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[en] In recent years, annual electricity consumption in France amounted to around 470 TWh, 90% being decarbonized; at the same time, oil and natural gas consumption has been around 900 TWh and 450 TWh respectively. At present, electricity accounts for only a quarter of energy consumption. Energy savings alone will not be enough to move away from oil and natural gas: as equally anticipated for Germany and Great Britain, French reliance on electricity will have to increase significantly to replace oil and gas consumption. Various recent projections underestimate this growth. However, erroneous assumptions would affect the security of our energy supply and the daily life of the French people; the impacts on the cost of electricity and energy in general, and on the competitiveness of our economy would be considerable. In this position paper, the National Academy of Technologies of France (NATF) proposes a reasonable assessment of electricity demand in 2050. It points out that the European electricity system will be more vulnerable in coming years. It proposes some principles for the choice of economic data to be used in optimisation models. On the basis of these elements, it highlights some key points for managing change in the electricity system.
[fr]La consommation annuelle d'electricite en France a ete d'environ 470 TWh, decarbonee a plus de 90%; dans le meme temps, les consommations de petrole et de gaz naturel ont ete respectivement d'environ 900 TWh et 450 TWh. L'electricite ne represente aujourd'hui que le quart de la consommation d'energie. Les seules economies d'energie ne suffiront pas a sortir du petrole et du gaz naturel: comme le prevoient egalement l'Allemagne et la Grande-Bretagne, le recours a l'electricite en France devra croitre significativement pour se substituer aux consommations de petrole et de gaz. Diverses estimations recentes sous-estiment cette croissance. Or des anticipations erronees affecteraient la securite de notre approvisionnement energetique et la vie quotidienne des francais; les impacts sur le cout de l'electricite et des energies en general, et sur la competitivite de notre economie seraient majeurs. Dans cet avis, l'Academie des technologies propose une evaluation raisonnable de la demande d'electricite en 2050. Elle rappelle que le systeme electrique europeen sera plus fragile dans les prochaines annees. Elle propose quelques principes pour le choix des donnees economiques a retenir dans les optimisations. A partir de ces elements, elle souligne quelques points clefs de la conduite du changement du systeme electrique.
[en] The fishing industry of the China is the largest in world which is usually believed to be facing overexploitation risk. In this condition, it becomes necessary to estimate stock status of fishery resources particularly having commercial importance. Thus, this study is the first time attempt to know whether Spanish mackerel, a major landed fishery resource in Shandong, China, is experiencing overexploitation or not by estimating its stock status. For this purpose, long data series, 2006-2016, comprised of catch and effort figures was statistically analyzed to know maximum sustainable yield (MSY) of this resource and its ongoing regime. In total, three surplus production models (SPMs) were used in this study, viz., Fox (FM), Schaefer (SM) and Pella-Tomlinson (PTM) with the help of two famous fishery statistical routines, viz., catch and effort data analysis (CEDA) and a stock production model incorporating covariates (ASPIC). For initial proportion (IP) 1, CEDA estimated MSY in a range between 41000-50000 t, whereas, ASPIC calculations remained between 44000-52000 t. Furthermore, results also showed that fishing mortality (F) is increasing while biomass (B) is swiftly decreasing. Based on the results it can be concluded that Spanish mackerel is facing the risk of overexploitation. Thus, it is recommended to make such policies which can conserve this fishery resource for future. (author)
[en] Fuel pool cooling is an essential task in the scope of nuclear power applications. During the first years of commercial nuclear power implementation robust fuel pool cooling systems have been developed and used for several decades. Two decades ago the development of a new cooling technology/concept was initiated to ensure prevention of accidents, including fuel damage. The so-called advanced cooling technology offers a modular design system which enables tailor-made robust and cost efficient cooling solutions. However, all the advanced cooling systems feature an indispensable and distinctive fall back option of a passive heat removal in case of a station blackout as most important feature. In contradiction to conventional cooling systems the advanced cooling solutions use immersed heat exchangers to establish an additional safety barrier inside the heat removal chain. This results in the necessity of a free convective heat transfer on pool water side. This in turn requires a special design approach and methodology. Because of the huge nominal heat load and the size of the heat removal systems itself full size test are under economical aspects nearly impossible. In this paper a purpose-built simulation and design methodology is presented, which has been developed and proved in the scope of several first-of-a-kind projects during the last years.
[en] The government of India is promoting the electric vehicle industry to reduce the import dependence on crude oil and natural gas and to achieve ecological benefits. Electric vehicle projects are forging ahead due to the proactive policies of the government. The lithium-ion battery is an essential component of an electric vehicle. The lithium-ion battery is also used in the energy storage device and the communication sector. Presently, lithium-ion battery cells are not produced in India. Indian demand for lithium-ion cells are entirely met by import. However, battery packs are assembled in India with imported battery cells by a few units. (author)
[en] Quinone-based macrocyclic compounds have been proposed as promising electrode materials for rechargeable lithium-ion batteries (LIBs). To improve the electrochemical performance, in this paper, two heteroatom-bridged pillarquinones (namely, oxa- and thia-pillarquinones) are presented as active cathode materials for LIBs. The geometry structures, electronic structural properties, and electrochemical properties of these new species are calculated by Density Functional Theory (DFT) at the M06-2X/6-31G(d,p) level of theory. Two heteroatom-bridged pillarquinones possess higher theoretical specific capacity (659 mA h g-1 and 582 mA h g-1 for oxa- and thia- pillarquinones, respectively) than that of parental pillarquinone (446 mA h g-1). The electrochemical performances of oxa- and thia-pil-larquinones are predicted theoretically to be superior to those of pillarquinone as cathode material for LIBs. Compared with oxa-pillarquinone, thia-pillarquinone is predicted to be slightly more suitable as cathode electrode material. These results may provide fresh ideas and guidelines for enhancing the performance of quinones organic electrode materials for LIBs. (author)
[en] The cyanobacterium, Leptolyngbya sp. and green microalga, Chlorella sorokiniana as biofertilizers, play an important role in agriculture development. Due to a lack of information concerning microalgae as biofertilizers in crop production, the present research aimed to evaluate the possibility of increasing growth using microalgae as biofertilizers on seed germination of four commercially important vegetables i.e., radish (Raphanus sativus) subsp. sativus, spinach (Spinacia oleracea), turnip (Brassica rapa) subsp. rapa and fenugreek (Trigonella foenum-graecum). In the current study the fresh biomass of cyanobacterium, Leptolyngbya sp. and green microalga, C. sorokiniana was used as bio-fertilizers to note the effect on seed germination of four vegetables. The In vitro effects of bio-fetilizers were also noted on the different growth parameters i.e., germination percentage, days to germination (50%), plumule length, radical length, fresh weight and dry weight using Randomize Complete Designed (RCD) with factorial arrangement. The results compared with control showed an improved germination percentage using Leptolyngbya sp. (83.17%) and C. sorokiniana (80.47%). Both strains exhibited early germination (4.50 days) while C. sorokiniana showed the maximum plumule (33.88cm), radical length (4.46cm), fresh (1.38g) and dry weight (0.0708g) associated with Leptolyngbya sp. The treatment with B. rapa seed germination was 98.67% and took 1.78 days to germinate. The lowest germination (34.44%) was recorded in S. oleracea and took 6.56 days to germinate. After applying Leptolyngbya sp. on B. rapa and T. foenum-graecum seeds indicated the highest seed germination (99.67%). While B. rapa seeds germinated after one day while primed with C. sorokiniana. The maximum increase over check of germination percentage was observed in Leptolyngbya sp. (11.63%) and C. sorokiniana (8.60%). Both strains improved early germination (3.78%), plumule length (33.88%), radical length (60.31%), fresh weight (7.97%) and dry weight (5.79%). (author)
[en] Solar energy is radiant light as a form of thermal heat energy which can be obtained and used by means of a variety of solar apparatus. As apparatus the flat and curved plate solar collector is specifically designed for assembling solar energy as a solar water heater system. The designing potency of this collector lone can generate medium level hot water from radiant sunlight source via absorbed plates. Standard type flat and curved plates solar collector plates are mostly used in remote coldest regions of the world where hot water is consumed for commercial and domestic purposes. These types of solar collector Plates can cheaply be manufactured compared to other solar panels like solar Shingles, Polycrystalline Solar Panels, Monocrystalline Solar Panels, and Thin Film Solar Panels. For future work, this proposed pre-design is recommended for fabrication. A numerical study was carried-out on eight city locations in China by tracing their horizontal and vertical longitudinal, latitudinal lines noting the date, time and sunlight feeding of temperatures in the Celsius scale with the help of simulation and modeling tools like CFD, ANSYS FLUENT software, mesh geometry tools, and by using the Navier-Stokes and Continuity equations by fluid flow discharge rate, mass flow, water temperature and dropping of temperature, radiation working mechanisms, dimensions of water flowing tubes and absorber plates, density, the velocity of water as the working fluid, the viscosity of water in a cold and hot state as a process of Pre-design. Work also focuses on the comparison between flat plate collector and curved plate collector radiant sunlight absorption, As end result it is found the Curved plate collector produces 22% more elevated heat of outgoing water than flat plate collector. (author)
[en] The performance of Li-ion batteries (LIBs) is highly dependent on their interfacial chemistry, which is regulated by electrolytes. Conventional electrolyte typically contains polar solvents to dissociate Li salts. Herein we report a weakly solvating electrolyte (WSE) that consists of a pure non-polar solvent, which leads to a peculiar solvation structure where ion pairs and aggregates prevail under a low salt concentration of 1.0 M. Importantly, WSE forms unique anion-derived interphases on graphite electrodes that exhibit fast-charging and long-term cycling characteristics. First-principles calculations unravel a general principle that the competitive coordination between anions and solvents to Li ions is the origin of different interfacial chemistries. By bridging the gap between solution thermodynamics and interfacial chemistry in batteries, this work opens a brand-new way towards precise electrolyte engineering for energy storage devices with desired properties. (© 2020 Wiley‐VCH GmbH)
[en] Nowadays, alloy nanoparticles (NPs) consisting of noble metals find much importance due to their enhanced localized surface plasmon resonance (SPR) in the visible range. Besides the compositional changes, the SPR of alloy NPs independently can be tailored by changing the shape and interparticle separation. Here, we report the effects of shape and interaction parameters ( b and K , respectively) on the plasmonic properties of Au–Cu alloy NPs considering Au concentrations in the range of 0.0–1.0 using a modified effective medium theory. There is always a single SPR for the alloys’ NPs. A large shift of this SPR peak from visible to infrared regions is seen with decrease or increase in the values of b or K . A linear variation of peak shift with 1/ b and an exponential decay variation of peak shift with 1/ K are observed. Although there is a small increase in the values of slopes (in the peak shift vs .1/ b curves) with increase in concentration of Au in the Au–Cu alloys, there is almost no change in the fitting parameter, s of the exponential decay function (in the curves for peak shift vs. 1/ K ) for different sizes of NPs and concentration of Au or Cu in the alloys. This establishes the universal nature of the exponential decay behaviour. These observations are consistent with the data for elemental (Au and Cu) NPs. The correlations between (i) shape parameter, b and the aspect ratio, AR and (ii) interaction parameter, K with the interparticle separation, s are established as in case of elemental NPs. The study thus, verifies the model further and establishes universality of the applicability of the model. (author)
[en] Here we have studied locally rotationally symmetric Bianchi-V Universe in the presence of modified theory for gravitation [f(R,T)theory] and for that, we considered a perfect fluid with heat conduction as the energy source. We used the law of variation for the deceleration parameter (DP) to solve field equations, as it gives a constant value of DP and is related to the average scale factor metric. Also, we have discussed the physical and geometrical properties of the model in detail. (author)