Showing papers by "University of Wollongong published in 2013"
TL;DR: Wet-spinning of composite formulation based on functionalized PEG-SWNT and PEDOT:PSS shows outstanding mechanical, electrical and electrochemical performances that place these fibers among the best performing multifunctional composite fibers.
Abstract: With the aim of fabricating multifunctional fibers with enhanced mechanical properties, electrical conductivity and electrochemical performance, we develop wet-spinning of composite formulation based on functionalized PEG-SWNT and PEDOT:PSS. The method of addition and loading are directly correlated to the quality and the ease of spinnability of the formulation and to the mechanical and electrical properties of the resultant fibers. Both the fiber modulus (Y) and strength (σ) scaled linearly with PEG-SWNT volume fraction (Vf). A remarkable reinforcement rate of dY/dVf = 417 GPa and dσ/dVf = 4 GPa were obtained when PEG-SWNTs at Vf ≤ 0.02. Further increase of PEG-SWNTs loading (i.e. up to Vf 0.12) resulted in further enhancements up to 22.8 GPa and 254 MPa in Modulus and ultimate stress, respectively. We also show the enhancement of electrochemical supercapacitor performance of composite fibers. These outstanding mechanical, electrical and electrochemical performances place these fibers among the best performing multifunctional composite fibers.
681 citations
TL;DR: A ten-item instrument for the measurement of the three types of cognitive load is presented and a three-component solution is revealed, consistent with the types of load that the different items were intended to measure.
Abstract: According to cognitive load theory, instructions can impose three types of cognitive load on the learner: intrinsic load, extraneous load, and germane load. Proper measurement of the different types of cognitive load can help us understand why the effectiveness and efficiency of learning environments may differ as a function of instructional formats and learner characteristics. In this article, we present a ten-item instrument for the measurement of the three types of cognitive load. Principal component analysis on data from a lecture in statistics for PhD students (n = 56) in psychology and health sciences revealed a three-component solution, consistent with the types of load that the different items were intended to measure. This solution was confirmed by a confirmatory factor analysis of data from three lectures in statistics for different cohorts of bachelor students in the social and health sciences (ns = 171, 136, and 148), and received further support from a randomized experiment with university freshmen in the health sciences (n = 58).
576 citations
TL;DR: This work identified five key characteristics of fire regimes—size, frequency, intensity, season, and extent—and combined new and existing global datasets to represent each and assessed how these global fire regime characteristics are related to patterns of climate, vegetation, and human activity.
Abstract: Fire is a ubiquitous component of the Earth system that is poorly understood. To date, a global-scale understanding of fire is largely limited to the annual extent of burning as detected by satellites. This is problematic because fire is multidimensional, and focus on a single metric belies its complexity and importance within the Earth system. To address this, we identified five key characteristics of fire regimes—size, frequency, intensity, season, and extent—and combined new and existing global datasets to represent each. We assessed how these global fire regime characteristics are related to patterns of climate, vegetation (biomes), and human activity. Cross-correlations demonstrate that only certain combinations of fire characteristics are possible, reflecting fundamental constraints in the types of fire regimes that can exist. A Bayesian clustering algorithm identified five global syndromes of fire regimes, or pyromes. Four pyromes represent distinctions between crown, litter, and grass-fueled fires, and the relationship of these to biomes and climate are not deterministic. Pyromes were partially discriminated on the basis of available moisture and rainfall seasonality. Human impacts also affected pyromes and are globally apparent as the driver of a fifth and unique pyrome that represents human-engineered modifications to fire characteristics. Differing biomes and climates may be represented within the same pyrome, implying that pathways of change in future fire regimes in response to changes in climate and human activity may be difficult to predict.
502 citations
TL;DR: In this article, the electrochemical properties of sodium ion storage in reduced graphene oxide (RGO) were studied in an electrolyte consisting of 1M NaClO 4 in propylene carbonate (PC).
490 citations
TL;DR: Simulating the mucosal gut microbiota represents a breakthrough in modeling and mechanistically studying the human intestinal microbiome in health and disease and may enhance butyrate bioavailability, which could be useful in treating diseases, such as inflammatory bowel disease.
Abstract: The human gut is colonized by a complex microbiota with multiple benefits. Although the surface-attached, mucosal microbiota has a unique composition and potential to influence human health, it remains difficult to study in vivo. Therefore, we performed an in-depth microbial characterization (human intestinal tract chip (HITChip)) of a recently developed dynamic in vitro gut model, which simulates both luminal and mucosal gut microbes (mucosal-simulator of human intestinal microbial ecosystem (M-SHIME)). Inter-individual differences among human subjects were confirmed and microbial patterns unique for each individual were preserved in vitro. Furthermore, in correspondence with in vivo studies, Bacteroidetes and Proteobacteria were enriched in the luminal content while Firmicutes rather colonized the mucin layer, with Clostridium cluster XIVa accounting for almost 60% of the mucin-adhered microbiota. Of the many acetate and/or lactate-converting butyrate producers within this cluster, Roseburia intestinalis and Eubacterium rectale most specifically colonized mucins. These 16S rRNA gene-based results were confirmed at a functional level as butyryl-CoA:acetate-CoA transferase gene sequences belonged to different species in the luminal as opposed to the mucin-adhered microbiota, with Roseburia species governing the mucosal butyrate production. Correspondingly, the simulated mucosal environment induced a shift from acetate towards butyrate. As not only inter-individual differences were preserved but also because compared with conventional models, washout of relevant mucin-adhered microbes was avoided, simulating the mucosal gut microbiota represents a breakthrough in modeling and mechanistically studying the human intestinal microbiome in health and disease. Finally, as mucosal butyrate producers produce butyrate close to the epithelium, they may enhance butyrate bioavailability, which could be useful in treating diseases, such as inflammatory bowel disease.
489 citations
TL;DR: Weavable, sewable, knottable and braidable yarns that function as high performance electrodes of redox supercapacitors that deliver high energy and power densities for the applications in electronic textiles are demonstrated.
Abstract: Flexible, wearable, implantable and easily reconfigurable supercapacitors delivering high energy and power densities are needed for electronic devices. Here we demonstrate weavable, sewable, knottable and braidable yarns that function as high performance electrodes of redox supercapacitors. A novel technology, gradient biscrolling, provides fast-ion-transport yarn in which hundreds of layers of conducting-polymer-infiltrated carbon nanotube sheet are scrolled into ~20 μm diameter yarn. Plying the biscrolled yarn with a metal wire current collector increases power generation capabilities. The volumetric capacitance is high (up to ~179 F cm(-3)) and the discharge current of the plied yarn supercapacitor linearly increases with voltage scan rate up to ~80 V s(-1) and ~20 V s(-1) for liquid and solid electrolytes, respectively. The exceptionally high energy and power densities for the complete supercapacitor, and high cycle life that little depends on winding or sewing (92%, 99% after 10,000 cycles, respectively) are important for the applications in electronic textiles.
459 citations
TL;DR: Alginate (Alg) was selected as the major component of the 'bio-ink' formulations for extrusion printing of cells and the viability of primary myoblasts delivered as a myoblast/Alg-Gel bio-ink was not affected by the printing process, indicating that the Alg-gel matrix provides a potential means to print 3D constructs that may find application in myoregenerative applications.
Abstract: Additive biofabrication (3D bioprinting) makes it possible to create scaffolds with precise geometries, control over pore interconnectivity and architectures that are not possible with conventional techniques. Inclusion of cells within the ink to form a “bio-ink” presents the potential to print 3D structures that can be implanted into damaged/diseased tissue to promote highly controlled cell-based regeneration and repair. The properties of an ‘ink’ are defined by its formulation and critically influence the delivery and integrity of structure formed. Importantly, the ink properties need to conform to biological requirements necessary for the cell system that they are intended to support and it is often challenging to find conditions for printing that facilitate this critical aspect of tissue bioengineering. In this study, alginate (Alg) was selected as the major component of the ‘bio-ink’ formulations for extrusion printing of cells. The rheological properties of alginate-gelatin (Alg-Gel) blends were compared with pre-crosslinked alginate and alginate solution to establish their printability whilst maintaining their ability to support optimal cell growth. Pre-crosslinked alginate on its own was liquid-like during printing. However, by controlling the temperature, Alg-Gel formulations had higher viscosity, storage modulus and consistency which facilitated higher print resolution/precision. Compression and indentation testing were used to examine the mechanical properties of alginate compared to Alg-Gel. Both types of gels yielded similar results with modulus increasing with alginate concentration. Decay in mechanical properties over time suggests that Alg-Gel slowly degrades in cell culture media with more than 60% decrease in initial modulus over 7 days. The viability of primary myoblasts delivered as a myoblast/Alg-Gel bio-ink was not affected by the printing process, indicating that the Alg-Gel matrix provides a potential means to print 3D constructs that may find application in myoregenerative applications.
453 citations
Deakin University1, University of Auckland2, University of Pennsylvania3, Curtin University4, The George Institute for Global Health5, Australian National University6, University of Wollongong7, University of Toronto8, Queensland University of Technology9, Chinese Center for Disease Control and Prevention10, Public Health Foundation of India11, University of São Paulo12, British Heart Foundation13, University of the Western Cape14, Southwest University of Visual Arts15, Global Alliance for Improved Nutrition16
TL;DR: Through monitoring and benchmarking, INFORMAS will strengthen the accountability systems needed to help reduce the burden of obesity, NCDs and their related inequalities.
Abstract: 20 Global Alliance for Improved Nutrition (GAIN), Geneva, Switzerland Summary Non-communicable diseases (NCDs) dominate disease burdens globally and poor nutrition increasingly contributes to this global burden. Compre- hensive monitoring of food environments, and evaluation of the impact of public and private sector policies on food environments is needed to strengthen accountability systems to reduce NCDs. The International Network for Food and Obesity/NCDs Research, Monitoring and Action Support (INFORMAS) is a global network of public-interest organizations and researchers that aims to monitor, benchmark and support public and private sector actions to create healthy food environments and reduce obesity, NCDs and their related inequalities. The INFORMAS framework includes two 'process' modules, that monitor the policies and actions of the public and private sectors, seven 'impact' modules that monitor the key characteristics of food environments and three 'outcome' modules that monitor dietary quality, risk factors and NCD morbidity and mortality. Monitoring frameworks and indicators have been developed for 10 modules to provide consistency, but allowing for stepwise approaches ('minimal', 'expanded', 'optimal') to data collection and analysis. INFORMAS data will enable benchmarking of food environments between countries, and monitoring of progress over time within countries. Through monitoring and benchmarking, INFORMAS will strengthen the account- ability systems needed to help reduce the burden of obesity, NCDs and their related inequalities.
436 citations
TL;DR: Recommendations are made that early childhood should be targeted as a critical time to promote healthy lifestyle behaviors through methodologically sound prevention studies and future tracking studies should assess a broad range of sedentary behaviors using objective measures.
406 citations
TL;DR: It is reported that simply hand-grinding commercial microsized red phosphorus and carbon nanotubes and CNTs can deliver a reversible capacity of 1675 mA h g(-1) for sodium ion batteries (SIBs), with capacity retention of 76.6% over 10 cycles.
Abstract: Recently, sodium ion batteries (SIBs) have been given intense attention because they are the most promising alternative to lithium ion batteries for application in renewable power stations and smart grid, owing to their low cost, their abundant natural resources, and the similar chemistry of sodium and lithium. Elemental phosphorus (P) is the most promising anode materials for SIBs with the highest theoretical capacity of 2596 mA h g–1, but the commercially available red phosphorus cannot react with Na reversibly. Here, we report that simply hand-grinding commercial microsized red phosphorus and carbon nanotubes (CNTs) can deliver a reversible capacity of 1675 mA h g–1 for sodium ion batteries (SIBs), with capacity retention of 76.6% over 10 cycles. Our results suggest that the simply mixed commercial red phosphorus and CNTs would be a promising anode candidate for SIBs with a high capacity and low cost.
382 citations
TL;DR: In this article, the authors present a standard methodology for testing of ODMP membranes based on experience gained and operating conditions used in forward osmosis (FO) and pressure-retarded osmo-sis (PRO) studies.
TL;DR: In this paper, a rational relation between GO sheet size and polydispersity, concentration, liquid crystallinity, and spinnability is proposed, leading to an understanding of lyotropic LC behavior and fiber spinnable.
Abstract: Key points in the formation of liquid crystalline (LC) dispersions of graphene oxide (GO) and their processability via wet-spinning to produce long lengths of micrometer-dimensional fibers and yarns are addressed. Based on rheological and polarized optical microscopy investigations, a rational relation between GO sheet size and polydispersity, concentration, liquid crystallinity, and spinnability is proposed, leading to an understanding of lyotropic LC behavior and fiber spinnability. The knowledge gained from the straightforward formulation of LC GO “inks” in a range of processable concentrations enables the spinning of continuous conducting, strong, and robust fibers at concentrations as low as 0.075 wt%, eliminating the need for relatively concentrated spinning dope dispersions. The dilute LC GO dispersion is proven to be suitable for fiber spinning using a number of coagulation strategies, including non-solvent precipitation, dispersion destabilization, ionic cross-linking, and polyelectrolyte complexation. One-step continuous spinning of graphene fibers and yarns is introduced for the first time by in situ spinning of LC GO in basic coagulation baths (i.e., NaOH or KOH), eliminating the need for post-treatment processes. The thermal conductivity of these graphene fibers is found to be much higher than polycrystalline graphite and other types of 3D carbon based materials.
TL;DR: The ANCDS establishes that malnutrition and poor food intake are independently associated with in-hospital mortality in the Australian and New Zealand acute care setting.
TL;DR: In a recent review as discussed by the authors, the authors revisited these key studies emphasizing their continuing influence on Quaternary research and incorporating relatively recent investigations to interpret the nature of postglacial sea-level change around Australia.
TL;DR: Findings indicate that most mouse strains develop metabolic defects on an HFD, however, there are inherent differences between strains, and thus the genetic background needs to be considered carefully in metabolic studies.
Abstract: Metabolic disorders are commonly investigated using knockout and transgenic mouse models. A variety of mouse strains have been used for this purpose. However, mouse strains can differ in their inherent propensities to develop metabolic disease, which may affect the experimental outcomes of metabolic studies. We have investigated strain-dependent differences in the susceptibility to diet-induced obesity and insulin resistance in five commonly used inbred mouse strains (C57BL/6J, 129X1/SvJ, BALB/c, DBA/2 and FVB/N). Mice were fed either a low-fat or a high-fat diet (HFD) for 8 weeks. Whole-body energy expenditure and body composition were then determined. Tissues were used to measure markers of mitochondrial metabolism, inflammation, oxidative stress and lipid accumulation. BL6, 129X1, DBA/2 and FVB/N mice were all susceptible to varying degrees to HFD-induced obesity, glucose intolerance and insulin resistance, but BALB/c mice exhibited some protection from these detrimental effects. This protection could not be explained by differences in mitochondrial metabolism or oxidative stress in liver or muscle, or inflammation in adipose tissue. Interestingly, in contrast with the other strains, BALB/c mice did not accumulate excess lipid (triacylglycerols and diacylglycerols) in the liver; this is potentially related to lower fatty acid uptake rather than differences in lipogenesis or lipid oxidation. Collectively, our findings indicate that most mouse strains develop metabolic defects on an HFD. However, there are inherent differences between strains, and thus the genetic background needs to be considered carefully in metabolic studies.
University of Illinois at Urbana–Champaign1, Chinese Academy of Sciences2, Nanjing Agricultural University3, Washington State University4, Cold Spring Harbor Laboratory5, University of Utah6, University of Georgia7, J. Craig Venter Institute8, University of Arizona9, Michigan State University10, University of Tennessee Health Science Center11, University of California, Los Angeles12, Pennsylvania State University13, Youngstown State University14, Purdue University15, Texas A&M University16, University of Central Oklahoma17, University of Adelaide18, Iwate University19, University of Wollongong20, Donald Danforth Plant Science Center21, Lawrence Berkeley National Laboratory22, Fudan University23, Oklahoma State University–Stillwater24, University of Hawaii at Manoa25, Fujian Normal University26, Montclair State University27, Chinese Academy of Tropical Agricultural Sciences28, University of California29, United States Department of Agriculture30
TL;DR: In this article, the China Antique variety of the sacred lotus was sequenced with Illumina and 454 technologies, at respective depths of 101× and 5.2×, and the final assembly has a contig N50 of 38.8 kbp and a scaffold n50 of 3.4 Mbp, covering 86.5% of the estimated 929 Mbp total genome size.
Abstract: Background: Sacred lotus is a basal eudicot with agricultural, medicinal, cultural and religious importance. It was domesticated in Asia about 7,000 years ago, and cultivated for its rhizomes and seeds as a food crop. It is particularly noted for its 1,300-year seed longevity and exceptional water repellency, known as the lotus effect. The latter property is due to the nanoscopic closely packed protuberances of its self-cleaning leaf surface, which have been adapted for the manufacture of a self-cleaning industrial paint, Lotusan. Results: The genome of the China Antique variety of the sacred lotus was sequenced with Illumina and 454 technologies, at respective depths of 101× and 5.2×. The final assembly has a contig N50 of 38.8 kbp and a scaffold N50 of 3.4 Mbp, and covers 86.5% of the estimated 929 Mbp total genome size. The genome notably lacks the paleo-triplication observed in other eudicots, but reveals a lineage-specific duplication. The genome has evidence of slow evolution, with a 30% slower nucleotide mutation rate than observed in grape. Comparisons of the available sequenced genomes suggest a minimum gene set for vascular plants of 4,223 genes. Strikingly, the sacred lotus has 16 COG2132 multi-copper oxidase family proteins with root-specific expression; these are involved in root meristem phosphate starvation, reflecting adaptation to limited nutrient availability in an aquatic environment. Conclusions: The slow nucleotide substitution rate makes the sacred lotus a better resource than the current standard, grape, for reconstructing the pan-eudicot genome, and should therefore accelerate comparative analysis between eudicots and monocots.
01 Oct 2013
TL;DR: The Australasian Nutrition Care Day Survey (ANCDS) ascertained if malnutrition and poor food intake are independent risk factors for health-related outcomes in Australian and New Zealand hospital patients as mentioned in this paper.
Abstract: Background & aims
The Australasian Nutrition Care Day Survey (ANCDS) ascertained if malnutrition and poor food intake are independent risk factors for health-related outcomes in Australian and New Zealand hospital patients.
Methods
Phase 1 recorded nutritional status (Subjective Global Assessment) and 24-h food intake (0, 25, 50, 75, 100% intake). Outcomes data (Phase 2) were collected 90-days post-Phase 1 and included length of hospital stay (LOS), readmissions and in-hospital mortality.
Results
Of 3122 participants (47% females, 65 ± 18 years) from 56 hospitals, 32% were malnourished and 23% consumed ≤ 25% of the offered food. Malnourished patients had greater median LOS (15 days vs. 10 days, p < 0.0001) and readmissions rates (36% vs. 30%, p = 0.001). Median LOS for patients consuming ≤ 25% of the food was higher than those consuming ≤ 50% (13 vs. 11 days, p < 0.0001). The odds of 90-day in-hospital mortality were twice greater for malnourished patients (CI: 1.09–3.34, p = 0.023) and those consuming ≤ 25% of the offered food (CI: 1.13–3.51, p = 0.017), respectively.
Conclusion
The ANCDS establishes that malnutrition and poor food intake are independently associated with in-hospital mortality in the Australian and New Zealand acute care setting.
TL;DR: LiFePO4/C nanoparticles from citric acid as carbon source, which has good crystallinity and a narrow particle size distribution, provided an initial discharge capacity of 112 mAh g−1 at 0.5 C with excellent capacity retention.
Abstract: Uniform LiFePO4/C particles were prepared by a fast, facile, and environmentally friendly microwave-assisted low-heating solid-state reaction using different organic carbon sources. The particles are very uniform and are 50–80 nm in size. The effects of the carbon sources on the microstructure and electrochemical properties of LiFePO4/C nanoparticles were investigated by X-ray diffraction, transmission electron microscopy, and electrochemical measurements. The results showed that the LiFePO4/C nanoparticles prepared from citric acid as carbon source, which has good crystallinity and a narrow particle size distribution, provided an initial discharge capacity of 112 mAh g−1 at 0.5 C with excellent capacity retention. These advantages, coupled with the simple and effective preparation method, render LiFePO4/C nanoparticles attractive for practical and large-scale applications.
TL;DR: In this article, the authors investigated the solar PV impacts and developed a mitigation strategy by an effective use of distributed energy storage systems integrated with solar PV units in lowvoltage distribution networks, where the storage is used to consume surplus solar PV power locally during PV peak, and the stored energy is utilized in the evening for the peak-load support.
Abstract: A high penetration of rooftop solar photovoltaic (PV) resources into low-voltage (LV) distribution networks creates reverse power-flow and voltage-rise problems This generally occurs when the generation from PV resources substantially exceeds the load demand during high insolation period This paper has investigated the solar PV impacts and developed a mitigation strategy by an effective use of distributed energy storage systems integrated with solar PV units in LV networks The storage is used to consume surplus solar PV power locally during PV peak, and the stored energy is utilized in the evening for the peak-load support A charging/discharging control strategy is developed taking into account the current state of charge (SoC) of the storage and the intended length of charging/discharging period to effectively utilize the available capacity of the storage The proposed strategy can also mitigate the impact of sudden changes in PV output, due to unstable weather conditions, by putting the storage into a short-term discharge mode The charging rate is adjusted dynamically to recover the charge drained during the short-term discharge to ensure that the level of SoC is as close to the desired SoC as possible A comprehensive battery model is used to capture the realistic behavior of the distributed energy storage units in a distribution feeder The proposed PV impact mitigation strategy is tested on a practical distribution network in Australia and validated through simulations
Manchester Academic Health Science Centre1, University of Leicester2, Hull York Medical School3, University of Exeter4, VU University Medical Center5, Karolinska Institutet6, University of New South Wales7, City University London8, VU University Amsterdam9, University of Sheffield10, University of Wollongong11, University of Manchester12, Fu Jen Catholic University13
TL;DR: The data suggest that patients with more severe depression at baseline show at least as much clinical benefit from low intensity interventions as less severely depressed patients and could usefully be offered these interventions as part of a stepped care model.
Abstract: Objective To assess how initial severity of depression affects the benefit derived from low intensity interventions for depression.
TL;DR: School- and community-based programs that include developmentally appropriate FMS learning experiences delivered by physical education specialists or highly trained classroom teachers significantly improve FMS proficiency in youth.
Abstract: BACKGROUND: Fundamental movement skill (FMS) proficiency is positively associated with physical activity and fitness levels. The objective of this study was to systematically review evidence for the benefits of FMS interventions targeting youth. METHODS: A search with no date restrictions was conducted across 7 databases. Studies included any school-, home-, or community-based intervention for typically developing youth with clear intent to improve FMS proficiency and that reported statistical analysis of FMS competence at both preintervention and at least 1 other postintervention time point. Study designs included randomized controlled trials (RCTs) using experimental and quasi-experimental designs and single group pre-post trials. Risk of bias was independently assessed by 2 reviewers. RESULTS: Twenty-two articles (6 RCTs, 13 quasi-experimental trials, 3 pre-post trials) describing 19 interventions were included. All but 1 intervention were evaluated in primary/elementary schools. All studies reported significant intervention effects for ≥1 FMS. Meta-analyses revealed large effect sizes for overall gross motor proficiency (standardized mean difference [SMD] = 1.42, 95% confidence interval [CI] 0.68–2.16, Z = 3.77, P Z = 3.25, P = .001). A medium effect size for object control skill competency was observed (SMD = 0.63, 95% CI 0.28–0.98, Z = 3.53, P = .0004). Many studies scored poorly for risk of bias items. CONCLUSIONS: School- and community-based programs that include developmentally appropriate FMS learning experiences delivered by physical education specialists or highly trained classroom teachers significantly improve FMS proficiency in youth.
TL;DR: It is shown, through theoretical analysis, that the proposed framework not only encompasses many widely used feature selection criteria, but also naturally overcomes their common weakness in handling feature redundancy.
Abstract: In the literature of feature selection, different criteria have been proposed to evaluate the goodness of features. In our investigation, we notice that a number of existing selection criteria implicitly select features that preserve sample similarity, and can be unified under a common framework. We further point out that any feature selection criteria covered by this framework cannot handle redundant features, a common drawback of these criteria. Motivated by these observations, we propose a new "Similarity Preserving Feature Selection” framework in an explicit and rigorous way. We show, through theoretical analysis, that the proposed framework not only encompasses many widely used feature selection criteria, but also naturally overcomes their common weakness in handling feature redundancy. In developing this new framework, we begin with a conventional combinatorial optimization formulation for similarity preserving feature selection, then extend it with a sparse multiple-output regression formulation to improve its efficiency and effectiveness. A set of three algorithms are devised to efficiently solve the proposed formulations, each of which has its own advantages in terms of computational complexity and selection performance. As exhibited by our extensive experimental study, the proposed framework achieves superior feature selection performance and attractive properties.
TL;DR: Both of them, especially the Li3VO4/graphene nanosheets composite, show superior electrochemical performance to the formerly reported vanadium-based anode materials.
Abstract: To explore good anode materials of high safety, high reversible capacity, good cycling, and excellent rate capability, a Li3VO4 microbox with wall thickness of 40 nm was prepared by a one-pot and template-free in situ hydrothermal method. In addition, its composite with graphene nanosheets of about six layers of graphene was achieved. Both of them, especially the Li3VO4/graphene nanosheets composite, show superior electrochemical performance to the formerly reported vanadium-based anode materials. The composite shows a reversible capacity of 223 mAh g–1 even at 20C (1C = 400 mAh g–1). After 500 cycles at 10C there is no evident capacity fading.
TL;DR: In this paper, a mixture of liquid phase exfoliation with single-walled carbon nanotubes (SWNTs) was used to form a composite thin film for lithium battery applications.
Abstract: Layered MoS2 prepared by liquid-phase exfoliation has been blended with single-walled carbon nanotubes (SWNTs) to form novel composite thin films for lithium battery applications. The films were formed by vacuum filtration of blended dispersions onto nitrocellulose membranes. The resulting composite films were transferred onto Cu foil electrodes via a facile filtration/wet transfer technique from nitrocellulose membranes. The morphology of the film was characterised by field emission scanning electron microscopy, which suggests that the MoS2-SWNT composite film shows good adherence to the Cu foil substrate. The MoS2-SWNT composite thin films show strong electrochemical performance at different charge-discharge rates. The capacity of a MoS2-SWNT composite film with thickness of 1 μm is approximately 992 mAh g−1 after 100 cycles. The morphology study showed that the MoS2-SWNT thin film retains structural integrity after 100 cycles, while the MoS2 thin film without SWNTs displays significant cracking. In addition, the novel composite thin film preparation and transfer protocols developed in this study could be extended to the preparation of various layered-material-based composite films, with the potential for new device designs for energy applications.
TL;DR: The authors can live with many of the uncertainties of big data for now, with the hope that its benefits will outweigh its harms, but they shouldnit blind ourselves to the possible irreversibility of changes-whether good or bad-to society.
Abstract: We can live with many of the uncertainties of big data for now, with the hope that its benefits will outweigh its harms, but we shouldn't blind ourselves to the possible irreversibility of changes-whether good or bad-to society The first Web extra at http://youtube/24czULRCI9c is an audio recording in which Katina Michael at the University of Wollongong discusses the June 2013 Computer magazine special issue on "Big Data: New Opportunities and New Challenges," introducing the special issue, the guest editors, the authors, the articles, and the IEEE Society on Social Implications of Technology (SSIT) The second Web extra at http://youtube/9zpFqEDydDA is an audio recording in which Katina Michael at the University of Wollongong talks about the IEEE Society on the Social Implications of Technology (SSIT), IEEE Technology and Society (T&S) magazine, and the International Symposium on Technology and Society (ISTAS) The third Web extra at http://youtube/mn_9YHV2RGQis an audio recording in which Katina Michael at the University of Wollongong discusses how we can live with many of the uncertainties of big data for now, with the hope that its benefits will outweigh its harms, but we shouldnit blind ourselves to the possible irreversibility of changes-whether good or bad-to society
TL;DR: This paper proposes a distance-based train trajectory searching model, upon which three optimization algorithms are applied to search for the optimum train speed trajectory, found that the ant colony optimization (ACO) algorithm obtains better balance between stability and the quality of the results, in comparison with the genetic algorithm (GA).
Abstract: An energy-efficient train trajectory describing the motion of a single train can be used as an input to a driver guidance system or to an automatic train control system. The solution for the best trajectory is subject to certain operational, geographic, and physical constraints. There are two types of strategies commonly applied to obtain the energy-efficient trajectory. One is to allow the train to coast, thus using its available time margin to save energy. The other one is to control the speed dynamically while maintaining the required journey time. This paper proposes a distance-based train trajectory searching model, upon which three optimization algorithms are applied to search for the optimum train speed trajectory. Instead of searching for a detailed complicated control input for the train traction system, this model tries to obtain the speed level at each preset position along the journey. Three commonly adopted algorithms are extensively studied in a comparative style. It is found that the ant colony optimization (ACO) algorithm obtains better balance between stability and the quality of the results, in comparison with the genetic algorithm (GA). For offline applications, the additional computational effort required by dynamic programming (DP) is outweighed by the quality of the solution. It is recommended that multiple algorithms should be used to identify the optimum single-train trajectory and to improve the robustness of searched results.
TL;DR: In this article, the authors report the findings of a study examining the relationship between transformational leadership and work engagement through the mediating role of meaning in work, which is partially mediated by employees' perceptions of meaningful in work.
Abstract: Purpose – This paper reports the findings of a study examining the relationship between transformational leadership and work engagement through the mediating role of meaning in work.Design/methodology/approach – Transformational leadership, work engagement and perceptions of meaning in work were assessed in an empirical study based on a sample of 530 full‐time employees working in Australia.Findings – The results from structural equation modelling reveal that the transformational leadership style influences followers’ attributes of work engagement. The direct relationship between transformational leadership and work engagement was found to be partially mediated by employees’ perceptions of meaning in work.Practical implications – Industry reports show that globally, the number of unengaged employees have increased, costing nations billions in productivity losses. We present a model that could help reduce these losses by providing human resource managers with new insights into developing training programme...
TL;DR: The GeO2/Ge/C composite shows a high capacity and good electrochemical performance and is related to the fact that the elemental germanium nanoparticles present in the composite increases the reversibility of the conversion reaction of GeO 2.
Abstract: GeO2/Ge/C anode material synthesized using a simple method involving simultaneous carbon coating and reduction by acetylene gas is composed of nanosized GeO2/Ge particles coated by a thin layer of carbon, which is also interconnected between neighboring particles to form clusters of up to 30 μm. The GeO2/Ge/C composite shows a high capacity of up to 1860 mAh/g and 1680 mAh/g at 1 C (2.1 A/g) and 10 C rates, respectively. This good electrochemical performance is related to the fact that the elemental germanium nanoparticles present in the composite increases the reversibility of the conversion reaction of GeO2. These factors have been found through investigating and comparing GeO2/Ge/C, GeO2/C, nanosized GeO2, and bulk GeO2.
National Institute for Environmental Studies1, University of Oxford2, University of Tokyo3, Jet Propulsion Laboratory4, University of Wollongong5, University of Bremen6, National Institute of Water and Atmospheric Research7, Karlsruhe Institute of Technology8, Finnish Meteorological Institute9, University of Toronto10
TL;DR: In this article, column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES).
Abstract: . The column-averaged dry-air mole fractions of carbon dioxide and methane (XCO2 and XCH4) have been retrieved from Greenhouse gases Observing SATellite (GOSAT) Short-Wavelength InfraRed (SWIR) observations and released as a SWIR L2 product from the National Institute for Environmental Studies (NIES). XCO2 and XCH4 retrieved using the version 01.xx retrieval algorithm showed large negative biases and standard deviations (−8.85 and 4.75 ppm for XCO2 and −20.4 and 18.9 ppb for XCH4, respectively) compared with data of the Total Carbon Column Observing Network (TCCON). Multiple reasons for these error characteristics (e.g., solar irradiance database, handling of aerosol scattering) are identified and corrected in a revised version of the retrieval algorithm (version 02.xx). The improved retrieval algorithm shows much smaller biases and standard deviations (−1.48 and 2.09 ppm for XCO2 and −5.9 and 12.6 ppb for XCH4, respectively) than the version 01.xx. Also, the number of post-screened measurements is increased, especially at northern mid- and high-latitudinal areas.
TL;DR: The most comprehensive measurement of biomass burning emissions to date and it should enable improved representation of smoke composition in atmospheric models is presented in this article, where the results support a recent estimate of global NMOC emissions from biomass burning that is much higher than widely used estimates and they provide important insights into the nature of smoke.
Abstract: . An extensive program of experiments focused on biomass burning emissions began with a laboratory phase in which vegetative fuels commonly consumed in prescribed fires were collected in the southeastern and southwestern US and burned in a series of 71 fires at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particulate matter (PM2.5) emissions were measured by gravimetric filter sampling with subsequent analysis for elemental carbon (EC), organic carbon (OC), and 38 elements. The trace gas emissions were measured by an open-path Fourier transform infrared (OP-FTIR) spectrometer, proton-transfer-reaction mass spectrometry (PTR-MS), proton-transfer ion-trap mass spectrometry (PIT-MS), negative-ion proton-transfer chemical-ionization mass spectrometry (NI-PT-CIMS), and gas chromatography with MS detection (GC-MS). 204 trace gas species (mostly non-methane organic compounds (NMOC)) were identified and quantified with the above instruments. Many of the 182 species quantified by the GC-MS have rarely, if ever, been measured in smoke before. An additional 153 significant peaks in the unit mass resolution mass spectra were quantified, but either could not be identified or most of the signal at that molecular mass was unaccounted for by identifiable species. In a second, "field" phase of this program, airborne and ground-based measurements were made of the emissions from prescribed fires that were mostly located in the same land management units where the fuels for the lab fires were collected. A broad variety, but smaller number of species (21 trace gas species and PM2.5) was measured on 14 fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. The field measurements of emission factors (EF) are useful both for modeling and to examine the representativeness of our lab fire EF. The lab EF/field EF ratio for the pine understory fuels was not statistically different from one, on average. However, our lab EF for "smoldering compounds" emitted from the semiarid shrubland fuels should likely be increased by a factor of ~2.7 to better represent field fires. Based on the lab/field comparison, we present emission factors for 357 pyrogenic species (including unidentified species) for 4 broad fuel types: pine understory, semiarid shrublands, coniferous canopy, and organic soil. To our knowledge this is the most comprehensive measurement of biomass burning emissions to date and it should enable improved representation of smoke composition in atmospheric models. The results support a recent estimate of global NMOC emissions from biomass burning that is much higher than widely used estimates and they provide important insights into the nature of smoke. 31–72% of the mass of gas-phase NMOC species was attributed to species that we could not identify. These unidentified species are not represented in most models, but some provision should be made for the fact that they will react in the atmosphere. In addition, the total mass of gas-phase NMOC divided by the mass of co-emitted PM2.5 averaged about three (range ~2.0–8.7). About 35–64% of the NMOC were likely semivolatile or of intermediate volatility. Thus, the gas-phase NMOC represent a large reservoir of potential precursors for secondary formation of ozone and organic aerosol. For the single lab fire in organic soil about 28% of the emitted carbon was present as gas-phase NMOC and ~72% of the mass of these NMOC was unidentified, highlighting the need to learn more about the emissions from smoldering organic soils. The mass ratio of total NMOC to "NOx as NO" ranged from 11 to 267, indicating that NOx-limited O3 production would be common in evolving biomass burning plumes. The fuel consumption per unit area was 7.0 ± 2.3 Mg ha−1 and 7.7 ± 3.7 Mg ha−1 for pine-understory and semiarid shrubland prescribed fires, respectively.