Retransmission avoidance is an essential need for any type of wireless communication.As retransmissions induce the unnecessary presence of redundant data in every accessible node.As storage capacity is symmetrical to ...Retransmission avoidance is an essential need for any type of wireless communication.As retransmissions induce the unnecessary presence of redundant data in every accessible node.As storage capacity is symmetrical to the size of the memory,less storage capacity is experienced due to the restricted size of the respective node.In this proposed work,we have discussed the integration of the Energy Proficient Reduced Coverage Set with Particle Swarm Optimization(PSO).PSO is a metaheuristic global search enhancement technique that promotes the searching of the best nodes in the search space.PSO is integrated with a Reduced Coverage Set,to obtain an optimal path with only high-power transmitting nodes.Energy Proficient Reduced Coverage Set with PSO constructs a set of only best nodes based on the fitness solution,to cover the whole network.The proposed algorithm has experimented with a different number of nodes.Comparison has been made between original and improved algorithm shows that improved algorithm performs better than the existing by reducing the redundant packet transmissions by 18%~40%,thereby increasing the network lifetime.展开更多
The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the ex...The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the exogenous carbon reduction targets,carbon prices,and carbon tax-rates,by computable general equilibrium modeling methods and factor decomposition methods,this article investigates direct and cascaded effects of the hybrid policy on economic growth,energy utilization,and carbon emission on the national level and the sector level,with China's national input-output data-set.Stepwisely,policy scenarios with irrational estimated results are selectively excluded based on comprehensive evaluation among economic,carbon reduction and other policy targets.As a result,against national economic conditions in 2007,the hybrid policy,with a carbon reduction target of -10%,a carbon tax-rate of around $10,and a ceiling carbon price of $40,is highly recommended,because of its significant lower economic loss,lower energy utilization cost,and practical robustness against fluctuation of energy market and carbon market.Furthermore,by decomposition analysis,carbon reduction-related costs are decomposed into a direct part that includes carbon allowance price and carbon tax,and an indirect part as the energy price incremental induced by direct carbon costs.Gross carbon reduction may be decomposed into three parts such as energy intensity,economic scale,and technical progress.And,carbon taxation is the main policy tool that stimulates to improve the energy efficiency.展开更多
Background:The study objective was to test the hypothesis that 1)lowering dietary crude protein(CP)increases dietary energetic efficiency and reduces metabolic heat associated with lactation,and 2)excessive dietary le...Background:The study objective was to test the hypothesis that 1)lowering dietary crude protein(CP)increases dietary energetic efficiency and reduces metabolic heat associated with lactation,and 2)excessive dietary leucine(Leu)supplementation in a low CP diet decreases dietary energetic efficiency and increases metabolic heat associated with lactation.Methods:Fifty-four lactating multiparous Yorkshire sows were allotted to 1 of 3 isocaloric diets(10.80 MJ/kg net energy):1)control(CON;18.75%CP),2)reduced CP with a near ideal or optimal AA profile(OPT;13.75%CP)and 3)diet OPT with excessive Leu(OPTLEU;14.25%CP).Sow body weight and backfat were recorded on day 1 and 21 of lactation and piglets were weighed on day 1,4,8,14,18,and 21 of lactation.Energy balance was measured on sows during early(day 4 to 8)and peak(day 14 to18)lactation,and milk was sampled on day 8 and 18.Results:Over 21-day lactation,sows fed OPT lost body weight and body lipid(P<0.05).In peak lactation,sows fed OPT had higher milk energy output(P<0.05)than CON.Sows fed OPTLEU tended(P=0.07)to have less milk energy output than OPT and did not differ from CON.Maternal energy retention was lower(P<0.05)in OPT and OPTLEU compared to CON sows,and did not differ between OPTLEU and OPT sows.Sows fed OPT had higher(P<0.05)apparent energy efficiency for milk production compared to CON.Heat production associated with lactation was lower(P<0.05)or tended to be lower(P=0.082),respectively,in OPT and OPTLEU compared to CON sows.Conclusion:The OPT diet,in peak lactation,improved dietary energy utilization for lactation due to less urinary energy and metabolic heat loss,and triggered dietary energy deposition into milk at the expense of maternal lipid mobilization.Leucine supplementation above requirement may reduce dietary energy utilization for lactation by decreasing the energy partitioning towards milk,partially explaining the effectiveness of OPT diet over CON diets.展开更多
Comparison between the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue provides information about apparent stress. In spite of its significant uncertainties and limited reliability, the clues ob...Comparison between the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue provides information about apparent stress. In spite of its significant uncertainties and limited reliability, the clues obtained from this comparison seem interesting in the physics of earthquakes. Scaling of apparent stress provides information about the dynamic friction along an earthquake fault. Relation between reduced energy and seismic moment implies that for strike-slip earthquakes, velocity-dependent friction plays a predominant role, while for non-strike-slip earthquakes, slip-dependent friction is predominant. It is also found that strike-slip events with extremely low apparent stress tend to occur “in single”, which is applied to the prediction of the seismic tendency following the 2001 Qinghai-Xizang (Tibet) border M W7.8 earthquake.展开更多
Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix an...Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen.Based on the incremental cost principle,we quantified the provincial and national clean hydrogen production cost performance levels in 2030.The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces,with a national average value of less than 2 USD·kg^(-1) at the 40-megaton hydrogen supply scale.Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg^(-1).However,performance is affected by the potential distribution of hydrogen demand.From the supply side,competitiveness of the mechanism is limited to clean hydrogen production,while from the demand side,it could help electrolytic hydrogen fulfil a more significant role.This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.展开更多
This paper presents a peer-to-peer community cost optimization approach based on a single-prosumer energy management system.Its objective is to optimize energy costs for prosumers in the community by enhancing the con...This paper presents a peer-to-peer community cost optimization approach based on a single-prosumer energy management system.Its objective is to optimize energy costs for prosumers in the community by enhancing the consumption efficiency.This study was conducted along two main axes.The first axis focuses on designing a digital twin for a residential community microgrid platform.This phase involves data collection,cleaning,exploration,and interpretation.Moreover,it includes replicating the functionality of the real platform and validating the results.The second axis involves the development of a novel approach that incorporates two distinct prosumer behaviors within the same community microgrid,while maintaining the concept of peer-to-peer energy trading.Prosumers without storage utilize their individual PV systems to fulfill their energy requirements and inject excess energy into a local microgrid.Meanwhile,a single prosumer with a storage system actively engages in energy exchange to maximize the community’s profit.This is achieved by optimizing battery usage using a cost optimization solution.The proposed solution is validated using the developed digital twin.展开更多
This work attempts to investigate some practical measures that may reduce severe power outages that lead to energy curtailments. The first step of this attempt is to explore, from the consumer’s perspective, the adve...This work attempts to investigate some practical measures that may reduce severe power outages that lead to energy curtailments. The first step of this attempt is to explore, from the consumer’s perspective, the adverse effects of the energy curtailments that reflect enormous damages (tangible and intangible) to the residential sector in the city of Riyadh (the capital of the Kingdom of Saudi Arabia). The second step is to propose, analyze, and employ energy conservation strategies that lead to both energy conservation and costs savings. The study results show that some customers will suffer enormous tangible and intangible losses should these outages occur during specific times, seasons, and for prolonged durations. In order to reduce these power outages and hence mitigate their adverse effects and consequences, the study proposes proper practical measures and solutions without compromising the consumers’ needs, satisfaction, and convenience.展开更多
Rainwater harvesting?provides an important alternative source of water in household buildings which?increases water security in urban areas. However, high energy cost consumption by the rainwater harvesting systems re...Rainwater harvesting?provides an important alternative source of water in household buildings which?increases water security in urban areas. However, high energy cost consumption by the rainwater harvesting systems results in higher management costs which may derail the investment viability of these systems in households. This prompted this study to establish ways through which the management cost of rainwater harvesting systems can be minimized in household buildings. A survey of 200 households from Greenspan, Komarock, Utawala, Kileleshwa and Runda in Nairobi?County was undertaken as?well?as?data?on?the?type?of?rainwater harvesting?systems, their operation and maintenance cost collected using observation checklists and questionnaires. The findings indicated that rainwater harvesting typologies 1, 2, 4 and 5 had their water pumped from first-level storage to the second-level storage then supplied to usage points by gravity. Whereas, typologies 3 and 6 had their water moved manually and by gravity respectively. On annual operation cost, 100% of households with typology 3 and 6 spent no money whereas, 100%, 75% and 70.6% with typology 4 and 5, 1 and 2 respectively spent Ksh. 1?-?5000. On annual maintenance cost, 100%, 93.7% and 77.8% of households with typology 5 and 6, 3 and 4 respectively spent Ksh. 1?-?5000 while 25% and 22.2% of households with typology 1 and 2 respectively spent Ksh. 5000?-?10,000. Advanced typology 6 with one-level storage point supplies rainwater to all parts of the household by gravity. This eliminates operation costs spent on energy consumption due to pumping of water,?thus minimizing overall management cost spent on rainwater harvesting systems in household buildings.展开更多
China should pilot renewable energy integration policies similar to those adopted in Germany and Texas in the Beijing-Tianjin-Hebei region to transmit excess energy and reduce wasted wind power.Renewable energy integr...China should pilot renewable energy integration policies similar to those adopted in Germany and Texas in the Beijing-Tianjin-Hebei region to transmit excess energy and reduce wasted wind power.Renewable energy integration will be fundamental to China?s transition to a low-carbon economy.Although China now leads the world in terms展开更多
This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount...This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount of molten iron,is analyzed,and the concept of a steel scrap threshold price is proposed.According to the analysis results,when the steel scrap unit price exceeds the steel scrap threshold price, an increase in the iron/steel ratio can reduce the production cost,and vice versa.When the gap between the steel scrap unit price and the steel scrap threshold price is relatively large, the impact of the iron/steel ratio on the production cost is more prominent.According to the calculation example,when steel production is fixed (284 358 t/month)and the steel scrap unit price is 263.2 yuan/t more than the steel scrap threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 750 000 yuan (2.63 yuan/t).When the amount of molten iron is fixed (270 425 t/month)and the steel scrap unit price is 140.7 yuan/t more than the threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 430 000 yuan (1.5 yuan/t).The results indicate that iron and steel enterprise should adjust the production strategy in time when the scrap price fluctuates, and then the production cost will be reduced.展开更多
[Objective] The study aimed at evaluating the ability to save energy and reduce CO2 emission in China's cement industry. [Method] Based on long-term energy alternative planning system software (LEAP), "LEAP of Ch...[Objective] The study aimed at evaluating the ability to save energy and reduce CO2 emission in China's cement industry. [Method] Based on long-term energy alternative planning system software (LEAP), "LEAP of China's cement industry" model was established to simulate energy conservation and emission reduction in China's cement industry from 2010 to 2040 in different technologic situations. E ResultJ To save ener- gy and reduce CO2 emissions, new dry process kiln has priority over other technologies or measures, followed by equipment enlargement, mechani- cal shaft kiln, power generation system based on waste heat, as well as high-efficiency and energy-saving grinding technology, and new prepara- tion technology. If all the advanced technologies and measures are adopted, energy consumption and C02 emissions can be reduced by about 40.76% and 42.97% respectively. [ Condusion] LEAP of model is suitable for analyzing energy saving and emission reducing in China's cement industry and other industrial fields.展开更多
AIM To investigate whether adductor canal nerve block(ACB) reduces patient falls when compared to femoral nerve block(FNB) after total knee arthroplasty(TKA). METHODS We conducted an institutional review of all-cause ...AIM To investigate whether adductor canal nerve block(ACB) reduces patient falls when compared to femoral nerve block(FNB) after total knee arthroplasty(TKA). METHODS We conducted an institutional review of all-cause falls after TKA from January 2013 to August 2016 using a quality improvement database. Our inclusion criteria were patients with diagnosis of primary knee osteoarthritis who underwent primary unilateral TKA with either a FNB or an ACB and sustained a fall during their hospitalization. We excluded patients who had revision TKA and extensor mechanism reconstruction. We also excluded patients with a history of post-traumatic arthritis, prior history of lower extremity fracture, history of neurological disease, or cerebrovascular disease. RESULTS A total of 834 patients had TKA with femoral nerve block and knee immobilizer(FNB + KI). Of those patients, 11(1.3%) experienced a fall during their hospital stay. In contrast, 791 patients had TKA with ACB. Of those patients, only one(0.13%) patient fall was recorded within this group. We used the Fisher's exact test to compare the differences between the two groups. The difference between the two groups achieves statistical significance(P = 0.006). We also found that 11 out of the 12 patients that fell had a right TKA procedure while one patient had a left TKA procedure. Nine out of twelve patients that fell were female, while only three patients were male.CONCLUSION Given the reduction in the number of falls with ACB, it is recommended that ACB be considered the preferred analgesia for patients undergoing a TKA procedure.展开更多
China has set carbon emission goals for 2030 and 2060.Renewable energy sources,primarily wind and photovoltaic power,are being considered as the future of power generation.The major limitation to the development of ne...China has set carbon emission goals for 2030 and 2060.Renewable energy sources,primarily wind and photovoltaic power,are being considered as the future of power generation.The major limitation to the development of new energies is the limited flexibility of regulations on power system resources,resulting in insufficient consumption capacity.Thus,the flexible resource costs for peak shaving as well as the reasonable coordinated development and operation optimization of regional renewable energy need to be considered.In this study,a renewable energy development layout configuration analysis method was established by considering the composite cost of a power system,comprehensively analyzing the potential of various flexibility regulation resources for the power system and its composite peak shaving cost,and combining renewable energy output characteristics,load forecasting,grid development,and other factors.For the optimization of various flexible resource utilization methods,a peak shaving cost estimation method from the perspective of the entire power system was established by combining the on-grid electricity prices and operating costs of different power sources.A collaborative optimization model of power system operation that aims at the lowest peak shaving cost and satisfies the constraints of operation,safety,and environmental protection was proposed.Finally,a certain area of Gansu Province was used as an example to perform detailed analysis and calculation,which demonstrated that the model has an optimal effect.This model can provide an analysis method for regional renewable energy development layout configurations and system optimization operations.展开更多
With the expansion of cloud computing,optimizing the energy efficiency and cost of the cloud paradigm is considered significantly important,since it directly affects providers’revenue and customers’payment.Thus,prov...With the expansion of cloud computing,optimizing the energy efficiency and cost of the cloud paradigm is considered significantly important,since it directly affects providers’revenue and customers’payment.Thus,providing prediction information of the cloud services can be very beneficial for the service providers,as they need to carefully predict their business growths and efficiently manage their resources.To optimize the use of cloud services,predictive mechanisms can be applied to improve resource utilization and reduce energy-related costs.However,such mechanisms need to be provided with energy awareness not only at the level of the Physical Machine(PM)but also at the level of the Virtual Machine(VM)in order to make improved cost decisions.Therefore,this paper presents a comprehensive literature review on the subject of energy-related cost issues and prediction models in cloud computing environments,along with an overall discussion of the closely related works.The outcomes of this research can be used and incorporated by predictive resource management techniques to make improved cost decisions assisted with energy awareness and leverage cloud resources efficiently.展开更多
Acetone,which is volatile,flammable,toxic,expen- sive and causing serious air pollution,is often used as extracting solvent in the production of powdery soy phospholipid.Recycling and reusing acetone is the key of red...Acetone,which is volatile,flammable,toxic,expen- sive and causing serious air pollution,is often used as extracting solvent in the production of powdery soy phospholipid.Recycling and reusing acetone is the key of reducing the cost of production. Therefore,saving energy and reducing emission when recycling acetone are the most important technologies during the production of phospholipid.On the basis of the productivity of powdery phospholipid being 2.4 t every day,43.2 t acetone is reused every 8 h and the total volume of acetone gas emitted is 450.75 m3 (about 901.5 kg).According to the current price of acetone,the lost money is about 7212 yuan RMB.展开更多
The necessity of lowering the mean power consumption of various facilities, due to the lack of their enormous future energy needs, led to an ongoing advance of various technologies. These technologies have been orient...The necessity of lowering the mean power consumption of various facilities, due to the lack of their enormous future energy needs, led to an ongoing advance of various technologies. These technologies have been oriented towards the concept of a Reduced Ecological Footprint. Massive structures (such as building complexes and hospitals) have been redesigned and upgraded;many interior designs have been dramatically altered while new electronic devices are constantly being produced in order to revolutionize a long term perspective towards a “Green Planet” while they exhibit astonishing signal processing. Consequently, an enormous technology already exists which needs to be properly combined to a proposed methodology and to new ideas relevant to systems’ administration through automatic wireless control. This paper intends to reduce the gap between design and realization of the aforementioned research. Consequently, the primary contribution of this research is the proposal of a complete design protocol with minimized defects relevant to Reduced Ecological Footprints of Facilities (REFF) along with its beneficial advantages relevant to providing a healthy and productive work environment. This protocol consists of four main parts which are 1) the main key points-guidelines, 2) its objectives, 3) the know-how methodology for implementation in existing installations and 4) the description of the imminent benefits in workforce/human resources.展开更多
As one of prussian blue analogues,Co_(3)[Co(CN)_(6)]_(2) has been explored as a promising anode material for potassium-ion batteries(PIBs) owing to its high potassium storage capacity.Unfortunately,Co_(3)[Co(CN)_(6)]_...As one of prussian blue analogues,Co_(3)[Co(CN)_(6)]_(2) has been explored as a promising anode material for potassium-ion batteries(PIBs) owing to its high potassium storage capacity.Unfortunately,Co_(3)[Co(CN)_(6)]_(2) possesses low electronic conductivity and its structure collapses easily during potassiation and depotassiation,resulting in poor rate performance and cyclic stability.To solve these problems,we develop a facile multi-step method to successfully combine uniformCo_(3)[Co(CN)_(6)]_(2) nanocubes with rGO by C-O-Co bonds.As expected,these chemcial bonds shorten the distance betweenCo_(3)[Co(CN)_(6)]_(2) and rGO to the angstrom meter level,which significantly improve the electronic conductivity ofCo_(3)[Co(CN)_(6)]_(2).Besides,the complete encapsulation ofCo_(3)[Co(CN)_(6)]_(2) nanocubes by rGO endows the structure ofCo_(3)[Co(CN)_(6)]_(2) with high stability,thus withstanding repeated insertion/extraction of potassium-ions without visible morphological and structural changes.Benefiting from the abovementioned structural advantages,the CO3 [Co(CN)6]2/rGO nanocomposite exhibits a high reversible capacity of 400.8 mAh g^(-1) at a current density of 0.1 A g^(-1),an exceptional rate capability of 115.5 mAh g^(-1) at 5 A g^(-1), and an ultralong cycle life of 231.9 mAh g^(-1) at 0.1 A g^(-1) after 1000 cycles.Additionally,the effects of different amounts of rGO and different sizes ofCo_(3)[Co(CN)_(6)]_(2) nanocubes on the potassium storage performance are also studied.This work offers an ideal route to significantly enhance the electrochemical properties of prussian blue analogues.展开更多
To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The con...To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The control strategy consists of an open loop optimization controller and a closed-loop guaranteed cost periodically intermittent-switch controller(GCPISC). The error dynamics system of the closed-loop control is modelled based on the GCPISC principle. The difference,compared to the previous DX A/C system control methods, is that the controller designed in this paper performs control at discrete times. For the ease of designing the controller, a series of matrix inequalities are derived to be the sufficient conditions of the lower-layer closed-loop GCPISC controller. In this way, the DX A/C system output is derived to follow the optimal references obtained through the upper-layer open loop controller in exponential time, and the energy efficiency of the system is improved. Moreover, a static optimization problem is addressed for obtaining an optimal GCPISC law to ensure a minimum upper bound on the DX A/C system performance considering energy efficiency and output tracking error. The advantages of the designed hierarchical controller for a DX A/C system with uncertain parameters are demonstrated through some simulation results.展开更多
In the urban residential building stock, a major proportion is constituted by low-rise individual buildings. In addition to cost, quality and duration, energy consumed for the project needs to be accounted in the deci...In the urban residential building stock, a major proportion is constituted by low-rise individual buildings. In addition to cost, quality and duration, energy consumed for the project needs to be accounted in the decision making process. Minimizing the cost of construction without compromising on the architectural and structural requirements is the primary objective of the residential buildings of stake-holders, especially the owners. The choice of structural system and the materials used for construction play a crucial role in this effort. This means that the use of expensive and/or voluminous materials such as cement, steel, masonry etc. is optimized. This could lead to significant reduction in embodied energy as well, if the choice of the structural system is prudently made. In this paper, an attempt has been made to quantify the cost and embodied energy benefits for a low-rise residential building by choosing two different structural systems, namely moment resisting framed (MRF) construction system and the partly load-bearing (PLB) system. The influence of choice of materials, contributing to reduction of cost and/or energy is discussed. It is clearly noticed that, when the structural system is re-configured as a PLB system from the existing MRF system there is significant reduction in cost and embodied energy without changing the architectural form.展开更多
文摘Retransmission avoidance is an essential need for any type of wireless communication.As retransmissions induce the unnecessary presence of redundant data in every accessible node.As storage capacity is symmetrical to the size of the memory,less storage capacity is experienced due to the restricted size of the respective node.In this proposed work,we have discussed the integration of the Energy Proficient Reduced Coverage Set with Particle Swarm Optimization(PSO).PSO is a metaheuristic global search enhancement technique that promotes the searching of the best nodes in the search space.PSO is integrated with a Reduced Coverage Set,to obtain an optimal path with only high-power transmitting nodes.Energy Proficient Reduced Coverage Set with PSO constructs a set of only best nodes based on the fitness solution,to cover the whole network.The proposed algorithm has experimented with a different number of nodes.Comparison has been made between original and improved algorithm shows that improved algorithm performs better than the existing by reducing the redundant packet transmissions by 18%~40%,thereby increasing the network lifetime.
基金supported by the Fundamental Research Funds for the Central Universities[CDJSK10 00 68]NSFC Young Scientist Research Fund[0903080]
文摘The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the exogenous carbon reduction targets,carbon prices,and carbon tax-rates,by computable general equilibrium modeling methods and factor decomposition methods,this article investigates direct and cascaded effects of the hybrid policy on economic growth,energy utilization,and carbon emission on the national level and the sector level,with China's national input-output data-set.Stepwisely,policy scenarios with irrational estimated results are selectively excluded based on comprehensive evaluation among economic,carbon reduction and other policy targets.As a result,against national economic conditions in 2007,the hybrid policy,with a carbon reduction target of -10%,a carbon tax-rate of around $10,and a ceiling carbon price of $40,is highly recommended,because of its significant lower economic loss,lower energy utilization cost,and practical robustness against fluctuation of energy market and carbon market.Furthermore,by decomposition analysis,carbon reduction-related costs are decomposed into a direct part that includes carbon allowance price and carbon tax,and an indirect part as the energy price incremental induced by direct carbon costs.Gross carbon reduction may be decomposed into three parts such as energy intensity,economic scale,and technical progress.And,carbon taxation is the main policy tool that stimulates to improve the energy efficiency.
基金This study was financially supported by USDA-NIFA(award number 2014–67015-21832).
文摘Background:The study objective was to test the hypothesis that 1)lowering dietary crude protein(CP)increases dietary energetic efficiency and reduces metabolic heat associated with lactation,and 2)excessive dietary leucine(Leu)supplementation in a low CP diet decreases dietary energetic efficiency and increases metabolic heat associated with lactation.Methods:Fifty-four lactating multiparous Yorkshire sows were allotted to 1 of 3 isocaloric diets(10.80 MJ/kg net energy):1)control(CON;18.75%CP),2)reduced CP with a near ideal or optimal AA profile(OPT;13.75%CP)and 3)diet OPT with excessive Leu(OPTLEU;14.25%CP).Sow body weight and backfat were recorded on day 1 and 21 of lactation and piglets were weighed on day 1,4,8,14,18,and 21 of lactation.Energy balance was measured on sows during early(day 4 to 8)and peak(day 14 to18)lactation,and milk was sampled on day 8 and 18.Results:Over 21-day lactation,sows fed OPT lost body weight and body lipid(P<0.05).In peak lactation,sows fed OPT had higher milk energy output(P<0.05)than CON.Sows fed OPTLEU tended(P=0.07)to have less milk energy output than OPT and did not differ from CON.Maternal energy retention was lower(P<0.05)in OPT and OPTLEU compared to CON sows,and did not differ between OPTLEU and OPT sows.Sows fed OPT had higher(P<0.05)apparent energy efficiency for milk production compared to CON.Heat production associated with lactation was lower(P<0.05)or tended to be lower(P=0.082),respectively,in OPT and OPTLEU compared to CON sows.Conclusion:The OPT diet,in peak lactation,improved dietary energy utilization for lactation due to less urinary energy and metabolic heat loss,and triggered dietary energy deposition into milk at the expense of maternal lipid mobilization.Leucine supplementation above requirement may reduce dietary energy utilization for lactation by decreasing the energy partitioning towards milk,partially explaining the effectiveness of OPT diet over CON diets.
文摘Comparison between the NEIC broadband radiated energy catalogue and the Harvard CMT catalogue provides information about apparent stress. In spite of its significant uncertainties and limited reliability, the clues obtained from this comparison seem interesting in the physics of earthquakes. Scaling of apparent stress provides information about the dynamic friction along an earthquake fault. Relation between reduced energy and seismic moment implies that for strike-slip earthquakes, velocity-dependent friction plays a predominant role, while for non-strike-slip earthquakes, slip-dependent friction is predominant. It is also found that strike-slip events with extremely low apparent stress tend to occur “in single”, which is applied to the prediction of the seismic tendency following the 2001 Qinghai-Xizang (Tibet) border M W7.8 earthquake.
基金support provided by the National Science Fund for Distinguished Young Scholars(52325703)Postdoctoral Innovation Talents Support Program(BX20220066)+1 种基金China Postdoctoral Science Foundation(2022M720709)State Key Laboratory of Power System Operation and Control(SKLD23KM06).
文摘Scaling up clean hydrogen supply in the near future is critical to achieving China’s hydrogen development target.This study established an electrolytic hydrogen development mechanism considering the generation mix and operation optimization of power systems with access to hydrogen.Based on the incremental cost principle,we quantified the provincial and national clean hydrogen production cost performance levels in 2030.The results indicated that this mechanism could effectively reduce the production cost of clean hydrogen in most provinces,with a national average value of less than 2 USD·kg^(-1) at the 40-megaton hydrogen supply scale.Provincial cooperation via power transmission lines could further reduce the production cost to 1.72 USD·kg^(-1).However,performance is affected by the potential distribution of hydrogen demand.From the supply side,competitiveness of the mechanism is limited to clean hydrogen production,while from the demand side,it could help electrolytic hydrogen fulfil a more significant role.This study could provide a solution for the ambitious development of renewables and the hydrogen economy in China.
基金supported by the Tunisian Ministry of Higher Education and Scientific Research under Grant LSE-ENIT-LR 11ES15funded in part by the PAQ-Collabora(PAR&I-Tk)program。
文摘This paper presents a peer-to-peer community cost optimization approach based on a single-prosumer energy management system.Its objective is to optimize energy costs for prosumers in the community by enhancing the consumption efficiency.This study was conducted along two main axes.The first axis focuses on designing a digital twin for a residential community microgrid platform.This phase involves data collection,cleaning,exploration,and interpretation.Moreover,it includes replicating the functionality of the real platform and validating the results.The second axis involves the development of a novel approach that incorporates two distinct prosumer behaviors within the same community microgrid,while maintaining the concept of peer-to-peer energy trading.Prosumers without storage utilize their individual PV systems to fulfill their energy requirements and inject excess energy into a local microgrid.Meanwhile,a single prosumer with a storage system actively engages in energy exchange to maximize the community’s profit.This is achieved by optimizing battery usage using a cost optimization solution.The proposed solution is validated using the developed digital twin.
文摘This work attempts to investigate some practical measures that may reduce severe power outages that lead to energy curtailments. The first step of this attempt is to explore, from the consumer’s perspective, the adverse effects of the energy curtailments that reflect enormous damages (tangible and intangible) to the residential sector in the city of Riyadh (the capital of the Kingdom of Saudi Arabia). The second step is to propose, analyze, and employ energy conservation strategies that lead to both energy conservation and costs savings. The study results show that some customers will suffer enormous tangible and intangible losses should these outages occur during specific times, seasons, and for prolonged durations. In order to reduce these power outages and hence mitigate their adverse effects and consequences, the study proposes proper practical measures and solutions without compromising the consumers’ needs, satisfaction, and convenience.
文摘Rainwater harvesting?provides an important alternative source of water in household buildings which?increases water security in urban areas. However, high energy cost consumption by the rainwater harvesting systems results in higher management costs which may derail the investment viability of these systems in households. This prompted this study to establish ways through which the management cost of rainwater harvesting systems can be minimized in household buildings. A survey of 200 households from Greenspan, Komarock, Utawala, Kileleshwa and Runda in Nairobi?County was undertaken as?well?as?data?on?the?type?of?rainwater harvesting?systems, their operation and maintenance cost collected using observation checklists and questionnaires. The findings indicated that rainwater harvesting typologies 1, 2, 4 and 5 had their water pumped from first-level storage to the second-level storage then supplied to usage points by gravity. Whereas, typologies 3 and 6 had their water moved manually and by gravity respectively. On annual operation cost, 100% of households with typology 3 and 6 spent no money whereas, 100%, 75% and 70.6% with typology 4 and 5, 1 and 2 respectively spent Ksh. 1?-?5000. On annual maintenance cost, 100%, 93.7% and 77.8% of households with typology 5 and 6, 3 and 4 respectively spent Ksh. 1?-?5000 while 25% and 22.2% of households with typology 1 and 2 respectively spent Ksh. 5000?-?10,000. Advanced typology 6 with one-level storage point supplies rainwater to all parts of the household by gravity. This eliminates operation costs spent on energy consumption due to pumping of water,?thus minimizing overall management cost spent on rainwater harvesting systems in household buildings.
文摘China should pilot renewable energy integration policies similar to those adopted in Germany and Texas in the Beijing-Tianjin-Hebei region to transmit excess energy and reduce wasted wind power.Renewable energy integration will be fundamental to China?s transition to a low-carbon economy.Although China now leads the world in terms
基金The National Key Technology R&D Program during the 12th Five-Year Plan Period(No.2012BAF10B05)
文摘This paper establishes a model for the production cost of iron and steel enterprise.The variation rule of the production cost versus the iron/steel ratio for two cases, namely,fixed steel production and a fixed amount of molten iron,is analyzed,and the concept of a steel scrap threshold price is proposed.According to the analysis results,when the steel scrap unit price exceeds the steel scrap threshold price, an increase in the iron/steel ratio can reduce the production cost,and vice versa.When the gap between the steel scrap unit price and the steel scrap threshold price is relatively large, the impact of the iron/steel ratio on the production cost is more prominent.According to the calculation example,when steel production is fixed (284 358 t/month)and the steel scrap unit price is 263.2 yuan/t more than the steel scrap threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 750 000 yuan (2.63 yuan/t).When the amount of molten iron is fixed (270 425 t/month)and the steel scrap unit price is 140.7 yuan/t more than the threshold price,an increase of 0.01 in the iron/steel ratio causes a monthly production cost reduction of approximately 430 000 yuan (1.5 yuan/t).The results indicate that iron and steel enterprise should adjust the production strategy in time when the scrap price fluctuates, and then the production cost will be reduced.
基金Supported by Special Project for Developing National Major Scientific Instruments and Equipments (2011YQ060111)Scientific Research Project of Environmental Protection in Commonweal Industry(201009032)
文摘[Objective] The study aimed at evaluating the ability to save energy and reduce CO2 emission in China's cement industry. [Method] Based on long-term energy alternative planning system software (LEAP), "LEAP of China's cement industry" model was established to simulate energy conservation and emission reduction in China's cement industry from 2010 to 2040 in different technologic situations. E ResultJ To save ener- gy and reduce CO2 emissions, new dry process kiln has priority over other technologies or measures, followed by equipment enlargement, mechani- cal shaft kiln, power generation system based on waste heat, as well as high-efficiency and energy-saving grinding technology, and new prepara- tion technology. If all the advanced technologies and measures are adopted, energy consumption and C02 emissions can be reduced by about 40.76% and 42.97% respectively. [ Condusion] LEAP of model is suitable for analyzing energy saving and emission reducing in China's cement industry and other industrial fields.
文摘AIM To investigate whether adductor canal nerve block(ACB) reduces patient falls when compared to femoral nerve block(FNB) after total knee arthroplasty(TKA). METHODS We conducted an institutional review of all-cause falls after TKA from January 2013 to August 2016 using a quality improvement database. Our inclusion criteria were patients with diagnosis of primary knee osteoarthritis who underwent primary unilateral TKA with either a FNB or an ACB and sustained a fall during their hospitalization. We excluded patients who had revision TKA and extensor mechanism reconstruction. We also excluded patients with a history of post-traumatic arthritis, prior history of lower extremity fracture, history of neurological disease, or cerebrovascular disease. RESULTS A total of 834 patients had TKA with femoral nerve block and knee immobilizer(FNB + KI). Of those patients, 11(1.3%) experienced a fall during their hospital stay. In contrast, 791 patients had TKA with ACB. Of those patients, only one(0.13%) patient fall was recorded within this group. We used the Fisher's exact test to compare the differences between the two groups. The difference between the two groups achieves statistical significance(P = 0.006). We also found that 11 out of the 12 patients that fell had a right TKA procedure while one patient had a left TKA procedure. Nine out of twelve patients that fell were female, while only three patients were male.CONCLUSION Given the reduction in the number of falls with ACB, it is recommended that ACB be considered the preferred analgesia for patients undergoing a TKA procedure.
基金the National Natural Science Foundation of China(No.71273088).
文摘China has set carbon emission goals for 2030 and 2060.Renewable energy sources,primarily wind and photovoltaic power,are being considered as the future of power generation.The major limitation to the development of new energies is the limited flexibility of regulations on power system resources,resulting in insufficient consumption capacity.Thus,the flexible resource costs for peak shaving as well as the reasonable coordinated development and operation optimization of regional renewable energy need to be considered.In this study,a renewable energy development layout configuration analysis method was established by considering the composite cost of a power system,comprehensively analyzing the potential of various flexibility regulation resources for the power system and its composite peak shaving cost,and combining renewable energy output characteristics,load forecasting,grid development,and other factors.For the optimization of various flexible resource utilization methods,a peak shaving cost estimation method from the perspective of the entire power system was established by combining the on-grid electricity prices and operating costs of different power sources.A collaborative optimization model of power system operation that aims at the lowest peak shaving cost and satisfies the constraints of operation,safety,and environmental protection was proposed.Finally,a certain area of Gansu Province was used as an example to perform detailed analysis and calculation,which demonstrated that the model has an optimal effect.This model can provide an analysis method for regional renewable energy development layout configurations and system optimization operations.
文摘With the expansion of cloud computing,optimizing the energy efficiency and cost of the cloud paradigm is considered significantly important,since it directly affects providers’revenue and customers’payment.Thus,providing prediction information of the cloud services can be very beneficial for the service providers,as they need to carefully predict their business growths and efficiently manage their resources.To optimize the use of cloud services,predictive mechanisms can be applied to improve resource utilization and reduce energy-related costs.However,such mechanisms need to be provided with energy awareness not only at the level of the Physical Machine(PM)but also at the level of the Virtual Machine(VM)in order to make improved cost decisions.Therefore,this paper presents a comprehensive literature review on the subject of energy-related cost issues and prediction models in cloud computing environments,along with an overall discussion of the closely related works.The outcomes of this research can be used and incorporated by predictive resource management techniques to make improved cost decisions assisted with energy awareness and leverage cloud resources efficiently.
文摘Acetone,which is volatile,flammable,toxic,expen- sive and causing serious air pollution,is often used as extracting solvent in the production of powdery soy phospholipid.Recycling and reusing acetone is the key of reducing the cost of production. Therefore,saving energy and reducing emission when recycling acetone are the most important technologies during the production of phospholipid.On the basis of the productivity of powdery phospholipid being 2.4 t every day,43.2 t acetone is reused every 8 h and the total volume of acetone gas emitted is 450.75 m3 (about 901.5 kg).According to the current price of acetone,the lost money is about 7212 yuan RMB.
文摘The necessity of lowering the mean power consumption of various facilities, due to the lack of their enormous future energy needs, led to an ongoing advance of various technologies. These technologies have been oriented towards the concept of a Reduced Ecological Footprint. Massive structures (such as building complexes and hospitals) have been redesigned and upgraded;many interior designs have been dramatically altered while new electronic devices are constantly being produced in order to revolutionize a long term perspective towards a “Green Planet” while they exhibit astonishing signal processing. Consequently, an enormous technology already exists which needs to be properly combined to a proposed methodology and to new ideas relevant to systems’ administration through automatic wireless control. This paper intends to reduce the gap between design and realization of the aforementioned research. Consequently, the primary contribution of this research is the proposal of a complete design protocol with minimized defects relevant to Reduced Ecological Footprints of Facilities (REFF) along with its beneficial advantages relevant to providing a healthy and productive work environment. This protocol consists of four main parts which are 1) the main key points-guidelines, 2) its objectives, 3) the know-how methodology for implementation in existing installations and 4) the description of the imminent benefits in workforce/human resources.
基金supported by the National Natural Science Foundation of China(51577094)the Natural Science Foundation of Jiangsu Province of China(BK20180086)。
文摘As one of prussian blue analogues,Co_(3)[Co(CN)_(6)]_(2) has been explored as a promising anode material for potassium-ion batteries(PIBs) owing to its high potassium storage capacity.Unfortunately,Co_(3)[Co(CN)_(6)]_(2) possesses low electronic conductivity and its structure collapses easily during potassiation and depotassiation,resulting in poor rate performance and cyclic stability.To solve these problems,we develop a facile multi-step method to successfully combine uniformCo_(3)[Co(CN)_(6)]_(2) nanocubes with rGO by C-O-Co bonds.As expected,these chemcial bonds shorten the distance betweenCo_(3)[Co(CN)_(6)]_(2) and rGO to the angstrom meter level,which significantly improve the electronic conductivity ofCo_(3)[Co(CN)_(6)]_(2).Besides,the complete encapsulation ofCo_(3)[Co(CN)_(6)]_(2) nanocubes by rGO endows the structure ofCo_(3)[Co(CN)_(6)]_(2) with high stability,thus withstanding repeated insertion/extraction of potassium-ions without visible morphological and structural changes.Benefiting from the abovementioned structural advantages,the CO3 [Co(CN)6]2/rGO nanocomposite exhibits a high reversible capacity of 400.8 mAh g^(-1) at a current density of 0.1 A g^(-1),an exceptional rate capability of 115.5 mAh g^(-1) at 5 A g^(-1), and an ultralong cycle life of 231.9 mAh g^(-1) at 0.1 A g^(-1) after 1000 cycles.Additionally,the effects of different amounts of rGO and different sizes ofCo_(3)[Co(CN)_(6)]_(2) nanocubes on the potassium storage performance are also studied.This work offers an ideal route to significantly enhance the electrochemical properties of prussian blue analogues.
基金supported by the National Natural Science Foundation of China(61773220,61876192,61907021)the National Natural Science Foundation of Hubei(ZRMS2019000752)+2 种基金the Fundamental Research Funds for the Central Universities(2662018QD057,CZT20022,CZT20020)Academic Team in Universities(KTZ20051)School Talent Funds(YZZ19004)。
文摘To improve the energy efficiency of a direct expansion air conditioning(DX A/C) system while guaranteeing occupancy comfort, a hierarchical controller for a DX A/C system with uncertain parameters is proposed. The control strategy consists of an open loop optimization controller and a closed-loop guaranteed cost periodically intermittent-switch controller(GCPISC). The error dynamics system of the closed-loop control is modelled based on the GCPISC principle. The difference,compared to the previous DX A/C system control methods, is that the controller designed in this paper performs control at discrete times. For the ease of designing the controller, a series of matrix inequalities are derived to be the sufficient conditions of the lower-layer closed-loop GCPISC controller. In this way, the DX A/C system output is derived to follow the optimal references obtained through the upper-layer open loop controller in exponential time, and the energy efficiency of the system is improved. Moreover, a static optimization problem is addressed for obtaining an optimal GCPISC law to ensure a minimum upper bound on the DX A/C system performance considering energy efficiency and output tracking error. The advantages of the designed hierarchical controller for a DX A/C system with uncertain parameters are demonstrated through some simulation results.
文摘In the urban residential building stock, a major proportion is constituted by low-rise individual buildings. In addition to cost, quality and duration, energy consumed for the project needs to be accounted in the decision making process. Minimizing the cost of construction without compromising on the architectural and structural requirements is the primary objective of the residential buildings of stake-holders, especially the owners. The choice of structural system and the materials used for construction play a crucial role in this effort. This means that the use of expensive and/or voluminous materials such as cement, steel, masonry etc. is optimized. This could lead to significant reduction in embodied energy as well, if the choice of the structural system is prudently made. In this paper, an attempt has been made to quantify the cost and embodied energy benefits for a low-rise residential building by choosing two different structural systems, namely moment resisting framed (MRF) construction system and the partly load-bearing (PLB) system. The influence of choice of materials, contributing to reduction of cost and/or energy is discussed. It is clearly noticed that, when the structural system is re-configured as a PLB system from the existing MRF system there is significant reduction in cost and embodied energy without changing the architectural form.