Suchergebnisse

Spark ignited internal combustion engines are expected to continue to be the mainstay for the passenger cars and light duty trucks for the next few decades. It is understood that to conform to the stringent fuel efficiency legislations as well as meet the regulated exhaust emission limits, combustion technology must evolve significantly. It is imperative to develop a deeper understanding of the fundamental engine processes such as air intake, fuel-air interaction, and ignition so that avenues for incremental improvements may be explored. With this broad objective, the present study focuses on spark ignition engines in which premixed and lean (air in excess) charge of fuel and air can be burned efficiently. Studies have indicated that under these conditions, it is possible to simultaneously reduce the oxides of nitrogen (NOx), while keeping the carbon monoxide (CO) and unburned hydrocarbons (UHCs) at low levels. The in-cylinder turbulence plays a major role in the fuel-air mixture preparation. When this mixture ignites, the combustion may propagate through what is known as a premixed turbulent flame. Turbulence is beneficial since it enhances the mass burning rate. This is particularly critical in lean burn engines in which it is difficult to complete the combustion within the extremely short time scales typical of modern engines. Excess turbulence however, may lead to flame quenching. In order to investigate the conditions leading up to and the propagation of the turbulent flame itself, analytical and empirical studies are performed. Tests are conducted on a constant volume combustion chamber with optical access to provide insight into the combustion characteristics of lean mixtures subject to turbulence. Fundamental studies on premixed flame propagation are performed with a variety of fuels at different equivalence ratios with different fuels. Impacts of engine operating conditions such as air-fuel ratio, exhaust gas recirculation, engine load, fuels, and ignition strategies on the flame initiation and development are investigated in detail on a research engine test setup. Chemical simulation and computational fluid dynamics (CFD) tools are used to supplement the understanding of the results. Finally, an attempt is made to comprehensively understand the combined effects of in-cylinder flow and fuel reactivity on premixed and lean combustion.

The international prices of agricultural commodities have exhibited a rising trend since the mid-2000s. This article explains the phenomenon using demand–supply framework from a macroeconomic perspective. It does not find any evidence in favour of the mainstream argument of increased demand from India and China being responsible for this price rise. It argues that the pursuit of neoliberal policies have squeezed the earnings of the peasantry and made agriculture an unviable occupation, adversely affecting its supply. During 1995–2004, the annual per capita production of cereals in the world declined at an alarming rate of 0.32 per cent and then over 2005–2012 grew at a meagre rate of 0.85 per cent, respectively. The production of biofuels, using food crops as feed, has further distorted the international food market. Moreover, speculative activities in the futures market fuelled the existing tendencies of rising prices. If sufficient policy support is given to the agrarian economy of developing countries, then this phenomenon can be reversed.

In the recent past, the developing countries, in particular the Newly Industrialising Countries (NICs), Association of Southeast Asian Nations (ASEAN), China and India, have become a major player in the global market of manufactured goods. It had been argued that this changing composition in the export baskets of these developing countries in favour of the manufactured goods had helped the developing countries to escape from the problems of 'deteriorating' terms of trade and doubts the validity of the Prebisch–Singer hypothesis in the present world economic order. This study empirically finds a secular negative trend in the movement of the manufacture-manufacture terms of trade of the developing countries vis-à-vis the developed countries spanning over the period between 1975 and 2005. It also identifies the probable factors responsible for this negative trend in the terms of trade index and whether this diversification of exports towards more of manufactured goods helps the developing countries to escape from the problem of Prebisch–Singer hypothesis.

Is imperialism dead? While economists on the Right would readily answer in the affirmative, some even on the Left, like Hardt and Negri, would agree that it is indeed. To be sure, for the latter, global hegemony has taken a different shape, which they call 'Empire'. But is imperialism, as understood in the classical sense, dead indeed? In varied frameworks of imperialism—world systems, dependency, unequal interdependence—the world has been theorised as constitutive of two parts: capitalist core (global North) and pre/semi-capitalist periphery (global South). This neat classification has been smudged by the emergence of China from the global South as a major economic player in the global economy. We argue its emergence, far from weakening imperialism, is a key factor in explaining today's imperialism. Imperialism of the twenty-first century constitutes of three, not two, parts—capitalist core, periphery's core, and periphery's periphery. JEL Codes: F54; F60

One of the two components of the United Nations Sustainable Development Goal (SDG) 8 is "economic growth", a term which people in the 21st century are quite familiar with. The question of growth, or the lack thereof, has often featured prominently in political debates, scholarly writings, as well as popular media. Nevertheless, sustained economic growth was only a recent phenomenon in human history. The world economy remained stagnant throughout the first 1800 years in the Common Era and started to grow exponentially after that. 1Measured by international dollars in 1990, the world has seen more than 5 times increase in population in the last two centuries, but the real GDP has increased by more than 700 times.

Hardt and Negri in Empire argue that "Imperialism is over." On the contrary, others argue that not only is imperialism not dead, but its machinations have amplified during the phase of globalisation (Patnaik's The Value of Money, Patnaik and Patnaik's A Theory of Imperialism, John Smith's Imperialism in the Twenty-First Century, among others). The reason for this sharp division among progressives is because of the current world scenario. On the one hand, some countries in the periphery (emerging economies) are growing faster than those in the core. On the other hand, the terms of trade has started moving in favour of the primary commodities over the last two decades. This paper argues that imperialism exists not in spite of but because of the globalisation of capital. Mature capitalism in the core needs to deal with three instabilities: accumulation, price and political (Patnaik), the first because of expectations in investment decisions (Luxemburg), the second because of the wage-price spiral (Rowthorn) and the third because of the social unacceptability of high rates of unemployment. We argue that globalisation solves the first two problems but, in the process, aggravates the third instability. The world is no longer divided into two camps of a capitalist core and non-capitalist periphery. Today, we have a tripartite division of the world with a capitalist core (G-8), predominantly capitalist periphery (China, Taiwan among others) and a pre-capitalist periphery (the African subcontinent and the rest). The capitalist periphery, through its low wage costs, keeps the wage shares in the capitalist core under check, thereby providing price, and hence, financial stability to the US dollar. The same low wage costs induce a shift in the site of accumulation to the capitalist periphery even as the capitalist core retains the surplus generated through the IPRs. Due to increased accumulation, the raw material requirements create debilitating conditions for the pre-capitalist periphery in effect forming a pyramidal structure of imperialism. However, a significant contradiction develops in this process. While globalisation provides the core with price and output stability, it comes at the cost of political instability because a declining wage share and outsourcing creates unemployment or declining income for the workers in the US resulting in a rightward shift (election of Trump and others) in the polity in the core.

Can growth in India be simultaneously made equitable and environ- mentally sustainable? The recent pattern of high growth in India has been inequitable even as serious questions have been raised about its ecological sustainability. In contrast to the current growth trajectory, this paper argues that an alternative growth trajectory can be de- veloped which answers the question in the affirmative. We propose an Energy Policy with Equity (EPE), which fundamentally changes the energy mix of the Indian economy towards greener forms of en- ergy as well as guarantees universal access to energy thus generated to the entire population, a feat that almost all the governments since independence have dreamt of but failed to deliver. This policy also fundamentally changes the energy mix of the Indian economy towards greener forms of energy as well as guarantees universal access to energy thus generated to the entire population. This can be done by taxing carbon to control CO2 emissions. A part of the revenue thus generated can be used for a systemic overhaul of the energy mix, which to a large extent addresses the pressing problem of environmental degradation. And the other part can be used for an in-kind transfer of free electricity to the population who contribute less carbon than the economy average and issue universal travel passes to compensate for the rise in transport costs and encourage the use of public transport. The methodology employed in this paper is an Input-Output analy- sis which involves two steps: calculating the carbon content (IO data) and its impact on the household budget (NSS). The level of carbon tax required for this policy to come into effect is USD 60.4 per met- ric ton of carbon dioxide. On the one hand, a portion of these taxes mobilised is allocated for the improvement in energy efficiency and ex- pansion of renewable energy. On the other, the free entitlement of fuel and electricity from these taxes for a household comes out to be 2268 kWh per annum or 189 kWh per month, which is 412 kWh per year multiplied by the average size of the household (i.e. 5.5). Universal travel passes with pre-loaded balance amount of USD 17.9 can be used on any mode of public transport. While the energy mix of the growth process changes in favour of clean sources through investment in green energy as well as controlling demand for fossil fuels through a carbon tax/cap, distribution of the tax revenue in the form of universal access to energy makes the process egalitarian.

El artículo plantea que hay una nueva forma de imperialismo en el siglo XXI, gracias al cambio climático, sus causas antropogénicas —en particular, originadas por la explotación desmedida de parte de los países desarrollados— y los impactos que está teniendo, especialmente en países en desarrollo. Hace una crítica a las acciones insuficientes que han tomado los países ricos para combatirlo sin realmente responsabilizarse por sus efectos, en contraste con el gran financiamiento y las políticas con los que estos mismos países fomentan la explotación de recursos naturales, y con ello el deterioro ambiental y la desigualdad social y económica.