• Energy Research
• Restricted close
• Open Source close
• Embargo close
• 7. Clean energy close
• 13. Climate action close
• 6. Clean water close
• GB close

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.

AbstractClimate change effects along with anthropogenic activities present the main factors that threaten the existence of heritage sites across the north Nile Delta of Egypt close to the coastline of the Mediterranean Sea. Observing the changes in the landscape close to the archaeological sites is an important issue for decision‐makers in terms of reducing the negative impact of natural events and human activities. The coastal heritage sites are becoming strongly threatened by the rising sea level phenomena that will happen due to global warming. Focusing on the distribution of the archaeological sites, this study aims to detect the areas at risk of shoreline erosion or accretion in the northern shoreline of the Nile Delta. In this study, the changes in the northern shoreline of the Nile Delta were observed and calculated during the last hundred years based on the integration between the old topographic maps from surveys in 1900, 1925 and 1945, optical satellite images captured by Landsat in 1972, 1986 and 2000; Sentinel2 2021; and the Radar SRTM data. The results of this study showed that the changes were enormous with a great shoreline erosion process over the last 121 years recorded along the shoreline in the periods between 1900–1925, 1925–1945, 1945–1972, 1972–1986, 1986–2000 and 2000–2021. The areas eroded were about 5.3, 4.7, 5.6, 8.9, 2.5 and 5.4 km2, respectively. Such negative movements caused the loss of two heritage sites, and the expected changes will lead to the loss of additional heritage sites in the next 500 years. Furthermore, a model was suggested for protecting the coastal heritage sites threatened by the risk of submergence. This study can help the decision‐makers to detect the coastal archaeological sites at risk and create innovative solutions for protecting these irreplaceable heritage sites.

The development of heat transfer fluids (HTF) and heat storage materials (HSM) is crucial to design concentrating solar plant (CSP). Binary alkaline nitrate mixtures are currently used as sensible thermal energy storage materials. However, multi-component nitrate/nitrite systems were proposed as possible better candidates. In particular, ternaries mixtures containing sodium, potassium, and calcium are extremely promising as thermal fluids, given their reduced toxicity and greater cost-effectiveness. Nevertheless, very few data are present in the scientific literature regarding the correspondent phase diagram, and only the properties of specific compositions are reported. For this reason, a regular solution model was developed and employed in this work, and validated by comparing the simulation results with experimentally obtained phase change values. In particular, given that the common calorimetric techniques are impracticable for detecting the transition temperatures of calcium containing nitrate mixtur...

Artículos en revistas Numerical models of transmission-constrained electricity markets are used to inform regulatory decisions. How robust are their results? Three research groups used the same data set for the northwest Europe power market as input for their models. Under competitive conditions, the results coincide, but in the Cournot case, the predicted prices differed significantly. The Cournot equilibria are highly sensitive to assumptions about market design (whether timing of generation and transmission decisions is sequential or integrated) and expectations of generators regarding how their decisions affect transmission prices and fringe generation. These sensitivities are qualitatively similar to those predicted by a simple two-node model. info:eu-repo/semantics/publishedVersion

Coherence in Photosynthesis It is unclear how energy absorbed by pigments in antenna proteins is transferred to the central site of chemical catalysis during photosynthesis. Hildner et al. (p. 1448 ) observed coherence—prolonged persistence of a quantum mechanical phase relationship—at the single-molecule level in light-harvesting complexes from purple bacteria. The results bolster conclusions from past ensemble measurements that coherence plays a pivotal role in photosynthetic energy transfer. Hayes et al. (p. 1431 , published online 18 April) examined a series of small molecules comprised of bridged chromophores that also manifest prolonged coherence.

The lifetime and reliability of power transformers are primarily dependent on the hot-spot temperature in the windings, as temperature is the most important factor determining the insulation degradation rate. Key to removing the heat from the transformer is the radiator which must be carefully designed to keep the temperatures within limits under all operating conditions whilst minimizing the transformer size, weight and cost. This paper compares the analytical method used to predict the radiator performance with computational fluid dynamics (CFD) models in terms of heat dissipation. It is found that the analytical method and CFD models give similar results in the air natural (AN) cooling modes, whereas the analytical method overestimates the heat dissipation in the air forced (AF) cooling modes. Moreover, the thermal conduction effect in the radiator wall is investigated under different operating conditions and for different radiator sizes using the CFD models. The simulation results indicate that the radiator wall contributes to 6%-10% of the total heat dissipation under some circumstances and therefore should not be simply ignored in radiator models.

This paper presents a new approach to assess and improve the environmental and economic performance of integrated electricity and heat district energy systems in light of (i) optimal operation of available multi-energy components (e.g., cogeneration and heat pumps) and (ii) energy exchanges within the district through internal electricity and heat networks. The latter is particularly attractive as, instead of constraining energy flows within each building, it enables the production and consumption of energy in the most attractive locations (e.g., in buildings that can accommodate photovoltaic panels). The proposed methodology is formulated as a mixed integer linear programming problem, and demonstrated with a real UK district comprising internal electricity and heat networks and several buildings. The results highlight the attractiveness of optimising multiple energy vectors, particularly in light of energy exchanges between buildings, in economic and environmental terms.

It is widely known that fossil fuels are limited; consequently, the generation of new sources of energy in a clean and environmentally friendly manner is a research priority. Bioethanol appears to be one potential solution, especially second-generation production from renewable biomass.In order to use lignocellulosic feedstock to produce bioethanol, its polysaccharide components, cellulose and hemicellulose, must be hydrolysed into soluble sugars, which can then be converted into ethanol by fermentative microorganisms such as Geobacillus thermoglucosidasius TM242 used by the company ReBio Technologies Ltd.To date, the cost of commercial enzymes used during the hydrolysis process remains a major economic consideration in the production of second-generation bioethanol as an alternative fuel. The research project presented in this thesis aims to improve this rate-limiting step of microbial bioethanol production through an investigation of the different enzymes associated with hemicellulose hydrolysis. Firstly, the TM242 genome sequence revealed a number of genes encoding glycoside-hydrolases. Six of these genes were cloned and expressed in E. coli and the recombinant enzymes characterised; three of them, two β-xylosidases and an α arabinofuranosidase, are relevant to xylan hydrolysis, and were found to be highly active and thermostable. Crystallisation of one of the β-xylosidases permitted the determination of a high-resolution (1.7 Å) structure of the apo-enzyme along with a lower resolution (2.6 Å) structure of the enzyme-substrate complex, resulting in the first reported structure of a GH52 family member (Espina et al., 2014).Secondly, as the TM242 microorganism lacks xylanase enzymes, four genes encoding xylanases from closely-related Geobacillus strains were cloned and expressed in E. coli, with one of them being also successfully cloned and expressed in G. thermoglucosidasius TM242. This heterologous xylanase was secreted in active form representing an enhanced biomass utilisation by TM242.In conclusion, it is felt that the findings presented here have the potential to make a valuable contribution towards second-generation bioethanol production.