919 resultados para recent 300 years


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work focuses on the development of a stand-alone gas nanosensor node, powered by solar energy to track concentration of polluted gases such as NO2, N2O, and NH3. Gas sensor networks have been widely developed over recent years, but the rise of nanotechnology is allowing the creation of a new range of gas sensors [1] with higher performance, smaller size and an inexpensive manufacturing process. This work has created a gas nanosensor node prototype to evaluate future field performance of this new generation of sensors. The sensor node has four main parts: (i) solar cells; (ii) control electronics; (iii) gas sensor and sensor board interface [2-4]; and (iv) data transmission. The station is remotely monitored through wired (ethernet cable) or wireless connection (radio transmitter) [5, 6] in order to evaluate, in real time, the performance of the solar cells and sensor node under different weather conditions. The energy source of the node is a module of polycrystalline silicon solar cells with 410cm2 of active surface. The prototype is equipped with a Resistance-To-Period circuit [2-4] to measure the wide range of resistances (KΩ to GΩ) from the sensor in a simple and accurate way. The system shows high performance on (i) managing the energy from the solar panel, (ii) powering the system load and (iii) recharging the battery. The results show that the prototype is suitable to work with any kind of resistive gas nanosensor and provide useful data for future nanosensor networks.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A number of mathematical models investigating certain aspects of the complicated process of wound healing are reported in the literature in recent years. However, effective numerical methods and supporting error analysis for the fractional equations which describe the process of wound healing are still limited. In this paper, we consider numerical simulation of fractional model based on the coupled advection-diffusion equations for cell and chemical concentration in a polar coordinate system. The space fractional derivatives are defined in the Left and Right Riemann-Liouville sense. Fractional orders in advection and diffusion terms belong to the intervals (0; 1) or (1; 2], respectively. Some numerical techniques will be used. Firstly, the coupled advection-diffusion equations are decoupled to a single space fractional advection-diffusion equation in a polar coordinate system. Secondly, we propose a new implicit difference method for simulating this equation by using the equivalent of the Riemann-Liouville and Gr¨unwald-Letnikov fractional derivative definitions. Thirdly, its stability and convergence are discussed, respectively. Finally, some numerical results are given to demonstrate the theoretical analysis.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Black rat (Rattus rattus), a serious pest of Australian macadamia orchards has been estimated to cause up to 30% crop damage in Australian orchards. In recent years an increase in the number of commercially available cultivars has seen a change in orchard characteristics in Australia, primarily effecting fruiting and flowering patterns. This has been suggested to affect the feeding behaviour of rodents and in turn altered the damage process. In this study we compare the extent of damage in orchards containing one of three prevalent cultivars (A4/A16, A268 and HAES 344/741) and investigate the influence of these cultivars, particularly their distinctive fruiting traits, on rodent damage within the orchard. We demonstrate that the temporal pattern and extent of damage differs between cultivar types. Newer Australian macadamia cultivars tested in this study were found to be far more susceptible to rodent damage than the older Hawaiian developed cultivars, most likely due to an extended fruiting period and thinner shells. This has resulted in a more sustained period of crop damage than the patterns of crop damage observed in previous Australian studies. Crop damage caused by R. rattus is significantly higher in orchards that maintain high levels of canopy resources through the fruiting season and we postulate that this is due to the extended fruiting periods of the new cultivars used. The maintenance of canopy resource load in turn corresponds to high crop damage, in this study resulting in crop losses of up to 25%.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Anomalous subdiffusion equations have in recent years received much attention. In this paper, we consider a two-dimensional variable-order anomalous subdiffusion equation. Two numerical methods (the implicit and explicit methods) are developed to solve the equation. Their stability, convergence and solvability are investigated by the Fourier method. Moreover, the effectiveness of our theoretical analysis is demonstrated by some numerical examples. © 2011 American Mathematical Society.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There is a tax amendment bill which will be debated. The Government has promised to outline its plan for the reform of the taxation system sometime this year. The plans appear to go beyond the mere introduction of some sort of goods and services tax to reform of the whole taxation system including fiscal relations with the States. Not for profit organisations will find their taxation environment will change. Governments are reluctant to permit exemptions to a GST style arrangements. GST trade offs such as reduced income tax rates and abolishing indirect taxes are useless to nonprofit organisations, as many are already exempt from such imposts. Administrative changes to tax collections may also have an impact. If the government decides to make an individual PAYE taxpayer return optional in exchange for no or standard deductions, this may have an effect on fundraising. The FBT and salary packaging schemes that not for profit organisations use will be under intense scrutiny. A regionalisation of the ATO along the successful model of the ASC would see discrete areas such as not for profit exemptions being centralised in one regional office for the whole of Australia. For example the Tasmanian ASC Office has the responsibility for much work in respect of corporate charities and not for profit companies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Internet Child Abuse: Current Research and Policy provides a timely overview of international policy, legislation and offender management and treatment practice in the area of Internet child abuse. Internet use has grown considerably over the last five years, and information technology now forms a core part of the formal education system in many countries. There is however, increasing evidence that the Internet is used by some adults to access children and young people in order to ‘groom’ them for the purposes of sexual abuse; as well as to produce and distribute indecent illegal images of children. This book presents and assesses the most recent and current research on internet child abuse, addressing: its nature, the behaviour and treatment of its perpetrators, international policy, legislation and protection, and policing. It will be required reading for an international audience of academics, researchers, policy-makers and criminal justice practitioners with interests in this area.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In recent years ‘‘welfare reform’’ has become a vehicle for many neo-conservative social commentators to invoke marriage vows as a cure for poverty and the abuse of poor women. Their basic claim is that cohabiting relationships are not only more violent than marriages, but that married couples are happier, healthier, and wealthier than cohabiting ones. A policy then of encouraging cohabitants to marry, they claim, would lead to increased family wealth and decreased family violence. We examine these claims in this article, along with the alternative argument that marriage per se is not a solution to these problems. Alternatively we propose an economic exclusion/male peer support model that explains why many cohabiting men abuse women in intimate relationships. If forcing these couples to marry is not a solution, then structural solutions are necessary, along with progressive policy suggestions that address the antecedents of poverty and abuse.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The study of biologically active peptides is critical to the understanding of physiological pathways, especially those involved in the development of disease. Historically, the measurement of biologically active endogenous peptides has been undertaken by radioimmunoassay, a highly sensitive and robust technique that permits the detection of physiological concentrations in different biofluid and tissue extracts. Over recent years, a range of mass spectrometric approaches have been applied to peptide quantification with limited degrees of success. Neuropeptide Y (NPY), peptide YY (PYY), and pancreatic polypeptide (PP) belong to the NPY family exhibiting regulatory effects on appetite and feeding behavior. The physiological significance of these peptides depends on their molecular forms and in vivo concentrations systemically and at local sites within tissues. In this report, we describe an approach for quantification of individual peptides within mixtures using high-performance liquid chromatography electrospray ionization tandem mass spectrometry analysis of the NPY family peptides. Aspects of quantification including sample preparation, the use of matrix-matched calibration curves, and internal standards will be discussed. This method for the simultaneous determination of NPY, PYY, and PP was accurate and reproducible but lacks the sensitivity required for measurement of their endogenous concentration in plasma. The advantages of mass spectrometric quantification will be discussed alongside the current obstacles and challenges. © 2012 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 357–366, 2012.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There has been a renaissance in Australian genre cinema in recent years. Indeed, not since the 1980s have Australian genre movies across action, adventure, horror, and science-fiction among others, experienced such prominence within production, policy discourse, and industry debate. Genre movies, typically associated with commercial filmmaking and entertainment, have been identified as a strategy to improve the box-office performance of Australian feature films and to attract larger audiences. Much of this conversation has revolved around the question of whether or not genre can deliver on these high expectations and transform the unpredictable local film industry into a popular and profitable commercial production sector. However, this debate for the most part has been disconnected from analysis of Australia’s genre movie heritage in terms of their position within Australian cinema and their reception with domestic audiences, and how this correlates to contemporary trends. As this chapter argues, genre production is not a silver bullet which will single handedly improve the Australian feature film industry’s commercial performance. Genre movies have occupied, and continue to occupy, a difficult position within Australian cinema and face numerous challenges in terms of reception with national audiences, limited production scale and enterprise structures, and ongoing tensions between culture and commerce.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In November 1999, the Queensland Health (QH) Transition to Practice Nurse Education Program - Intensive Care (TPNEP-IC) was initiated in QH Intensive Care Units (ICUs) across Queensland. This 12-month, state-wide, workplace based education program has set minimum standards for intensive care nursing education and therefore minimum standards for intensive care nursing practice in QH. In the 12 years of operation, 824 nurses have completed TPNEP-IC, 761 achieving academic credit status and 453 utilising this academic credit status to undertake postgraduate study in critical/intensive care nursing at three Queensland universities. These outcomes were achieved through the appointment of nurse educators within ICUs who, through a united and strong commitment to this state-wide approach formed collaborative professional networks, which resulted in the development, implementation and maintenance of the program. Furthermore, these networks enabled a framework of support for discussion and dissemination of evidence based practice, to endorse quality processes for TPNEP-IC and to nurture leadership potential among educators. Challenges to overcome included obtaining adequate resources to support all aspects of the program, gaining local management and administrative support, and embedding TPNEP-IC within ICU culture. The 12 years of operation of the program have demonstrated its long term sustainability. The program is being launched through a new blended learning approach utilising e-learning strategies. To capitalise on the current success, a strong commitment by all stakeholders will be required to ensure the ongoing sustainability of the program.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: To evaluate a healthy lifestyle intervention to reduce adiposity in children aged 5 to 9 years and assess whether adding parenting skills training would enhance this effect. PARTICIPANTS AND METHODS: We conducted a single-blinded randomized controlled trial of prepubertal moderately obese (International Obesity Task Force cut points) children, aged 5 to 9 years. The 6-month program targeted parents as the agents of change for implementing family lifestyle changes. Only parents attended group sessions. We measured BMI and waist z scores and parenting constructs at baseline, 6, 12, 18, 24 months. RESULTS: Participants (n = 169; 56% girls) were randomized to a parenting skills plus healthy lifestyle group (n = 85) or a healthy lifestyle–only group (n = 84). At final 24-month assessment 52 and 54 children remained in the parenting skills plus healthy lifestyle and the healthy lifestyle–only groups respectively. There were reductions (P < .001) in BMI z score (0.26 [95% confidence interval: 0.22–0.30]) and waist z score (0.33 [95% confidence interval: 0.26–0.40]). There was a 10% reduction in z scores from baseline to 6 months that was maintained to 24 months with no additional intervention. Overall, there was no significant group effect. A similar pattern of initial improvement followed by stability was observed for parenting outcomes and no group effect. CONCLUSIONS: Using approaches that specifically target parent behavior, relative weight loss of ∼10% is achievable in moderately obese prepubertal children and can be maintained for 2 years from baseline. These results justify an investment in treatment as an effective secondary obesity-prevention strategy.