38 resultados para Highest occupied molecular orbital energy levels

em Deakin Research Online - Australia


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In this paper, a new amino acid derivative, namely Adenine-L-Alanine ramification (ALAR) was synthesized and investigated as a green corrosion inhibitor for X80 pipeline steel in 0.1 mol/L hydrochloric acid solution using the weight loss, AC impedance, and polarization curve method. The structure of the derivative was characterized by IR and UV–vis spectrum. The weight loss and AC impedance found that the inhibition efficiency increased with the increase in concentration of the inhibitor but decreased with rise in temperature, the corrosion inhibition efficiency attains 91.26% in 8 × 10−2 g/L concentration at 30 °C. The polarization studies showed that the studied amino acid derivative can be used as a corrosion inhibitor. The surface of inhibited and uninhibited specimens was analyzed by scanning electron microscopy and the adsorption of the inhibitor on the mild steel surface obeys Langmuir adsorption isotherm. The quantum chemical descriptors such as the energy of highest occupied molecular orbital, energy of lowest unoccupied molecular orbital were calculated and the inhibition mechanism can be analyzed by the distribution of electrons. Analysis indicated that the inhibitor molecular and empty d orbital of metal forms the coordination bond, covers on the surface of metal, and prevents corrosion reaction.

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A class of new conjugated copolymers containing a donor (thiophene)−acceptor (2-pyran-4-ylidene-malononitrile) was synthesized via Stille coupling polymerization. The resulting copolymers were characterized by 1H NMR, elemental analysis, GPC, TGA, and DSC. UV−vis spectra indicated that the increase in the content of the thiophene units increased the interaction between the polymer main chains to cause a red-shift in the optical absorbance. Cyclic voltammetry was used to estimate the energy levels of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) and the band gap (Eg) of the copolymers. The basic electronic structures of the copolymers were also studied by DFT calculations with the GGA/B3LYP function. Both the experimental and the calculated results indicated an increase in the HOMO energy level with increasing the content of thiophene units, whereas the corresponding change in the LUMO energy level was much smaller. Polymer photovoltaic cells of a bulk heterojunction were fabricated with the structure of ITO/PEDOT/PSS (30 nm)/copolymer−PCBM blend (70 nm)/Ca (8 nm)/Al (140 nm). It was found that the open-circuit voltage (Voc) increased (up to 0.93 V) with a decrease in the content of thiophene units. Although the observed power convention efficiency is still relatively low (up to 0.9%), the corresponding low fill factor (0.29) indicates considerable room for further improvement in the device performance. These results provided a novel concept for developing high Voc photovoltaic cells based on donor-π-acceptor conjugated copolymers by adjusting the donor/acceptor ratio.

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Replacement of precious Pt catalyst with cost-effective alternatives would be significantly beneficial for hydrogen production via electrocatalytic hydrogen evolution reaction (HER). All candidates thus far are exclusively metallic catalysts, which suffer inherent corrosion and oxidation susceptibility during acidic proton-exchange membrane electrolysis. Herein, based on theoretical predictions, we designed and synthesized nitrogen (N) and phosphorus (P) dual-doped graphene as a nonmetallic electrocatalyst for sustainable and efficient hydrogen production. The N and P heteroatoms could coactivate the adjacent C atom in the graphene matrix by affecting its valence orbital energy levels to induce a synergistically enhanced reactivity toward HER. As a result, the dual-doped graphene showed higher electrocatalytic HER activity than single-doped ones and comparable performance to some of the traditional metallic catalysts.

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Background: Active commuting to school may be an important opportunity for children to accumulate adequate physical activity for improved cardiovascular risk factors, enhanced bone health, and psychosocial well-being. The purpose of this study was to examine personal, family, social, and environmental correlates of active commuting to school among children. Methods: Cross-sectional study of 235 children aged 5 to 6 years and 677 children aged 10 to 12 years from 19 elementary schools in Melbourne, Australia. Self-administered questionnaires were completed by parents, and the older children. The shortest possible routes to school were examined using a geographic information system. Results: Among both age groups, negative correlates of active commuting to school included parental perception of few other children in the neighborhood and no lights or crossings for their child to use, and an objectively assessed busy road barrier en route to school. In younger children, an objectively assessed steep incline en route to school was negatively associated with walking or cycling to school. Good connectivity en route to school was negatively associated with walking or cycling to school among older children. Among both age groups, children were more likely to actively commute to school if their route was <800 meters. There were no associations with perceived energy levels or enjoyment of physical activity, weight status, or family factors. Conclusions: For children, creating child-friendly communities and providing skills to safely negotiate the environment may be important. Environmental correlates of active transport in children and adults may differ and warrant further investigation.

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A novel fabrication process for advanced composite components—the QuicktepTM process was described. 2/2 twill weave MTM56/CF0300 carbon epoxy composite laminates were manufactured by the Quickstep and the autoclave processes. The response of these laminates to drop-weight low velocity impact at energy levels ranging from 5 to 30 J was investigated. It was found that the laminates fabricated by the Quickstep had better impact damage tolerance than those fabricated by the autoclave. Optical microscopy revealed extensive matrix fracture in the center of the backside of the autoclave laminates indicating the more brittle property of the epoxy matrix cured by the autoclave process. Interfacial shear strength (IFSS) for two composite systems were measured by micro–debond experiments. The MTM56/CF0300 material cured by the Quickstep showed stronger fibre matrix adhesion. Since the thickness and density of the impact targets produced by two processes were different, finite element analysis (FEA) was performed to study the effect of these factors on the impact response. The simulation results showed that the difference in thickness and density affects the stress distribution under impact loading. Higher thickness and lower density caused by processing lead to less endurance to drop weight impact loading. Therefore the better performance of Quickstep laminates under impact loading was not due to the thickness and density change, but resulted from stronger mechanical properties.

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Wireless sensor networks (WSN) are attractive for information gathering in large-scale data rich environments. In order to fully exploit the data gathering and dissemination capabilities of these networks, energy-efficient and scalable solutions for data storage and information discovery are essential. In this paper, we formulate the information discovery problem as a load-balancing problem, with the combined aim being to maximize network lifetime and minimize query processing delay resulting in QoS improvements. We propose a novel information storage and distribution mechanism that takes into account the residual energy levels in individual sensors. Further, we propose a hybrid push-pull strategy that enables fast response to information discovery queries.

Simulations results prove the proposed method(s) of information discovery offer significant QoS benefits for global as well as individual queries in comparison to previous approaches.

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The present invention relates to nucleic acid molecules which encode expression products associated with the modulation of obesity, anorexia, weight maintenance, diabetes and/or metabolic energy levels. The nucleic acid molecules and expression products of the present invention are produced by recombinant means or isolated from natural resources. The subject nucleic acid molecules and expression products and their derivatives, homologs, analogs and mimetics are proposed to be useful as therapeutic and diagnostic agents for obesity, anorexia, weight maintenance, diabetes and/or energy imbalance or as targets for the design and/or identification of modulators of their activity and/or function. The subject nucleic acid molecules and expression products are identified using differential display techniques.

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In this research I investigated ecological attributes of Powerful Owls (Ninox strenua) in a continuum of habitats throughout the Yarra Valley corridor of Victoria, Australia. These habitats ranged from a highly urbanized parkland (the Yarra Valley Metropolitan Park) to a relatively undisturbed closed forest (Toolangi State Forest). Different aspects of the owls' ecology were investigated at six sites to determine whether their behaviour changed when they occupied habitats with different levels of urbanization and disturbance. The ecological attributes investigated were habitat utilization and habitat requirements (for both roosting and nesting), adult behaviour (through radio-tracking), juvenile behaviour and dispersal (through radio tracking), diet (through analysing regurgitated food pellets) and breeding success rates. A number of methods were used to capture adult Powerful Owls. These are described and their effectiveness discussed. The types of radio-transmitters and colour bands used for identification of owls are also described. The results showed that Powerful Owls are present and successfully breed in urban and suburban areas and that they can tolerate moderate levels of disturbance. However, Powerful Owls do require sites with high prey densities, roost trees and trees with suitable breeding hollows. In comparison with Powerful Owls living elsewhere in forests, the urban owls displayed higher tolerance levels to disturbance and were less selective in terms of habitat usage and diet. Home range sizes of urban Powerful Owls also appeared much smaller than those of the forest-dwelling Powerful Owls. This is probably due to the high prey densities in the urban areas. The ecology of the Powerful Owl is compared with that of two owl species from North America, the Northern Spotted Owl (Strix occidentalis caurind) and the Great Horned Owl (Bubo virginianus). In particular, I compared the similarities and differences in habitat requirements and breeding successes in different habitats for the three species. Overall, it would appear that urban areas can support Powerful Owls providing some old-growth trees are maintained to provide nest hollows. Implications for the long-term management of Powerful Owls in urban areas are also discussed.

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The aim of the present investigation was to determine the orientation dependence of substructure characteristics in an austenitic Fe−30wt%Ni model alloy subjected to hot plane strain compression. Deformation was carried out at a temperature of 950 °C using a strain rate of 10 s−1 to equivalent strain levels of approximately 0.2, 0.4, 0.6 and 0.8. The specimens obtained were analysed using a fully automatic electron backscatter diffraction technique. The crystallographic texture was characterized for all the strain levels studied and the subgrain structure was quantified in detail at a strain of 0.4. The substructure characteristics displayed pronounced orientation dependence. The major texture components, namely the copper, S, brass, Goss and rotated Goss, generally contained one or two prominent families of parallel larger-angle extended subboundaries, the traces of which on the longitudinal viewing plane appeared systematically aligned along the {111} slip plane traces, bounding long microbands subdivided into slightly elongated subgrains by short lower-angle transverse subboundaries. Relatively rare cube-orientated grains displayed pronounced subdivision into coarse deformation bands containing large, low-misorientated subgrains. The misorientation vectors across subboundaries largely showed a tendency to cluster around the sample transverse direction. Apart from the rotated Goss texture component, the stored energy levels for the remaining components were principally consistent with the corresponding Taylor factor values.

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The present invention relates generally to a nucleic acid molecule which encodes a protein associated with the modulation of obesity, diabetes and metabolic energy levels. More particularly, the present invention is directed to a nucleic and a recombinant and purified naturally occurring protein encoded thereby and their uses in therapeutic and diagnostic protocols for conditions such as obesity, diabetes and energy imbalance. The subject nucleic acid molecule and protein and their derivatives, homologues, analogues and mimetics are proposed as therapeutic and diagnostic agents for obesity, diabetes and energy imbalance.

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The present invention relates generally to a nucleic acid molecule which encodes a protein associated with the modulation of obesity, diabetes and metabolic energy levels. More particularly, the present invention is directed to a nucleic and a recombinant and purified naturally occurring protein encoded thereby and their uses in therapeutic and diagnostic protocols for conditions such as obesity, diabetes and energy imbalance. The subject nucleic acid molecule and protein and their derivatives, homologues, analogues and mimetics are proposed as therapeutic and diagnostic agents for obesity, diabetes and energy imbalance.

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The present invention relates generally to a nucleic acid molecule which encodes a protein associated with the modulation of obesity, diabetes and metabolic energy levels. More particularly, the present invention is directed to a nucleic and a recombinant and purified naturally occurring protein encoded thereby and their uses in therapeutic and diagnostic protocols for conditions such as obesity, diabetes and energy imbalance. The subject nucleic acid molecule and protein and their derivatives, homologues, analogues and mimetics are proposed as therapeutic and diagnostic agents for obesity, diabetes and energy imbalance.

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Describes a method that relates generally to a nucleic acid molecule which encodes a protein associated with the modulation of obesity, diabetes and metabolic energy levels. More particularly, the present method is directed to a nucleic acid molecule and a recombinant and purified naturally occurring protein encoded thereby and their use in therapeutic and diagnostic protocols for conditions such as obesity, diabetes and energy imbalance. The subject nucleic acid molecule and protein and their derivatives, homologues, analogues and mimetics are proposed as therapeutic and diagnostic agents for obesity, diabetes and energy imbalance.

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The present invention relates generally to a nucleic acid molecule which encodes a protein associated with the modulation of obesity, diabetes and metabolic energy levels. More particularly, the present invention is directed to a nucleic and a recombinant and purified naturally occurring protein encoded thereby and their uses in therapeutic and diagnostic protocols for conditions such as obesity, diabetes and energy imbalance. The subject nucleic acid molecule and protein and their derivatives, homologues, analogues and mimetics are proposed as therapeutic and diagnostic agents for obesity, diabetes and energy imbalance.

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The present invention relates generally to a nucleic acid molecule which encodes a protein associated with the modulation of obesity, diabetes and metabolic energy levels. More particularly, the present invention is directed to a nucleic and a recombinant and purified naturally occurring protein encoded thereby and their uses in therapeutic and diagnostic protocols for conditions such as obesity, diabetes and energy imbalance. The subject nucleic acid molecule and protein and their derivatives, homologues, analogues and mimetics are proposed as therapeutic and diagnostic agents for obesity, diabetes and energy imbalance.