Direct synthesis, growth mechanism, and optical properties of 3D AlN nanostructures with urchin shapes

Aluminum nitride (AƖN) nanostructures have shown novel physical and chemical properties that are essential for technological applications. We report a vapor-solid growth of novel three-dimensional (3D) A1N urchin-like nanostmcture in DC arc plasma via the direct reaction between Al vapor and N₂ gas without any catalyst or template. The as-prepared 3D A1N nanostructures which have urchin-like shapes consist of numerous microdaggers with sharp tips and lengths of up to several micrometers and widths of 0.5-2 µm. A growth mechanism of A1N nanostructures with urchin shapes was suggested and explained in detail. The optical properties of the AƖN nanostructures with urchin shapes were also studied with photoluminescence spectrum, which reveals a broad emission, suggesting potential applications in electronic and optoelectronic nanodevices.

Phenyl-type and C1 stationary phases for environmentally friendlier chromatography

C1 and phenyl-type stationary phases were assessed in terms of their environmental impact on separations using as test solutes polycyclic aromatic hydrocarbons. Methanol (MeOH) and acetonitrile (ACN) mobile-phase gradients were employed. These stationary phases were examined to determine if different physical and chemical properties possessed by these surfaces decreased the organic solvent consumption, and yet maintained peak capacity. The cumulative energy demand (CED) was used to gauge the environmental impact of the separations. The separation of the polycyclic aromatic hydrocarbon test mixture using current methodologies (i.e. a C18/ACN combination) had a CED of 1.13 MJ-eq, and a peak capacity of 27 peaks (resolving 7 of 12 peak pairs with R_s>1). In comparison, a butyl phenyl stationary phase with a methanol mobile phase had a peak capacity of 26, but with a CED of 0.670 MJ-eq. Monolithic columns containing C18 and C1 phases were also tested. A monolithic C18 column with MeOH had the lowest CED at 0.675 MJ-eq, a peak capacity of 28 peaks and good resolving power (resolving ten peak pairs with R_s>1), suggesting that this is a viable option with respect to reducing environmental impact for these types of analyses.

The use of molecular and morphological characters to resolve the taxonomic identity of cryptic species : the case of Miniopterus manavi (Chiroptera, Miniopteridae)

Based on recent molecular phylogenetic studies, the Old World bat family Miniopteridae, composed of species in the genus Miniopterus, has been shown to contain complex paraphyletic species, many of which are cryptic based on convergent morphological characters. Herein we resolve the phylogenetic relationships and taxonomy of the species complex M. manavi on Madagascar and in the Comoro Archipelago, where these animals occur in different bioclimatic zones. First using mitochondrial cytochrome-b sequence data to define clades and then morphology to corroborate the molecular data, including comparisons to type specimens, we demonstrate that animals identified as this taxon are a minimum of three species: M. manavi sensu stricto occurs in at least the central portion of the Central Highlands; M. griveaudi has a broad distribution in lowland northern and central western Madagascar and the Comoros (Anjouan and Grande Comore), and M. aelleni sp. n. has been found in northern and western Madagascar and the Comoros (Anjouan). In each case, these three clades were genetically divergent and monophyletic and the taxa are diagnosable based on different external and craniodental characters. One aspect that helped to define the systematics of this group was isolation of DNA from one of the paratypes of M. manavi collected in 1896 and new topotypic material. Miniopterus manavi is most closely allied to a recently described species, M. petersoni. At several localities, M. griveaudi and M. aelleni have been found in strict sympatry, and together with M. manavi sensu stricto show considerable convergence in morphological characters, but are not immediate sister taxa. In defining and resolving the systematics of cryptic species, such as miniopterid bats, the process of defining clades with molecular tools, segregating the specimens accordingly, and identifying corroborative morphological characters has been notably efficient.

Indigenous climate change adaption in the Port Philip Bay region : a longitudinal investigation into the physical and cultural transformation of the bay from an indigenous and landscape architectural perspective

Currently there is a dearth of research into Australian Indigenous knowledge and their understanding of climate change especially in regard to how it fits into their world view. Recent discussions by the National Climate Change Adaptation Research facility (NCCARF) have highlighted this deficiency but also the need to source relevant research projects that may address this knowledge and perspective, and enable the incorporation of Traditional ecological Knowledge into the planning climate change adaptions strategies in the Port Phillip Bay region thereby increasing their engagement in this discussion. Within this context, this paper examines the use and understanding of landscape, both urban and regional, surrounding Port Phillip Bay and the risks and opportunities climate change adaptation brings to the local Indigenous communities. It synthesises focused interviews with the (Wurundjeri (Yarra Valley), Wathaurong Geelong-Bellarine Peninsular) & Boon Wurrung (Mornington Peninsula)) to elicit a contemporary and local response to issues raised by NCCARF but importantly to articulate a possible Indigenous position about the formation, change and direction that Port Phillip Bay and its environs should take from their perspectives. Research draws upon how these communities have adapted to climate change physically, mentally and spiritually over their long habitation of a shared geological asset and their perceptions of climate change in respect to forecasting and adapting to climate change for this century. The project looks to uncover a longitudinal perspective of change and adaptation focused upon Indigenous views of ‘country’ and traditional custodial obligations to ‘country’ including accumulated cultural and environmental histories.

Utilizing polypropylene fibers to improve physical and mechanical properties of concrete

The influence of polypropylene fibers has been studied in different proportioning and fiber aspect ratios to improve physical and mechanical properties of fiber-reinforced concretes. Fibers are used in two different lengths (12 mm and 19 mm) and proportions (0.1% and 0.3%) in concrete mixture design. Hardened concrete properties, such as 7- and 28-day compressive strength, splitting tensile strength, flexural strength, water and air absorption, and restrained shrinkage cracking were evaluated.

No statistically significant effects were observed for polypropylene fibers on the compressive strength of concrete, while toughness indexes, splitting tensile and flexural strength and durability parameters showed an increase in the presence of polypropylene fibers. Increased fiber availability (fiber aspect ratio) in the concrete matrix, in addition to the ability of longer polypropylene fibers to bridge on the micro cracks, are suggested as the reasons for the enhancement in mechanical properties. Finally, crack width in fiber-reinforced concrete is calculated analytically with fiber property variables (fiber type, length, diameter and proportion). Results are compared with experimental values and concluded that with an increase in fiber length and/or decrease in fiber diameter crack width, decrease significantly.

Surface modification and properties analysis of shell powder with sodium stearate surface modifier

In this study, shell powder was modified by sodium stearate surface modifier for improving the compatibility of SP with polymer materials. The surface modifiers influence on the physical and chemical properties of SP were studied by scanning electron microscope(SEM), fourier infrared spectrum(FT-IR), surface contact angle meter, XRD diffraction analysis meter and other modern instruments and analysis method. The results showed that the surface modifier was successfully coupled to the shell powder surface. After surface modifier modification, the interfacial compatibility of the shell powder with polymer materials was effectively improved. The contact angle of shell powder surface increased from 73.5 ° to 110.8 °, along with the dosage of sodium stearate surface modifier was 4.0%. All results suggested that modified shell powder is promising for using as a reinforcement filler in polymer materials. © (2014) Trans Tech Publications, Switzerland.

Co-morbid depression and chronic illness related to coping and physical and mental health status

A partial latent structural regression analysis was used to evaluate the role of coping resources, depression, diet and exercise on mental and physical health status. The sample consisted of 113 participants (59 females and 54 males) with a mean age of 59.38 years (SD = 10.52). Coping resources, depression and exercise explained 52 and 26% of the variance in mental and physical health status, respectively. Fewer coping resources predicted higher levels of depression and both predicted worse mental health. Only higher levels of depression predicted worse physical health status. There were also significant indirect effects of coping on mental and physical health status through depression. The development of cognitive, social and emotional coping strategies is important for managing depression and supporting positive mental health. These results highlight the important role of health psychologists in the care of individuals with chronic illness. Additionally, the management of depression is important in maintaining positive physical health.

In-situ and tunable nitrogen-doping of MoS2 nanosheets.

Molybdenum disulfide (MoS2) nanosheets have unique physical and chemical properties, which make it a perfect candidate for next generation electronic and energy storage applications. Herein, we show the successful synthesis of nitrogen-doped MoS2 nanosheets by a simple, effective and large-scale approach. MoS2 nanosheets synthesised by this method show a porous structure formed by curled and overlapped nanosheets with well-defined edges. Analysis of the nanosheets shows that they have an enlarged interlayer distance and high specific surface area. X-ray photoelectron spectroscopy analysis shows the nanosheets have Mo-N bond indicating successful nitrogen doping. The nitrogen content of the product can be modulated by adjusting the ratio of starting materials easily within the range from ca. 5.8 to 7.6 at%.

Physical and psychosocial wellbeing of nurses in a regional Queensland hospital

Occupational stress is common among nurses. Two factors that may influence stress levels are diet and physical activity. The purpose of this study was to investigate the diets and physical activity levels of nurses and to quantify the relationships between these behaviours and anxiety, depressed mood, stress, and burnout. Nurses (N = 52) from one regional hospital completed a survey assessing physical activity, nutrition, and psychological functioning. Almost two-thirds (65%) of participants had met recommended levels of both moderate and vigorous physical activity in the week prior. Participants met recommended levels for fruit, but not vegetable, consumption. Burnout and stress levels were close to norms for physicians and nurses. Scores for depressed mood, anxiety, and stress symptoms were within one standard deviation of norms for the Australian adult population. Several moderately sized correlations were found between the psychological constructs measured and both physical activity and nutrition. Although most of the participants were physically active and seemed to be consuming nutritious diets, some nurses may need encouragement to adopt similarly healthy behaviours.