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Gas exchange and ventilation during dormancy in the tegu lizard Tupinambis merianae

De Andrade, D. V.; Abe, Augusto Shinya
Fonte: Company of Biologists Ltd Publicador: Company of Biologists Ltd
Tipo: Artigo de Revista Científica Formato: 3677-3685
ENG
Relevância na Pesquisa
65.58%
The tegu lizard Tupinambis merianae exhibits an episodic ventilatory pattern when dormant at 17 degrees C but a uniform ventilatory pattern when dormant at 25 degrees C. At 17 degrees C, ventilatory episodes were composed of 1-22 breaths interspaced by non-ventilatory periods lasting 1.8-26min, Dormancy at the higher body temperature was accompanied by higher rates of O-2 consumption and ventilation. The increase in ventilation was due only to increases in breathing frequency with no change observed in tidal volume. The air convection requirement for O-2 did not differ at the two body temperatures. The respiratory quotient was 0.8 at 17 degrees C and 1.0 at 25 degrees C. We found no consistent relationship between expired gas composition and the start/end of the ventilatory period during episodic breathing at 17 degrees C. However, following non-ventilatory periods of increasing duration, there was an increase in the pulmonary O-2 extraction that was not coupled to an equivalent increase in elimination of CO2 from the lungs. None of the changes in the variables studied could alone explain the initiation/termination of episodic ventilation in the tegus, suggesting that breathing episodes are shaped by a complex interaction between many variables. The estimated oxidative cost of breathing in dormant tegus at 17 degrees C was equivalent to 52.3% of the total metabolic rate...

Estudo da minimização do custo de um processo de separação de misturas gasosas multicomponentes atraves da membrana de fibra oca; Study of cost minimization of separation process of a multi components gas mixtures through the hollow fiber membrane

Ana Elisa Lavezo
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/11/2006 PT
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55.77%
A separação de misturas gasosas é efetuada com o objetivo de obter um ou mais dos constituintes na forma altamente puros. Existem quatro métodos principais aplicados para a separação de gases: absorção, adsorção, destilação criogênia e membranas. A economia do processo determinará qual desses métodos é usado para alguma aplicação particular (Scott, 1995). A era moderna das membranas de separação de gases foi introduzída após 1980, quando as membranas poliméricas se tomaram economicamente viáveis (Robeson, 1999).Atualmente a separação baseada em membranas é utilizada largamente em escala industrial para produção de nitrogênio de alta pureza a partir do ar, tendo importante aplicação na inertização do ambiente para conservação de frutas e vegetais, reatores químicos e produção de NH3, assim como para segurança na operação com líquidos inflamáveis (Spillman, 1989). O objetivo deste trabalho é a otimização do custo total do processo de separação de misturas gasosas multicomponentes utilizando membrana de fibra oca. A otimização foi realizada utilizando o método "Constrained Rosenbrock (Hill AIgorithm)", para obter um produto final com alta qualidade e com um custo total minimizado. Para a otimização do custo total do processo são necessários os seguintes dados fornecidos pelo programa de Caramello (2002): pressão do permeado e da alimentação...

Potential of Energy Integration in Mashreq and Neighboring Countries

World Bank
Fonte: Washington, DC Publicador: Washington, DC
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55.79%
The objective of this study is to carry out a country-by-country analysis of the power and gas sector demand and supply picture in order to assess opportunities for regional energy integration in the Mashreq and neighboring countries, and to identify specific interconnection projects that may require support from the World Bank and other international financiers. The study is conducted in the context of the World Bank Arab World Initiative. Although the present study focuses on Mashreq countries, issues of regional integration are intertwined among various Middle East and North Africa (MENA) sub-regions, and Turkey with eventual integration with Europe, so Mashreq is not considered in isolation. There are two other parallel efforts to examine the energy integration potential in the Maghreb and the Gulf Cooperation Council (GCC) countries. In addition, the World Bank and its partners are implementing a major solar power initiative with support from the Clean Technology Fund (CTF) to assist the MENA countries with development of large scale concentrated solar power (CSP) electricity generation capabilities for their own use or for export to other countries. Large scale development of solar power is expected to support and facilitate regional integration among MENA countries and with Europe as well.

Balancing Act : Cutting Energy Subsidies While Protecting Affordability

Laderchi, Caterina Ruggeri; Olivier, Anne; Trimble, Chris
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
EN_US
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55.78%
The cost of energy in Eastern Europe and Central Asia, as elsewhere, is an important policy issue, as shown by the concerns for energy affordability during the past harsh winter. Governments try to moderate the burden of energy expenditures that is experienced by households through subsidies to the energy providers, so that households pay tariffs below the cost recovery level for the energy they use. These subsidies result in significant pressures on government budgets when international prices rise. They also provide perverse incentives for the overconsumption of energy as households do not pay the true cost of energy, and therefore, have fewer incentives to save or to invest in energy efficiency. Balancing competing claims-fiscal and environmental concerns which would push for raising energy tariffs on the one hand, and affordability and political economy concerns which push for keeping tariffs artificially low on the other-is a task that policy makers in the region are increasingly unable to put off. Addressing this issue is all the more pressing as the ongoing crisis continues to add stress to government budgets...

Integration Strategy for the Southern Cone Gas Networks

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
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65.74%
Experts from the governments of Argentina, Bolivia, Brazil, Chile, Paraguay, Peru and Uruguay, who participated in this strategic study for the Southern Cone Gas Pipeline Networks, combined their efforts to identify a shared energy alternative which would help boost the development of natural gas in the sub region, and, thus, its sustainable economic development. This study was developed in two phases: a first phase which evaluates the economic advantages of the integration of the gas networks in the sub region on the basis of data provided mainly by the governments, determining the priority projects to initiate it; and a second phase containing more detailed technical, economic, environmental and financial pre-feasibility studies for these projects. The studies clearly demonstrate that integration of gas networks has a very positive impact as a mechanism for supplying natural gas, a clean and abundant fuel in the sub region. The study concludes that implementing an integration plan will result in an increase in the competitiveness of regional economies.

Greenfield Gas Distribution : Cross-country Experience

World Bank
Fonte: Washington, DC Publicador: Washington, DC
EN_US
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65.62%
The study aims to present information about specific countries which have initiated gas distribution projects rather than suggestions. However, by drawing on the experience of a large number of countries, it also aims to provide practical lessons about issues which could potentially foster or impede gas distribution projects. The study emphasizes how countries vary in terms of the level of development of gas distribution networks. Chapter 3 outlines the major factors contributing to such diversity. These factors fall into three categories which form the basis for analyzing gas distribution in the countries selected in the study : supply-side factors, demand-side factors and policy choices of governments

The Cost Structure of the Clean Development Mechanism

Rahman, Shaikh M.; Larson, Donald F.; Dinar, Ariel
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
55.78%
This paper examines the cost of producing emission reduction credits under the Clean Development Mechanism. Using project-specific data, cost functions are estimated using alternative functional forms. The results show that, in general, the distribution of projects in the pipeline does not correspond exclusively to the cost of generating anticipated credits. Rather, investment choices appear to be influenced by location and project type considerations in a way that is consistent with variable transaction costs and investor preferences among hosts and classes of projects. This implies that comparative advantage based on the marginal cost of abatement is only one of several factors driving Clean Development Mechanism investments. This is significant since much of the conceptual and applied numerical literature concerning greenhouse gas mitigation policies relies on presumptions about relative abatement costs. The authors also find that Clean Development Mechanism projects generally exhibit constant or increasing returns to scale. In contrast...

Export Restraints on Russian Natural Gas and Raw Timber : What Are the Economic Impacts?

Tarr, David G.
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
55.77%
Export restraints by the Russian Federation on natural gas and timber have been the source of major controversy between the European Union and the Russian Federation. The analysis of this paper suggests that the export restraints in natural gas very substantially benefit Russia. On the other hand, in raw timber the analysis suggests that a substantial reduction of Russian export taxes would increase Russian welfare. The paper explains that Gazprom has failed to invest adequately, resulting in little development of new gas supplies. The result has been progressively increasing use by Gazprom of Central Asian gas supplies, at progressively higher prices for Russia. The increased prices of gas for Russian consumers have shown that it is crucial for Russia to allow new entrants and to introduce competition in the Russian domestic market. Without export restraints, however, competition among multiple gas suppliers from Russia would erode or eliminate the monopoly profits of the Russian Federation on gas exports. Thus...

The Design and Sustainability of Renewable Energy Incentives : An Economic Analysis

Meier, Peter; Vagliasindi, Maria; Imran, Mudassar; Eberhard, Anton; Siyambalapitiya, Tilak
Fonte: Washington, DC: World Bank Publicador: Washington, DC: World Bank
EN_US
Relevância na Pesquisa
55.77%
Rapid urbanization and economic growth, new demographic trends, and climate change are key challenges that developing countries must face as they strive to meet growing energy demand. The main objectives of this study are to offer: (a) a global taxonomy of the economic and financial incentives provided by renewable support schemes and (b) an economic modeling of the sustainability and affordability of such support schemes. In an attempt to contribute to the lively debate, this study provides a global taxonomy of the economic and financial incentives provided by renewable energy (RE) support schemes. It summarizes economic models of the sustainability and affordability of such support schemes, alongside operational advice on how the regulatory design may need to be modified to minimize the impact on the budget and be affordable to the poor, as well as how to identify and fill the financing gap. This analytical framework: (a) differentiates and illustrates tradeoffs among local, regional, and national impacts...

The Cost of Environmental Degradation : Case Studies from the Middle East and North Africa

Croitoru, Lelia; Sarraf, Maria
Fonte: World Bank Publicador: World Bank
Tipo: Publications & Research :: Publication; Publications & Research :: Publication
ENGLISH
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65.52%
Environmental degradation is costly, to individuals, to societies, and to the environment. This book, edited by Lelia Croitoru and Maria Sarraf, makes these costs clear by examining a number of studies carried out over the past few years by the World Bank's Middle East and North Africa region. Even more important than estimating the monetary cost of environmental degradation (COED), however, are the clear guidance and policy implications derived from these findings. This volume presents a new approach to estimating the impacts of environmental degradation. In the past, when government officials asked researchers the simple question how large are the impacts of environmental degradation? The response was often an emphatic 'large!' a rather imprecise number. The strength of this work is that it actually quantifies in economic terms how large is 'large' and thereby gains the attention of decision makers and offers specific insights for improved policy making. Finally, this book demonstrates the benefits of doing a coordinated...

Poverty and Distributional Impact of Gas Price Hike in Armenia

Ersado, Lire
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
75.68%
Armenia meets about 75 percent of its energy needs through imports, with natural gas imports from Russia accounting for about 80 percent of total energy imports and 60 percent of total primary energy supply. Because of high dependence on imported energy, Armenia is vulnerable to external energy price shocks, which are often beyond the control of its policymakers. A most recent case in point was the 2010 Russian gas tariff increase, which led to a nearly 40 percent increase in the retail gas price for residential consumers. Coming on the heels of the global economic recession that hit Armenia's economy hard, the price hike amplified the impact on households that rely primarily on gas for heating and cooking. Using aggregate energy consumption data and a nationally representative household survey immediately before the crisis, this paper provides an overview of household energy consumption patterns, highlights Armenia's energy vulnerability, and estimates the direct poverty and distributional impacts of the increase in the cost of imported gas. The analysis shows that the gas price hike resulted in a significant increase in energy expenditures...

Optimal Transition from Coal to Gas and Renewable Power under Capacity Constraints and Adjustment Costs

Lecuyer, Oskar; Vogt-Schilb, Adrien
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
55.77%
This paper studies the optimal transition from existing coal power plants to gas and renewable power under a carbon budget. It solves a model of polluting, exhaustible resources with capacity constraints and adjustment costs (to build coal, gas, and renewable power plants). It finds that optimal investment in renewable energy may start before coal power has been phased out and even before investment in gas has started, because doing so allows for smoothing investment over time and reduces adjustment costs. Gas plants may be used to reduce short-term investment in renewable power and associated costs, but must eventually be phased out to allow room for carbon-free power. One risk for myopic agents comparing gas and renewable investment is thus to overestimate the lifetime of gas plants -- e.g., when computing the levelized cost of electricity -- and be biased against renewable power. These analytical results are quantified with numerical simulations of the European Commission's 2050 energy roadmap.

Yemen : A Natural Gas Incentive Framework

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Mining/Oil and Gas; Economic & Sector Work
ENGLISH; EN_US
Relevância na Pesquisa
55.77%
Yemen is planning to export gas through Yemen Liquefied Natural Gas (YLNG) starting from 2009. Yemen is also aiming to develop the domestic gas market, in particular gas-to-power. Liquefied Natural Gas (LNG) export revenue and domestic gas sales are expected to partially offset the decline in crude oil revenue from currently producing fields. The development of a gas sector has the potential to substantially contribute to Yemen's economic growth and fiscal revenue generation. Because of the high risk and considerable investment involved in developing a gas sector, attracting foreign capital and expertise will be essential. To this end, in addressing the public interest and developing the preferred policies, Yemen should ensure that decisions on project development and technologies will be based on their economic merits, and gas will be allowed to find its highest value market.

Harnessing African Natural Gas : A New Opportunity for Africa's Energy Agenda?

Santley, David; Schlotterer, Robert; Eberhard, Anton
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
65.7%
Sub-Saharan Africa's persistent power shortages act as a severe constraint on its economic and human development. Over the last several years, a series of major offshore gas discoveries in Mozambique and Tanzania have rekindled interest in expanding the use of natural gas to address the continent's power shortages. Once thought of as a Nigeria-only story, gas-to power in Sub-Saharan Africa is now being considered in a continent-wide context, both as a supplement to Africa's abundant hydropower resources and as a replacement for more carbon intensive coal and liquid fuels. But the concentration of gas resources in just a few countries and the virtual absence of gas transportation infrastructure create economic challenges to the wider adoption of gas as a power generation fuel, particularly in smaller countries that cannot achieve economies of scale in gas production and transportation. As a result, the timeline between the discovery of gas and its commercialization is often measured in decades. This study examines the economic conditions facing policy makers...

Bulgaria : Options to Improve Security of Gas Supply

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Energy Study; Economic & Sector Work
ENGLISH; EN_US
Relevância na Pesquisa
75.77%
This report presents the findings of a study aiming to define the least cost short (up to 2015) and medium term (up to 2020) measures that the Government of Bulgaria (GoB) can implement to meet gas security of supply requirements seen in the light of Bulgaria's vulnerability to gas supply disruptions and its increasingly important role for regional gas cross-border transmission and trade. Bulgarian gas demand is of modest size (3.0 bcm in 2011) and natural gas only plays a small role in Bulgaria's energy mix (14 percent of the total primary energy supply). Over the next ten years gas demand patterns are likely to change, however, and consumption levels are expected to grow steadily. The growth rate of gas demand and its importance in the supply mix will be driven by choices of electricity generation strategy and the rate of household gasification. There is a significant risk that a gas-focused electricity strategy would reduce Bulgaria's overall security of supply. However, this would only be the case if the new gas supply was contracted from the same sources and routes as the existing contracts (from Russia via Ukraine) and if the gas-fired power plants did not have back-up fuels. Conversely...

Regional Gas Trade Projects in Arab Countries, Volumes 1 and 2

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Tipo: Economic & Sector Work :: Mining/Oil and Gas; Economic & Sector Work
ENGLISH; EN_US
Relevância na Pesquisa
65.7%
Arab countries hold about 29 percent of the world's proven gas reserves, but every country (except Qatar and Algeria) is short of the gas supply needed to meet its current and projected demand. The rapid growth in gas demand is mostly a consequence of a sharp increase in electricity consumption. Gas trade in the Arab world has been dominated by the objective of exporting gas in the form of liquefied natural gas (LNG) to points in Asia, Europe, and North America. Gas trade within the region is limited to rather small volumes, moved from Algeria to Tunisia and Morocco; from Egypt to Jordan, Syria, and Lebanon; and from Qatar to the United Arab Emirates (UAE) - all through pipelines. The shortage of gas in the Arab countries has become more pronounced, justifying the higher gas prices needed to secure imported gas or to encourage domestic gas production. Such changes in the landscape provide an impetus for the Arab world to optimize the region's gas resources, at least partly on the basis of meeting growing regional demand. The objective of this study is to assist the attempt by: (i) identifying the opportunities for gas trade through cross-border gas pipelines and LNG; (ii) assessing the economic and political aspects of the identified projects; (iii) presenting financing and implementation schemes that utilize the synergy between the public and private sector in project formulation and development; and (iv) reviewing the legal...

Study of Equipment Prices in the Power Sector

Pauschert, Dirk
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: ESMAP Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
65.72%
Global economic growth, particularly from 2004 to 20071, has fueled an expansion in the construction of industrial, power plant, and manufacturing facilities in the United States and a dramatic escalation in the construction of these types of heavy construction projects overseas. In addition, the increase in demand for oil by rapidly growing countries such as China and India and the falling value of the dollar has resulted in an unprecedented rise in the price of oil. This has significantly accelerated oil exploration and resulted in capacity-expansion projects at existing oil refineries. The combination of power plant, infrastructure, and oil-related projects has resulted in significant growth in demand for boilers, rotating equipment, piping, structural steel, concrete, electrical components, and electric wiring. In light of this finding, this study compared the cost of power plants without market demand to the actual costs incurred in constructing power plants. The results indicate that owners are purchasing plants in a sellers' market...

Planning for Higher Oil Prices : Power Sector Impact in Latin America and the Caribbean

Yépez-García, Rigoberto Ariel; San Vicente Portes, Luis; García, Luis Enrique
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Economic & Sector Work :: Energy Study
ENGLISH; EN_US
Relevância na Pesquisa
55.8%
A scenario with higher oil prices has important implications for diverting from oil-based technologies to renewables, as well as gas, coal, and nuclear alternatives. By 2030, energy demand in Latin America and the Caribbean (LAC) is expected to double from 2008 levels. A key issue is deciding on the most appropriate mix of fuels for power generation, given the various prices of energy sources and technologies, as well as availability of renewable energy. The study's broad aim is to evaluate the impact of higher oil prices on the cost of generating electricity in countries of the LAC region so that better-informed energy policy planners can buffer future adverse effects. The study defines high oil prices as those above United States (U.S.) $100 per barrel. This price is considered a reasonable starting point for discussion given the recent range in oil prices, which averaged $95 a barrel in 2011. A price of $150 per barrel is defined as considerably high yet plausible given historical and current price levels...

The Value of Statistical Life and the Social Cost of Carbon

Case, Ethan
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 25/04/2013 EN_US
Relevância na Pesquisa
65.54%
In light of the consistent inability of the legislative branch to craft and pass legislation that effectively addresses global warming and a series of court cases that compel action on climate change from the executive branch, it appears likely that short and medium-term efforts to address the problem must come in the form of executive branch actions. These executive actions must be justified by cost-benefit analyses. The current metric used to value the benefits of greenhouse gas reduction policies is the Social Cost of Carbon estimate, a number intended to price the damage done to the economy by each ton of CO2. This paper examines the intersection of the Social Cost of Carbon (SCC) estimate and the Value of Statistical Life (VSL) estimate currently used by federal agencies to value mortality risk reductions in policymaking. Two of the three climate damage models underlying the SCC estimate currently use comparable mathematical approaches to model VSL equivalents. The mathematical approaches for modeling VSL estimates in climate damage models have been isolated to reveal how various national VSL values would likely appear if the SCC estimate was subject to a more thorough analysis. Modeled VSL results also then compared with observed VSL results from the literature. While the magnitude of the effect of changes in the VSL remains small except in cases of catastrophic events...

Climate change: The opportunity cost of Medupi and Kusile power stations

Blignaut,James
Fonte: Journal of Energy in Southern Africa Publicador: Journal of Energy in Southern Africa
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2012 EN
Relevância na Pesquisa
65.54%
Eskom has embarked on the construction of two coal-fired power stations (Medupi and Kusile) that use a new dry-cooling process with flue gas desulphurisation (FGD). While the introduction of these new technologies does have meaningful environmental benefits beyond the conventional coal-fired power stations, they still emit greenhouse gasses. The question at stake here is what is the opportunity cost, viewed from a climate change perspective, of these two new power stations? This question is answered by considering the carbon footprint of the two power stations and a range of unit values for CO2. From this analysis, it is evident that the most likely range of the opportunity cost is between R6.3 billion and R10.7 billion per year. This converts to a damage cost of between R0.10 and R0.17/kWh when assuming a net combined generation capacity of 8 677 MW and a load factor of 85%.