A probabilistic paradigm for spacecraft random reentry disassembly

A new probabilistic paradigm for calculating the uncertainty in casualty area of randomly reentering debris from orbital objects is presented with exemplar calculations of casualty area associated with elements of a reentering Delta II launch vehicle second stage. Sensitivity studies using a probabilistic paradigm for simulation of spacecraft random reentry disassembly have shown the importance of including uncertainties. The sensitivity of casualty area to spacecraft orientation and consequent free-flying ballistic element orientation is extreme. The notion of inherently stochastic processes during reentry is supported by recent data on recovered debris from the Space Shuttle Columbia. Casualty area standards for spacecraft that rely on deterministic estimates may not be providing the level of safety assurance that was intended.     

Effect of organic/inorganic coating on moisture diffusion in a chip-on-board package with globtop

The moisture diffusion in globtop material for a chip-on-board (COB) package coated with SiN_x and silicone, respectively, or coated with SiN_x plus silicone were measured by embedding a humidity sensor in the globtop and recording the capacitive change in three different temperature/humidity environments. The experimental results were simulated by Fick’s diffusion law with finite-element method modeling. The moisture diffusion coefficients and activation energies were calculated to quantitatively compare the moisture-resistance effects of different coatings. For example, at 85°C/85% RH, the moisture diffusion coefficients for the uncoated reference, SiN_x-coated, silicone-coated, and silicone/SiN_x double-layered coated samples are 1E-5, 0.8E-5, 0.7E-5, and 0.2E-5 mm²/s, respectively. The experimental and simulation results show that double-layered coating with silicone/SiN_x has excellent moisture-resistance properties because it not only smoothes the steps on a printed circuit board (PCB) but also keeps the good moisture resistance of the inorganic films.     

Superiority of blood over saline resuscitation from hemorrhagic shock: a 31P magnetic resonance spectroscopy study

OBJECTIVE: To study the relation between blood and saline administration, postresuscitation hematocrit (Hct) level, and metabolic recovery after hemorrhagic shock. SUMMARY BACKGROUND DATA: It is generally believed that crystalloid can be substituted, in whole or in part, for blood during resuscitation of hemorrhagic shock. This is based on the belief that Hct can be safely reduced but should not fall below a critical level. METHODS: Male rats weighing 200 g were subjected to an isobaric hemorrhagic shock at a mean arterial pressure of 30 mmHg for 14 minutes, after which they were randomized to one of three resuscitation regimens. Control group (n = 36) were resuscitated by return of all shed blood. Mid-Hct (n = 39) and low-Hct (n = 60) groups were depleted of one third and one half of their circulating blood volumes, respectively, and were resuscitated with three times that volume of normal saline. Skeletal muscle intracellular energetics and pH were measured serially using 31P magnetic resonance spectroscopy at baseline, during shock, and after resuscitation. Arterial blood was sampled at the same time points. The number of surviving animals in each group at 24 hours was recorded. RESULTS: After resuscitation, surviving rats in the low-Hct group demonstrated a greater consumption of high-energy phosphocreatine stores than did the other groups (control = 0.479 +/- 0.003, mid-Hct = 0.465 +/- 0.004, low-Hct = 0.457 +/- 0.007, mean +/- standard error of the mean; p < 0.01 low-Hct vs. other groups by analysis of variance). The rats that received saline resuscitation developed a relative intracellular acidosis (control = 7.29 +/- 0.02, mid-Hct = 7.25 +/- 0.02, low-Hct = 7.23 +/- 0.02; p < 0.05 controls vs. other groups by analysis of variance). At 24 hours, the death rates were significantly different among the groups: control = 1 of 36 rats (2.8%), mid-Hct = 6 of 39 (15.4%), and low-Hct = 14 of 60 (23.3%) (p < 0.05 by chi square analysis). CONCLUSION: The oxygen-carrying capacity of resuscitation fluid has an important impact on intracellular metabolism and outcome.     

Social support and depression following spinal cord injury.

Examined the associations of different social relationships with depressive behavior among 182 adults with acquired spinal cord injuries. Trained interviewers administered a social provisions scale and an inventory to diagnose depression. A cross-sectional design was used to investigate possible differential effects across time since the onset of injury. Relationships that reassured the worth of the individual were predictive of lower depression scores. To a lesser extent, relationships providing a sense of social integration were associated with lower depression scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interventions for children of divorce: Toward greater integration of research and action.

A number of child-, family-, and system-focused interventions have been designed to prevent or reduce the negative effects of divorce on children. This article critically evaluates these intervention efforts by examining (1) their relation to basic research on the processes proposed to mediate children's postdivorce adjustment and (2) evaluation studies assessing the effectiveness of various programs. Although interventions address some of the factors proposed to mediate children's adaptation to divorce, the interplay between interventions and basic research on children's postdivorce adaptation is limited. Moreover, some intervention efforts appear to be beneficial but most lack empirical documentation of their efficacy. This analysis leads to several recommendations for basic and applied research and for improving the response of the mental health field to the problems experienced by many children from divorcing families. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adolescent Gambling: Relationships With Parent Gambling and Parenting Practices.

This study explored the possible links between family risk factors (i.e., parent gambling and parenting practices) and adolescent gambling. A community sample of 938 adolescents (496 females and 442 males) completed the South Oaks Gambling Screen Revised for Adolescents (SOGS-RA; K. C. Winters, R. Stinchfield, & J. Fulkerson, 1993b) along with a questionnaire assessing parenting practices. Both parents completed the SOGS (H. R. Lesieur & S. B. Blume, 1987). Results showed that adolescent gambling frequency was related to both parents' gambling frequency and problems. However, adolescent gambling problems were linked only to fathers' severity of gambling problems. Low levels of parental monitoring enhanced adolescents' risk of getting involved in gambling activities and developing related problems. A higher level of inadequate disciplinary practices was also related to greater gambling problems in youth. These links were significant after controlling for socioeconomic status, gender, and impulsivity- hyperactivity problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

OMCVD-grown In0.4Al0.6As/InP quantum-wellHEMT

The transport properties and device characteristics of pseudomorphic In_0.4Al_0.6As/InP modulation-doped heterostructures are investigated. The existence of a two-dimensional electron gas at the heterojunction was confirmed by Shubnikov-de Haas measurements. A high electron mobility transistor (HEMT) having a gate length of 1.5 μm showed extrinsic transconductances and drain current densities as high as 160 mS/mm and 300 mA/mm, respectively. The HEMT also showed a very small output conductance of less than 2 mS/mm and high gate-drain breakdown voltage of larger than 15 V. These results show the great potential of this HEMT for high-voltage gain and high-power microwave applications     

Family process and adaptation to children with mental retardation: Disruption and resilience in family problem-solving interactions.

Family problem-solving interactions were examined in families (N?=?165) of school-aged children with mild or moderate mental retardation (MR) and a comparison sample (N?=?52). The results demonstrated a disruptive impact of children with MR in the form of more directiveness by mothers and fathers, less supportive problem solving by single mothers, and less active problem solving by the target children in the MR group. Nevertheless, the absence of high rates of aversive behaviors in the MR group and the similarities in siblings' behaviors across the groups suggested that the MR families were also resilient in the face of special demands. Role differences among mothers, fathers, and siblings also were highly consistent in the two groups. Evidence of difficulties for single mothers and problem behaviors by other children in the family suggested that mental retardation is one of many challenges that families learn to cope with successfully. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Block copolymers of poly(vinyl ethers) and poly(ethylene glycol) by means of the living cationic polymerization of vinyl ethers

Summary If living poly(vinyl ethers) are terminated with a large excess of methanol, containing aqueous ammonia, well-defined products are obtained. If only a slight excess of methanol is used, aldehydes and coupling products are formed. However, termination with an excess of a hydroxy terminated polymer is cumbersome. According to a given reaction scheme, the termination with methanol in the presence of an anhydrous organic base, should give better results. With two equivalents of triethylamine with respect to the initiator only two equivalents of methanol are needed to give a clean reaction. With this recipe block copolymers of poly(vinyl ether) and poly(ethylene glycol) are prepared.     

Research selection bias and the prevalence of depressive disorders in psychiatric facilities.

Applied a statistical technique to correct for selection bias in estimating the prevalence of depressive disorders in community mental health centers (CMHCs). Approximately 243 Ss completed the screening instruments at 2 CMHCs. Results indicate that the prevalence of depression in total CMHC populations may approach 44% rather than the 25% derived from a censored sample. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)