Synthesis and Photocatalytic Properties of Single Crystalline (Ga1-xZnx)(N1-xOx) Nanotubes

Recently, (Ga_1-xZn_x)(N_1-xO_x) has gained widespread attention as a comparatively high efficiency photocatalyst for visible-light-driven overall water splitting. Despite significant gains in efficiency over the past several years, a majority of the photogenerated carriers recombine within bulk powders. To improve the photocatalytic activity, we used an epitaxial casting method to synthesize single-crystalline, high surface area (Ga_1-xZn_x)(N_1-xO_x) nanotubes with ZnO compositions up to x=0.10. Individual nanotubes showed improved homogeneity over powder samples due to a well defined epitaxial interface for ZnO diffusion into GaN. Absorption measurements showed that the ZnO incorporation shifts the absorption into the visible region with a tail out to 500 nm. Gas chromatography (GC) was used to compare the solar water splitting activity of (Ga_1-xZn_x)(N_1-xO_x) nanotubes (x=0.05–0.10) with similar composition powders. Cocatalyst decorated samples were dispersed in aqueous solutions of CH₃OH and AgO₂CCH₃ to monitor the H⁺ reduction and H₂O oxidation half reactions, respectively. The nanotubes were found to have approximately 1.5–2 times higher photocatalytic activity than similar composition powders for the rate limiting H⁺ reduction half reaction. These results demonstrate that improvements in homogeneity and surface area using the nanotube geometry can enhance the photocatalytic activity of GaN:ZnO for solar water splitting.     

The Japanese Photographers of Broome: Photography and Cross-Cultural Encounter

The remote West Australian town of Broome has a unique photography heritage that sheds new light on the complexities of photography and intercultural relations. During the early twentieth century thriving Japanese communities were established in this region around the lucrative pearling industry. These Japanese communities also helped to develop a fascinating photography culture in Broome. Photography was not simply a business opportunity for the Japanese or a means of documenting people and events; it was a medium through which hierarchised social relations were produced, redefined, and challenged. This article examines photographs by these Japanese residents as an important site of cross-cultural communication and interpretation. These photographs of Anglo-Australian, Japanese, and Aboriginal residents of Broome enrich the study of cross-cultural photographic encounters, and emphasise the dynamic and dispersed qualities of Australian photographic practice and history. Here national histories of photography are usefully conceptualised as the products of imbricated social, economic, and cultural relations that operate across regional, national, and international realms.     

Local Notions of Healthy Eating and National Dietary Guidelines: A Comparison in Vulnerable Salvadoran Communities

This study presents an assessment of local definitions and perceptions concerning healthy eating through a study in four resource-poor border communities in El Salvador. The study included focus groups, key-informant interviews, and observations of the food environment. Local definitions of healthy eating elicited through focus groups were compared to the national Salvadoran dietary guidelines recommendations. The comparison revealed several areas of overlap (including the importance of dietary variety, fruits, and vegetables, among others) and omissions (mention of limiting sweets/candy, salt, sugar, and alcohol). Focus group participants expressed concerns over the origin of their foods and whether food contained harmful chemicals. These conversations also revealed the contradictions between nutrition knowledge and preferences for foods classified as unhealthy. This article concludes with a discussion about barriers to healthy eating identified in the focus groups and through the food environment assessment.     

A neural approach for estimation of per capita electricity consumption due to age and income

Electricity consumption is influenced by number of adults and children and their relationship at household level. Household income also plays a critical role on expenditure on electricity. Accordingly, this article presents a joint probability model of electricity demand based on occupants’ age grades and household income levels. A bottom-up strategy is developed using a micro level database of 70 Australian households. A neural regression-generalization technique is devised to estimate electricity demand using back-propagation and cognitive mapping. The aggregated result is then validated against 2012 Australian national census. Accordingly, the model is improved based on a top-down review. The results show per capita electricity demand by adult and child at 0.408 kW (69 kWh/week) and 0.226 kW (38 kWh/week), respectively. The equivalent dollar values are $13.6/week and $7.6/week in 2012. At macro level, the model reveals per capita demand by all individuals at 0.324 kW (54.35 kWh/week) equivalent to dollar value of $10.87/week, across Australia. The results also show higher percentage of per capita demand for adults in high and medium income classes, and the otherwise for low income class. Ratio of child’s demand over adult’s demand is highest among the low income households, and lowset among the middle income households, while best balance between adult and child per capita demand belongs to the high income.

     

Optical and electrical characterization of a gold nanoparticle dispersion in a chiral liquid crystal matrix

We report on the effect of gold nanoparticle (Au NP) dispersion in a chiral nematic liquid crystal (LC). Polarized optical microscopy and X-ray diffraction measurements evidence the insurgence of an order change in the LC host. Moreover, a comparative analysis based on dielectric and voltammetric spectroscopies performed on pure LC and on Au NP-doped LC shows that Au NP’s presence besides affecting LC order influences its electric properties: ion conductivity results importantly reduced, and beyond a threshold value of the applied field electrophoresis phenomena are induced.     

Silicone membranes to inhibit water uptake into thermoset polyurethane shape‐memory polymer conductive composites

Electroactive shape memory polymer (SMP) composites capable of shape actuation via resistive heating are of interest for various biomedical applications. However, water uptake into SMPs will produce a depression of the glass transition temperature (T_g) resulting in shape recovery in vivo. While water actuated shape recovery may be useful, it is foreseen to be undesirable during early periods of surgical placement into the body. Silicone membranes have been previously reported to prevent release of conductive filler from an electroactive polymer composite in vivo. In this study, a silicone membrane was used to inhibit water uptake into a thermoset SMP composite containing conductive filler. Thermoset polyurethane SMPs were loaded with either 5 wt % carbon black or 5 wt % carbon nanotubes, and subsequently coated with either an Al₂O₃‐ or silica‐filled silicone membrane. It was observed that the silicone membranes, particularly the silica‐filled membrane, reduced the rate of water absorption (37°C) and subsequent T_g depression versus uncoated composites. In turn, this led to a reduction in the rate of recovery of the permanent shape when exposed to water at 37°C. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41226.     

Developing and Maintaining an Inspection-Ready Pipeline Safety Program

For the past several decades, pipeline incidents have resulted in highly publicized accounts of property damage, environmental harm, neighborhood destruction, serious injury, and death.     

Activity of Fluorine‐Containing Analogues of WC‐9 and Structurally Related Analogues against Two Intracellular Parasites: Trypanosoma cruzi and Toxoplasma gondii

Two obligate intracellular parasites, Trypanosoma cruzi, the agent of Chagas disease, and Toxoplasma gondii, an agent of toxoplasmosis, upregulate the mevalonate pathway of their host cells upon infection, which suggests that this host pathway could be a potential drug target. In this work, a number of compounds structurally related to WC‐9 (4‐phenoxyphenoxyethyl thiocyanate), a known squalene synthase inhibitor, were designed, synthesized, and evaluated for their effect on T. cruzi and T. gondii growth in tissue culture cells. Two fluorine‐containing derivatives, the 3‐(3‐fluorophenoxy)‐ and 3‐(4‐fluorophenoxy)phenoxyethyl thiocyanates, exhibited half‐maximal effective concentration (EC₅₀) values of 1.6 and 4.9 μm , respectively, against tachyzoites of T. gondii, whereas they showed similar potency to WC‐9 against intracellular T. cruzi (EC₅₀ values of 5.4 and 5.7 μm , respectively). In addition, 2‐[3‐ (phenoxy)phenoxyethylthio]ethyl‐1,1‐bisphosphonate, which is a hybrid inhibitor containing 3‐phenoxyphenoxy and bisphosphonate groups, has activity against T. gondii proliferation at sub‐micromolar levels (EC₅₀=0.7 μm ), which suggests a combined inhibitory effect of the two functional groups.     

Veteran interest in family involvement in PTSD treatment.

[Correction Notice: An erratum for this article was reported in Vol 7(3) of Psychological Services (see record 2010-17074-004). The copyright for the article was listed incorrectly. This article is in the Public Domain. The online version has been corrected.] The present study examined interest in family involvement in treatment and preferences concerning the focus of family oriented treatment for veterans (N = 114) participating in an outpatient Veterans Affairs outpatient posttraumatic stress disorder (PTSD) program. Most veterans viewed PTSD as a source of family stress (86%) and expressed interest in greater family involvement in their treatment (79%). These results suggest the need to consider increasing family participation in the clinical care of individuals with PTSD and to develop specialized family educational and support services for this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of Viscoelasticity and HIV Transport as a Function of pH in a Reversibly Crosslinked Hydrogel

Materials that respond to physiological stimuli are important in developing advanced biomaterials for modern therapies. The reversibility of covalent crosslinks formed by phenylboronate (PBA) and salicylhydroxamate (SHA) has been exploited to provide a pH‐responsive gel for application to the vaginal tract. Dynamic rheology reveals that the gel frequency‐dependent viscoelastic properties are modulated by pH. At pH 4.8 the viscous component dominates throughout most of the frequency range. As the pH increases, the characteristic relaxation time continues to increase while the G′_Plateau levels off above pH 6. At pH 7.5, the elastic component dominates throughout the frequency sweep and is predominately independent of frequency. Particle tracking assesses the transport of both fluorescently labeled HIV‐1 and 100‐nm latex particles in the PBA–SHA crosslinked gel as a function of pH. At pH 4.8 the ensemble‐averaged mean squared displacement at lag times greater than three seconds reveals that transport of the HIV‐1 and 100‐nm particles becomes significantly impeded by the matrix, exhibiting diffusion coefficients less than 0.0002 µm² s^?1. This pH‐responsive gel thus displays properties that have the potential to significantly reduce the transport of HIV‐1 to susceptible tissues and thus prevent the first stage of male‐to‐female transmission of HIV‐1.