denominators: per population and per number of licensed drivers. Some data limitations notwithstanding, older drivers in jurisdictions with age-based mandatory assessment programs could not be shown to be safer than drivers in Victoria. Further, there is some indicative evidence that older drivers in Victoria may have a significantly safer record regarding overall involvement in serious casualty crashes.