943 resultados para HIGHWAY SECTION
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The impact-induced deposition of Al13 clusters with icosahedral structure on Ni(0 0 1) surface was studied by molecular dynamics (MD) simulation using Finnis–Sinclair potentials. The incident kinetic energy (Ein) ranged from 0.01 to 30 eV per atom. The structural and dynamical properties of Al clusters on Ni surfaces were found to be strongly dependent on the impact energy. At much lower energy, the Al cluster deposited on the surface as a bulk molecule. However, the original icosahedral structure was transformed to the fcc-like one due to the interaction and the structure mismatch between the Al cluster and Ni surface. With increasing the impinging energy, the cluster was deformed severely when it contacted the substrate, and then broken up due to dense collision cascade. The cluster atoms spread on the surface at last. When the impact energy was higher than 11 eV, the defects, such as Al substitutions and Ni ejections, were observed. The simulation indicated that there exists an optimum energy range, which is suitable for Al epitaxial growth in layer by layer. In addition, at higher impinging energy, the atomic exchange between Al and Ni atoms will be favourable to surface alloying.
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In this paper we analyse the effects of highway traffic flow parameters like vehicle arrival rate and density on the performance of Amplify and Forward (AF) cooperative vehicular networks along a multi-lane highway under free flow state. We derive analytical expressions for connectivity performance and verify them with Monte-Carlo simulations. When AF cooperative relaying is employed together with Maximum Ratio Combining (MRC) at the receivers the average route error rate shows 10-20 fold improvement compared to direct communication. A 4-8 fold increase in maximum number of traversable hops can also be observed at different vehicle densities when AF cooperative communication is used to strengthen communication routes. However the theorical upper bound of maximum number of hops promises higher performance gains.
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Highway infrastructure development typically requires major capital input. Unless planned properly, such requirements can cause serious financial constraints for investors. The push for sustainability adds a new dimension to the complexity of evaluating highway projects. Finding environmentally and socially responsible solutions for highway construction will improve its potential for acceptance by the society and in many instances the infrastructure's life span. Even so, the prediction and determination of a project's long-term financial viability can be a precarious exercise. Existing studies in this area have not indicated details of how to identify and deal with costs incurred in pursuing sustainability measures in highway infrastructure. This paper provides insights into the major challenges of implementing sustainability in highway project development in terms of financial concerns and obligations. It discusses the results from recent research through a literature study and a questionnaire survey of key industry stakeholders involved in highway infrastructure development. The research identified critical cost components relating to sustainability measures based on perspectives of industry stakeholders. All stakeholders believe sustainability related costs are an integral part of the decision making. However, the importance rating of these costs is relative to each stakeholder's core business objectives. This will influence the way these cost components are dealt with during the evaluation of highway investment alternatives and financial implications. This research encourages positive thinking among the highway infrastructure practitioners about sustainability. It calls for the construction industry to maximise sustainability deliverables while ensuring financial viability over the life cycle of highway infrastructure projects.
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Background Women undergoing Cesarean Section (CS) are vulnerable to the adverse effects associated with perioperative core temperature drop, in part due to the tendency for CS to be performed under neuraxial anesthesia, blood and fluid loss, and vasodilation. Inadvertent perioperative hypothermia (IPH) is a common condition that affects patients undergoing surgery of all specialties and is detrimental to all age groups, including neonates. Previous systematic reviews on IPH prevention largely focus on either adult or all ages populations, and have mainly overlooked pregnant or CS patients as a distinct group. Not all recommendations made by systematic reviews targeting all adult patients may be transferable to CS patients. Alternative, effective methods for preventing or managing hypothermia in this group would be valuable. Objectives To synthesize the best available evidence in relation to preventing and/or treating hypothermia in mothers after CS surgery. Types of participants Adult patients over the age of 18 years, of any ethnic background, with or without co-morbidities, undergoing any mode of anesthesia for any type of CS (emergency or planned) at healthcare facilities who have received interventions to limit or manage perioperative core heat loss were included. Types of intervention(s) Active or passive warming methods versus usual care or placebo, that aim to limit or manage core heat loss as applied to women undergoing CS were included. Types of studies Randomized controlled trials (RCTs) that met the inclusion criteria, with reduction of perioperative hypothermia a primary or secondary outcome were considered. Types of outcomes Primary outcome: maternal core temperature measured during the preoperative, intraoperative and postoperative phases of care Secondary outcomes: newborn core temperature at birth, umbilical pH obtained immediately after birth, Apgar scores, length of Post Anesthetic Care Unit (PACU) stay, maternal thermal comfort. Search strategy A comprehensive search was undertaken of the following databases from their inception until May 2012: ProQuest, Web of Science, Scopus, Dissertation and Theses PQDT (via ProQuest), Current Contents, CENTRAL, Mednar, OpenGrey, Clinical Trials. There were no language restrictions. Methodological quality Retrieved papers were assessed for methodological quality by two independent reviewers prior to inclusion using JBI software. Disagreements were resolved via consultation with the third reviewer. An assessment of quality of the included papers was also made in relation to five key quality factors. Data collection Two independent reviewers extracted data from the included papers using a previously piloted customized data extraction tool. Results 12 studies with a combined total of 719 participants were included. Three broad intervention groups were identified; intravenous (IV) fluid warming, warming devices, leg wrapping. IV fluid warming, whether administered intraoperatively or preoperatively, was found to be effective at maintaining maternal (but not neonatal) temperature and preventing shivering, but does not improve thermal comfort. The effectiveness of IV fluid warming on Apgar scores and umbilical pH remains unclear. Warming devices, including forced air warming and under body carbon polymer mattresses, were effective at preventing hypothermia and reduced shivering, however were most effective if applied preoperatively. The effectiveness of warming devices to improve thermal comfort remains unclear. Preoperative forced air warming appears to aid maintenance of neonatal temperature, while intraoperative forced air warming does not. Forced air warming was not effective at improving Apgar scores and the effects for umbilical pH remain unclear. Conclusions Intravenous fluid warming, by any method, improves maternal temperature and reduces shivering for women undergoing CS. Preoperative body warming devices also improve maternal temperature, in addition to reducing shivering.
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Pilot cars are used in one-lane two-way work zones to guide traffic and keep their speeds within posted limits. While many studies have examined the effectiveness of measures to reduce vehicle speeds in work zones, little is known about the reductions achievable through the use of pilot cars. This paper examines the effectiveness of a pilot car in reducing travel speeds in a rural highway work zone in Queensland, Australia. Analysis of speed data covering a period of five days showed that a pilot car reduced average speeds at the treatment location, but not downstream. The proportion of vehicles speeding through the activity area was also reduced, particularly those traveling at 10 km/h or more above the posted limit. Motorists were more likely to speed during the day, under a 40 kh/h limit, when traffic volumes were higher and when there were fewer vehicles in the traffic stream. Medium vehicles were less likely to speed in the presence of a pilot car than light vehicles. To maximize these benefits, it is necessary to ensure that the pilot car itself is not speeding.
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This Media Arts-POP implements Media Arts curriculum in a Year 4 classroom at Waterford West State School, Queensland. While media arts form was the lead area for this package, students developed knowledge of and skills in English, visual arts and some elements of music. In the media arts elements, students learned to use media production equipment (in this case iPads, although other tablets could be used), and to use techniques such as composition and lighting to capture digital images and to record voice and sound effects. The package demonstrates that a number of curriculum areas can be combined to ensure that various curriculum areas are covered without losing the specificity of any one area.
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Highway construction works have significant bearings on all aspects of sustainability. With the increasing level of public awareness and government regulatory measures, the construction industry is experiencing a cultural shift to recognise, embrace and pursue sustainability. Stakeholders are now keen to identify sustainable alternatives and the financial implications of including them on a lifecycle basis. They need tools that can aid the evaluation of investment options. To date, however, there have not been many financial assessments on the sustainability aspects of highway projects. This is because the existing life-cycle costing analysis (LCCA) models tend to focus on economic issues alone and are not able to deal with sustainability factors. This paper provides insights into the current practice of life-cycle cost analysis, and the identification and quantification of sustainability-related cost components in highway projects through literature review, questionnaire surveys and semi-structured interviews. The results can serve as a platform for highway project stakeholders to develop practical tools to evaluate highway investment decisions and reach an optimum balance between financial viability and sustainability deliverables.
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This article examines some questions of statutory interpretation as they apply to section 130 of the Land Title Act 1994 (Qld)
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Background Most studies examining determinants of rising rates of caesarean section have examined patterns in documented reasons for caesarean over time in a single location. Further insights could be gleaned from cross-cultural research that examines practice patterns in locations with disparate rates of caesarean section at a single time point. Methods We compared both rates of and main reason for pre-labour and intrapartum caesarean between England and Queensland, Australia, using data from retrospective cross-sectional surveys of women who had recently given birth in England (n = 5,250) and Queensland (n = 3,467). Results Women in Queensland were more likely to have had a caesarean birth (36.2%) than women in England (25.1% of births; OR = 1.44, 95% CI = 1.28-1.61), after adjustment for obstetric characteristics. Between-country differences were found for rates of pre-labour caesarean (21.2% vs. 12.2%) but not for intrapartum caesarean or assisted vaginal birth. Compared to women in England, women in Queensland with a history of caesarean were more likely to have had a pre-labour caesarean and more likely to have had an intrapartum caesarean, due only to a previous caesarean. Among women with no previous caesarean, Queensland women were more likely than women in England to have had a caesarean due to suspected disproportion and failure to progress in labour. Conclusions The higher rates of caesarean birth in Queensland are largely attributable to higher rates of caesarean for women with a previous caesarean, and for the main reason of having had a previous caesarean. Variation between countries may be accounted for by the absence of a single, comprehensive clinical guideline for caesarean section in Queensland. Keywords: Caesarean section; Childbirth; Pregnancy; Cross-cultural comparison; Vaginal birth after caesarean; Previous caesarean section; Patient-reported data; Quality improvement
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Here we report on an unconventional Ni-P alloy-catalyzed, high-throughput, highly reproducible chemical vapor deposition of ultralong carbon microcoils using acetylene precursor in the temperature range 700-750 °C. Scanning electron microscopy analysis reveals that the carbon microcoils have a unique double-helix structure and a uniform circular cross-section. It is shown that double-helix carbon microcoils have outstanding superelastic properties. The microcoils can be extended up to 10-20 times of their original coil length, and quickly recover the original state after releasing the force. A mechanical model of the carbon coils with a large spring index is developed to describe their extension and contraction. Given the initial coil parameters, this mechanical model can successfully account for the geometric nonlinearity of the spring constants for carbon micro- and nanocoils, and is found in a good agreement with the experimental data in the whole stretching process.
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SupaCee section is one of the cold-formed steel members which is increasingly used in the construction sector. It is characterized by unique ribbed web and curved lip elements, and is claimed to be more economical with extra strength than the traditional channel sections. SupaCee sections are widely used in Australia as floor joists, bearers, purlins and girts. Many experimental and numerical studies have been carried out to evaluate the behaviour and design of conventional channel beams subject to web crippling. To date, however, no investigation has been conducted into the web crippling behaviour and strength of SupaCee sections. Current cold-formed steel design equations do not include any design procedures for SupaCee sections. Hence experimental studies were conducted to assess the web crippling behaviour and strengths of SupaCee sections under ETF and ITF load cases. Thirty six web crippling tests were conducted and the capacity results were compared with the predictions from the AS/NZS 4600 and AISI design rules developed for conventional channel sections. Comparison of ultimate web crippling capacities from tests showed that AS/NZS 4600 and AISI design equations are unconservative for SupaCee sections under ETF load case, but are overly conservative for ITF load case. Hence new equations were proposed to determine the web crippling capacities of SupaCee sections based on the experimental results from this study. Suitable design rules were also developed within the direct strength method format. This paper presents the details of this experimental study of SupaCee sections subject to web crippling and the results.
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Surgical site infections following caesarean section are a serious and costly adverse event for Australian hospitals. In the United Kingdom, 9% of women are diagnosed with a surgical site infection following caesarean section either in hospital or post-discharge (Wloch et al 2012, Ward et al 2008). Additional staff time, pharmaceuticals and health supplies, and increased length of stay or readmission to hospital are often required (Henman et al 2012). Part of my PhD investigated the economics of preventing post-caesarean infection. This paper summarises a review of relevant infection prevention strategies. Administering antibiotic prophylaxis 15 to 60 minutes pre-incision, rather than post cordclamping, is probably the most important infection prevention strategy for caesarean section (Smaill and Gyte2010, Liu et al 2013, Dahlke et al 2013). However the timing of antibiotic administration is reportedly inconsistent in Australian hospitals. Clinicians may be taking advice from the influential, but out-dated RANZCOG and United States Centers for Disease Control and Prevention guidelines (Royal Australian and New Zealand College of Obstetricians and Gynaecologists 2011, Mangram et al 1999). A number of other important international clinical guidelines, including Australia's NHMRC guidelines, recommend universal prophylactic antibiotics pre-incision for caesarean section (National Health and Medical Research Council 2010, National Collaborating Centre for Women's and Children's Health 2008, Anderson et al 2008, National Collaborating Centre for Women's and Children's Health 2011, Bratzler et al 2013, American College of Obstetricians and Gynecologists 2011a, Antibiotic Expert Group 2010). We need to ensure women receive preincision antibiotic prophylaxis, particularly as nurses and midwives play a significant role in managing an infection that may result from sub-optimal practice. It is acknowledged more explicitly now that nurses and midwives can influence prescribing and administration of antibiotics through informal approaches (Edwards et al 2011). Methods such as surgical safety checklists are a more formal way for nurses and midwives to ensure that antibiotics are administered pre-incision (American College of Obstetricians and Gynecologists 2011 b). Nurses and midwives can also be directly responsible for other infection prevention strategies such as instructing women to not remove pubic hair in the month before the expected date of delivery and wound management education (Ng et al 2013). Potentially more costly but effective strategies include using a Chlorhexidine-gluconate (CHG) sponge preoperatively (in addition to the usual operating room skin preparation) and vaginal cleansing with a povidone-iodine solution (Riley et al 2012, Rauk 2010, Haas, Morgan, and Contreras 2013).