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Dans cet article, nous étudions l'utilisation du flux de lots dans les problèmes de planification de flowhop sans permutation. L'objectif est de minimiser le makepan soumis aux contraintes de flowhop standard, mais où il est maintenant autorisé de réorganiser les tâches entre les machines. En outre, les tâches peuvent être divisées en sous-lots gérables, une stratégie connue sous le nom de flux de lots. Les expériences informatiques montrent que le flux de lots réduit le makepan jusqu'à 43% pour un large éventail de cas par rapport au cas où aucun fractionnement de tâches n'est appliqué. Les avantages augmentent à mesure que le nombre d'étapes du processus de production augmente mais atteignent une limite. Au-delà d'un certain point, la division des tâches en sous-lots supplémentaires n'améliore pas la solution. En este documento investigamos el uso de la transmisión de lotes en problemas de programación de Flowshop sin permutación. El objetivo es minimizar el makepan sujeto a las restricciones estándar de Flowshop, pero donde ahora se permite reordenar trabajos entre máquinas. Además, los trabajos se pueden dividir en sublotes manejables, una estrategia conocida como transmisión de lotes. Los experimentos computacionales muestran que la transmisión de lotes reduce el makepan hasta un 43% para una amplia gama de instancias en comparación con el caso en el que no se aplica la división de trabajos. Los beneficios crecen a medida que aumenta el número de etapas en el proceso de producción, pero alcanzan un límite. Más allá de cierto punto, la división de trabajos en sublotes adicionales no mejora la solución. In this paper we investigate the use of lot streaming in non-permutation flowshop scheduling problems.The objective is to minimize the makespan subject to the standard flowshop constraints, but where it is now permitted to reorder jobs between machines.In addition, the jobs can be divided into manageable sublots, a strategy known as lot streaming.Computational experiments show that lot streaming reduces the makespan up to 43% for a wide range of instances when compared to the case in which no job splitting is applied.The benefits grow as the number of stages in the production process increases but reach a limit.Beyond a certain point, the division of jobs into additional sublots does not improve the solution. في هذه الورقة، نتحقق من استخدام تدفق اللوت في مشاكل جدولة ورشة التدفق غير القابلة للتحويل. الهدف هو تقليل فترة التشغيل وفقًا لقيود ورشة التدفق القياسية، ولكن حيث يُسمح الآن بإعادة ترتيب الوظائف بين الآلات. بالإضافة إلى ذلك، يمكن تقسيم الوظائف إلى أقسام فرعية يمكن التحكم فيها، وهي استراتيجية تعرف باسم تدفق اللوت. تظهر التجارب الحاسوبية أن تدفق اللوت يقلل من فترة التشغيل إلى 43 ٪ لمجموعة واسعة من الحالات عند مقارنتها بالحالة التي لا يتم فيها تطبيق تقسيم الوظائف. تنمو الفوائد مع زيادة عدد المراحل في عملية الإنتاج ولكنها تصل إلى حد. بعد نقطة معينة، لا يؤدي تقسيم الوظائف إلى أقسام فرعية إضافية إلى تحسين الحل.

AbstractThe Environmental Kuznets Curve hypothesis suggests that, as a country's national income grows, environmental degradation subsides as the population demands a cleaner environment. On the other hand, critics of the Environmental Kuznets Curve claim that many polluting industries simply relocate offshore, where environmental compliance is less costly. They then export their products back to their previous home countries. This is known as the Pollution Haven hypothesis. This article demonstrates how pollution havens can falsely give the appearance of an Environmental Kuznets Curve by analysing lead emissions from the US automotive tyre manufacturing industry.

Abstract Hydrogen is considered a potential game changer for world energy systems and a solution to climate change concerns, as it generates zero waste and it is suited for power generation and transportation. Despite its several advantages, there are significant technical challenges in deploying a stable hydrogen economy including improving its process efficiencies, lowering production costs, maintaining cost-effective transmission and distribution, and exploiting inexpensive and sustainable feedstocks. In this context, a detailed study was conducted to analyze the production sources, technologies, storage and transport systems, and global potential exportable feedstocks to produce hydrogen. A comprehensive analysis of current hydrogen production technologies with their energy efficiencies and hydrogen selling prices was reported in this study. Various hydrogen production technologies with their capital investments and CO2 emissions were also presented. Potential feedstocks for hydrogen production were identified and analyzed through a product space model, which characterizes a network of global exportable products based on their similarities and productive knowledge. It was established that the hydrogen production feedstocks and sources currently used are primarily available in six countries: the United States of America, France, Russia, Sweden, the Netherlands, and Spain. Broadly, the results revealed that the United States of America and Russia shared the highest hydrogen feedstock exports, indicating a higher probability of hydrogen production in these countries. Except for Russia, all the studied countries fell in the most desired quadrant, indicating that they can move in all product space directions to exploit unexplored hydrogen feedstocks for better sustainable economic growth.

Abstract The rapid economic development of China has been accompanied by the emission of a great number of pollutants, which in turn have caused severe environmental problems. To strengthen environmental management and to establish a pollution source information database covering all key pollution sources and activities, China carried out its first National Census of Pollution Sources (NCPS) in 2007. The survey contents include the basic environmental situation in 2007, the generation levels of the main pollutants at that time, and the amount of pollution actually discharged into the environment after end-of-pipe treatment at all kinds of pollution sources. Based on the first NCPS report for China released in 2011, and taking two typical industry pollutants, sulfur dioxide (SO 2 ), and chemical oxygen demand (COD) as examples, we first revised the historical data concerning environmental statistics based on the NCPS documents. Subsequently, we analyzed the overall industrial scale in the change of SO 2 and COD emissions using index decomposition analysis, and then studied the contributions and comparative significance of the “three pollution emission reduction measures” put forward by the Chinese government. The latter are: Engineering Emission Reduction (EER), Structure Emission Reduction (SrER) and Supervision Emission Reduction (SuER). From these analyses, we were able to identify the main driving forces for SO 2 and COD emission reduction in China's industrial system. The results indicate that, with continually increasing pollution pressure caused by rapid economic development, EER and SuER have made the greatest contributions to reducing SO 2 and COD emissions; but SrER has not had an obvious effect. In the future, EER and SuER will gradually have less and less potential and become more challenging, while SrER should be achievable through adjusting the economic structure.

According to the United Nations population projections, the population of the elderly is expected to roughly triple in China from 2000 to 2050, particularly when the generations who were born between the 1950s and 1970s move through the age structure, and also because people are living longer and fertility rates have fallen, population aging is expected to put pressure on government's fiscal balance through higher old-age security benefits and health-care expenditures. This work draws together the broad range of elements involved within a consistent framework, based on a computable dynamic general equilibrium model with an overlapping generation structure. Further analysis using model simulation illustrates that the alternative schemes for the benefit rate, retirement age and technological progress are likely to be beneficial, and that an obvious slow-down in the growth of living standards is likely to be avoided.

Abstract This paper provides the first estimates of China's global developmental finance institutions in general and China's policy bank lending to foreign governments for energy in particular. According to the China Global Energy Finance database, between 2000 and 2017, China Development Bank (CDB) and China Export-Import Bank (CHEXIM) provided $225.75 billion in overseas energy development finance. We find that: China's ‘policy banks’ and funds have doubled the availability of global development finance –and hold more assets than the major Western-backed MDBs operating in developing countries. With the onset of a new family of funds and multilateral development banks co-financed by China, China is poised to be the largest development lender in the world as Western-backed MDBs appear stagnated in their ability to increase their capital bases. China's global energy portfolio is heavily exposed to country, macroeconomic, climate, and social risks, however. To mitigate such risks and meet the broader sustainable development challenge for the 21st Century, China's development finance will need to shift the composition of its global energy lending in a significant manner.

Abstract China's carbon emissions have been ranking first in the world. This study filled in the gaps in research, decomposed carbon intensity from the perspective of time, space and industry. A decoupling effort model based on factor decomposition models was constructed to analyze the driving factors of carbon emissions and economic decoupling, which builded a foundation for achieving sustainable economic development. Using the Logarithmic Mean Divisia Index method (LMDI), the paper measured the carbon emission intensity of 29 provinces and cities in China from 1998 to 2019, and decomposed the decoupling effect between GDP and carbon emission on the basis of factor decomposition by tapio. The results showed that: (1) Carbon intensity declined first, then rise lightly, and finally declined steadily. For the primary industry and the tertiary industry, the carbon intensity declined steadily, while the carbon intensity increased accordingly to the overall carbon intensity. In terms of spatial evolution, the regional differences between different provinces decreased correspondingly. (2) The cumulative contribution rates of these three effects, i.e., technological progress, industrial structure and regional scale were 106.3299%, −15.1486% and 8.8188%, respectively. There were obvious differences of these cumulative contribution rates of carbon intensity among different provinces. (3) From the perspective of industrial, technological progress effect is the largest contribution for carbon intensity in the secondary industry. The Industrial structure effect mainly affects the primary and tertiary industries; and no significant difference in regional scale effect. (4) The decoupling effect gradually improved, and technological progress has played an absolute leading role in promoting the decoupling effect. Based on the research results, the key policy recommendation are put forward as follows: (1) Further improve the technological level and support clean technology enterprises. (2) Promote industrial upgrading in backward industrial provinces (3) Promote regional assistance and the introduction of high-quality foreign investment.

Abstract The ecological footprint is a measure of the resources necessary to produce the goods that an individual or population consumes. It is also used as a measure of sustainability, though evidence suggests that it falls short. The assumptions behind footprint calculations have been extensively criticized; I present here further evidence that it fails to satisfy simple economic principles because the basic assumptions are contradicted by both theory and historical data. Specifically, I argue that the footprint arbitrarily assumes both zero greenhouse gas emissions, which may not be ex ante optimal, and national boundaries, which makes extrapolating from the average ecological footprint problematic. The footprint also cannot take into account intensive production, and so comparisons to biocapacity are erroneous. Using only the assumptions of the footprint then, one could argue that the Earth can sustain greatly increased production, though there are important limitations that the footprint cannot address, such as land degradation. Finally, the lack of correlation between land degradation and the ecological footprint obscures the effects of a larger sustainability problem. Better measures of sustainability would address these issues directly.

Accurate measurement of the shadow price of carbon dioxide (CO2) is fundamental to the scientific assessment of the carbon emission reduction cost and the formulation and execution of China’s carbon emission mitigation policies. Underpinned by the directional distance function, this research uses a parametric linear programming method and a Bayes bootstrap estimation method to estimate the marginal CO2 emission reduction cost of the industrial sector in China and to quantify the related influencing factors. The results revealed that the marginal reduction cost of industrial CO2 is CNY 4565/ton. The marginal reduction cost of CO2 varies by industry, with the textile industry being the highest and the petroleum, coking and nuclear fuel processing industries the lowest. Meanwhile, an increasing number of industries are shifting to cleaner production. Furthermore, the marginal reduction cost of industrial CO2 has an “inverted U-shaped” relation with carbon intensity. Carbon emission reduction can be accomplished effectively if the carbon intensity is kept below the threshold value of 0.41 tons/CNY 10,000.