997 resultados para walking efficiency


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This study assessed the workday step counts of lower active (<10,000 daily steps) university employees using an automated, web-based walking intervention (Walk@Work). METHODS: Academic and administrative staff (n=390; 45.6±10.8years; BMI 27.2±5.5kg/m2; 290 women) at five campuses (Australia [x2], Canada, Northern Ireland and the United States), were given a pedometer, access to the website program (2010-11) and tasked with increasing workday walking by 1000 daily steps above baseline, every two weeks, over a six week period. Step count changes at four weeks post intervention were evaluated relative to campus and baseline walking. RESULTS: Across the sample, step counts significantly increased from baseline to post-intervention (1477 daily steps; p=0.001). Variations in increases were evident between campuses (largest difference of 870 daily steps; p=0.04) and for baseline activity status. Those least active at baseline (<5000 daily steps; n=125) increased step counts the most (1837 daily steps; p=0.001), whereas those most active (7500-9999 daily steps; n=79) increased the least (929 daily steps; p=0.001). CONCLUSIONS: Walk@Work increased workday walking by 25% in this sample overall. Increases occurred through an automated program, at campuses in different countries, and were most evident for those most in need of intervention.

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Compression ignition (CI) engine design is subject to many constraints which presents a multi-criteria optimisation problem that the engine researcher must solve. In particular, the modern CI engine must not only be efficient, but must also deliver low gaseous, particulate and life cycle greenhouse gas emissions so that its impact on urban air quality, human health, and global warming are minimised. Consequently, this study undertakes a multi-criteria analysis which seeks to identify alternative fuels, injection technologies and combustion strategies that could potentially satisfy these CI engine design constraints. Three datasets are analysed with the Preference Ranking Organization Method for Enrichment Evaluations and Geometrical Analysis for Interactive Aid (PROMETHEE-GAIA) algorithm to explore the impact of 1): an ethanol fumigation system, 2): alternative fuels (20 % biodiesel and synthetic diesel) and alternative injection technologies (mechanical direct injection and common rail injection), and 3): various biodiesel fuels made from 3 feedstocks (i.e. soy, tallow, and canola) tested at several blend percentages (20-100 %) on the resulting emissions and efficiency profile of the various test engines. The results show that moderate ethanol substitutions (~20 % by energy) at moderate load, high percentage soy blends (60-100 %), and alternative fuels (biodiesel and synthetic diesel) provide an efficiency and emissions profile that yields the most “preferred” solutions to this multi-criteria engine design problem. Further research is, however, required to reduce Reactive Oxygen Species (ROS) emissions with alternative fuels, and to deliver technologies that do not significantly reduce the median diameter of particle emissions.

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Fibrous scaffolds of engineered structures can be chosen as promising porous environments when an approved criterion validates their applicability for a specific medical purpose. For such biomaterials, this paper sought to investigate various structural characteristics in order to determine whether they are appropriate descriptors. A number of poly(3-hydroxybutyrate) scaffolds were electrospun; each of which possessed a distinguished architecture when their material and processing conditions were altered. Subsequent culture of mouse fibroblast cells (L929) was carried out to evaluate the cells viability on each scaffold after their attachment for 24 h and proliferation for 48 and 72 h. The scaffolds’ porosity, pores number, pores size and distribution were quantified and none could establish a relationship with the viability results. Virtual reconstruction of the mats introduced an authentic criterion, “Scaffold Percolative Efficiency” (SPE), with which the above descriptors were addressed collectively. It was hypothesized to be able to quantify the efficacy of fibrous scaffolds by considering the integration of porosity and interconnectivity of the pores. There was a correlation of 80% as a good agreement between the SPE values and the spectrophotometer absorbance of viable cells; a viability of more than 350% in comparison to that of the controls.

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This note examines the productive efficiency of 62 starting guards during the 2011/12 National Basketball Association (NBA) season. This period coincides with the phenomenal and largely unanticipated performance of New York Knicks’ starting point guard Jeremy Lin and the attendant public and media hype known as Linsanity. We employ a data envelopment analysis (DEA) approach that includes allowance for an undesirable output, here turnovers per game, with the desirable outputs of points, rebounds, assists, steals and blocks per game and an input of minutes per game. The results indicate that depending upon the specification, between 29% and 42% of NBA guards are fully efficient, including Jeremy Lin, with a mean inefficiency of 3.7% and 19.2%. However, while Jeremy Lin is technically efficient, he seldom serves as a benchmark for inefficient players, at least when compared with established players such as Chris Paul and Dwayne Wade. This suggests the uniqueness of Jeremy Lin's productive solution and may explain why his unique style of play, encompassing individual brilliance, unselfish play and team leadership, is of such broad public appeal.

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Water and ammonium retention by sandy soils may be low and result in leaching of applied fertiliser. To increase water and nutrient retention, zeolite is sometimes applied as a soil ameliorant for high value land uses including turf and horticulture. We have used a new modified kaolin material (MesoLite) as a soil amendment to test the efficiency of NH4+ retention and compared the results with natural zeolite. MesoLite is made by caustic reaction of kaolin at temperature between 80-95°C; although it has a moderate surface area, its cation exchange capacity is very high;(SA=13m2/g,CEC=500meq/100g). A 13cm tall sand column filled with ~450g of sandy soil homogeneously mixed with 1, 2, 4, and 8g of MesoLite or natural zeolite per 1kg of soil was prepared. After saturation with local bore water, concentrated ammonium sulfate solution was injected at the base. Then, bore water was passed from bottom to top through the column at amounts up to 6 pore volumes and at a constant flow rate of 10ml/min using a peristaltic pump. Concentrations of leached NH4+ were determined using an AutoAnalyser. The concentration of NH4+ leached from the column with 0.4% MesoLite was greatly (90%) reduced relative to unamended soil. Under these conditions NH4+ retention by the soil-MesoLite mixture was 11.5 times more efficient than the equivalent soil-natural zeolite mixture. Glasshouse experiments conducted in a separate study show that NH4+ adsorbed by MesoLite is available to plants.

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Introduction: Participants may respond to phases of a workplace walking program at different rates. This study evaluated the factors that contribute to the number of steps through phases of the program. The intervention was automated through a web-based program designed to increase workday walking. Methods: The study reviewed independent variable influences throughout phases I–III. A convenience sample of university workers (n=56; 43.6±1.7 years; BMI 27.44±.2.15 kg/m2; 48 female) were recruited at worksites in Australia. These workers were given a pedometer (Yamax SW 200) and access to the website program. For analyses, step counts entered by workers into the website were downloaded and mean workday steps were compared using a seemingly unrelated regression. This model was employed to capture the contemporaneous correlation within individuals in the study across observed time periods. Results: The model predicts that the 36 subjects with complete information took an average 7460 steps in the baseline two week period. After phase I, statistically significance increases in steps (from baseline) were explained by age, working status (full or part time), occupation (academic or professional), and self reported public transport (PT) use (marginally significant). Full time workers walked more than part time workers by about 440 steps, professionals walked about 300 steps more than academics, and PT users walked about 400 steps more than non-PT users. The ability to differentiate steps after two weeks among participants suggests a differential affect of the program after only two weeks. On average participants increased steps from week two to four by about 525 steps, but regular auto users had nearly 750 steps less than non-auto users at week four. The effect of age was diminished in the 4th week of observation and accounted for 34 steps per year of age. In phase III, discriminating between participants became more difficult, with only age effects differentiating their increase over baseline. The marginal effect of age by phase III compared to phase I, increased from 36 to 50, suggesting a 14 step per year increase from the 2nd to 6th week. Discussion: The findings suggest that participants responded to the program at different rates, with uniformity of effect achieved by the 6th week. Participants increased steps, however a tapering off occurred over time. Age played the most consistent role in predicting steps over the program. PT use was associated with increased step counts, while Auto use was associated with decreased step counts.

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Bunker fuels used in the aviation and maritime sectors are responsible for nearly 10% of global greenhouse gas emissions.1 According to a scientific survey: ‘[s]hipping is estimated to have emitted 1,046 million tonnes of CO2 in 2007, which corresponds to 3.3% of the global emissions during 2007. International shipping is estimated to have emitted 870 million tonnes, or about 2.7% of the global emissions of CO2 in 2007’. The study also predicted that ‘by 2050, in the absence of policies, ship emissions may grow by 150% to 250% (compared to the emissions in 2007) as a result of the growth in shipping.’

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Recent literature has emphasized the pivotal role of knowledge integration in Enterprise Systems (ES) success. This research-in-progress paper, building upon Knowledge Based Theory of the firm (KBT), examines the efficiency of knowledge integration in the context of ES implementation and identifies the factors contributing to its enhancement. The proposed model in this paper suggests that the efficiency of knowledge integration in an ES implementation process depends upon the level of common knowledge and the level of coordination in the ES adopting organization. It further suggests that the level of common knowledge can be enhanced by proper training, improving ES users’intrinsic and extrinsic motivations and business process modeling and the level of coordination can be improved by articulating a clear unified organizational goal for the ES adoption in the organization, forming a competent ES team, enhancing interdepartmental communication and the cross-functionality in the organization structure.

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With internationalisation and globalisation, English has proliferated in urban spaces around the world. This creates new opportunities for EFL learning and teaching. An English literacy walk is one activity that can be used productively to capitalise on this potential. The activity has roots in: (i) long-established approaches to emergent literacy education for young children; and (ii) pedagogic projects inspired by recent research on linguistic landscapes. Drawing on these traditions, teachers can target reading outcomes involving code, semantic, pragmatic and critical knowledge and skills. We use the four resources model of literate practices to systematically map some of the potential of literacy walks in multilingual, multimodal linguistic landscapes. We suggest tasks and teacher questions that might be used for purposes of explicit teaching of reading during and after literacy walks. Although grounded in Taipei, our ideas might be of interest to EFL teachers in other globalised cities around the world.

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Electrospun scaffolds manufactured using conventional electrospinning configurations have an intrinsic thickness limitation, due to a charge build-up at the collector. To overcome this limitation, an electrostatic lens has been developed that, at the same relative rate of deposition, focuses the polymer jet onto a smaller area of the collector, resulting in the fabrication of thick scaffolds within a shorter period of time. We also observed that a longer deposition time (up to 13 h, without the intervention of the operator) could be achieved when the electrostatic lens was utilised, compared to 9–10 h with a conventional processing set-up and also showed that fibre fusion was less likely to occur in the modified method. This had a significant impact on the mechanical properties, as the scaffolds obtained with the conventional process had a higher elastic modulus and ultimate stress and strain at short times. However, as the thickness of the scaffolds produced by the conventional electrospinning process increased, a 3-fold decrease in the mechanical properties was observed. This was in contrast to the modified method, which showed a continual increase in mechanical properties, with the properties of the scaffold finally having similar mechanical properties to the scaffolds obtained via the conventional process at longer times. This “focusing” device thus enabled the fabrication of thicker 3-dimensional electrospun scaffolds (of thicknesses up to 3.5 mm), representing an important step towards the production of scaffolds for tissue engineering large defect sites in a multitude of tissues.

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This paper presents two efficiency models for the regenerative dynamometer to be built at the University of Queensland. The models incorporate an accurate accounting of the losses associated with the regenerative dynamometer and the battery modelling technique used. In addition to the models the cycle and instantaneous efficiencies were defined for a regenerative system that requires a desired torque output. The simulation of the models allowed the instantaneous and cycle efficiencies to be examined. The results show the intended dynamometer machine has significant efficiency draw backs but incorporating field winding control, the efficiency can be improved.

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The measurement of losses in high efficiency / high power converters is difficult. Measuring the losses directly from the difference between the input and output power results in large errors. Calorimetric methods are usually used to bypass this issue but introduce different problems, such as, long measurement times, limited power loss measurement range and/or large set up cost. In this paper the total losses of a converter are measured directly and switching losses are exacted. The measurements can be taken with only three multimeters and a current probe and a standard bench power supply. After acquiring two or three power loss versus output current sweeps, a series of curve fitting processes are applied and the switching losses extracted.

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The auxiliary load DC-DC converters of the Sunshark solar car have never been examined. An analysis of the current design reveals it is complicated, and inefficient. Some simple measures to greatly improve the efficiency are present which will achieve an overall worthwhile power saving. Two switch-mode power supply DC-DC converter designs are presented. One is a constant current supply for the LED brake and turn indicators, which allows them to be powered directly from the main DC bus, and switched only as necessary. The second is a low power flyback converter, which employs synchronous rectification among other techniques to achieve good efficiency and regulation over a large range of output powers. Practical results from both converters, and an indication of the overall improvement in system efficiency will be offered.

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This paper evaluates the efficiency of a number of popular corpus-based distributional models in performing discovery on very large document sets, including online collections. Literature-based discovery is the process of identifying previously unknown connections from text, often published literature, that could lead to the development of new techniques or technologies. Literature-based discovery has attracted growing research interest ever since Swanson's serendipitous discovery of the therapeutic effects of fish oil on Raynaud's disease in 1986. The successful application of distributional models in automating the identification of indirect associations underpinning literature-based discovery has been heavily demonstrated in the medical domain. However, we wish to investigate the computational complexity of distributional models for literature-based discovery on much larger document collections, as they may provide computationally tractable solutions to tasks including, predicting future disruptive innovations. In this paper we perform a computational complexity analysis on four successful corpus-based distributional models to evaluate their fit for such tasks. Our results indicate that corpus-based distributional models that store their representations in fixed dimensions provide superior efficiency on literature-based discovery tasks.

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Defence projects are typically undertaken within a multi-project-management environment where a common agenda of project managers is to achieve higher project efficiency. This study adopted a multi-facet qualitative approach to investigate factors contributing to or impeding project efficiency in the Defence sector. Semi-structured interviews were undertaken to identify additional factors to those compiled from the literature survey. This was followed by a three-round Delphi study to examine the perceived critical factors of project efficiency. The results showed that project efficiency in the Defence sector went beyond its traditional internally focused scope to one that is externally focused. As a result, efforts are needed on not only those factors related to individual projects but also those factors related to project inter-dependencies and external customers. The management of these factors will help to enhance the efficiency of a project within the Defence sector.