961 resultados para Equações de Gross-Pitaevskii
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In this study, the mixed convection heat transfer and fluid flow behaviors in a lid-driven square cavity filled with high Prandtl number fluid (Pr = 5400, ν = 1.2×10-4 m2/s) at low Reynolds number is studied using thermal Lattice Boltzmann method (TLBM) where ν is the viscosity of the fluid. The LBM has built up on the D2Q9 model and the single relaxation time method called the Lattice-BGK (Bhatnagar-Gross-Krook) model. The effects of the variations of non dimensional mixed convection parameter called Richardson number(Ri) with and without heat generating source on the thermal and flow behavior of the fluid inside the cavity are investigated. The results are presented as velocity and temperature profiles as well as stream function and temperature contours for Ri ranging from 0.1 to 5.0 with other controlling parameters that present in this study. It is found that LBM has good potential to simulate mixed convection heat transfer and fluid flow problem. Finally the simulation results have been compared with the previous numerical and experimental results and it is found to be in good agreement.
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Gross value of cons truction work in the repair , maintenance, minor alte ration and addition (RMAA) sector in Hong Kong has expanded dramatically by 58% from 1998 to 2007, accounting for over 53% of the whole construction market in 2007. Unfortunately, the portion of industrial accidents arising from this sector also increased substantially during the same period. It is important to improve the safety performance of the RMAA sector. This paper has set out the objectives to examine safety statistics of RMAA works; to compare them with those of green field projects; and more importantly, to highlight potential hurdles en countered in the process of comparison and finally to provide effective recommendations for overcoming these impediments. To strive for continuous safety improvement of RMAA works, comparable safety statistics should be compiled for this sector.
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Teachers are continually bombarded with change programs for improvements in areas such as literacy and numeracy, however; the focus is often on the program and not on results (Pertuzé, Calder, Greitzer & Lucas, 2010). When the inevitable failure follows (Fullan, 2005; Gross, Giacquinta & Bernstein, 1971)the school moves on to a new activities-based model.
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Background Regenerative endodontics is an innovative treatment concept aiming to regenerate pulp, dentin and root structures. In the diseased or necrotic tooth, the limitation in vascular supply renders successful tissue regeneration/generation in a whole tooth challenging. The aim of this study is to evaluate the ability of vascularized tissue to develop within a pulpless tooth using tissue engineering techniques. Materials and methods A pulpless tooth chamber, filled with collagen I gel containing isolated rat dental pulp cells (DPC) and angiogenic growth factors, was placed into a hole created in the femoral cortex or into its own tooth socket, respectively. The gross, histological and biochemical characteristics of the de novo tissue were evaluated at 4 and 8weeks post-transplantation. Results Tooth revascularization and tissue generation was observed only in the femur group, confirming the important role of vascular supply in tissue regeneration. The addition of cells and growth factors significantly promoted connective tissue production in the tooth chamber. Conclusion Successful revascularization and tissue regeneration in this model demonstrate the importance of a direct vascular supply and the advantages of a stem cell approach. © 2012 John Wiley & Sons A/S.
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The accuracy of early cost estimates is critical to the success of construction projects. The selected tender price (clients' building cost) is usually seen in previous research as a holistic dependent variable when examining early stage estimates. Unlike other components of construction cost, the amount of contingencies is decided by clients/consultants with consideration of early project information. Cost drivers of contingencies estimates are associated with uncertainty and complexity, and include project size, schedule, ground condition, construction site access, market condition and so on. A path analysis of 133 UK school building contracts was conducted to identify impacts of nine major cost drivers on the determination of contingencies by different clients/cost estimators. This research finds that gross floor area (GFA), schedule and requirement of air conditioning have statistically significant impacts on the contingency determination. The mediating role of schedule between gross floor area and contingencies (GFA→Schedule→Contingencies) was confirmed with the Soble test. The total effects of the three variables on contingencies estimates were obtained with the consideration of this indirect effect. The squared multiple correlation (SMC) of contingencies (=0.624) indicates the identified three variables can explain 62.4% variance of contingencies, and it is comparatively satisfactory considering the heterogeneity among different estimators, unknown estimating techniques and different projects
Human breast cancer cell metastasis to long bone and soft organs of nude mice : a quantitative assay
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Bone is a common metastatic site in human breast cancer (HBC). Since bone metastasis occurs very rarely from current spontaneous or experimental metastasis models of HBC cells in nude mice, an arterial seeding model involving the direct injection of the cells into the left ventricle has been developed to better understand the mechanisms involved in this process. We present here a sensitive polymerase chain reaction (PCR) method to detect and quantitate bone and soft organ metastasis in nude mice which have been intracardially inoculated with Lac Z transduced HBC cells. Amplification of genomically incorporated Lac Z sequences in MDA-MB-231-BAG HBC cells enables us to specifically detect these cells in mouse organs and bones. We have also created a competitive template to use as an internal standard in the PCR reactions, allowing us to better quantitate levels of HBC metastasis. The results of this PCR detection method correlate well with cell culture detection from alternate long bones from the same mice, and are more sensitive than gross Lac Z staining with X-gal or routine histology. Comparable qualitative results were obtained with PCR and culture in a titration experiment in which mice were inoculated with increasing numbers of cells, but PCR is more quantifiable, less time consuming, and less expensive. This assay can be employed to study the molecular and cellular aspects of bone metastasis, and could easily be used in conjunction with RT-PCR-based analyses of gene products which may be involved with HBC metastasis.
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Objective To determine if a clinic-based behavioral intervention program for low-income mid-life women that emphasizes use of community resources will increase moderate intensity physical activity (PA) and improve dietary intake. Methods Randomized trial conducted from May 2003 to December 2004 at one community health center in Wilmington, NC. A total of 236 women, ages 40–64, were randomized to receive an Enhanced Intervention (EI) or Minimal Intervention (MI). The EI consisted of an intensive phase (6 months) including 2 individual counseling sessions, 3 group sessions, and 3 phone calls from a peer counselor followed by a maintenance phase (6 months) including 1 individual counseling session and 7 monthly peer counselor calls. Both phases included efforts to increase participants' use of community resources that promote positive lifestyle change. The MI consisted of a one-time mailing of pamphlets on diet and PA. Outcomes, measured at 6 and 12 months, included the comparison of moderate intensity PA between study groups as assessed by accelerometer (primary outcome) and questionnaire, and dietary intake assessed by questionnaire and serum carotenoids (6 months only). Results For accelerometer outcomes, follow-up was 75% at 6 months and 73% at 12 months. Though moderate intensity PA increased in the EI and decreased in the MI, the difference between groups was not statistically significant (p = 0.45; multivariate model, p = 0.08); however, moderate intensity PA assessed by questionnaire (92% follow-up at 6 months and 75% at 12 months) was greater in the EI (p = 0.01; multivariate model, p = 0.001). For dietary outcomes, follow-up was 90% for questionnaire and 92% for serum carotenoids at 6 months and 74% for questionnaire at 12 months. Dietary intake improved more in the EI compared to the MI (questionnaire at 6 and 12 months, p < 0.001; serum carotenoid index, p = 0.05; multivariate model, p = 0.03). Conclusion The EI did not improve objectively measured PA, but was associated with improved self-reported and objective measures of dietary intake.
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According to 2011 Australian Census figures, embedded creative employees (creative employees not working in the core Creative Industries) make up 2 per cent (or a total of 17 635) of manufacturing industry employees. The average for all industries is 1.6 per cent. In the 2011–2012 financial year the manufacturing industry formed 7.3 per cent of Australia’s gross domestic product (GDP), contributing approximately AU$106.5 billion to the economy (Department of Industry, Innovation, Science, Research and Tertiary Education 2013). Manufacturing is central to innovation, accounting for over one-quarter of all business expenditure in R&D in 2010–2011, representing around AU$4.8 billion invested in R&D (ibid.). Facing challenges such as sustainability concerns, ever-increasing offshore production and the global financial crisis, the Australian manufacturing industry needs to remain relevant and competitive to succeed. Innovation is one way to do this. Given the contribution of the manufacturing industry to the Australian economy, and the above-average portion of embedded creatives in manufacturing, it is important to consider what exactly embedded creatives add to the industry. This chapter, inspired by the Getting Creative in Healthcare report (Pagan, Higgs and Cunningham 2008), examines the contribution of embedded creatives to innovation in the manufacturing industry via case studies and supplemental data.
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We tested direct and indirect measures of benthic metabolism as indicators of stream ecosystem health across a known agricultural land-use disturbance gradient in southeast Queensland, Australia. Gross primary production (GPP) and respiration (R24) in benthic chambers in cobble and sediment habitats, algal biomass (as chlorophyll a) from cobbles and sediment cores, algal biomass accrual on artificial substrates and stable carbon isotope ratios of aquatic plants and benthic sediments were measured at 53 stream sites, ranging from undisturbed subtropical rainforest to catchments where improved pasture and intensive cropping are major land-uses. Rates of benthic GPP and R24 varied by more than two orders of magnitude across the study gradient. Generalised linear regression modelling explained 80% or more of the variation in these two indicators when sediment and cobble substrate dominated sites were considered separately, and both catchment and reach scale descriptors of the disturbance gradient were important in explaining this variation. Model fits were poor for net daily benthic metabolism (NDM) and production to respiration ratio (P/R). Algal biomass accrual on artificial substrate and stable carbon isotope ratios of aquatic plants and benthic sediment were the best of the indirect indicators, with regression model R2 values of 50% or greater. Model fits were poor for algal biomass on natural substrates for cobble sites and all sites. None of these indirect measures of benthic metabolism was a good surrogate for measured GPP. Direct measures of benthic metabolism, GPP and R24, and several indirect measures were good indicators of stream ecosystem health and are recommended in assessing process-related responses to riparian and catchment land use change and the success of ecosystem rehabilitation actions.
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This chapter reviews almost a decade of research and writing undertaken by the authors into ethical dilemmas faced by leaders in a number of different operational contexts, including schools, universities and the public sector. The importance of this body of work is emphasised by one of our research participants who argued that ethical dilemmas were the 'bread and butter' of what leaders do. The chapter comprises four main sections. The first section overviews key theoretical aspects as background to the chapter, including relevant discussions about ethics and ethical decision-making. The second section synthesises the research findings from our work in the three contexts noted above, drawing out a set of learnings that contribute to better understandings of the nature, complexities and challenges of ethical dilemmas. This section is followed by a discussion of an explanatory conceptual model of ethical dilemmas that was developed initially from the literature and confirmed by our research. The model reminds us of some of the critical issues at play in ethical dilemmas, and some of the consequences and implications for organisational culture building they can generate. By way of a short scenario, the final section provides a theory-to-practice illustration of an ethical dilemma in action. A set of recommendations, drawn from the ideas of school leaders who have worked with this and similar dilemmas, is offered as a way forward to better understanding and resolution of such dilemmas so prevalent in our schools today.
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The productivity of the construction industry has a significant effect on national economic growth. Gains from higher construction productivity flow through the economy, as all industries rely on construction to some extent as part of their business investment. Contractions and expansions of economic activity are common phenomena in an economy. Three construction cycles occurred between the years 1970 and 2011 in Malaysia. The relationships between construction productivity and economic development are examined by the partial correlation method to establish the underlying factors driving the change in construction productivity. Construction productivity is statistically significantly correlated with gross domestic product (GDP) per capita in a positive direction for the 1985–98 and 1998–2009 cycles, but not the 1970–85 cycle. Fluctuations in construction activities and the influx of foreign workers underlie the changes of construction productivity in the 1985–98 cycle. There was less fluctuation in construction activities in the 1998–2009 cycle, with changes being mainly due to the fiscal stimulation policies of the government in attempting to stabilize the economy. The intensive construction of mega-projects resulted in resource constraints and cost pressures during the 1980s and 1990s. A better management of the ‘boom-bust’ nature of the construction business cycle is required to maintain the capability and capacity of the industry.
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Organic photovoltaic devices with either bulk heterojunction (BHJ) or nanoparticulate (NP) active layers have been prepared from a 1:2 blend of (poly{3,6-dithiophene-2-yl-2,5-di(2-octyldodecyl)-pyrrolo[3,4-c]pyrrole-1, 4-dione-alt-naphthalene}) (PDPP-TNT) and the fullerene acceptor, ([6,6]-phenyl C71-butyric acid methyl ester) (PC70BM). Atomic force microscopy (AFM) and scanning electron microscopy (SEM) have been used to investigate the morphology of the active layers of the two approaches. Mild thermal treatment of the NP film is required to promote initial joining of the NPs in order for the devices to function, however the NP structure is retained. Consequently, whereas gross phase segregation of the active layer occurs in the BHJ device spin cast from chloroform, the nanoparticulate approach retains control of the material domain sizes on the length scale of exciton diffusion in the materials. As a result, NP devices are found to generate more than twice the current density of BHJ devices and have a substantially greater overall efficiency. The use of aqueous nanoparticulate dispersions offers a promising approach to control the donor acceptor morphology on the nanoscale with the benefit of environmentally- friendly, solution-based fabrication. © 2014 the Owner Societies.
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So called “knowledge work” is seen as integral to post-industrial society and, for some, information and communications technologies (ICTs) are critical enablers of the associated practices. Many still propose the technologically deterministic route of rolling out ICTs and expecting that users will, and indeed can, “download” what they know into a system that can then be used in a number of ways. This approach is usually underpinned by the predominant assumption that the system will be developed by one group (developers) and used by another group (users). In this paper, we report on an exploratory case study of the enactment of ICT supported knowledge work in a human resources contact center which illustrates the negotiable boundary between the developer and user in local level innovation processes. Drawing upon ideas from the social shaping of technology, we examine how discussions regarding producer-user relations in innovation processes require a degree of greater sophistication as we show how users often develop (or produce) technologies and work practices in situ—in this case, to enable knowledge work practices and contribute to the project of constructing the knowledge component of professional identity. Much has been made of contextualizing the user; further work is required to contextualize the developer as a user and understand the social actors in ICT innovation environments who straddle both domains
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A. Background and context 1. Education, particularly basic education (grades1-9), has been considered critical to promoting national economic growth and social well being1. Three factors that con-tribute to the above are: (i) Education increases human capital inherent in a labor force and thus increases productivity. It also increases capacity for working with others and builds community consensus to support national development. (ii) Education can in-crease the innovative capacity of a community to support social and economic growth—use of new technologies, products and services to promote growth and wellbeing. (iii) Education can facilitate knowledge transfer needed to understand the social and eco-nomic innovations and new processes, practices and values. Cognizant of the above benefits of education, the Millennium Development Goals (MDG) and the Education for All (EFA) declarations advocating universal basic education were formulated and ratified by UN member countries. 2. Achieving universal primary education (grade 6) may not be sufficient to maxim-ize the above noted socio-economic and cultural benefits. There is general consensus that basic literacy and numeracy up to grade 9 are essential foundational blocks for any good education system to support national development. Basic Education provides an educational achievement threshold that ensures the learning is retained. To achieve this, the donor partner led interventions and the UN declarations such as the MDG goals have sought universal access to basic education (grades 1-9). As many countries progress towards achieving the universal access targets, recent research evidence suggests that we need more than just access to basic education to impact on the na-tional development. Measuring basic education completion cycle, gross enrolment rate (GER) and participation rate etc., has to now include a focus on quality and relevance of the education2. 3. While the above research finding is generally accepted by the Government of In-donesia (GoI), unlike many other developing countries, Indonesia is geographically and linguistically complex and has the fourth largest education sector in the world. It has over 3000 islands, 17,000 ethnic groups and it takes as long as 7 hours to travel from east to west of the country and has multiple time differences. The education system has six years of primary education (grades 1-6), 3 years of junior secondary education (grades 7-9) and three years of senior secondary education (grades 10-12). Therefore, applying the findings of the above cited research in a country like Indonesia is a chal-lenge. Nevertheless, since the adoption of the National Education Law (2003)3 the GoI has made significant progress in improving access to and quality of basic education (grades 1-9). The 2011/12 national education statistics show the primary education (grades 1-6) completion rate was 99.3%, the net enrolment rate (NER) was 95.4% and the GER was 115.4%. This is a significant achievement considering the complexities faced within Indonesia. This increase in the primary education sub-sector, however, has not flowed onto the Junior Secondary School (JSS) education. The transition from pri-mary to JSS is still short of the GoI targets. In 2012, there were 146,826 primary schools feeding into 33,668 junior secondary schools. The transition rate from primary to secondary in 2011/12 was 78%. When considering district or sub-district level data the transition in poor districts could be less than the aggregated national rate. Poverty and lack of parents’ education, confounded by opportunity cost, are major obstacles to transitioning to JSS4. 4. Table 1 presents a summary of GoI initiatives to accelerate the transition to JSS. GoI, with assistance from the donor community, has built 2465 new regular JSS, mak-ing the total number of regular JSS 33,668. In addition, 57,825 new classrooms have been added to existing regular JSS. Also, in rural and remote areas 4136 Satu-Atap5 (SATAP) schools were built to increase access to JSS. These SATAP schools are the focus of this study as they provide education opportunities to the most marginalized, ru-ral, remote children who otherwise would not have access to JSS and consequently not complete basic education.
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Establishment of asymptomatic bacteriuria (ABU) with Escherichia coli 83972 is a viable prophylactic alternative to antibiotic therapy for the prevention of recurrent bacterial urinary tract infection in humans. Approximately 2 x 108 viable E. coli 83972 cells were introduced into the bladder of six healthy female dogs via a sterile urinary catheter. The presence of pyuria, depression, stranguria, pollakiuria and haematuria was documented for 6 weeks and urinalysis and aerobic bacterial cultures were performed every 24–72 h. Pyuria was present in all dogs on day 1 post-inoculation and 4/6 dogs (67%) had a positive urine culture on this day. Duration of colonization ranged from 0 to 10 days (median 4 days). Four dogs were re-inoculated on day 20. Duration of colonization following the second inoculation ranged from 1 to 3 days. No dog suffered pyrexia or appeared systemically unwell but all dogs initially exhibited mild pollakiuria and a small number displayed gross haematuria and/or stranguria. By day 3 of each trial all clinical signs had resolved. Persistent bacteriuria was not achieved in any dog but two dogs were colonized for 10 days following a single inoculation. Further research is required to determine whether establishment of ABU in dogs with recurrent urinary tract infection is a viable alternative to repeated doses of antimicrobial agents.