• Energy Research
• 2016-2025close
• Restricted close
• AU close
• BE close
• IN close

The present study is motivated by the need to decouple economic growth from environmental degradation given the new wave of chase for higher economic growth trajectories comes with its environmental cost implications, especially among developing blocs like the Emerging 7 (E7) countries. There is a consistent trade-off between economic growth versus environmental quality. Government apparatus are perpetually on the chase for low-carbon emission policies via the pursuit for green economy. To this end, this present study extends the conventional environmental Kuznets curve (EKC) argument by incorporating the role of institution in emerging industrialized economies (E7) and using second-generation panel analysis methods like mean group (MG), augmented mean group (AMG), common correlated effects mean group (CCEMG), and the Dumitrescu and Hurlin causality test for more robust estimates and inferences. To this end, we explore the long-run and causality relationship between economic growth, quadratic form of economic growth, institutional quality, trade flow, investment in energy sector, and financial development in an EKC environment. Empirical analysis established a long-run equilibrium relationship among the outlined variables over the study period. The long-run regression shows the presence of EKC in the E7. Thus, suggesting the preference for GDP growth over environmental quality at the earlier stage of growth curve. Interestingly, investment in energy, trade flow dynamics across the blocs, and financial development dampens the detrimental effect of environmental pollution as we observed negative relationship with the ecological footprint. On the contrary, quality of institution is weak as institutional quality increase (worsen) the quality of environment in the E7 economies. From a policy perspective, this current study proposed the need for more stringent environmental treaties and regulations and promotion of green economy without compromising economic growth. In the conclusion part of the study, more details and specifics about the policy blueprint are presented.

This study highlights how Chinese economic development detrimentally impacted water quality in recent decades and how this has been improved by enormous investment in environmental remediation funded by the Chinese government. To our knowledge, this study is the first to describe the variability of surface water quality in inland waters in China, the affecting drivers behind the changes, and how the government-financed conservation actions have impacted water quality. Water quality was found to be poorest in the North and the Northeast China Plain where there is greater coverage of developed land (cities + cropland), a higher gross domestic product (GDP), and higher population density. There are significant positive relationships between the concentration of the annual mean chemical oxygen demand (COD) and the percentage of developed land use (cities + cropland), GDP, and population density in the individual watersheds (p < 0.001). During the past decade, following Chinese government-financed investments in environmental restoration and reforestation, the water quality of Chinese inland waters has improved markedly, which is particularly evident from the significant and exponentially decreasing GDP-normalized COD and ammonium (NH4+-N) concentrations. It is evident that the increasing GDP in China over the past decade did not occur at the continued expense of its inland water ecosystems. This offers hope for the future, also for other industrializing countries, that with appropriate environmental investments a high GDP can be reached and maintained, while simultaneously preserving inland aquatic ecosystems, particularly through management of sewage discharge.

Abstract The implementation of energy efficiency measures is an effective way to gain energy savings in the Italian residential sector. This paper assesses the embodied energy impact related to the envelope insulation and evaluates the energy and carbon payback of the efficiency measures. The proposed method consists of (1) an estimation of the baseline operational energy consumption, (2) simulations of realistic retrofit solutions and, (3) the assessment of the ‘retrofitting’ embodied energy and the energy and carbon payback time calculation. The payback is based on the comparison between the saved operational energy and the embodied energy of the materials selected for insulation. Ten Italian cities are analysed, and the results show a deep dependence on the climate zone. In Northern Italian cities, envelope insulation gains relevance as the energy and carbon payback periods are shorter, about 3 years against the 84 years for the Southern city of Palermo. The optimal thickness is estimated for the city of Milan considering the building’s typology, the insulation materials, and the energy payback. This study shows how the total energy savings can be used as a criterion to obtain design indications.

Urban environments provide opportunities for greater resource efficiency and the fostering of urban ecosystems. Brownfield areas are a typical example of underused land resources. Brownfield redevelopment projects that include green infrastructure allow for further ecosystems to be accommodated in urban environments. Green infrastructure also deliver important urban ecosystem services (UES) to local residents, which can greatly contribute to improving quality of life in cities. In this case study, we quantify and assess the economic value of five UES for a brownfield redevelopment project in Antwerp, Belgium. The assessment is carried out using the “Nature Value Explorer” modelling tool. The case includes three types of green infrastructure (green corridor,infiltration gullies and green roofs) primarily intended to connect nature reserves on the urban periphery and to avoid surface runoff. The green infrastructure also provides air filtration, climate regulation, carbon sequestration and recreation ecosystem services. The value of recreation far exceeds other values, including the value of avoided runoff. The case study raises crucial questions as to whether existing UES valuation approaches adequately account for the range of UES provided and whether such approaches can be improved to achieve more accurate and reliable value estimates in future analyses.

This paper introduces an adaptive current control strategy for DC-DC boost converters without input-output voltage sensing. In addition, accurate current control is achieved in the presence of dynamical uncertainties. Unlike many controllers available for DC-DC converters, the adaptive controller's stability is guaranteed by Lyapunov stability theory. A comparison to PI counterpart has been carried out. Results show higher performance, which lead to more efficient operations of DC-DC converters.

Abstract In this study, the external surface of a finned tube was coated by 13X zeolite powder, and the CO2 adsorption equilibrium and dynamics were investigated experimentally. A slurry consisting of dionized water, 13X zeolite powder, and Acrylic latex emulsion (ALE) was used to coat the finned tube. The finned tube was coated by deep coating method. The equilibrium isotherms were measured at the range of 20–90 °C and fitted well by the dual-site Langmuir model. The average difference between the model and the results obtained from the experiments is about 2.5%. The nitrogen adsorption/desorption at 77 K was used for characterization of adsorbents. A 11% reduction was observed in pore volume and surface area. The dynamic test showed that the desorption of adsorbed CO2 takes place in about 14 s which is an order of magnitude faster than the fastest developed method. A conservative criterion was developed for estimating adsorbent working capacity. This criterion showed that the working capacities of the adsorbent are about 80% of its ideal values.

Abstract Highly three-dimensional and complex flow structure within the tip gap of an axial flow turbine is a substantial source of aerodynamic loss and heat transfer due to the interaction between the tip leakage vortex, secondary flows and the main passage flow. Most contemporary shroudless high pressure (HP) turbine designs employ squealer tips for durability, structural, aerodynamic design and heat transfer reasons. The present research deals with the influence of squealer width and height on the aerothermal performance of a HP turbine blade. In this study, four different squealer heights and seven squealer width values are investigated using a computational approach for an axial turbine blade depicting an E 3 “Energy Efficient Engine” design. The specific HP turbine airfoil under investigation is identical to the rotor tip profile of the Axial Flow Turbine Research Facility (AFTRF) of the Pennsylvania State University. Numerical calculations are performed by solving the three-dimensional, steady and turbulent form of the Reynolds-Averaged Navier-Stokes (RANS) equations. A two-equation turbulence model, Shear Stress Transport (SST) k-ω is used in the present set of calculations. The current numerical predictions show a very good agreement with the extensive aerodynamic measurements obtained in the nozzle guide vane passages of AFTRF. The results indicate that determining proper squealer width and height is crucial to obtain better aerothermal performance in the form of reduced aerodynamic loss and heat transfer to the tip platform. Extensive numerical analysis within the tip gap reveals that increasing squealer height and reducing squealer width increases cavity volume leading to enlarged vortical structures near the pressure side and suction side of the cavity. Because of this enhanced vortical activity in the tip cavity, a blockage to the incoming pass-over flow is introduced and as a result tip leakage mass flow rate is reduced. While the tip leakage flow rate tends to decrease with increased height and reduced width, there is a strong effect from the squealer width and height combination due to the presence of complex interactions in the tip gap region. From a heat transfer point of view, decreasing squealer width and increasing squealer height noticeably reduces the overall Nu ‾ on the blade tip platform. Nu ‾ on the cavity floor, blade tip and squealer side walls are reduced depending on the increasing height and decreasing width values.

Abstract In order to develop a deeper understanding of the behaviour of commercial automotive lithium-ion pouch cells under short-circuiting conditions, two scenarios were experimentally investigated and compared. Firstly, experiments were conducted by internally shorting 15 Ah cells by full nail penetration using three different nail materials; copper, steel and plastic. A second set of experiments involved externally shorting the cell tabs using an external circuit with a range of resistance values. In both scenarios the cell electrical and thermal response were determined by the shorting resistance. In the case of nail penetration there was a clear distinction between the outcome of the conducting and non-conducting nails, although the outcome using conducting nails suffered from poor reproducibility. The poor reproducibility was attributed to the variation in the contact resistance between the nail and the cell layers. Correlating the outcome of both tests can be used to estimate the shorting resistance and construct the current profile during nail penetration test.