970 resultados para Downsizing EGR CO2 emissioni sovralimentazione


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The surface modification and crystallization process of BaO-B2O3-SiO2 glass compositions when exposed to CO2 laser irradiation was evaluated as a function of the laser power, irradiation time and surface condition. The glass surface was modified by the application of laser power exceeding 0.40 W and an irradiation time of more than 300 s. Micro-Raman and X-ray diffraction measurements revealed at high laser power the formation of beta-BaB2O4 (beta-BBO) crystalline phase. The crystallization of the irradiated region was enhanced when beta-BBO micrometer sized particles were dispersed on the surface of the glass sample. The intensity of the second harmonic generation observed in the crystallized region was found to depend mainly on the condition of the glassy surface prior to glass irradiation. (C) 2007 Elsevier B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The pulp- and paper production is a very energy intensive industry sector. Both Sweden and the U.S. are major pulpandpaper producers. This report examines the energy and the CO2-emission connected with the pulp- and paperindustry for the two countries from a lifecycle perspective.New technologies make it possible to increase the electricity production in the integrated pulp- andpaper mill through black liquor gasification and a combined cycle (BLGCC). That way, the mill canproduce excess electricity, which can be sold and replace electricity produced in power plants. In thisprocess the by-products that are formed at the pulp-making process is used as fuel to produce electricity.In pulp- and paper mills today the technology for generating energy from the by-product in aTomlinson boiler is not as efficient as it could be compared to the BLGCC technology. Scenarios havebeen designed to investigate the results from using the BLGCC technique using a life cycle analysis.Two scenarios are being represented by a 1994 mill in the U.S. and a 1994 mill in Sweden.The scenariosare based on the average energy intensity of pulp- and paper mills as operating in 1994 in the U.S.and Sweden respectively. The two other scenarios are constituted by a »reference mill« in the U.S. andSweden using state-of-the-art technology. We investigate the impact of varying recycling rates and totalenergy use and CO2-emissions from the production of printing and writing paper. To economize withthe wood and that way save trees, we can use the trees that are replaced by recycling in a biomassgasification combined cycle (BIGCC) to produce electricity in a power station. This produces extra electricitywith a lower CO2 intensity than electricity generated by, for example, coal-fired power plants.The lifecycle analysis in this thesis also includes the use of waste treatment in the paper lifecycle. Both Sweden and theU.S. are countries that recycle paper. Still there is a lot of paper waste, this paper is a part of the countries municipalsolid waste (MSW). A lot of the MSW is landfilled, but parts of it are incinerated to extract electricity. The thesis hasdesigned special scenarios for the use of MSW in the lifecycle analysis.This report is studying and comparing two different countries and two different efficiencies on theBLGCC in four different scenarios. This gives a wide survey and points to essential parameters to specificallyreflect on, when making assumptions in a lifecycle analysis. The report shows that there arethree key parameters that have to be carefully considered when making a lifecycle analysis of wood inan energy and CO2-emission perspective in the pulp- and paper mill in the U.S. and in Sweden. First,there is the energy efficiency in the pulp- and paper mill, then the efficiency of the BLGCC and last theCO2 intensity of the electricity displaced by BIGCC or BLGCC generatedelectricity. It also show that with the current technology that we havetoday, it is possible to produce CO2 free paper with a waste paper amountup to 30%. The thesis discusses the system boundaries and the assumptions.Further and more detailed research, including amongst others thesystem boundaries and forestry, is recommended for more specificanswers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Planning policies in several European countries have aimed at hindering the expansion of out-of-town shopping centers. One argument for this is concern for the increase in transport and a resulting increase in environmental externalities such as CO2-emissions. This concern is weakly founded in science as few studies have attempted to measure CO2-emissions of shopping trips as a function of the location of the shopping centers. In this paper we conduct a counter-factual analysis comparing downtown, edge-of-town and out-of-town shopping. In this comparison we use GPS to track 250 consumers over a time-span of two months in a Swedish region. The GPS-data enters the Oguchi’s formula to obtain shopping trip-specific CO2-emissions. We find that consumers’ out-of-town shopping would generate an excess of 60 per cent CO2-emissions whereas downtown and edge-of-town shopping centers are comparable.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Most previous studies have focused on entire trips in a geographic region, while a few of them addressed trips induced by a city landmark. Therefore paper explores trips and their CO2 emissions induced by a shopping center from a time-space perspective and their usage in relocation planning. This is conducted by the means of a case study in the city of Borlänge in mid-Sweden where trips to the city’s largest shopping mall in its center are examined. We use GPS tracking data of car trips that end and start at the shopping center. Thereafter, (1) we analyze the traffic emission patterns from a time-space perspective where temporal patterns reveal an hourly-based traffic emission dynamics and where spatial patterns uncover a heterogeneous distribution of traffic emissions in spatial areas and individual street segments. Further, (2) this study reports that most of the observed trips follow an optimal route in terms of CO2 emissions. In this respect, (3) we evaluate how well placed the current shopping center is through a comparison with two competing locations. We conclude that the two suggested locations, which are close to the current shopping center, do not show a significant improvement in term of CO2 emissions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, the p-median model is used to find the location of retail stores that minimizes CO2 emissions from consumer travel. The optimal location is then compared with the existing retail location,and the excess CO2 emissions compared with the optimal solution is calculated. The results show that by using the environmentally optimal location, CO2 emissions from consumer travel could be reduced by approximately 25percent. 

Relevância:

20.00% 20.00%

Publicador:

Resumo:

To finance transportation infrastructure and to address social and environmental negative externalities of road transports, several countries have recently introduced or consider a distance based tax on trucks. In the competitive retail market such tax can be expected to lower the demand and thereby reduce CO2 emissions of road transports. However, as we show in this paper, such tax might also slow down the transition towards e-tailing. Considering that previous research indicates that a consumer switching from brick-and-mortar shopping to e-tailing reduces her CO2 emissions substantially, the direction and magnitude of the environmental net effect of the tax is unclear. In this paper, we assess the net effect in a Swedish regional retail market where the tax not yet is in place. We predict the net effect on CO2 emissions to be positive, but off-set by about 50% because of a slower transition to e-tailing.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper examines the relationships among per capita CO2 emissions, per capita GDP and international trade based on panel data sets spanning the period 1960-2008: one for 150 countries and the others for sub-samples comprising OECD and Non-OECD economies. We apply panel unit root and cointegration tests, and estimate a panel error correction model. The results from the error correction model suggest that there are long-term relationships between the variables for the whole sample and for Non-OECD countries. Finally, Granger causality tests show that there is bi-directional short-term causality between per capita GDP and international trade for the whole sample and between per capita GDP and CO2 emissions for OECD countries

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We develop a method for empirically measuring the difference in carbon footprint between traditional and online retailing (“e-tailing”) from entry point to a geographical area to consumer residence. The method only requires data on the locations of brick-and-mortar stores, online delivery points, and residences of the region’s population, and on the goods transportation networks in the studied region. Such data are readily available in most countries, so the method is not country or region specific. The method has been evaluated using data from the Dalecarlia region in Sweden, and is shown to be robust to all assumptions made. In our empirical example, the results indicate that the average distance from consumer residence to a brick-and-mortar retailer is 48.54 km in the studied region, while the average distance to an online delivery point is 6.7 km. The results also indicate that e-tailing increases the average distance traveled from the regional entry point to the delivery point from 47.15 km for a brick-and-mortar store to 122.75 km for the online delivery points. However, as professional carriers transport the products in bulk to stores or online delivery points, which is more efficient than consumers’ transporting the products to their residences, the results indicate that consumers switching from traditional to e-tailing on average reduce their CO2 footprints by 84% when buying standard consumer electronics products. 

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We develop a method for empirically measuring the difference in carbon footprint between traditional and online retailing (“e-tailing”) from entry point to a geographical area to consumer residence. The method only requires data on the locations of brick-and-mortar stores, online delivery points, and residences of the region’s population, and on the goods transportation networks in the studied region. Such data are readily available in most countries, so the method is not country or region specific. The method has been evaluated using data from the Dalecarlia region in Sweden, and is shown to be robust to all assumptions made. In our empirical example, the results indicate that the average distance from consumer residence to a brick-and-mortar retailer is 48.54 km in the studied region, while the average distance to an online delivery point is 6.7 km. The results also indicate that e-tailing increases the average distance traveled from the regional entry point to the delivery point from 47.15 km for a brick-and-mortar store to 122.75 km for the online delivery points. However, as professional carriers transport the products in bulk to stores or online delivery points, which is more efficient than consumers’ transporting the products to their residences, the results indicate that consumers switching from traditional to e-tailing on average reduce their CO2 footprints by 84% when buying standard consumer electronics products. 

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Transportation is seen as one of the major sources of CO2 pollutants nowadays. The impact of increased transport in retailing should not be underestimated. Most previous studies have focused on transportation and underlying trips, in general, while very few studies have addressed the specific affects that, for instance, intra-city shopping trips generate. Furthermore, most of the existing methods used to estimate emission are based on macro-data designed to generate national or regional inventory projections. There is a lack of studies using micro-data based methods that are able to distinguish between driver behaviour and the locational effects induced by shopping trips, which is an important precondition for energy efficient urban planning. The aim of this study is to implement a micro-data method to estimate and compare CO2 emission induced by intra-urban car travelling to a retail destination of durable goods (DG), and non-durable goods (NDG). We estimate the emissions from aspects of travel behaviour and store location. The study is conducted by means of a case study in the city of Borlänge, where GPS tracking data on intra-urban car travel is collected from 250 households. We find that a behavioural change during a trip towards a CO2 optimal travelling by car has the potential to decrease emission to 36% (DG), and to 25% (NDG) of the emissions induced by car-travelling shopping trips today. There is also a potential of reducing CO2 emissions induced by intra-urban shopping trips due to poor location by 54%, and if the consumer selected the closest of 8 existing stores, the CO2 emissions would be reduced by 37% of the current emission induced by NDG shopping trips.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Uma das tecnologias que mais avançou nas últimas décadas, como uma alternativa para as tradicionais técnicas de extração de produtos naturais, é a técnica de Extração com Fluidos Supercríticos. A extração com fluidos supercríticos destacase entre os processos industriais de extração pela qualidade dos produtos obtidos e por não causar danos ambientais quando usa dióxido de carbono (CO2) no estado supercrítico como solvente. Este trabalho teve como objetivo a realização de experimentos de extração de óleos essenciais com dióxido de carbono no estado supercrítico de folhas de duas variedades da árvore Canforeira (Cinnamomum camphor Ness & Eberm.) conhecidas como Hon-sho e Ho-sho, a fim de determinar as melhores condições operacionais de processo. Os óleos essenciais obtidos destas plantas têm importância econômica devido aos seus principais componentes: linalol e cânfora. Os melhores parâmetros de extração obtidos, quando se consideram os rendimentos de óleo essencial, foram os seguintes: vazão de CO2 = 2 mL/min, temperatura = 50°C, pressão = 90 bar e diâmetro de partícula = 0,1 mm. Outro objetivo foi a obtenção das curvas de extração: Rendimento de óleo essencial versus Tempo de extração, adequando, a partir dos dados experimentais, alguns modelos matemáticos encontrados na literatura para descrever o comportamento destas extrações. Dos modelos estudados o que melhor se adequou à extração de óleos essenciais de folhas foi o modelo proposto por Reverchon (1996), o qual proporcionou uma boa reprodutibilidade dos dados experimentais, mostrandose eficiente na representação de extração com fluidos supercríticos de óleos essenciais de Hon-sho e Ho-sho a partir de suas folhas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

O objetivo desta tese, "Economia Ecológica da Emissão Antropogênica de CO2 – uma Abordagem Filosófico-Científica sobre a Efetuação Humana Alopoiética da Terra em Escala Planetária utiliza o novo paradigma ambiental, que inclui as seguintes ferramentas teóricas originais: · o uso da filosofia da efetuação de Friedrich Wilhelm Joseph Schelling (1775-1854); · uso da teoria da auto-organização para demonstrar a existência de uma efetuação humana alopoiética de dimensões geológico-planetárias; · a articulação das implicações filosófico-científicas em uma via de recorrência que inclui a contingência, a reprocessualidade, a ética e a hermenêutica, além das abordagens e estratégias da interdisciplinaridade e da transdisicplinaridade; · uma nova estrutura de abordagem empírica para a coleta de dados ambientais, a matriz de amostragem ambiental. Nesta abordagem é proposto o posicionamento da Epistemologia Ambiental levando em conta o aspecto unificador sistêmico, após ser realizada a crítica das abordagens anarquista e pós-normal. A Economia é posta como antiexemplo no qual a Economia tradicional (Clássica, Neoclássica e Ambiental) é caracterizada como uma pseudociência, a partir das suas ilusões, dogmas, mitos, fantasias, falácias, falsa "lei", falsas metáforas e o abandono da ética e da visão sistêmica, sendo suas afirmativas (falsas) comparadas com os resultados das demais ciências e com a situação real do planeta Terra, no início do século XXI. O contraponto da Economia tradicional é estabelecido pela apresentação dos conceitos de ecodesenvolvimento, sustentabilidade, estado-estável, Economia Win-Win e o advento da Era Solar. A Economia Ecológica constitui uma nova Ciência Ambiental, passando atualmente por um processo de corrupção economicista. A apresentação da efetuação humana alopoiética é feita em duas principais escalas: a geológica e planetária. A efetuação humana alopoiética registrada em escala geológica inclui as seguintes formas: paisagística, pedogênica, litológica, geodinâmica (sísmica, vulcânica, hídrica, massiva e erosional), fossilífera e geoquímica. A efetuação humana alopoiética registrada em escala planetária apresenta as seguintes formas: climática, asteróide-meteorítica, da biodiversidade, aeroespacial próxima e extraplanetária. A emissão antropogênica de gás carbônico (CO2) na atmosfera terrestre, uma emissão difusa e sem fronteiras geográficas, é abordada com a Economia Ecológica. A partir da identificação do aquecimento global com "a conta entrópica devida à era da máquina" (Rifkin, 1992, p. 81) que a Natureza apresenta aos seres humanos, é feita a tentativa de estabelecer um valor real do fenômeno, tendo como ferramenta científica a abordagem emergética. A partir da constatação de que a efetuação humana alopoiética registrada até o final do século XX foi realizada de forma imprevista, imprudente e fora de controle e tendo em vista a emergência da Era da Terra-Pátria, no início do século XXI, e a necessidade de reorientar a globalização em curso, alternativas para a busca da efetuação terrestre consciente são apresentadas. As principais alternativas propostas para resolver (ou encaminhar a resolução) para a questão ambiental são as economicistas, da qualidade ambiental total (ISO 14000), as industrialistas (produção limpa, fator 4, fator 10 e capitalismo natural), as científicas (geofisiologia e terraforming), da Economia Ecológica e Economia Win-Win, as políticas (Política da Biosfera e Plano Marshall Global), as éticas, a utopia do reencantamento do Mundo e a proposta programática da Agenda 21. As conclusões e interpretações desta tese provém dos resultados obtidos pelo cálculo da emissão de CO2 para a atmosfera, sua emergia e valor real através de dados obtidos na Internet e da contextualização destes nas propostas existentes para o encaminhamento da questão ambiental. A mitologia de Ícaro na tentativa ambiciosa em se afastar da Natureza e o retorno à ela na forma de uma Fênix de ressurgimento autopoiético, fornece a visão do reenvolvimento ambiental humano.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este trabalho descreve um estudo e desenvolvimento de um sensor de dióxido de carbono (CO2), de baixo custo, para monitoramento da qualidade do ar em ambientes climatizados. O sensor aqui proposto baseia-se na técnica de absorção em infravermelho não dispersivo (NDIR). Este trabalho avalia alguns métodos já empregados e propõe um modelo alternativo visando uma solução de baixo custo que possa ser incorporada a sistemas de monitoramento e/ou condicionamento existentes, permitindo o controle do teor de CO2. A metodologia inclui o estudo dos diferentes tipos de sensores de CO2, a seleção da técnica mais apropriada para medição, o estudo das alternativas para implementação da técnica selecionada, o desenvolvimento, testes e avaliações da solução. Especificamente desenvolveu-se uma solução em termos de sensor de CO2 que utiliza componentes comerciais, sendo facilmente reprodutível e de custo reduzido. O sensor desenvolvido tem faixa de medição entre 330 a mais de 10000 ppm, com resolução estimada em torno de 20 a 30 ppm, com erro em relação ao padrão menor que 10% da medição ou 150 ppm,o que for maior.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

As transformações ocorridas a partir da década de 80 na economia, na maneira de administrar as empresas e nas relações de trabalho levaram à perda de emprego de milhares de pessoas. Downsizing e demissão passaram a ser comum tanto no Brasil como em outros lugares do mundo. Chama a atenção, entretanto, que a literatura na área de recursos humanos não contemple as atividades de gerenciamento das demissões. Fala-se dos quatro pilares da área de recursos humanos: recrutamento, seleção, avaliação de desempenho, desenvolvimento e remuneração, mas o tema da demissão parece estar discretamente omitido. O objetivo deste trabalho foi: a) apresentar uma revisão da literatura nacional e internacional com artigos sobre o tema e b) buscar como profissionais de recursos humanos e demissores descrevem as práticas de demissão, de modo a evidenciar o papel da área de recursos humanos (e de gestores) nestes processos. A retórica em Recursos Humanos, já descrita por Legge (1995), de que precisamos ser cruéis para amar, apresenta-se como uma ação fundamental na construção das práticas organizativas em demissão e downsizing.