Integrated design approach of the pebble BeD modular reactor using models

The pebble bed modular reactor (PBMR) is the first pebble bed reactor that will be utilised in a high temperature direct Brayton cycle configuration. This implies that there are a number of unique features in the PBMR that extend from the German experience base. One of the challenges in the design of the PBMR is developing an understanding of the expected behaviour of the reactor through analyses and simulations and managing the integrated design process between the designers, the physicists and the analysts.This integrated design process is managed through model-based development work. Three-dimensional CAD models are constructed of the components and parts in the reactor. From the CAD models, CFD models, neutronic models, shielding models, FEM models and other thermodynamic models are derived. These models range from very simple models to extremely detailed and complex models. The models are used in legacy software as well as commercial off-the-shelf software. The different models are also used in code-to-code comparisons to verify the results.This paper will briefly discuss the different models and the interaction between the models, and how the models are used in the iterative design process that is used in the development of the reactor at PBMR.     

Romantic attachment in individuals with physical disabilities.

Objective: To examine the relationship between adult attachment style and physical disability in intimate romantic relationships. Method: Participants were 50 individuals with adult-onset spinal cord injuries (SCI) and 50 individuals with congenital disabilities (CON) living in the community. The main outcome measures were adult attachment style and dyadic relationship adjustment. Results: Participants with SCI and CON did not differ in rates of secure versus insecure attachment, and the rates of neither group differed significantly from rates reported for persons without disability. Dyadic adjustment was clearly predicted by attachment variables and differed between the participants with SCI and those with CON; individuals with SCI reported greater total dyadic adjustment. Avoidance showed a strong negative association with dyadic satisfaction, but no association was found with dyadic cohesion. Social participation variables were associated with dyadic adjustment. For instance, mobility was positively associated with dyadic satisfaction. Conclusions: Dyadic adjustment in people with disabilities, as in other groups, is affected by attachment style, but disability and social participation variables may also affect dyadic adjustment. Clinicians should consider differences in attachment styles among persons with disabilities and their implications for intimate close relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Computational Techniques and Shear Band Development for Cylindrical and Spherical Penetrometers in Strain-Softening Clay

This paper addresses numerical simulation of deep penetration of full-flow penetrometers in strain-softening, rate-dependent, cohesive soil, and the observed phenomenon of periodic shear bands. The analysis was conducted using a large deformation finite element approach, modifying the simple elastic–perfectly plastic Tresca soil model to allow strain-softening, with strain-rate dependency being incorporated in order to avoid spurious mesh dependency. Parametric analyses were carried out varying the strain-softening parameters (hence the relative brittleness of the soil), the rigidity index of the soil, and the strain-rate parameter. Increased brittleness of the soil led to reduction in the penetration resistance, but also to increasingly significant oscillations in the resistance–penetration responses. The oscillation was found to result from periodic shear bands evolving cyclically ahead of the advancing cylindrical and spherical penetrometers. Analyses with different values of rigidity index confirmed further that the periodic shear bands were a real material phenomenon, rather than due to errors in numerical simulation. Similar phenomena have been observed for continuous flow problems in granular materials. However, rising strain-rate dependency tended to suppress the oscillations.     

Fraternity and sorority involvement, social influences, and alcohol use among college students: A prospective examination.

This study used latent growth curve modeling to investigate whether the effects of gender and Greek involvement on alcohol use and problems over the first 2 years of college are best characterized by selection, socialization, or reciprocal influence processes. Three social influences (alcohol offers, social modeling, and perceived norms) were examined as potential mediators of these effects. Undergraduate participants (N = 388) completed self-report measures prior to enrollment and in the spring of their freshmen and sophomore years. Male gender and involvement in the Greek system were associated with greater alcohol use and problems prior to college. Both gender and Greek involvement significantly predicted increases in alcohol use and problems over the first 2 years of college. Cross-domain analyses provided strong support for a mediational role of each of the social influence constructs on alcohol use and problems prior to matriculation, and prematriculation social modeling and alcohol offers mediated relations between Greek involvement and changes in alcohol use over time. Findings suggest that students, particularly men, who affiliate with Greek organizations constitute an at-risk group prior to entering college, suggesting the need for selected interventions with this population, which should take place before or during the pledging process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of continuing care adherence on environmental risks, substance use, and substance-related problems following adolescent residential treatment.

The effectiveness of adolescent treatment to reduce substance use has been demonstrated by a number of different literature reviews, yet longer term outcome studies have suggested that continued alcohol and other drug use is common. Participation in continuing care services and reductions in environmental risk factors (e.g., peer substance use or alcohol or drug use in the home) have both been found to be associated with improved posttreatment substance use. The authors conducted Path analysis to examine the experimental direct effect of the Assertive Continuing Care Protocol (S. H. Godley, M. D. Godley, & M. L. Dennis, 2001) on general continuing care adherence following residential treatment and the protocol's indirect effect (via general continuing care adherence) on social and environmental risk factors, as well as subsequent substance use and substance-related problems. Supporting previous findings, the final model indicates that greater adherence to continuing care is associated with reductions in environmental risk, which in turn is associated with reduced adolescent substance use and substance-related problems 9 months after discharge from residential treatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impaired processing of local geometric features during navigation in a water maze following hippocampal lesions in rats.

Hippocampal damage impairs navigation with respect to information provided by the shape of an arena. Recent evidence has suggested that normal rats use local geometric information, as opposed to a global geometric representation, to navigate to a correct corner. One implication of this pattern of results is that hippocampal lesions may impair processing of 1 or more of the local geometric features of an environment. The authors therefore investigated the effects of hippocampal cell loss in rats on navigation to a hidden goal with respect to a variety of local cues in an environment with a distinctive shape. Rats with lesions of the hippocampus were impaired in discriminating a right-angled corner from its mirror image. However, they were able to use cues provided by an acute-angled corner (Experiment 1) or a local polarizing cue (Experiment 2). In contrast, lesioned rats were impaired in discriminating long versus short walls (Experiment 3). Results indicate that the hippocampus plays a role in disambiguating locations by processing (metric) information related to the distance between corners. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kinetics of Phosphorus Release and Uptake in a Membrane-Assisted Biological Phosphorus Removal Process

A long-term comparative study on the kinetics of enhanced biological phosphorus removal (EBPR) was carried out in pilot scale membrane-assisted and conventional biological phosphorus removal processes, by monitoring system performance, phosphorus mass balances, and maximum specific rates in off-line batch tests. The two systems exhibited similar performance in the removal of soluble phosphorus (P) from the influent wastewater, in the specific P release observed in the anaerobic zone, and in the maximum specific P release and volatile fatty acid (VFA) uptake rates. However, when the VFA in the influent was limiting, the conventional EBPR (CEBPR) process performed significantly better than the membrane (MEBPR) counterpart, and this behavior was also reflected in the kinetics of P release. Denitrifying dephosphatation was observed to be significant in both processes during periods of satisfactory P removal. When the aerobic recycle ratio was reduced to a minimum level, the anoxic P uptake activity in the CEBPR sludge was lower than that of the MEBPR sludge. Finally, the biomass decay rates of the two sludge types were estimated to be comparable, with significant reduction of the decay under unaerated conditions.     

Multisensory recognition of actively explored objects.

Shape recognition can be achieved through vision or touch, raising the issue of how this information is shared across modalities. Here we provide a short review of previous findings on cross-modal object recognition and we provide new empirical data on multisensory recognition of actively explored objects. It was previously shown that, similar to vision, haptic recognition of objects fixed in space is orientation specific and that cross-modal object recognition performance was relatively efficient when these views of the objects were matched across the sensory modalities (Newell, Ernst, Tjan, & Bülthoff, 2001). For actively explored (i.e., spatially unconstrained) objects, we now found a cost in cross-modal relative to within-modal recognition performance. At first, this may seem to be in contrast to findings by Newell et al. (2001). However, a detailed video analysis of the visual and haptic exploration behaviour during learning and recognition revealed that one view of the objects was predominantly explored relative to all others. Thus, active visual and haptic exploration is not balanced across object views. The cost in recognition performance across modalities for actively explored objects could be attributed to the fact that the predominantly learned object view was not appropriately matched between learning and recognition test in the cross-modal conditions. Thus, it seems that participants naturally adopt an exploration strategy during visual and haptic object learning that involves constraining the orientation of the objects. Although this strategy ensures good within-modal performance, it is not optimal for achieving the best recognition performance across modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

磁控反应溅射氧流量变化对TiO2薄膜影响的实验研究

通过中频交流磁控溅射设备,利用金属Ti靶制备出了有一定厚度的、质量较好的TiO2薄膜,TiO2薄膜被沉积在玻璃基底上.利用各种分析测试手段对其性能进行了测试,初步探讨了不同氧流量对TiO2薄膜的影响.实验表明,不同氧流量下制备的TiO2薄膜的亲水特性发生了变化.     

Detecting back irrelevant responding on the Personality Assessment Inventory in a psychiatric inpatient setting.

The present studies focus on strategies for detecting back irrelevant responding (BIR) on the Personality Assessment Inventory (PAI; L. C. Morey, 1991). Moderate BIR levels can greatly affect the clinical scales of the PAI. Further, the PAI's Inconsistency and Infrequency validity scales are less than optimal for detecting BIR. L. C. Morey and C. J. Hopwood (2004) developed an alternative strategy for detecting BIR that involves comparison of 2 scales from the PAI short-form with the same 2 scales from the PAI full-instrument. The present study examines how different BIR levels affect the clinical, treatment, and interpersonal scales of the PAI in 2 psychiatric inpatient samples. The effectiveness of various strategies for detecting BIR in an inpatient setting is also discussed. Consistent with previous research, moderate rates of BIR impacted several PAI scales in a meaningful way. The Inconsistency and Infrequency validity scales of the PAI were relatively ineffective for detecting low-to-moderate BIR levels. Conversely, the short-form full-instrument comparison strategy was much more sensitive to BIR. Finally, a new BIR detection indicator is presented that improves sensitivity rates for detecting all BIR levels in an acute setting. The implications of these results for detecting BIR in inpatient settings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)