Early deuteration steps of Pd- and Ta/Pd- catalyzed Mg70Al30 thin films observed at room temperature

Deuterium absorption in Mg₇₀Al₃₀ thin films coated with a Pd layer and a Ta/Pd bilayer were investigated using in situ neutron reflectometry at room temperature and deuterium pressures up to 1.3 bar. The approach used provides a detailed profile, at the nanoscale, of the deuterium content inside the specific layers that constitute the films. It is found that Mg₇₀Al₃₀ can store up to 5 wt.% under these mild conditions following a two-step mechanism. The latter involves the deuteration of the top and bottom catalyst layers first, followed by the main Mg₇₀Al₃₀ layer. The presence of deuterium throughout the films in the early absorption stages evidences atomic deuterium spillover from the catalyst layers. The addition of a Ta layer between the Pd and Mg₇₀Al₃₀ was found to allow observable absorption at a pressure 10 times lower than on the Ta-free sample, without affecting the storage capacity. Our measurements imply that this improvement in kinetics is due to a lowering of the nucleation barrier for the formation of the hydride phase in the Mg₇₀Al₃₀ layer.     

Autodetection of ancient Arabian tombs in high-resolution satellite imagery

High circular tombs (HCTs) in southern Arabia provide valuable information for anthropologists who seek fundamental understanding of the transition of ancient peoples from a nomadic pastoral lifestyle, to agro-pastoralism, and eventually to the formation of ancient states. In particular, knowing the geographical distribution of HCTs across the region informs theories on patterns of territoriality and environmental and social factors that are implicated in the emergence of ancient civilizations.

The small size of the HCTs, vast search regions, and rugged terrain make mapping them in the field difficult and costly. In this article, a detection algorithm is described and quantitatively evaluated and establishes the feasibility of automatically detecting these tombs in satellite imagery. By narrowing the search to a smaller set of candidate locations, wide area discovery and mapping can be performed much more effectively.     

Linear approximations of muscle mechanics in isometric contraction

The relationship of sensitivity and specificity to disease frequency is considered in quantitative detail for typical screening situations. It is shown by illustrative examples that most screening procedures applied unselectively to total populations will yield a vast abundance of false positive results. The important role of prior probability in interpreting diagnostic test results is spelled out and applied to paradigms for screening.     

Pulsed-plasma gas-discharge inactivation of microbial pathogens in chilled poultry wash water

A pulsed-plasma gas-discharge (PPGD) system was developed for the novel decontamination of chilled poultry wash water. Treatment of poultry wash water in the plasma generation chamber for up to 24 s at 4 degrees C reduced Escherichia coli NCTC 9001, Campylobacter jejuni ATCC 33560, Campylobacter coli ATCC 33559, Listeria monocytogenes NCTC 9863, Salmonella enterica serovar Enteritidis ATCC 4931, and S. enterica serovar Typhimurium ATCC 14028 populations to non-detectable levels (< or = 8 log CFU/ml). Although similar PPGD treatments at 4 degrees C also produced significant reductions (> or = 3 log CFU/ml) in recalcitrant B. cereus NCTC 11145 endospore numbers within 30 s, the level of endospore reduction was dependent on the nature of the sparged gas used in the plasma treatments. Scanning electron microscopy revealed that significant damage occurred at the cellular level in PPGD-treated test organisms. This electrotechnology delivers energy in intense ultrashort bursts, generating products such as ozone, UV light, acoustic and shock waves, and pulsed electric fields that have multiple bactericidal properties. This technology offers an exciting complementary or alternative approach for treating raw poultry wash water and for preventing cross-contamination in processing environments.     

Thyroxine and triiodothyronine levels in hyperthyroid patients during treatment with propranolol

In the last few years, there has been an active effort in Italy to involve the population in solving health problems at the community level. This movement had its origin in the industrial setting, where workers succeeded in promoting legislation which gives them control over matters affecting their health. This experience lead to the development of a health education methodology based on the following principles: (a) the assessment of health needs must be based on the subjective experience of the people who have acquired knowledge and interest in health problems; (b) the evaluation of health needs by professionals serves to complement and integrate the assessment of needs as experienced by the community; (c) the self-diagnosis of the community -- in particular of homogenous community groups exposed to similar health risks and experiencing the same needs--and the diagnosis of the professionals must undergo cross-validation and be accepted by both parties; (d) on the basis of this mutual agreement, community health programmes should be planned and carried out jointly by the professionals and the people.     

An overview of the Central Queensland University self-contained evapotranspiration beds.

The Central Queensland University (CQU) has championed a self-contained concrete lined evapotranspiration channel. Any non-transpired effluent returns to a holding tank and is recirculated through the evapotranspiration channel until it is used. This paper examines the results from the Rockhampton trial site. Nutrient ions in the effluent were quantified over time and found not to accumulate in solution. Microbial analysis of the treated effluent was performed and was found to be within the ranges required by the relevant legislative codes. Citrus fruit grown in the evapotranspiration channel were sampled and no elevated levels of faecal coliforms were recorded. Macronutrients and micronutrients of the soil in the channels were measured over a 5-year period. No toxic accumulations or nutrient deficiencies in the soil occurred. Levels of salinity and sodicity in the evapotranspiration channel soil were quantified. Salinity rose slightly, as did sodium. Concentrations of salts and sodium did not reach unsustainable levels. The aim of the trial was to develop an on-site treatment and reuse system that is sustainable and protects public and environmental health.     

Hydrogen storage in binary and ternary Mg-based alloys: A comprehensive experimental study

This study focused on hydrogen sorption properties of 1.5 μm thick Mg-based films with Al, Fe and Ti as alloying elements. The binary alloys are used to establish as baseline case for the ternary Mg–Al–Ti, Mg–Fe–Ti and Mg–Al–Fe compositions. We show that the ternary alloys in particular display remarkable sorption behavior: at 200 °C the films are capable of absorbing 4–6 wt% hydrogen in seconds, and desorbing in minutes. Furthermore, this sorption behavior is stable over cycling for the Mg–Al–Ti and Mg–Fe–Ti alloys. Even after 100 absorption/desorption cycles, no degradation in capacity or kinetics is observed. For Mg–Al–Fe, the properties are clearly worse compared to the other ternary combinations. These differences are explained by considering the properties of all the different phases present during cycling in terms of their hydrogen affinity and catalytic activity. Based on these considerations, some general design principles for Mg-based hydrogen storage alloys are suggested.     

A. R. Luria: A personal remembrance.

A research assistant to Koffka remembers Alexander Romanovich Luria, whom she met in 1932 when he invited Koffka to take part in a Soviet-organized, psychologically oriented expedition to Uzbekistan to study thinking patterns of the Uzbek natives prior to their incorporation in the USSR. (0 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)