Ragone Plot Comparison of Radioisotope Cells and the Direct Sodium Borohydride/Hydrogen Peroxide Fuel Cell With Chemical Batteries

Radioisotope cells (RCs) and a direct sodium borohydride/hydrogen peroxide fuel cell ( FC) are compared to conventional chemical batteries through Ragone plots of theoretical (RCs) and experimental (chemical batteries and FC) data. It is found that the RCs are projected to have superior specific energy but inferior specific power, while the borohydride/peroxide FC shows an impressive range for both parameters. Thus, RCs may be especially useful in battery charging, communications, or other applications that require a long-lived, low-power source or periodic pulses of energy. While the borohydride/peroxide FC can be scaled to a variety of high-power applications, it is especially well suited for space and undersea use where air independence is essential.     

Record tuning range of InP-based multiple air-gap MOEMS filter

Continuously tunable Fabry-Perot filters based on multiple InP/air-gap MOEMS technology are presented. Record wavelength tuning >112 nm with an actuation voltage of only 5 V is demonstrated. The FWHM remains constant over the entire tuning range. The stopband covers both the second and third optical telecommunication window (1250-1800 nm).     

Microcounseling Skill Discrimination Scale: A methodological note.

Absolute ratings on the Microcounseling Skill Discrimination Scale (MSDS) confound the individual's use of the rating scale (response language) and actual ability to discriminate effective and ineffective counselor behaviors. The present article suggests methods of scoring the MSDS that will eliminate variability attributable to response language and thereby improve the validity of the instrument. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personality traits: Fact or fiction? A critique of the Shweder and D'Andrade systematic distortion hypothesis.

According to R. A. Shweder and R. G. D'Andrade (1980; see also PA, Vol 64:9282), covariation in memory-based ratings of people's behavior is determined more by semantic relations between behavior categories than by actual co-occurrence. They claim therefore that the existence of personality traits is largely a fiction. Contrary to this hypothesis, it is argued that semantics are logically implicated in both the observation and recall of behavior and that support for this assumption can be found if immediate encodings of behavior are as sensitively scaled as subsequent memory-based ratings. Results of a study with 8 graduate students support this conclusion. When immediate encodings were scaled across all behavior categories, the relation between semantics and memory was completely explained by the role of semantics in the immediate encoding of behavior. However, when immediately encoded behavior was simply identified (rather than scaled), support for systematic distortion was obtained. Previous support for the systematic distortion hypothesis may therefore be attributed to the use of too simple a coding scheme for the measurement of immediate behavior. Implications for the existence of personality traits and for personality measurement are discussed. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are News Reports of Suicide Contagious? A Stringent Test in Six U.S. Cities

Past evidence of suicidal contagion from news reports in the United States is based largely on national data prior to 1980 using proxies for suicide stories rather than local news sources. Our research examined more proximal effects of suicide news reporting for 4 months in 1993 in 6 U.S. cities controlling for a wide range of alternative sources of media and interpersonal influence. In addition, predictions for the effect based on suicide contagion theories were examined for 3 age groups (15–25, 25–44, and older than 44). Local television news was associated with increased incidence of deaths by suicide among persons younger than 25 years. Newspaper reports were associated with suicide deaths for both young persons and persons older than 44 years. An unexpected protective effect of television news reports was observed in the 25–44 age range; nevertheless, news reporting was associated with an aggregate increase in suicide deaths. The results support theories of media contagion but also suggest that media depiction can inhibit suicide among some audience members.     

Group cohesiveness, social norms, and bystander intervention.

Previous research suggests that the larger a group of bystanders is, the less likely any one bystander is to offer a victim help in an emergency. Nearly all of this research has been conducted with unacquainted bystanders, and thus, an important group characteristic—cohesiveness—may have been held at a low level. Two studies with 192 male undergraduates assessed the impact of group cohesiveness on the bystander effect. Study 1 found support for the hypothesis that group size inhibits helping in low-cohesive groups but facilitates helping in high-cohesive groups. Study 2 found support for the hypothesis that the effects of cohesiveness on bystander intervention depend on the salience of the social-responsibility norm: Cohesiveness facilitated helping more when the social-responsibility norm was salient than when it was not. Thus, group cohesiveness is a theoretically critical variable for understanding bystander effect. Results suggest that the effects of group and situation variables depend on the group's meaning to the individual. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Physical and microstructural aspects of sulfate attack on ordinary and limestone blended Portland cements

The consequences of external sulfate attack were investigated by traditional test methods, i.e. length and mass change, as well as by a newly developed, surface sensitive ultrasonic method, using Leaky Rayleigh waves (1 MHz). The macroscopic changes are discussed and compared with thermodynamic calculations and microstructural findings (SEM/EDS). The results show that the main impact of limestone additions on resistance to sulfate degradation are physical — i.e. addition of a few percent in Portland cement reduces the porosity and increases the resistance of Portland cement systems to sulfate; but higher addition of 25% increase porosity and lower resistance to sulfate. The kinetics of degradation were dramatically affected by the solution concentration (4 or 44 g Na₂SO₄/l) and the higher concentration also resulted in the formation of gypsum, which did not occur at the low concentration. However the pattern of cracking was similar in both cases and it appears that gypsum precipitates opportunistically in pre-formed cracks so it is not considered as making a significant contribution to the degradation. At 8 °C limited formation of thaumasite occurred in the surface region of the samples made from cement with limestone additions. This thaumasite formation led to loss of cohesion of the paste and loss of material from the surface of the samples. However thaumasite formation was always preceded by expansion and cracking of the samples due to ettringite formation and given the very slow kinetics of thaumasite formation it was probably facilitated by the opening up of the structure due to ettringite induced cracking.The expansion of the samples showed a steady stage, followed by a rapidly accelerating stage, with destruction of the samples. The onset of the rapidly accelerating stage occurred when the thickness of the cracked surface layer reached about 1–1.5 mm–10–15% of the total specimen thickness (10 mm).     

Teen driver crash risk and associations with smoking and drowsy driving

Motor vehicle crashes are the leading cause of death for young people in the United States. The goal of this study was to identify risk factor profiles of teen and young adult drivers involved in crashes. General demographic and behavioral as well as driving-related factors were considered. Analysis of a nationally representative telephone survey of U.S. young drivers ages 14 to 22 (N = 900) conducted in 2005 was restricted to 506 licensed drivers (learners excluded). Statistically significant univariate associations between factors of interest and the primary outcome, crash involvement (ever) as a driver, were identified and included within a multivariate logistic regression model, controlling for potential demographic confounders. Aside from length of licensure, only driving alone while drowsy and being a current smoker were associated with having been in a crash. Gaining a better understanding of these behaviors could enhance the development of more customized interventions for new drivers.