974 resultados para CO2 emission


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Two unique large buildings in the Kingdom of Bahrain were selected for make-over to sustainable buildings. These are the Almoayyed Tower (the first sky scraper) and the Bahrain International Circuit, BIC (The best world Formula 1 Circuit). The amount of electricity extracted from using renewable energy resource (solar and wind), integrated to the buildings-has been studied thoroughly. For the first building, the total solar electricity from the PV installed at the roof and the 4 vertical facades was found 3 017 500 kWh annually (3 million kWh), i.e. daily energy of 8219 kWh (enough to Supply electricity for 171 houses, each is rated as 2 kW house-in Europe the standard is 1.2 kW). This means that the annual solar electricity produced will be nearly 3 million kWh. This correspond to annual CO, reduction of 3000 t (assuming each kWh of energy from natural gas lead to emission of 1 kg of CO2). For the second building (BIC) the solar electricity from PV panels installed at the roof top, fixed at tilt angle of 26 degrees facing south, will provide annual solar electricity of is 2.8 x 10(6) kWh. The solar electricity from PV panels installed on the windows (12,000 m(2)) will be 45.3 x 10(6) kWh. This means that the total annual electrical power from PV panels (windows and roofs) will be nearly 12 MW (32 kW per day). The CO2 reduction will be 48,000 t. Under the carbon trading or CDM scheme the revenue (or the reward) would be (sic)480,000 million annually (the reward is (sic)10 per tonnes of CO2). The BIC circuit can have diversified electricity supply, i.e. from solar radiation (PV), from solar heat (CSP) and from wind (wind turbines), assuring its sustainability as well as reducing the CO2 emission.

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The Kodar Mountains in eastern Siberia accommodate 30 small, cold-based glaciers with a combined surface area of about 19 km2. Very little is known about these glaciers, with the first survey conducted in the late 1950s. In this paper, we use terrestrial photogrammetry to calculate changes in surface area, elevation, volume and geodetic mass balance of the Azarova Glacier between 1979 and 2007 and relate these to meteorological data from nearby Chara weather station (1938-2007). The glacier surface area declined by 20±6.9% and surface lowered on average by 20±1.8 m (mean thinning: 0.71 m a-1) resulting in a strongly negative cumulative and average mass balance of -18±1.6 m w.e. and -640±60 mm w.e.a-1 respectively. The July-August air temperature increased at a rate of 0.036oC a-1 between 1979 and 2007 and the 1980-2007 period was, on average, around 1oC warmer than 1938-1979. The regional climate projections for A2 and B2 CO2 emission scenarios developed using PRECIS regional climate model indicate that summer temperatures will increase in 2071–2100 by 2.6-4.7°C and 4.9-6.2°C respectively in comparison with 1961–1990. The annual total of solid precipitation will increase by 20% under B2 scenario but decline by 3% under A2 scenario. The length of the ablation season will extend from July–August to June-September. The Azarova Glacier exhibits high sensitivity to climatic warming due to its low elevation, exposure to comparatively high summer temperatures, and the absence of a compensating impact of cold season precipitation. Further summer warming and decline of solid precipitation projected under the A2 scenario will force Azarova to retreat further while impacts of an increase in solid precipitation projected under the B2 scenario require further investigation.

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Nowadays utilising the proper HVAC system is essential both in extreme weather conditions and dense buildings design. Hydraulic loops are the most common parts in all air conditioning systems. This article aims to investigate the performance of different hydraulic loop arrangements in variable flow systems. Technical, economic and environmental assessments have been considered in this process. A dynamic system simulation is generated to evaluate the system performance and an economic evaluation is conducted by whole life cost assessment. Moreover, environmental impacts have been studied by considering the whole life energy consumption, CO2 emission, the embodied energy and embodied CO2 of the system components. Finally, decision-making in choosing the most suitable hydraulic system among five well-known alternatives has been proposed.

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Grazing systems represent a substantial percentage of the global anthropogenic flux of nitrous oxide (N2O) as a result of nitrogen addition to the soil. The pool of available carbon that is added to the soil from livestock excreta also provides substrate for the production of carbon dioxide (CO2) and methane (CH4) by soil microorganisms. A study into the production and emission of CO2, CH4 and N2O from cattle urine amended pasture was carried out on the Somerset Levels and Moors, UK over a three-month period. Urine-amended plots (50 g N m−2) were compared to control plots to which only water (12 mg N m−2) was applied. CO2 emission peaked at 5200 mg CO2 m−2 d−1 directly after application. CH4 flux decreased to −2000 μg CH4 m−2 d−1 two days after application; however, net CH4 flux was positive from urine treated plots and negative from control plots. N2O emission peaked at 88 mg N2O m−2 d−1 12 days after application. Subsurface CH4 and N2O concentrations were higher in the urine treated plots than the controls. There was no effect of treatment on subsurface CO2 concentrations. Subsurface N2O peaked at 500 ppm 12 days after and 1200 ppm 56 days after application. Subsurface NO3− concentration peaked at approximately 300 mg N kg dry soil−1 12 days after application. Results indicate that denitrification is the key driver for N2O release in peatlands and that this production is strongly related to rainfall events and water-table movement. N2O production at depth continued long after emissions were detected at the surface. Further understanding of the interaction between subsurface gas concentrations, surface emissions and soil hydrological conditions is required to successfully predict greenhouse gas production and emission.

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In addition to CO2, the climate impact of aviation is strongly influenced by non-CO2 emissions, such as nitrogen oxides, influencing ozone and methane, and water vapour, which can lead to the formation of persistent contrails in ice-supersaturated regions. Because these non-CO2 emission effects are characterised by a short lifetime, their climate impact largely depends on emission location and time; that is to say, emissions in certain locations (or times) can lead to a greater climate impact (even on the global average) than the same emission in other locations (or times). Avoiding these climate-sensitive regions might thus be beneficial to climate. Here, we describe a modelling chain for investigating this climate impact mitigation option. This modelling chain forms a multi-step modelling approach, starting with the simulation of the fate of emissions released at a certain location and time (time-region grid points). This is performed with the chemistry–climate model EMAC, extended via the two submodels AIRTRAC (V1.0) and CONTRAIL (V1.0), which describe the contribution of emissions to the composition of the atmosphere and to contrail formation, respectively. The impact of emissions from the large number of time-region grid points is efficiently calculated by applying a Lagrangian scheme. EMAC also includes the calculation of radiative impacts, which are, in a second step, the input to climate metric formulas describing the global climate impact of the emission at each time-region grid point. The result of the modelling chain comprises a four-dimensional data set in space and time, which we call climate cost functions and which describes the global climate impact of an emission at each grid point and each point in time. In a third step, these climate cost functions are used in an air traffic simulator (SAAM) coupled to an emission tool (AEM) to optimise aircraft trajectories for the North Atlantic region. Here, we describe the details of this new modelling approach and show some example results. A number of sensitivity analyses are performed to motivate the settings of individual parameters. A stepwise sanity check of the results of the modelling chain is undertaken to demonstrate the plausibility of the climate cost functions.

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Mg alloys are one of promising eco-materials. The present paper describes the importance of grain refinement to develop high performance Mg alloys. The fine-grained Mg alloys exhibit not only a good combination of high strength and high ductility at room temperature, but also high formability (superplasticity) at elevated temperatures.

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In addition to water saving, the hybrid cooling concept presented in this book also has the potential to improve energy efficiency and possibly reduce CO2 emission by recovering and upgrading the 'waste' energy from the cooling water stream.Yilmaz and Kouzani are at Deakin Uni, Hessami is at Monash Uni, Hu is at Uni of Adelaide.

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In the 1970s, Corporate Social Responsibility (CSR) was discussed by Nobel laureate Milton Friedman in his article “The Social Responsibility of Business Is to Increase Its Profits.” (Friedman, 1970). His view on CSR was contemptuous as he referred to it as “hypocritical window-dressing” a reflection of the view of Corporate America on CSR back then. For a long time short-term maximization of shareholder value was the only maxim for top management across industries and companies. Over the last decade, CSR has become a more important and relevant factor of a company’s reputation, shifting the discussion from whether CSR is necessary to how best CSR commitments should be done (Smith, 2003). Inevitably, companies do have an environmental, social and economic impact, thereby imposing social costs on current and future generations. In 2013, 50 of the world biggest companies have been responsible for 73 percent of the total carbon dioxide (CO2) emission (Global 500 Climate Change Report 2013). Post et al. (2002) refer to these social costs as a company’s need to retain its “license to operate”. In the late 1990s, CSR reporting was nearly unknown, which drastically changed during the last decade. Allen White, co-founder of the Global Reporting Initiative (GRI), said that CSR reporting”… has evolved from the extraordinary to the exceptional to the expected” (Confino, 2013). In confirmation of this, virtually all of the world’s largest 250 companies report on CSR (93%) and reporting by now appears to be business standard (KPMG, 2013). CSR reports are a medium for transparency which may lead to an improved company reputation (Noked, 2013; Thorne et al, 2008; Wilburn and Wilburn, 2013). In addition, it may be used as part of an ongoing shareholder relations campaign, which may prevent shareholders from submitting Environmental and Social (E&S)1 proposals (Noked, 2013), based on an Ernst & Young report 1 The top five E&S proposal topic areas in 2013 were: 1. Political spending/ lobbying; 2. Environmental sustainability; 3. Corporate diversity/ EEO; 4.Labor/ human rights and 5. Animal testing/ animal welfare. Three groups of environmental sustainability proposal topics of sub-category number two (environmental sustainability) 6 2013, representing the largest category of shareholder proposals submitted. PricewaterhouseCoopers (PwC) even goes as far as to claim that CSR reports are “…becoming critical to a company’s credibility, transparency and endurance.” (PwC, 2013).

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Tillage stimulates soil carbon (C) losses by increasing aeration, changing temperature and moisture conditions, and thus favoring microbial decomposition. In addition, soil aggregate disruption by tillage exposes once protected organic matter to decomposition. We propose a model to explain carbon dioxide (CO2) emission after tillage as a function of the no-till emission plus a correction due to the tillage disturbance. The model assumes that C in the readily decomposable organic matter follows a first-order reaction kinetics equation as: dC(sail)(t)/dt = -kC(soil)(t) and that soil C-CO2 emission is proportional to the C decay rate in soil, where C-soil(t) is the available labile soil C (g m(-2)) at any time (t). Emissions are modeled in terms soil C available to decomposition in the tilled and non-tilled plots, and a relationship is derived between no-till (F-NT) and tilled (F-Gamma) fluxes, which is: F-T = a1F(NT)e(-a2t), where t is time after tillage. Predicted and observed fluxes showed good agreement based on determination coefficient (R-2), index of agreement and model efficiency, with R-2 as high as 0.97. The two parameters included in the model are related to the difference between the decay constant (k factor) of tilled and no-till plots (a(2)) and also to the amount of labile carbon added to the readily decomposable soil organic matter due to tillage (a,). These two parameters were estimated in the model ranging from 1.27 and 2.60 (a(1)) and - 1.52 x 10(-2) and 2.2 x 10(-2) day(-1) (a(2)). The advantage is that temporal variability of tillage-induced emissions can be described by only one analytical function that includes the no-till emission plus an exponential term modulated by tillage and environmentally dependent parameters. (C) 2008 Elsevier B.V. All rights reserved.

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The need to build durable structures and resistant to harsh environments enabled the development of high strength concrete, these activities generate a high cement consumption, which implies factor in CO2 emissions. Often the desired strength is not achieved using only the cement composition. This study aims to evaluate the influence of pozzolans with the addition of metakaolin on the physical mechanics of high strength concrete comparing them with the standard formulation. Assays were performed to characterize the aggregates according to NBR 7211, evaluation of cement and coarse aggregate through the trials of petrography (NBR 15577-3/08) and alkali-aggregate reaction (NBR 15577-05/08). Specimens were fabricated according to NBR 5738-1/04 with additions of 0%, 4%, 6%, 8% and 10% of metakaolin for cement mortars CP V in the formulations. For evaluation of the concrete hardened in fresh state and scattering assays were performed and compressive strength in accordance with the NBR 7223/1992 and NBR 5739-8/94 respectively. The results of the characterization of aggregates showed good characteristics regarding size analysis and petrography, as well as potentially innocuous as the alkali-aggregate reaction. As to the test of resistance to compression, all the formulations with the addition of metakaolin showed higher value at 28 days of disruption compared with the standard formulation. These results present an alternative to reduce CO2 emissions, and improvements in the quality and durability of concrete, because the fine particle size of metakaolin provides an optimal compression of the mass directly influencing the strength and rheology of the dough

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We present the results of a study on vinyl bromide for the search for new far infrared (FIR) laser lines. As the pump source, we use a CW waveguide CO2 laser with a tunability of 290 MHz around each line in order to pump large offset vibrational transitions. As a consequence, we obtained 28 new FIR laser emissions; 24 of them have wavelengths greater than 500 mum and are, therefore, suitable to be used in high-field EPR spectroscopy, For each of the new lines, we give the wavelength, the offset of the pumping transition with respect to the center Frequency of the CO2 emission, the polarization relative to that of the pumping laser line, the operating pressure, and the relative intensity. We also present a catalog including data of all of the FIR laser lines observed from this molecule up to now.

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The photodegradation of a 1:1 w/w blend of polycaprolactone and poly(vinyl chloride) has been studied by following carbon dioxide emission during UV exposure. Similar measurements were performed for polycaprolactone and poly(vinyl chloride) homopolymers which were prepared and irradiated in the same way. It was found that the blend gave lower CO2 emission than either of the two homopolymers, indicating that the interaction of the two components in the blend provided a beneficial reduction of photodegradation. It is therefore deduced that the detailed morphological characteristics of the blend have a controlling influence over the photo-oxidation. (c) 2007 Elsevier Ltd. All rights reserved.

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Devido às mudanças climáticas do planeta, principalmente ao aquecimento global, as formas de utilização dos solos na agricultura têm atraído grande atenção de pesquisadores. Mudanças de manejo podem influenciar a respiração do solo e, por conseguinte, alterar drasticamente o sequestro de C. Os objetivos deste trabalho foram avaliar, em semeadura direta, a influência da calagem nas emissões de CO2 do solo e correlacioná-las aos atributos químicos deste após dois anos da calagem. Utilizou-se o delineamento em blocos casualizados, com seis repetições. Os tratamentos constituíram de quatro doses de calcário e uma testemunha. Decorridos dois anos da calagem, avaliou-se a emissão residual de CO2 do solo, coletaram-se amostras nas camadas de 0-5, 5-10, 10-20 e 20-30 cm de profundidade e determinaram-se os teores de P, Ca2+ e Mg2+ e valores de pH e de saturação por bases. A emissão residual de CO2 do solo, quando a dose recomendada foi aplicada, foi 24,1 % superior, quando comparada à do solo sem aplicação de calcário, e 47,4 % maior, quando se aplicou o dobro da dose recomendada. A calagem melhorou as condições químicas do solo, e a emissão de CO2 aumentou linearmente com o aumento das doses. A emissão de CO2 do solo apresentou correlações positivas com os teores de P, Ca2+ e Mg2+ e com os valores de pH e de saturação por bases e negativas com os teores de H + Al e Al3+. Maiores coeficientes de correlação entre as taxas de emissão de CO2 do solo e os atributos químicos deste ocorreram na camada de 10-20 cm.

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Soil tillage may influence CO2 emissions in agricultural systems. Agricultural soils are managed in several ways in Brazil, ranging from no tillage to intensive land preparation. The objective of this study was to determine the effect of common soil tillage treatments (disk harrow, reversible disk plow, rotary tiller and chisel plow tillage systems) on the intermediate CO2 emissions of a dark red latosol, located in southern Brazil. Different tillage systems produced significant differences in the CO2 emissions, and the results indicate that the chisel plow produced the highest soil carbon loss during the 15 days period after tillage treatments were performed. Emissions to the atmosphere increased as much as 74 g CO2 m(-2), at the end of a 2-week period, in the plot where the chisel plow treatment was applied, in comparison to the non-disturbed plot. The results indicate that the total increase on the intermediate term soil CO2 emissions due to tillage treatments in southern Brazil is comparable to that reported for the more humid and cooler regions. (C) 2001 Elsevier B.V. B.V All rights reserved.