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AbstractThe concept of a ‘just transition’ to a low‐carbon economy is firmly embedded in mainstream global discourses about mitigating climate change. Drawing on Karl Polanyi's political economy elaborated inThe Great Transformation, we interrogate the idea of a just transition and place it within its historical context. We address a major contradiction at the core of global energy transition debates: the rapid shift to low‐carbon energy‐systems will require increased extraction of minerals and metals. In doing so, we argue that extractive industries are energy and carbon‐intensive, and will enlarge and intensify social and ecological injustice. Our findings reveal the importance of understanding how the idea of a just transition is used, and by who, and the type of justice that underpins this concept. We demonstrate the need to ground just transition policies and programmes in a notion of justice as fairness.

Societal relations in rural areas have entered into a new stage of adjustment over the past decade. However, the adjustment, which might bring about profound societal changes in countryside as well as in China as a whole, have not been paid much attention and very few studies have been conducted from the perspective of ecological resource crises. We use the case of a village as an example to show how water pollution, as one of the contributory factors, possibly affect the transition of clans and societal changes in Chinese villages. Through observation and interviews, we find that there is an apparent rise of “New Clanism” within clans, which gradually abandons the tradition of supremacy of clan interests and places family or individual interests at top priority. We also find that clan boundaries get increasingly obscure since the integrity of clans is undermined by the rise of new interest groups across clans, but the boundaries remain relatively clear due to the consistency (albeit incomplete) of clan interests. Some new clan élites and representatives of new interest groups get involved in village governance, which indicates that their goals have shifted from natural resources to social or political capital. The significance of our findings is that they provide not only a unique perspective for the interaction between society and resources, but also some new ideas for the future study of rural China at the environment-social interface.

Le Pakistan traverse une crise énergétique terrifiante et dévastatrice. Récemment, la prévision de la consommation d'énergie s'est intensifiée par rapport à sa capacité de production, ce qui est problématique pour la stabilité sociale et économique du Pakistan. Par conséquent, il est essentiel d'examiner le lien entre la consommation d'électricité, les prix de l'électricité, la transition urbaine, les autres utilisations d'électricité et l'expansion économique de 1970 à 2018 au Pakistan. Pour l'analyse, la technique économétrique de deuxième génération de Lee et Strazicich (2013), le nouveau Augmented Autoregressive Distributed Lag (AARDL) et Frequency Domain Causality (FDC) est utile pour détecter l'association à moyen et à court terme entre les variables. Les résultats montrent que la consommation d'électricité stimule l'expansion économique à court et à long terme, bien que la hausse des prix de l'électricité diminue l'activité économique à court et à long terme. En outre, la transition urbaine et d'autres utilisations de l'électricité ont un impact positif et négatif substantiel sur l'expansion économique à court et à long terme. Le résultat suggère qu'un approvisionnement énergétique efficace, des prix de l'énergie à faible coût, une bonne gestion de la transition urbaine et d'autres utilisations de l'énergie pourraient être utiles aux décideurs pour atteindre les ODD 7 et 11 au Pakistan. Pakistán se encuentra en una crisis energética aterradora y devastadora. Recientemente, la predicción del consumo de energía se ha intensificado en comparación con su capacidad de producción, lo que es problemático para la estabilidad social y económica de Pakistán. Por lo tanto, es vital examinar el vínculo entre el consumo de energía, los precios de la energía, la transición urbana, otros usos de la electricidad y la expansión económica de 1970 a 2018 en Pakistán. Para el análisis, la técnica econométrica de segunda generación de Lee y Strazicich (2013), el novedoso Retraso Distribuido Autoregresivo Aumentado (AARDL) y la Causalidad en el Dominio de la Frecuencia (FDC) son útiles para detectar la asociación a largo y corto plazo entre las variables. Los resultados muestran que el consumo de energía estimula la expansión económica a corto y largo plazo, aunque el aumento de los precios de la energía disminuye la actividad económica a corto y largo plazo. Además, la transición urbana y otros usos de la electricidad tienen un impacto positivo y negativo sustancial en la expansión económica a corto y largo plazo. El resultado sugiere que el suministro eficiente de energía, los precios de la energía de bajo coste, la gestión adecuada de la transición urbana y otros usos de la energía podrían ser útiles para que los responsables políticos alcancen los ODS 7 y 11 en Pakistán. Pakistan is in a terrifying and devastating energy crisis. Recently, the prediction for energy consumption has intensified compared to its production capacity, which is problematic for Pakistan's social and economic stability. Hence, it is vital to examine the link between power consumption, power prices, urban transition, other electricity use, and economic expansion from 1970 to 2018 in Pakistan. For analysis, the second-generation econometric technique of Lee and Strazicich (2013), novel Augmented Autoregressive Distributed Lag (AARDL), and Frequency Domain Causality (FDC) is useful to detect the long-medium and short-run association among the variables. The results show that power consumption stimulates economic expansion in the short and long-run, though the rise in power prices declines economic activity in the short and long-run. Also, urban transition and other electricity use are a substantial positive and negative impact on economic expansion in the short and long-run. The outcome suggests that efficient energy supply, low-cost power prices, proper urban transition management, and other energy use could be useful for policymakers to achieve SDGs 7 and 11 in Pakistan. باكستان في أزمة طاقة مرعبة ومدمرة. في الآونة الأخيرة، تكثف التنبؤ باستهلاك الطاقة مقارنة بقدرته الإنتاجية، مما يمثل مشكلة للاستقرار الاجتماعي والاقتصادي لباكستان. وبالتالي، من الضروري دراسة الصلة بين استهلاك الطاقة وأسعار الطاقة والتحول الحضري واستخدام الكهرباء الأخرى والتوسع الاقتصادي من 1970 إلى 2018 في باكستان. للتحليل، فإن تقنية الاقتصاد القياسي من الجيل الثاني من Lee and Strazicich (2013)، والتأخر الموزع الانحداري الذاتي المعزز (AARDL)، وسببية مجال التردد (FDC) مفيدة للكشف عن الارتباط طويل المدى وقصير المدى بين المتغيرات. تظهر النتائج أن استهلاك الطاقة يحفز التوسع الاقتصادي على المدى القصير والطويل، على الرغم من أن ارتفاع أسعار الطاقة يؤدي إلى انخفاض النشاط الاقتصادي على المدى القصير والطويل. كما أن التحول الحضري والاستخدامات الأخرى للكهرباء لها تأثير إيجابي وسلبي كبير على التوسع الاقتصادي على المدى القصير والطويل. تشير النتيجة إلى أن إمدادات الطاقة الفعالة، وأسعار الطاقة منخفضة التكلفة، وإدارة الانتقال الحضري المناسبة، وغيرها من استخدامات الطاقة يمكن أن تكون مفيدة لصانعي السياسات لتحقيق هدفي التنمية المستدامة 7 و 11 في باكستان.

Abstract In arid areas, dry cooling technology is a preferable alternate of wet cooling mainly owing to the scarcity of abundant water supply. However, the supercritical CO2 power cycle still offers considerable thermal performance even at higher ambient temperature using dry cooling. The novelty of this work is the exhaustive designing of dry cooler for supercritical CO2 cycles (recompression and partial cooling) in concentrating solar power application. Prior to the design of tower, a preliminary analysis is conducted in achieving the optimum main compressor inlet temperature (33 °C-recompression and 40 °C-partial cooling) at which the cycle delivers the maximal efficiency. The comparison is performed at same higher and lower pressure and for the partial cooling, the intermediate pressure is optimized. At relatively higher compressor inlet temperatures (above 50 °C), the partial cooling achieves higher efficiency while at lower temperatures (30–49 °C), the recompression shows superior performance. An iterative nodal method is used for the air-cooled finned tube heat exchanger units that takes account of the dramatic variation in thermodynamic properties of CO2 with the bulk temperature. Kroger’s detailed methodology of designing dry cooler is adapted with the implementation of nodal approach for CO2 property variation. A dry cooling tower with 52.45 m height is essential for the recompression cycle, whereas the partial cooling requires two towers of the height of 35.4 m and 38.7 m. A thermal assessment is carried out on the dry cooler under various cycle fluid inlet temperatures and ambient temperatures. During hot and humid ambient conditions, lower compressor inlet temperatures (up to 53.1 °C) are obtained with the recompression cycle compared to partial cooling (up to 64.5 °C). In extreme climate condition of 50 °C air temperature, the recompression cycle provides superior thermal efficiency (46.5% against 45.5%). For future commercialization of dry cooled sCO2 power plant, the recompression cycle is preferred due to its superior performance and lower capital cost for cooling tower design and solar field. The work demonstrates the impact of dry cooling tower design strategy in the context of cycle thermal assessment under various working condition.

Abstract Comprehensive information about the concentrations, distribution, and modes of occurrence of elements in coal are important from the environmental and economic point of view. Although a great number of previous studies have investigated the geology of coalbed methane in the Qinshui Basin, only a few studies focused on the inorganic constituents in coal. More specifically, the mode of occurrences of valuable element Li in the No. 3 Coal is still unclear, although Li was found enriched. In this study, we present mineral characteristics, as well as multi-element data on the Permian No. 3 Coal from the Sucun and Gaohe Mines, Changzhi City, southern Qinshui Basin. The studied coals are characterized by low- to medium-ash yield (Ad = 5.72%- 28.18%, 12.34% on average), low volatile matter yield (Vdaf = 8.49–15.17%, 10.96% on average), suggesting a low volatile bituminous coal to semi-anthracite. NH4-illite and kaolinite are the main minerals in the coals detected by XRD, and trace amount of minerals calcite, dolomite, quartz, pyrite and diaspore can also be found. The major elements of the studied No. 3 coals are dominated by SiO2 and Al2O3, ranging 2.49–16.45 wt% and 2.13–12.9 wt% (on a whole-coal basis), respectively. Li is enriched in the No. 3 coals (5

Short-term voltage stability is an increasing concern in today's power systems due to the growing penetration of induction motors. This paper proposes a systematic method for optimal placement of dynamic VAR support against short-term voltage instability. The problem is formulated as a multi-objective optimization model minimizing two conflicting objectives: 1) the total investment cost and 2) the expected unacceptable short-term voltage performance subject to a set of probable contingencies. STATCOM is employed for its stronger dynamic VAR support capability. Indices for quantifying the short-term voltage stability and the related risk level are proposed for problem modeling. Candidate buses are selected based on the concept of trajectory sensitivity. Load dynamics are fully considered using a composite load model containing induction motor and other typical components. A relatively new and superior multi-objective evolutionary algorithm called MOEA/D is introduced and employed to find the Pareto optimal solutions of the model. The proposed method is verified on the New England 39-bus system using industry-grade models and simulation tool.

Hybrid electric vehicles (HEVs) are perceived to be more energy efficient and less polluting than conventional internal combustion engine (ICE) vehicles. However, increasing evidence has shown that real-driving emissions (RDE) could be much higher than laboratory type approval limits and the advantages of HEVs over their conventional ICE counterparts under real-driving conditions have not been studied extensively. Therefore, this study was conducted to evaluate the real-driving fuel consumption and pollutant emissions performance of HEVs against their conventional ICE counterparts. Two pairs of hybrid and conventional gasoline vehicles of the same model were tested simultaneously in a novel convoy mode using two portable emission measurement systems (PEMSs), thus eliminating the effect of vehicle configurations, driving behaviour, road conditions and ambient environment on the performance comparison. The results showed that although real-driving fuel consumption for both hybrid and conventional vehicles were 44%-100% and 30%-82% higher than their laboratory results respectively, HEVs saved 23%-49% fuel relative to their conventional ICE counterparts. Pollutant emissions of all the tested vehicles were lower than the regulation limits. However, HEVs showed no reduction in HC emissions and consistently higher CO emissions compared to the conventional ICE vehicles. This could be caused by the frequent stops and restarts of the HEV engines, as well as the lowered exhaust gas temperature and reduced effectiveness of the oxidation catalyst. The findings therefore show that while achieving the fuel reduction target, hybridisation did not bring the expected benefits to urban air quality.

Direct numerical simulation (DNS) coupling with chemistry coordinate mapping (CCM) is presented to simulate flame propagation and auto-ignition in a partially premixed syngas/air mixture. In the CCM approach, the physical domain is mapped into a low dimensional phase space with a few thermodynamic variables as the independent variables. The integration of the chemical reaction rates and heat release rate are done on the grid in the phase space. Previously we showed that for premixed mixtures, two variables temperature and specific element mass fraction of H atom, can be sufficient to construct the phase space for a satisfactory mapping. However, for partially premixed combustion mode, a third phase space variable is required to map the physical cell into the phase space. It is shown that scalar dissipation rate of the element mass ratio of H atom can be used as the third dimension of the phase space. An investigation is carried out on the behavior of CCM and the choice over the element on which the local element mass ratio should be based. Mapping error in the CCM is investigated. It is shown that if the element mass ratio is based on the element involved in the most diffusive molecules, the error of the mapping can approach zero when the grid in the phase space is refined. To validate the CCM approach the results of DNS coupled with CCM (DNS-CCM) are compared with full DNS that integrates the chemical reaction rates and heat release rate directly in physical space. Good agreement between the results from DNS and DNS-CCM is obtained while the computational time is reduced at least by 70 %.