New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity

Highly porous, In filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit ZT 1 and corresponding dense samples were fabricated through the cost effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering PECS method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In NO3 3.5H2O separately and in a mixture. Two methods to synthesise the same material were examined a free sintering of an initially reduced powder and b PECS. The free sintered materials with higher porosities up to 40 exhibited lower values of electrical conductivity than the dense PECS samples porosity up to 5 , but the benefit of an even sixfold reduction in thermal conductivity resulted in higher ZT values. The theoretical values of thermal conductivity for various effective media models considering randomly oriented spheroid pores are in good agreement with the experimental thermal conductivity data. The assumed distribution and shape of the pores correlated well with the scanning electron microscope analysis of the microstructure. The lowest value of thermal conductivity, equal to 0.5 W m K, was measured at 523 K for In0.1Co4Sb12 with 41 porosity. The highest value of ZTmax 1.0 at 673 K was found for the In0.2Co4Sb12 sample in which the porosity was 3

Shady business: understanding the spatial ecology of exophilic Anopheles mosquitoes

Background: Understanding the ecology of exophilic anophelines is a key step toward developing outdoor control strategies to complement existing indoor control tools against malaria vectors. This study was conducted to assess the movement pattern of exophilic Anopheles mosquitoes between blood meal sources and resting habitats, and the landscape factors dictating their resting habitat choice. Results: Resting clay pots were placed at 5 m, 25 m, 50 m, 75 m and 100 m away from isolated focal houses, radiating from them in four directions. The locations of the clay pots represent heterogeneous land cover types at a relatively fine spatial scale in the landscape. The effect of the landscape characters on the number of both female and male anophelines caught was modelled using zero-inflated negative binomial regression with a log link function. A total of 420 Anopheles mosquitoes (353 females and 67 males) belonging to three species; Anopheles arabiensis, Anopheles pharoensis, and Anopheles tenebrosus were caught in the resting clay pots, with An. arabiensis being the dominant species. Canopy cover, distance from the house, and land cover type were the significant landscape characters influencing the aggregation of resting mosquitoes. Both the count and binary models showed that canopy cover was the strongest predictor variable on the counts and the presence of Anopheles mosquitoes in the clay pots. Female Anopheles were most frequently found resting in the pots placed in banana plantations, and at sampling points that were at the greater distances (75 m and 100 m) from the focal house. Conclusions: This study showed that exophilic Anopheles mosquitoes tend to rest in shaded areas some distance away from human habitation. These findings are important when targeting mosquitoes outdoors, complementing the existing effort being made to control malaria vectors indoors

Causes and proposed resolutions of high vibration in NWTF transfer pumps

This Technical Report is intended to communicate the findings from the latest phase of New Waste Transfer Facility (NWTF) transfer pump testing. These tests have identified causes for the high pump vibrations that have been observed during previous phases of transfer pump startup testing, and have led to recommendations for resolving the vibration problem. The paper describes the problem, the test methodology, observations, and recommend actions to correct the vibration problem

The spectatorship of portraits by naïve beholders

The spectatorship of portraits by naïve viewers (beholders) was explored in a singleexperiment. Twenty-five participants rated their liking for 142 portraits painted by Courbet (36 paintings), Fantin-Latour (36 paintings) and Manet (70 paintings) on a 4-point Likert scale. The portraits were classified in terms of focussed versus ambiguous nature of sitter gaze and the presence of salient features in the context beyond sitters. Participants rated portraits while having their eye movements recorded. The portraits were split into regions of interest (ROIs) defined by faces, bodies and context. Participants also completed individual difference measures of attention and task focus. Results showed naïve spectatorship to be subject to attentional capture by faces. Paradoxically, the presence of salient features in the context amplified the attentional capture by faces through increasing participants liking of portraits. Attentional capture by faces was also influenced by sitter gaze and task focus. Unsurprisingly, the spectatorship of portraits by naïve beholders is dominated by faces, but the extent of this dominance is influenced by exogenous and endogenous attentional factors