Radiation tolerance of type IIa synthetic diamond detector for 14 MeV neutrons

Radiation tolerance of a type IIa synthetic diamond detector was examined from irradiation of mono-energetic 14 MeV neutrons. Measurements of I–V (current–voltage) characteristics and energy spectrum for 5.486 MeV alpha particles were performed after neutron irradiation. In the I–V characteristics measurement, enhancement of rectification was observed after neutron irradiation of up to 2.0 × 10¹² n/cm². Concurrently with the enhancement of rectification, significant decrease in signal amplitude was observed in energy spectrum measurement for alpha particles. It is considered that these changes were due to increase in the concentration of defects acting as shallow energy levels in the forbidden band. For neutron irradiation of higher than 1.6 × 10¹³ n/cm², weakening of the rectification characteristics and recovery of the signal amplitude were observed. These changes imply that deep energy levels, which were also considered to be introduced by defects, were dominant and weakened the effects of the shallow energy levels. Increase in the concentration of the deep trapping levels resulted in gradual decrease of the signal amplitude and degradation in the energy resolution. The peak for the alpha particles was obtained up to 5.5 × 10¹³ n/cm².     

Capillary gas-liquid chromatographic separation of oxo and oxo-hydroxy bile acid isomers of theallo and normal series

Capillary gas-liquid chromatographic separation was studied for 60 oxo and oxo-hydroxy bile acids of theallo (5α-H, A/B-trans) and normal (5β-H, A/B-cis) series, which differ from one another in the number, position, and configuration of oxo and hydroxy groups at positions C−3, C−4, C−6, C−7, and/or C−12. Good separation of the isomers was achieved by the use of an aluminum-clad fused-silica capillary column coated with bonded and cross-linked methyl polysiloxane.     

A tree structure of automata for selective image scanning and its implementation

We propose a novel signal scanning method using a tree structure of automata. This method has a kind of image compression capability, about 1/6–1/20 for samples images, by skipping the scan of non-active elements with a selectively activated signal path only to active elements. We also demonstrate the effect of data compression for some examples and an implementation of tree structure on a VLSI chip.     

The nature of adolescent competencies predicted by preschool delay of gratification.

Delay of gratification, assessed in a series of experiments when the subjects were in preschool, was related to parental personality ratings obtained a decade later for 95 of these children in adolescence. Clear and consistent patterns of correlations between self-imposed delay time in preschool and later ratings were found for both sexes over this time span. Delay behavior predicted a set of cognitive and social competencies and stress tolerance consistent with experimental analyses of the process underlying effective delay in the preschool delay situation. Specifically, children who were able to wait longer at age 4 or 5 became adolescents whose parents rated them as more academically and socially competent, verbally fluent, rational, attentive, planful, and able to deal well with frustration and stress. Comparisons with related longitudinal research using other delay situations help to clarify the important features of the situations and person variables involved in different aspects of delay of gratification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simultaneous Synthesis and Densification of MoSi2 by Field-Activated Combustion

A method to simultaneously synthesize and consolidate MoSi₂ from powders of Mo and Si was investigated. Combustion synthesis was carried out under the combined effect of an electric field and mechanical pressure. Highly dense molybdenum silicide up to (99.2%) was produced from elemental powders in one step. Minor amounts of Mo₅Si₃ were present at the boundaries of MoSi₂ grains in the interior of samples made from stoichiometric reactants. The addition of 2.5 mol% Si excess, however, resulted in Mo₅Si₃-free, dense MoSi₂ products.     

Studies on propylene polymerization with a highly active MgCl2 supported TiCl4 catalyst system

Summary Propylene polymerization was performed with a highly active MgCl supported TiCl₄ in conjunction with Et₃Al and ethyl benzoate (EB). The obtained polypropylene sample was separated into four fractions by successive extraction with pentane, heptane and trichloroethylene (trichlene). Yield, Mn, Tm and microtacticity of each fraction were determined, and the effects of the concentration of EB on these items of results were investigated. It has been found that EB enhances yield, Mn and stereospecificity of trichlene insoluble (the most stereospecific) fraction, and in contrast, it decreases rapidly yields of other three fractions without changing the character of the polymers. From these findings, the functions of EB to the active centers were discussed.     

Dynamic mechanical properties and morphology of styrene-divinylbenzene copolymer/poly(vinyl chloride) systems. (II). Effect of polymerization temperature

Effect of polymerization temperature on the phase-separated structure of the composite materials [P(St-DVB)/PVC systems] prepared by copolymerization of styrene (St) and divinylbenzene (DVB) in the presence of fine poly(vinyl chloride) (PVC) powder was studied by electron microscopy and dynamic mechanical test. P(St-DVB)/PVC systems have the two-phase nature with a styrene-divinylbenzene copolymer as the continuous phase [P(St-DVB) phase) and a PSt/PVC composite as the dispersed phase (PSt-PVC phase), in which PSt penetrates into the PVC domain. The crosslinking density of the P(St-DVB) phase is larger than that estimated from the recipe in the feed, suggesting that there exists a difference of the diffusion constants of styrene and divinylbenzene into the PVC particles on the paste formation and the polymerization process. The changes of the phase-separated structure of P(St-DVB)/PVC systems polymerized at various temperatures are also explained on the basis of the difference between the diffusion behavior of styrene and that of divinylbenzene into fine PVC particles at these temperatures.     

Cognitive person variables in the delay of gratification of older children at risk.

The components of self-regulation were analyzed, extending the self-imposed delay of gratification paradigm to older children with social adjustment problems. Delay behavior was related to a network of conceptually relevant cognitive person variables, consisting of attention deployment strategies during delay, knowledge of delay rules, and intelligence. A positive relationship was demonstrated between concurrent indexes of intelligence, attention deployment, and actual delay time. Moreover, attention deployment, measured as an individual differences variable during the delay process, had a direct, positive effect on delay behavior. Specifically, as the duration of delay and the frustration of the situation increased, children who spent a higher proportion of the time distracting themselves from the tempting elements of the delay situation were able to delay longer. The effect of attention deployment on delay behavior was significant even when age, intelligence, and delay rule knowledge were controlled. Likewise, delay rule knowledge significantly predicted delay time, even when age, attention deployment, and intelligence were controlled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intuitive interactionism in person perception: Effects of situation-behavior relations on dispositional judgments.

To examine the effects of the relationships between behavior and the situation in which it occurs, we manipulated such relations and exposed subjects to them. Impressions were similar when based on the behaviors presented with situations unspecified (e.g., child hits) or when the situations in which they naturally occurred were specified (e.g., child hits when provoked). However, when situations were specified, subjects' impressions more accurately predicted individual differences in the children's actual levels of overall aggressive behavior. When the veridical situation–behavior relations were increasingly altered, the targets were perceived as being less plausible and increasingly maladjusted and odd, and correlations decreased between the perceived level of the children's aggressiveness and their actual aggressive behavior. Thus, both personality impressions and predictive accuracy were influenced by the relations between the target's behaviors and their situational contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)