121 resultados para Methane Consumption


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Food insecurity is the inadequate access to, or availability of, sufficient amounts of nutritious, culturally-appropriate and safe foods, or the inability to acquire such foods by socially acceptable means. Food insecurity has been shown to be associated with poor dietary intakes and poor health status. Recently, evidence has emerged suggesting increased rates of food insecurity among those with substance abuse problems, including those who smoke. This cross-sectional study investigates the potential moderating effect of smoking on the association between food insecurity and fruit and vegetable intakes among the Australian population, using regression analyses. Participants were adults 18 years and older participating in the 2004/05 National Health Survey (n = 19,500). Those from food insecure households were up to two-times more likely to report inadequate fruit and vegetable intakes compared to those who were food secure. Those who smoked were nearly six times more likely to report being food insecure, and up to three-times more likely to report inadequate fruit and vegetable intakes, compared to their non-smoking counterparts. Further analyses revealed a marked decline in the strength of the association between food insecurity and fruit consumption with the addition of smoking status into a regression model. These findings have important implications for the development of policy and interventions to address food insecurity, suggesting that those from food insecure households are less likely to comply with national dietary recommendations, and that this may in part be moderated by smoking status.

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It is often argued that consumption of alcohol, tobacco and drugs is detrimental to the cognitive abilities of teenagers. In order to disentangle a possible causal effect of these substances use from a self-selection bias, we control for pupils previous performance and for their previous rate of progression applying a DiDiD strategy. Using the NELS 1988 panel dataset, we find that the effects of alcohol and tobacco on test scores disappear once the selection bias is controlled for (this does not preclude long term detrimental effects). However, we find reliable evidence that heavy use of drugs (marijuana and cocaine) has direct detrimental effects on educational achievements. Hence, our results may have significant policy implications.

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Objective: Excessive alcohol consumption is common among people with psychotic disorders. While there is an extensive literature on the efficacy of psychological treatments for excessive drinking, few studies have examined interventions addressing this issue among people with psychotic disorders. Method: Systematic searches in PubMed and PsycINFO were conducted to identify randomized controlled trials comparing manual guided psychological interventions for excessive alcohol consumption among individuals with psychotic disorders. Of the 429 articles identified, 7 met inclusion criteria. Data were extracted from each study regarding study sample characteristics, design, results, clinical significance of alcohol consumption results, and methodological limitations. Results: Assessment interviews, brief motivational interventions and lengthier cognitive behavior therapy have been associated with reductions in alcohol consumption among people with psychosis. While brief interventions (i.e., 1-2 sessions) were generally as effective as longer duration psychological interventions (i.e., 10 session) for reducing alcohol consumption, longer interventions provided additional benefits for depression, functioning and other alcohol outcomes. Conclusion: Excessive alcohol consumption among people with psychotic disorders is responsive to psychological interventions. It is imperative that such approaches are integrated within standard care for people with psychosis.

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This paper details a team-based feedback approach for reducing resource consumption. The approach uses paper printing within office environments as a case study. It communicates the print usage of each participant’s team rather than the participant’s individual print usage. Feedback is provided weekly via emails and contains normative information, along with eco-metrics and team-based comparative statistics. The approach was empirically evaluated to study the effectiveness of the feedback method. The experiment comprised of 16 people belonging to 4 teams with data on their print usage gathered over 58 weeks, using the first 30-35 weeks as a baseline. The study showed a significant reduction in individual printing with an average of 28%. The experiment confirms the underlying hypothesis that participants are persuaded to reduce their print usage in order to improve the overall printing behaviour of their teams. The research provides clear pathways for future research to qualitatively investigate our findings.

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Cyclone Yasi struck the Cassowary Coast of Queensland in the early hours of Feb 3, 2011, destroying many homes sand property, including the destruction of the Cardwell and district historical society’s premises. With their own homes flattened, many were forced to live in mobile accommodation, with extended family, or leave altogether. The historical society members however were more devastated by their flattened foreshore museum and loss of their collection material. A call for assistance was made through the OHAA Qld branch, who along with QUT sponsored a trip to somehow plan how they could start to pick up the pieces to start again. This presentation highlights the need for communities to gather, preserve and present their own stories, in a way that is sustainable and meaningful to them, but that good advice and support along the way is important. Two 2 day workshops were held in March and then September, augmented by plenty of email correspondence and phone calls in between. Participants learnt that if they could conduct quality oral history interviews, they could later use these in many exhibitable ways including: documentary pieces; digital stories; photographic collections; creative short stories; audio segments –while also drawing closely together a suffering community. This story is not only about the people who were interviewed about the night Yasi struck, but the amazing women (all over 50) of the historical society who were willing to try and leap the digital divide that faces older Australians, especially those in rural Australia, so that their older local stories would not be lost and so that new stories could also be remembered.

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The status of entertainment as both a dimension of human culture, and a booming global industry is increasing. Given more recent consumer-centric definitions of entertainment, the entertainment consumer has grown in prominence and is now coming under closer scrutiny. However viewing entertainment consumers as always behaving in a similar fashion towards entertainment as to other products may be selling them short. For a start, entertainment consumers can exhibit a strong loyalty towards their favourite entertainment products that is the envy of the marketing world. Academic researchers and marketers who are keen to investigate entertainment consumers would benefit from a theoretical base from which to commence. This essay therefore, takes a consumer-oriented focus in defining entertainment and conceptualises a model of entertainment consumption. In approaching the study of entertainment one axiomatic question remains: how should we define it? Richard Dyer notes that, considering that the category of entertainment can include – by its own definition in the song ‘That’s entertainment!’ – everything from Hamlet and Oedipus Rex to ‘the clown with his pants falling down’ and ‘the lights on the lady in tights’, it doesn’t make much sense to try to define entertainment as being marked by particular textual features (as is done, for example, by Avrich, 2002). Dyer’s position is rather that ‘entertainment is not so much a category of things as an attitude towards things’ (Dyer, 1973: 9). He traces the modern conception of entertainment back to the writings of Molière. This writer defended the purpose of his plays against attacks from the church that they were not sufficiently edifying by insisting that, as entertainments he had no interest in edifying audiences – his ‘real purpose …was to provide people pleasure – and the definition of that was to be decided by “the people”’(Dyer, 1973: 9). In my own discipline of Marketing this approach has been embraced – Kaser and Oelkers, for example, define entertainment as ‘whatever people are willing to spend their money and spare time viewing’ (2008, 18). That is the approach taken in this paper, where I see entertainment as ‘consumer-driven culture’ (McKee and Collis, 2009) – a definition that is closely aligned with the marketing concept. Within a marketing framework I explore what the consumption of entertainment can tell us about the relationships between consumers and culture more generally. For entertainment offers an intriguing case study, and is often consumed in ways that challenge many of our assumptions about marketing and consumer behaviour.

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Shale is an increasingly important source of natural gas in the United States. The gas is held in fine pores that need to be accessed by horizontal drilling and hydrofracturing techniques. Understanding the nature of the pores may provide clues to making gas extraction more efficient. We have investigated two Mississippian Barnett Shale samples, combining small-angle neutron scattering (SANS) and ultrasmall-angle neutron scattering (USANS) to determine the pore size distribution of the shale over the size range 10 nm to 10 μm. By adding deuterated methane (CD4) and, separately, deuterated water (D2O) to the shale, we have identified the fraction of pores that are accessible to these compounds over this size range. The total pore size distribution is essentially identical for the two samples. At pore sizes >250 nm, >85% of the pores in both samples are accessible to both CD4 and D2O. However, differences in accessibility to CD4 are observed in the smaller pore sizes (∼25 nm). In one sample, CD4 penetrated the smallest pores as effectively as it did the larger ones. In the other sample, less than 70% of the smallest pores (<25 nm) were accessible to CD4, but they were still largely penetrable by water, suggesting that small-scale heterogeneities in methane accessibility occur in the shale samples even though the total porosity does not differ. An additional study investigating the dependence of scattered intensity with pressure of CD4 allows for an accurate estimation of the pressure at which the scattered intensity is at a minimum. This study provides information about the composition of the material immediately surrounding the pores. Most of the accessible (open) pores in the 25 nm size range can be associated with either mineral matter or high reflectance organic material. However, a complementary scanning electron microscopy investigation shows that most of the pores in these shale samples are contained in the organic components. The neutron scattering results indicate that the pores are not equally proportioned in the different constituents within the shale. There is some indication from the SANS results that the composition of the pore-containing material varies with pore size; the pore size distribution associated with mineral matter is different from that associated with organic phases.

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Methane gas has been identified as the most destructive greenhouse gas (Liu et al., 2004). It was reported that the global warming potential of methane per molecule relative to CO2 is approximately 23 on a 100-year timescale or 62 over a 20-year period (IPCC, 2001). Methane has high C-H bond energy of about 439 kJ/mol and other higher alkanes (or saturated hydrocarbons) also have a very strong C-C and C-H bonds, thus making their molecules to have no empty orbitals of low energy or filled orbitals of high energy that could readily participate in chemical reactions as is the case with unsaturated hydrocarbons such as olefins and alkynes (Crabtree, 1994; Labinger & Bercaw, 2002)...

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An investigation on hydrogen and methane sensing performance of hydrothermally formed niobium tungsten oxide nanorods employed in a Schottky diode structure is presented herein. By implementing tungsten into the surface of the niobium lattice, we create Nb5+ and W5+ oxide states and an abundant number of surface traps, which can collect and hold the adsorbate charge to reinforce a greater bending of the energy bands at the metal/oxide interface. We show experimentally, that extremely large voltage shifts can be achieved by these nanorods under exposure to gas at both room and high temperatures and attribute this to the strong accumulation of the dipolar charges at the interface via the surface traps. Thus, our results demonstrate that niobium tungsten oxide nanorods can be implemented for gas sensing applications, showing ultra-high sensitivities.

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In this paper characteristic of a DBD (Dielectric Barrier Discharge) plasma lamp is investigated based on the lamp intensity and power consumption. A pulsed power supply with controllable parameters based on a push-pull converter is developed for lamp excitation at different voltage levels and repetition rate. The experimentations were conducted for 28 different operating points with the frequency range of 2 kHz to 15 Khz at output voltage levels of between 7.4 kV up to 13 kV. The obtained results show the feasibility of finding an optimum operation point due to nonlinear behaviour of the DBD lamp.

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It is widely recognised that defining trade-offs between greenhouse gas emissions using ‘emission equivalence’ based on global warming potentials (GWPs) referenced to carbon dioxide produces anomalous results when applied to methane. The short atmospheric lifetime of methane, compared to the timescales of CO2 uptake, leads to the greenhouse warming depending strongly on the temporal pattern of emission substitution. We argue that a more appropriate way to consider the relationship between the warming effects of methane and carbon dioxide is to define a ‘mixed metric’ that compares ongoing methane emissions (or reductions) to one-off emissions (or reductions) of carbon dioxide. Quantifying this approach, we propose that a one-off sequestration of 1 t of carbon would offset an ongoing methane emission in the range 0.90–1.05 kg CH4 per year. We present an example of how our approach would apply to rangeland cattle production, and consider the broader context of mitigation of climate change, noting the reverse trade-off would raise significant challenges in managing the risk of non-compliance. Our analysis is consistent with other approaches to addressing the criticisms of GWP-based emission equivalence, but provides a simpler and more robust approach while still achieving close equivalence of climate mitigation outcomes ranging over decadal to multi-century timescales.

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We report a comprehensive theoretical study on reaction of methane by Fe4 cluster. This Letter gains insight into the mechanism of the reaction and indicate the Fe4 cluster has strong catalytic effect on the activation reaction of methane. In detail, the results show the cleavage of the first C–H bond is both an energetically and kinetically favourable process and the breaking of the second C–H is the rate-determining step. Moreover, our Letter demonstrates that the different cluster size of iron can not only determine the catalytic activity of methane but also control the product selectivity.

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Australia is the driest inhabited continent in the world and persisting droughts have triggered a move toward sensible and sustainable water consumption. Understanding how and where water is consumed in households enables streamlined development of demand management programs and efficient engineering of water infrastructure. End use water consumption analysis is required to gain necessary empirical data of how and where water is consumed. Several end use water consumption studies have been conducted within Australia and around the world with varying results produced. This pilot study paper provides preliminary data from the Gold Coast Watersaver End Use Project which is currently underway. Specifically, the paper includes water end use category volumetric and percentage break downs for 18 single and 32 dual reticulated homes on the Gold Coast (i.e. 50 in total). Moreover, a comparitive analysis between each of the individual households water end use levels is discussed along with other national studies previously completed. The paper finishes with an overview of the greater 200 home end use study conducted on the Gold Coast and its key deliverables and research outcomes.

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Density functional theory (DFT) calculations have been carried out to explore the catalytic activation of C–H bonds in methane by the iron atom, Fe, and the iron dimer, Fe2. For methane activation on an Fe atom, the calculations suggest that the activation of the first C–H bond is mediated via the triplet excited-state potential energy surface (PES), with initial excitation of Fe to the triplet state being necessary for the reaction to be energetically feasible. Compared with the breaking of the first C–H bond, the cleavage of the second C–H bond is predicted to involve a significantly higher barrier, which could explain experimental observations of the HFeCH3 complex rather than CH2FeH2 in the activation of methane by an Fe atom. For methane activation on an iron dimer, the cleavage of the first C–H bond is quite facile with a barrier only 11.2, 15.8 and 8.4 kcal/mol on the septet state energy surface at the B3LYP/6-311+G(2df,2dp), BPW91/6-311+G(2df,2dp) and M06/B3LYP level, respectively. Cleavage of the second C–H bond from HFe2CH3 involves a barrier calculated respectively as 18.0, 10.7 and 12.4 kcal/mol at the three levels. The results suggest that the elimination of hydrogen from the dihydrogen complex is a rate-determining step. Overall, our results indicate that the iron dimer Fe2 has a stronger catalytic effect on the activation of methane than the iron atom.