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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.

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.

The Poster proposes a research agenda for the creation of knowledge about the potential of Digital Product Passports (DPPs) as a means to promote the sustainability of the textiles sector. Analysis is called for to transition to a more sustainable society by focusing on the 1) Textiles ecosystem: relevant stakeholders and their interrelationships 2) Trust, transparency, reliability, sustainability, and information 3) DPPs as an information system 4) Data requirements for DPPs and 5) The societal impacts of DPPs.

Abstract Thermochemical energy storage (TCS) based on gas-solid reactions constitutes a promising concept to exploit reaction enthalpies for thermal energy storage. This concept facilitates the development of efficient storage solutions with higher energy densities compared to widely investigated sensible and latent thermal energy storage systems. Multivalent metal oxides are capable of undergoing a reversible redox reaction at high temperatures, which is why those storage materials are considered particularly suitable for the operating temperature range of concentrated solar power plants with central receiver systems to increase the total plant efficiency and ensure dispatchability of electricity. In the scope of this work a granular manganese-iron oxide with a Fe/Mn molar ratio of 1:3 has been selected as a potentially suitable storage material, which is non-toxic, abundant and economical. For this reason a preparation route from technical grade raw materials has been chosen. The reversible redox reaction is investigated with respect to the thermodynamic and kinetic characteristics by means of simultaneous thermal analysis in dynamic and isothermal series of measurements. Those revealed that the observed presence of a strong divergence of the reactive temperature range from the actual thermodynamic equilibrium can mainly be attributed to kinetic limitations. Expressions for the effective reaction rates are deduced from experimental data for the reduction and oxidation step, describing the dependence of the reaction rate on temperature and oxygen partial pressure, respectively. The expressions are valid for the temperature ranges in proximity to the equilibrium, which are relevant for the targeted operating conditions of the storage reactor in air. The storage material provides good cycling stability in terms of reversibility and widely maintained reactivity throughout 100 redox cycles in air. Future work comprises material modifications, which are expected to further enhance the mechanical stability of the particles. Overall, the manganese-iron oxide of the chosen composition exhibits a redox reactivity practical for regenerator-type storage systems combining a high temperature TCS zone and a lower temperature non-reactive zone merely used for sensible thermal energy storage.

Since the industrial revolution, the financial sector has become a significant claimant toward the growth of human society. However, supporting the adverse environmental projects in financial terms has raised several queries about creating a direct linkage between financial market products and the environment.This research examines the nexus between sustainability, green innovations, financial technologies (FinTech), financial development, and natural resources for BRICS economies during 2000–2019. Using the Method of Moments Quantile Regression (MMQR), the results show that FinTech and natural resources adversely impact environmental sustainability across all three ranges of quantiles (0.10th-0.30th, 0.40th-0.60, and 0.70th-0.90th).Conversely, green innovations and financial development promote environmental sustainability across lower to higher-order quantiles (0.10th-0.90th), while economic growth contributes to higher emissions at major quantiles. Similar findings are endorsed using alternative estimators and suggest practical policy implications.