Modeling Suspended Sediment during Construction in Great Barrier Reef World Heritage Area

A marina was constructed in the Great Barrier Reef World Heritage Area in close proximity to coral reefs that could be damaged by excess turbidity generated during construction. Since there was uncertainty about both the fate of suspended sediments and their effect on corals, initial water quality constraints were set very conservatively. In order to better understand the movement of suspended sediment during construction, a numerical model study was commissioned using three-dimensional, numerical, hydrodynamic, and Lagrangian particle tracking models. The study was successful in: (1) increasing the understanding of and reducing the uncertainty of sediment dispersal patterns under a range of common forcing conditions; (2) testing the variation in suspended sediment concentrations over sensitive areas for two different outfall locations; (3) offering evidence that a good choice in outfall locations will reduce the threat to corals; and importantly (4) presenting the results in a way that enhanced understanding by nontechnical reef managers. This final result was achieved by creating movies of sediment movement that clearly demonstrated the complex hydrodynamic processes involved with near-coastal water currents. Specific model results showed: (1) that a more seaward outfall increases effluent dispersal away from sensitive areas; (2) the highest concentrations of effluent over sensitive sites occur during no wind and neap tide conditions; and (3) prevailing southeast winds advect effluent offshore, away from sensitive sites.     

Bystander response to arterial bleeding: Helping skills, the decision-making process, and differentiating the helping response.

Explored the impact of variables on 2 different decisions in the decision-making process leading to help, using a mock injury involving arterial bleeding and 163 university students (100 females and 63 males). Expertise (Red Cross training), ambiguity, and number of bystanders were manipulated in a 2?×?2?×?2 design. The following responses were observed: nonhelp, ineffective direct help, indirect help, and direct help. The decision to help or not was affected by ambiguity, sex, and the presence or absence of other bystanders. Greater ambiguity led to less help; women helped less than men; fewer people helped when other bystanders were present. Expertise affected the decision leading to the type of help used but not the decision to help. Although training did not raise the intervention rate, it did dramatically change the effectiveness of the help used and could yield as many as 28 more saved lives out of 80 such incidents. Ineffective direct help occurred most frequently when the bystander was alone. The presence of other bystanders affected the type of indirect help that was used. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Examination of the relationship between true halo and halo error in performance ratings.

The purpose of this study was to test competing theories regarding the relationship between true halo (actual dimensional correlations) and halo rater error (effects of raters' general impressions on specific ratee qualities) at both the individual and group level of analysis. Consistent with the prevailing general impression model of halo rater error, results at both the individual and group level analyses indicated a null (vs. positive or negative) true halo-halo rater error relationship. Results support the ideas that (a) the influence of raters' general impressions is homogeneous across rating dimensions despite wide variability in levels of true halo; (b) in assigning ratings, raters rely both on recalled observations of actual ratee behaviors and on general impressions of ratees in assigning dimensional ratings; and (c) these 2 processes occur independently of one another. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral validation of several values from the Rokeach Value Scale as an index of honesty.

Of 131 female line workers responding to an attitude questionnaire, 39% returned the scoring pencil which was furnished with their questionnaire. It was hypothesized that the act of returning the pencils was related to the employee's feelings about being honest. As the great bulk of the employees were members of strict religious denominations, it was also hypothesized that the act of returning the pencils might be related to the hoped for attainment of a religious end state, i.e., salvation. Honest and Salvation are 2 of 36 values of the Rokeach Value Scale. Results are consistent with the hypotheses. In addition 2 other values, A World At Peace and Helpful appeared to distinguish between pencil returners and nonreturners. The Rokeach Value Scale may prove to be a potentially useful predictor of honesty in a corporate setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biomimetic autoseparation of leukocytes from whole blood in a microfluidic device

Leukocytes comprise less than 1% of all blood cells. Enrichment of their number, starting from a sample of whole blood, is the required first step of many clinical and basic research assays. We created a microfluidic device that takes advantage of the intrinsic features of blood flow in the microcirculation, such as plasma skimming and leukocyte margination, to separate leukocytes directly from whole blood. It consists of a simple network of rectangular microchannels designed to enhance lateral migration of leukocytes and their subsequent extraction from the erythrocyte-depleted region near the sidewalls. A single pass through the device produces a 34-fold enrichment of the leukocyte-to-erythrocyte ratio. It operates on microliter samples of whole blood, provides positive, continuous flow selection of leukocytes, and requires neither preliminary labeling of cells nor input of energy (except for a small pressure gradient to support the flow of blood). This effortless, efficient, and inexpensive technology can be used as a lab-on-a-chip component for initial whole blood sample preparation. Its integration into microanalytical devices that require leukocyte enrichment will enable accelerated transition of these devices into the field for point-of-care clinical testing.     

RETRAN thermal-hydraulic analyses: Theory and applications

This paper summarizes the RETRAN Code from both a theory and application point of view. The main emphasis in the theory section is to describe the features of RETRAN beyond standard homogeneous equilibrium, point kinetic codes like RELAP4 and FLASH-4. The application section emphasizes loss of fluid test facility (LOFT) results, Three-Mile Island, and Peach bottom analyses for which data exist. Current limitations of the code are indicated.     

Importance measures for modular software with uncertain parameters

Importance measures provide a sense of the relative priorities of components and can be used to guide the allocation of resources for cost‐effective improvement of system reliability starting from the early phases. Uncertainties in model parameters, prevalent in the early phases, can introduce errors into these measures, and hence, importance assessment must account for these parametric uncertainties. In this paper, a framework for importance assessment of a software system within the context of its architecture is proposed. The framework includes two methods; the first one systematically quantifies the confidence intervals in the model parameters, and the second one offers an analytical approach for importance analysis. The two methods in conjunction address the issue of importance assessment in the face of parametric uncertainties. Illustration of the framework using a banking application demonstrates the value and benefits of the methodology. Copyright © 2009 John Wiley & Sons, Ltd.     

Significant Improvement in Activity and Stability of Pt/TiO2 Catalyst for Water Gas Shift Reaction Via Controlling the Amount of Na Addition

Na promoted Pt/TiO₂ catalysts have been studied under high severity, near equilibrium, conditions for use as a single stage WGS catalyst. Addition of 3 wt% Na to a 1 wt% Pt/TiO₂ catalyst has been found to improve water gas shift activity significantly compared to Pt/TiO₂, Pt/CeO₂, and Pt–Re/TiO₂ catalysts. This catalyst is stable when the reaction temperature is higher than 250 °C. Deactivation occurred when the reaction temperature was lower than 250 °C, however, returning the temperature to higher than 250 °C fully recovered activity. TEM observations revealed that addition of Na inhibited Pt particle sintering. These results suggest that Na promoted Pt/TiO₂ is a promising single stage water gas shift catalyst for small scale hydrogen production.     

Mechanical property degradation of high crystalline SiC fiber–reinforced SiC matrix composite neutron irradiated to ∼100 displacements per atom

For the development of silicon carbide (SiC) materials for next-generation nuclear structural applications, degradation of material properties under intense neutron irradiation is a critical feasibility issue. This study evaluated the mechanical properties and microstructure of a chemical vapor infiltrated SiC matrix composite, reinforced with a multi-layer SiC/pyrolytic carbon–coated Hi-Nicalon^TM Type S SiC fiber, following neutron irradiation at 319 and 629?°C to ～100 displacements per atom. Both the proportional limit stress and ultimate flexural strength were significantly degraded as a result of irradiation at both temperatures. After irradiation at 319?°C, the quasi-ductile fracture behavior of the nonirradiated composite became brittle, a result that was explained by a loss of functionality of the fiber/matrix interface associated with the disappearance of the interphase due to irradiation. The specimens irradiated at 629?°C showed increased apparent failure strain because the fiber/matrix interphase was weakened by irradiation-induced partial debonding.