Journal articles on the topic 'Energy efficiency not elsewhere classified'
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1
Bisio, G. "Exergy Analysis of Thermal Energy Storage With Specific Remarks on the Variation of the Environmental Temperature." Journal of Solar Energy Engineering 118, no. 2 (May 1, 1996): 81–88. http://dx.doi.org/10.1115/1.2848020.
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Energy storage is a key technology for many purposes and in particular for air conditioning plants and a successful exploitation of solar energy. Thermal storage devices are usually classified as either variable temperature (“sensible heat”) or constant temperature (“latent heat”) devices. For both models a basic question is to determine the efficiency suitably: Only exergy efficiency appears a proper way. The aim of this paper is to examine exergy efficiency in both variable and constant temperature systems. From a general statement of exergy efficiency by the present author, two types of actual definitions are proposed, depending on the fact that the exergy of the fluid leaving the thermal storage during the charge phase can be either totally lost or utilized elsewhere. In addition, specific remarks are made about the exergy of a system in a periodically varying temperature environment.
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Yang, Li, Zedao Shi, and Wen Qin. "Research on Building Insulation and Energy Efficiency." E3S Web of Conferences 118 (2019): 01012. http://dx.doi.org/10.1051/e3sconf/201911801012.
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The purpose of this research is to investigate built building envelope renovation methods. Earlier studies on built building renovation have shown that the significant influence of using built building instead of the new building in terms of the energy crisis. However, these have not yet compared various renovation methods for building surface. Therefore, this study classified several reconstruction means into three types and evaluated their performances under three indicators: 1) construction; 2) material; 3) impact on original building appearance. The result shows that the integrated system of insulation and decoration is the best, and the method of additional components is the worst for building enclosure renovation.
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Siwei, Han, Wang Linyu, Guo Lei, Liu Shuai, Song Guojun, and Song Tianyi. "Evaluation on the Energy Efficiency for Chinese cities." E3S Web of Conferences 143 (2020): 02016. http://dx.doi.org/10.1051/e3sconf/202014302016.
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This study fully considers the incomparable factors in city's energy efficiency assessment, and proposes a framework for city's energy efficiency assessment based on classification. In the process of classifying cities, the SVM method is used to establish a quantitative relationship model between relevant factors and city's energy consumption. Based on the model, the objective energy demand of the city is calculated, and the city is classified according to the level of objective energy demand. By comparing the actual energy consumption of the city with the objective energy demand, we can eliminate the interference of the incomparable factors on the city's energy efficiency assessment.
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Shin, C. S., K. U. Kim, and Patrick Kwon. "Economic Analysis of Agricultural Tractors in South Korea: Classified Based on Energy Efficiency Grades." Applied Engineering in Agriculture 33, no. 5 (2017): 667–77. http://dx.doi.org/10.13031/aea.12026.
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Abstract. This study involved performing an economic analysis on agricultural tractors classified based on energy efficiency grades using the energy efficiency index. Specifically, 131 models of agricultural tractors commonly used between 2006 and 2010 in South Korea were classified into five categories. The relationship between energy efficiency and economic value was evaluated by a numerical method, and a method of predicting cost and fuel savings based on energy efficiency was developed. Grades of energy efficiency labeled from 1–5 were assumed in order to calculate annual fuel and cost savings. The results indicated that the use of the proposed method resulted in fuel and cost savings given an upgrade from the 5th level of energy efficiency to the 1st level and indicated subsequent improvements with each grade level. This method was applied to data from the year 2008, and total fuel and cost savings were obtained. This indicated that fuel and cost savings in an arbitrary year could be predicted using the proposed method and assuming data from an arbitrary year. Keywords: Agricultural tractors, Economic analysis, Energy efficiency classification grade, Energy efficiency index.
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Marín, M. F., H. Naya, E. A. Navajas, T. Devincenzi, A. C. Espasandin, and M. Carriquiry. "O45 Energy efficiency of Hereford heifers classified by paternal Residual Feed Intake." Animal - science proceedings 13, no. 3 (August 2022): 298–99. http://dx.doi.org/10.1016/j.anscip.2022.07.055.
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Yang, Dingcheng, Chuanqi Zhu, Lin Xiao, Xiaomei Shen, and Tiankui Zhang. "An Energy-Efficient Scheme for Multirelay Cooperative Networks with Energy Harvesting." Mobile Information Systems 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/5618935.
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This study investigates an energy-efficient scheme in multirelay cooperative networks with energy harvesting where multiple sessions need to communicate with each other via the relay node. A two-step optimal method is proposed which maximizes the system energy efficiency, while taking into account the receiver circuit energy consumption. Firstly, the optimal power allocation for relay nodes is determined to maximize the system throughput; this is based on directional water-filling algorithm. Secondly, using quantum particle swarm optimization (QPSO), a joint relay node selection and session grouping optimization is proposed. With this algorithm, sessions can be classified into multiple groups that are assisted by the specific relay node with the maximum energy efficiency. This approach leads to a better global optimization in searching ability and efficiency. Simulation results show that the proposed scheme can improve the energy efficiency effectively compared with direct transmission and opportunistic relay-selected cooperative transmission.
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Patel, Martin K., Jean-Sébastien Broc, Haein Cho, Daniel Cabrera, Armin Eberle, Alessandro Federici, Alisa Freyre, et al. "Why We Continue to Need Energy Efficiency Programmes—A Critical Review Based on Experiences in Switzerland and Elsewhere." Energies 14, no. 6 (March 21, 2021): 1742. http://dx.doi.org/10.3390/en14061742.
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Energy efficiency programmes (EEPs) are schemes operated by utilities or other bodies in order to incentivize energy efficiency improvement, in particular by adoption of energy-efficient products and typically by means of an economic reward. Ample experience has been gained, especially in the U.S., where EEPs have been in use for decades, with the rationale of avoiding additional energy supply by improving energy efficiency. More recently, EEPs have been implemented in Europe and in Switzerland. This review paper presents insights from the U.S., the EU and especially from Switzerland, with a focus on levelised programme cost of saved energy (LPC) as a key performance indicator. These LPC values, which take the perspective of the programme operator, are typically low to very low compared to the cost of electricity supply, thereby representing an important argument in favour of their use. The country examples show that EEPs are being effectively and successfully put into practice, for example, in Switzerland both as (i) a national tender-based scheme (called ProKilowatt) and in the form of a (ii) utility-operated obligation-based scheme (in Geneva). EEPs not only call for diligent implementation but also for suitable legal settings, e.g., in the form of mandatory energy efficiency savings targets (as realised for energy efficiency obligations, EEOs) in combination with programme cost recovery. The main criticism of EEPs is the free-rider effect, which needs to be minimised. On the other hand, EEPs are accompanied by significant co-benefits (environmental, health-related and social) and spillover effects. In their currently prevalent form, EEPs allow one to effectively save energy at a (very) low cost (“low-hanging fruit”). They can hence play an important role in fostering the energy transition; however, they should be implemented as part of a policy portfolio, in combination with other policy instruments.
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Huang, Guo Qin, and Xi Peng Xu. "Analysis of Energy Consumption Efficiency in Diamond Circular Sawing." Solid State Phenomena 175 (June 2011): 67–71. http://dx.doi.org/10.4028/www.scientific.net/ssp.175.67.
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. Experiments of sawing granite with diamond circular blades were carried out to study the energy efficiency in circular sawing. Energy consumed by machine spindle is classified into energy used without cutting and energy used with cutting. The energy used without cutting almost increases with the improvement of peripheral speed of blade. The energy consumption coefficient, the ratio of energy used with cutting to total energy consumed by spindle, increases with the increase of material removed rate, which reveals that higher material removed rate is favor for improving energy utilization. A fixed trend of energy consumption coefficient versus material removal rate was found and it might be useful for selecting cutting parameters for low energy sawing.
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Bortolini, Rafaela, Raul Rodrigues, Hamidreza Alavi, Luisa Felix Dalla Vecchia, and Núria Forcada. "Digital Twins’ Applications for Building Energy Efficiency: A Review." Energies 15, no. 19 (September 23, 2022): 7002. http://dx.doi.org/10.3390/en15197002.
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Over the last few decades, energy efficiency has received increasing attention from the Architecture, Engineering, Construction and Operation (AECO) industry. Digital Twins have the potential to advance the Operation and Maintenance (O&M) phase in different application fields. With the increasing industry interest, there is a need to review the current status of research developments in Digital Twins for building energy efficiency. This paper aims to provide a comprehensive review of the applications of digital twins for building energy efficiency, analyze research trends and identify research gaps and potential future research directions. In this review, Sustainability and Energy and Buildings are among the most frequently cited sources of publications. Literature reviewed was classified into four different topics: topic 1. Optimization design; topic 2. Occupants’ comfort; topic 3. Building operation and maintenance; and topic 4. Energy consumption simulation.
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Bánszki, Lívia, Tamás Rátonyi, and Endre Harsányi. "Evalution of energy for bioethanol production." Acta Agraria Debreceniensis, no. 51 (February 10, 2013): 77–80. http://dx.doi.org/10.34101/actaagrar/51/2066.
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The objective of this study was the ethanol which classified as agro fuels. The aim of our research was the calculation of efficiency of bioethanol production, and evaluates the yield of maize hybrids grown for this purpose. We examined the energy demand of corn production per hectare in two vintages of 2009 and 2010. The focus of the experiment was placed in three different doze of fertilizer. Results show that the control corn plot used the least amount of non-renewable energy. Improving starch yield by adding fertilizer required additional nonrenewable energy inputs. So then the invested energy has a great impact on the efficiency.
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Ahmad, Ehsan, Yun Wei Dong, and Bin Gu. "Research on Energy Efficiency of Embedded Systems: A Systematic Mapping Study." Advanced Materials Research 588-589 (November 2012): 2088–92. http://dx.doi.org/10.4028/www.scientific.net/amr.588-589.2088.
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The main object of this study is to systematically review existing research on energy efficiency of embedded systems in order to identify investigated aspects and needs for future research. We have conducted a systematic mapping study of the state-of-the-art on energy efficiency of embedded systems. 186 papers have been identified as primary studies from year 1994 to 2011 and classified by research focus, research type, and contribution type. 71% of the research papers are solutions proposals; power estimation is the most investigated aspect in terms of research focus (34%) and majority of the studies contributed in terms of methods.
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Bai, Lujian, Bing Song, and Liu Yang. "Developing the New Thermal Climate Zones of China for Building Energy Efficiency Using the Cluster Approach." Atmosphere 13, no. 9 (September 14, 2022): 1498. http://dx.doi.org/10.3390/atmos13091498.
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Climate is a key element in building design. The determination of adequate climate zoning is crucial for achieving building energy efficiency and reduced carbon emissions. In this study, a cluster analysis method was applied to develop new thermal climate zones for building envelope thermal design in China. In total, three different cluster analysis methods, including k-means, average-linkage, and Ward’s clustering, were considered. The analysis indicated that the average-linkage clustering was more appropriate for this study, and the elbow method could not accurately determine the best number of categories of average-linkage clustering. Further analysis showed that the unsupervised cluster processes may generate an unavoidable redundancy category and, to obtain precise results, supervision may be necessary in some contexts. Finally, China was classified into 10 climate zones. The North China plain and Qinghai–Tibet plateau are classified into two independent climate zones, and Turpan and Bayanbulak were classified into two newly defined climate zones different from their surrounding area in the new definition. Quantitative analysis indicated that the new zones were more precise when compared to the current ones, which can provide more precise climate information and contribute to formulating more precise standards and policies related to the thermal design of building envelopes in the future.
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Zhao, Jijun, Siyuan Gao, Danping Ren, Zhihua Li, and Liang Xue. "A multi-period joint energy scheduling algorithm in smart home based on prediction of the residents energy consumption." World Journal of Engineering 12, no. 2 (April 1, 2015): 135–48. http://dx.doi.org/10.1260/1708-5284.12.2.135.
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In this paper, considering a tradeoff between consumers comfort and energy efficiency, a multi-period joint energy scheduling algorithm (MPJ-ESA) based on prediction of residents energy consumption is proposed, which includes long-period preliminary sch eduling, short-period preliminary scheduling, and real-time fine-tuning scheduling. First, by analyzing historical data of energy consumption, preferred usage profile of consumers is inferred, and the dynamic comfort level is presented. Then the paper uses the wavelet neural networks (WNNs) prediction algorithm to predict the operation of the appliances which are classified into appliances with unschedulable mode and schedulable mode. Based on the energy consumption prediction and dynamic comfort level, home appliances running state are scheduled according to the prediction of renewable energy available amount and real-time pricing (RTP). The simulation results show that scheduling algorithm effectively improves the energy efficiency and enhances user satisfaction with the operation of scheduled appliances and let the consumers comfort and energy efficiency achieve a better tradeoff.
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Soleimani, Samira, and Markus Lehner. "Tri-Reforming of Methane: Thermodynamics, Operating Conditions, Reactor Technology and Efficiency Evaluation—A Review." Energies 15, no. 19 (September 28, 2022): 7159. http://dx.doi.org/10.3390/en15197159.
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The production of syngas with optimal energy usage, a minimal environmental impact, and an adjustable H2/CO molar ratio is possible using tri-reforming of methane (TRM). Despite the number of studies dedicated to the TRM process, this process is still in its infancy, with many technical obstacles to overcome. Except for its kinetics and catalysts, which have been reviewed elsewhere, the TRM process is evaluated thoroughly in this work. First, feasibility studies of TRM and the TRM process are presented. Second, the impacts of various operating conditions on the rate of gas conversions, syngas production, and coke formation are discussed. Third, different reactor configurations are compared. This review then goes through the energy and energetic efficiency, economic, environmental, and safety aspects of the TRM process. Finally, a research path for the future is suggested.
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Sun, Wanghu, Yuning Sun, Li Xu, Xing Chen, and Debin Zai. "Research on Energy Consumption Constitution and Energy Efficiency Strategies of Residential Buildings in China Based on Carbon Neutral Demand." Sustainability 14, no. 5 (February 25, 2022): 2741. http://dx.doi.org/10.3390/su14052741.
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To assist in the implementation of carbon peaking and carbon neutrality in China, due to the contradiction between the increasing energy consumption of residential buildings in China and the higher energy efficiency goals, this paper illustrates that the energy consumption constitution of residential buildings in the whole life cycle and then puts forward comprehensive energy efficiency strategies. With literature and statistical data, the main part of building energy consumption lies in the materialization and use phases, which both will be continually increasing, and divided into energy utilization and waste. By inducing the energy consumption in the use phase, the energy consumption of residential buildings can be further classified into the energy consumption of indoor environments, residential behavior, and public facilities, where the internal factor of continuous increase are all elaborated. Via the analysis of energy waste causes, this paper constructs a model of energy consumption in residential buildings, reveals that the key to energy efficiency in residential buildings lies in scientific decision-making, lifestyle improvement, and appropriate energy efficiency technologies and measures adoption, and points out that promoting building energy efficiency through the whole life cycle of buildings and building activities is needed to achieve carbon compliance and carbon neutrality.
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Flores, João, Miguel Cavique, and Júlia Seixas. "Energy Sustainability—Rebounds Revisited Using Axiomatic Design." Sustainability 14, no. 11 (May 31, 2022): 6737. http://dx.doi.org/10.3390/su14116737.
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Energy Sustainability has been addressed through advancing technology efficiency, which may increase the impact of the use of natural resources. However, the increase in efficiency makes services cheaper, which causes a rebound effect, direct or indirect, on energy consumption and materials. Moreover, the popular concept of recycling seems insufficient to reduce the use of critical raw materials to provide energy services. From the perspective of the Earth’s limited resources, the sustainability problem needs a design approach to tackle the rebound effect from efficiency. This work aims to create a theoretical holistic review regarding energy use linked to technology efficiency, to understand how rebound effects may be prevented. In this work, the Axiomatic Design (AD) theory creates the framework that defines the Energy Sustainability functions and identifies the couplings that create the rebounds. According to AD, cycles occur on coupled designs, classified as poor designs. Decoupling the design clarifies two possible and complementary policies to achieve sustainability goals regarding the use of resources. The first is the circular economy, with constraints on energy and raw materials. The second is the massive use of local renewable energies. Plausible solutions come from mandating efficiency and taxation, dematerializing the economy, and reducing, reusing, remanufacturing, and recycling materials from products and systems. These solutions impact economic, environmental, and societal behaviors. The novelty of this approach is the definition of a system model for Energy Sustainability in the frame of AD, while tackling the rebound effect from technological efficiency.
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Ganina, Vera, and Irina Krasnova. "Biological processes affecting energy efficiency and energy saving in the technology of fermented milk products." E3S Web of Conferences 279 (2021): 03001. http://dx.doi.org/10.1051/e3sconf/202127903001.
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The production of dairy products is classified as an energyconsuming industry, which is due to the use of heat exchange processes involving steam as a heat carrier. Indicators of energy efficiency and energy conservation in the production of fermented milk products, including cottage cheese, may sharply decrease due to violations of the fermentation process of raw milk. The intervention of a biological factor – the development of viruses that lyse the cells of lactic acid bacteria, leads to the inhibition or suspension of fermentation. This affects the quality and safety of resulting products and the need to re-implement technological processes that increase energy consumption. Researches on the detection of bacteriophages in the course of technological processes for the production of cottage cheese and yogurt showed the presence of phages at all stages of the technology of fermented milk products. Areas were identified where bacteriophages were detected in large numbers, which could negatively affect the fermentation process of raw milk. The data obtained allowed us to identify critical control points in the technology of cottage cheese and yogurt, where bacteriophages should be monitored to prevent a decrease in energy efficiency and occurrence of additional energy costs.
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Taghizadeh, Houshang, and Mir Vahid Pourrabbi. "Energy cost versus production as a performance benchmark for analysis of companies." Journal of Energy in Southern Africa 24, no. 1 (February 1, 2013): 2–8. http://dx.doi.org/10.17159/2413-3051/2013/v24i1a3001.
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In this paper, the efficiency of automobile and auto-parts producing companies is evaluated, using data envelopment analysis. The data envelopment analysis (DEA) is based on the linear programming model. This model needs a series of information by which the effectiveness and ineffectiveness of decision-making units are determined. In the present research, the inputs and outputs of the DEA model are determined by using the basic criteria, and the energy efficiency of automobile and auto-parts producing companies is specified. For this purpose, to evaluate the energy efficiency of the automotive industry and auto parts producing companies, deep2 software has been used. Finally, based on the results of the study, the efficient and inefficient companies have been identified and classified.
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Liang, Chuan Zhi, and Meng Meng Lu. "Research on the Remote Monitoring System of Building Energy Consumption Based on GSM/GPRS." Applied Mechanics and Materials 197 (September 2012): 782–86. http://dx.doi.org/10.4028/www.scientific.net/amm.197.782.
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The paper aim the remote monitoring system of energy consumption in buildings based on GSM/GPRS by a case, and introduces the system framework, operating mode, transmission technology, equipments and installation requirements, as well as illustrating software composition and function of the data center. The system can reflect classified electricity consumption in monitored buildings correctly. It not only understand situation of energy consumption in real-time, but also offers basic data for further energy auditing and energy efficiency assessment. The conclusion can develop management of building energy consumption and increase the building energy efficiency.
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Gao, Kaizhou, Yun Huang, Ali Sadollah, and Ling Wang. "A review of energy-efficient scheduling in intelligent production systems." Complex & Intelligent Systems 6, no. 2 (September 10, 2019): 237–49. http://dx.doi.org/10.1007/s40747-019-00122-6.
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Abstract Recently, many manufacturing enterprises pay closer attention to energy efficiency due to increasing energy cost and environmental awareness. Energy-efficient scheduling of production systems is an effective way to improve energy efficiency and to reduce energy cost. During the past 10 years, a large amount of literature has been published about energy-efficient scheduling, in which more than 50% employed swarm intelligence and evolutionary algorithms to solve the complex scheduling problems. This paper aims to provide a comprehensive literature review of production scheduling for intelligent manufacturing systems with the energy-related constraints and objectives. The main goals are to summarize, analyze, discuss, and synthesize the existing achievements, current research status, and ongoing studies, and to give useful insight into future research, especially intelligent strategies for solving the energy-efficient scheduling problems. The scope of this review is focused on the journal publications of the Web of Science database. The energy efficiency-related publications are classified and analyzed according to five criteria. Then, the research trends of energy efficiency are discussed. Finally, some directions are pointed out for future studies.
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Jung, Ho Gun, Min Cho Park, and Sung Woo Shin. "Principal Component Analysis in Building Energy Efficiency Rating System for Apartment Housings." Advanced Materials Research 919-921 (April 2014): 1716–20. http://dx.doi.org/10.4028/www.scientific.net/amr.919-921.1716.
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This study is aimed to establish the Carbon Emission Baseline for apartment housings. The carbon emissions at the operational stage were calculated through simulation based on the physical calculation. This method was chosen because it was necessary to estimate carbon emissions before the construction of the building. In fact, the energy consumption of buildings is more influenced by social statistics than by physical factors. This study used BEER and aggregated statistics of K-apt. system with a goal of estimating carbon emissions by buildings and establishing the carbon emission baseline. For this, the reliability of the related data which determine the energy consumption and carbon emissions of apartment housings were reviewed, and components were classified. Principle Component Analysis is used to determine the main components that are comprised of BEER indicators. The variable groups which are selected by PCA would be used in multivariate analysis.
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Davies Wykes, Megan S., Graham O. Hughes, and Stuart B. Dalziel. "On the meaning of mixing efficiency for buoyancy-driven mixing in stratified turbulent flows." Journal of Fluid Mechanics 781 (September 17, 2015): 261–75. http://dx.doi.org/10.1017/jfm.2015.462.
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The concept of a mixing efficiency is widely used to relate the amount of irreversible diabatic mixing in a stratified flow to the amount of energy available to support mixing. This common measure of mixing in a flow is based on the change in the background potential energy, which is the minimum gravitational potential energy of the fluid that can be achieved by an adiabatic rearrangement of the instantaneous density field. However, this paper highlights examples of mixing that is primarily ‘buoyancy-driven’ (i.e. energy is released to the flow predominantly from a source of available potential energy) to demonstrate that the mixing efficiency depends not only on the specific characteristics of the turbulence in the region of the flow that is mixing, but also on the density profile in regions remote from where mixing physically occurs. We show that this behaviour is due to the irreversible and direct conversion of available potential energy into background potential energy in those remote regions (a mechanism not previously described). This process (here termed ‘relabelling’) occurs without requiring either a local flow or local mixing, or any other process that affects the internal energy of that fluid. Relabelling is caused by initially available potential energy, associated with identifiable parcels of fluid, becoming dynamically inaccessible to the flow due to mixing elsewhere. These results have wider relevance to characterising mixing in stratified turbulent flows, including those involving an external supply of kinetic energy.
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Kashtanov, A. L., A. A. Komyakov, and M. M. Nikiforov. "Forecasting and verification of railway transport energy efficiency key indicators." Herald of the Ural State University of Railway Transport, no. 1 (2021): 46–54. http://dx.doi.org/10.20291/2079-0392-2021-1-46-54.
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The article reflects the issues of forecasting the target indicators of energy efficiency on the example of JSC «Russian Railways». The approaches selected for assessing the quantitative values of the key performance indicators of the Russian Railways holding in the development of the Energy Strategy for the period up to 2020 and for the future up to 2030 are considered. The accepted methods are conventionally classified into four groups, including: a heuristic method based on the analysis of time trends, an indirect method based on known values of indicators and using mathematical models. The method of forecasting the specific consumption of electricity and diesel fuel for train traction and the energy intensity of the production activity of JSC «Russian Railways» is considered in detail. Regression models have been developed that characterize the dependence of the specific fuel and energy consumption on such indicators as the volume of transportation work, the average mass of the train, and the share of freight work in the total work. In order to assess the accuracy of the obtained forecast values of the indicators included in the energy strategy of JSC «Russian Railways», they were verified by the results of 2017-2019. The results obtained allow us to speak about the sufficient effectiveness of the approaches considered in the article to predict the KPI of JSC «Russian Railways». The error in forecasting the main indicator of energy efficiency of JSC «Russian Railways» - the energy intensity of production activities - was 0,06 %.
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Abbasi, Mohammadjavad, Muhammad Shafie Bin Abd Latiff, and Hassan Chizari. "An Overview of Distributed Energy-Efficient Topology Control for Wireless Ad Hoc Networks." Mathematical Problems in Engineering 2013 (2013): 1–16. http://dx.doi.org/10.1155/2013/126269.
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A wireless ad hoc network is composed of several tiny and inexpensive device such as wireless sensor networks (WSNs) which have limited energy. In this network energy, efficiency is one of the most crucial requirements. Data transmitting in minimum power level is one way of maximizing energy efficiency. Thus, transmission power level of nodes should be managed in a smart way to improve energy efficiency. Topology control is one of the main algorithms used in a wireless network to decrease transmission power level while preserving network connectivity. Topology control could improve energy efficiency by reasonably tuning the transmission power level while preserving network connectivity in order to increase network capacity and lifetime. In pursuit of energy efficiency and connectivity, nodes can be selfish and are conflicting with each other. Therefore to overcome the conflict, game theory is used to construct energy efficient topology, as well as minimizing energy consumption. In this paper, the main goal and most recent energy efficient topology control algorithms in WSNs and ad hoc network are classified and studied according to their specific goals.
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Lucila Sobrinho, T., R. H. Branco, S. F. M. Bonilha, A. M. Castilhos, L. A. Figueiredo, A. G. Razook, and M. E. Z. Mercadante. "Residual feed intake and relationships with performance of Nellore cattle selected for post weaning weight." Revista Brasileira de Zootecnia 40, no. 4 (April 2011): 929–37. http://dx.doi.org/10.1590/s1516-35982011000400030.
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The objective of this work was to evaluate performance, efficiency parameters and phenotypic correlations among measurements of energy efficiency of Nellore cattle selected for post weaning weight and classified according to residual feed intake, calculated by the difference between observed and predicted intake, based on average metabolic body weight and average daily gain. Thus, animals were classified within three groups: high (> mean + 0.5 standard deviation, less efficient); medium (±0.5 standard deviation of the mean); and low (< mean - 0.5 standard deviation, more efficient) residual feed intake. No differences were observed at initial and final body weights, average daily gain and dry matter intake among groups. Animals with low residual feed intake also had greater feed efficiency, feed conversion and partial efficiency of growth and did not differ from the other animals regarding to relative growth rate and Kleiber ratio. Residual feed intake was significantly correlated to feed efficiency (-0.25), feed conversion (0.25), partial efficiency of growth (-0.37) and dry matter intake (0.16) but it did not present significant correlation with body weight (0.04), average daily gain (-0.02), relative growth rate (-0.03) and Kleiber ratio (-0.05). Significant correlations were found between feed conversion and initial body weight (0.34) and average daily gain (-0.46). Partial efficiency of growth presented significant correlation with all other efficiency parameters analyzed. Residual feed intake has high potential in productive efficiency, when compared to the other energy efficiency measurements, being independent of growth and size of the animals.
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Yang, Minyoung, and Jinsoo Kim. "A Critical Review of the Definition and Estimation of Carbon Efficiency." Sustainability 14, no. 16 (August 15, 2022): 10123. http://dx.doi.org/10.3390/su141610123.
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The concept of carbon efficiency is closely related to energy efficiency but embraces a broader range of carbon emission sources. Many studies have covered carbon efficiency, investigating the climate crisis, economic growth, and a sustainable future; however, it is hard to agree that there is a consensus on the definition of carbon efficiency. To fill this gap, we reviewed the literature on carbon efficiency, especially the empirical studies that quantitatively measured carbon efficiency. As a result, we have categorized the articles into three groups based on defined criteria of carbon efficiency. We have also classified the methodology to measure carbon efficiency and to discuss misleading definitions in the empirical studies. Lastly, we suggest a desirable direction to define and measure carbon efficiency along with discussion points. Carbon efficiency is different from energy efficiency and our review will help build the carbon efficiency concept in a proper direction.
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Chasiotis, Ioannis D., Yannis L. Karnavas, and Franck Scuiller. "Effect of Rotor Bars Shape on the Single-Phase Induction Motors Performance: An Analysis toward Their Efficiency Improvement." Energies 15, no. 3 (January 19, 2022): 717. http://dx.doi.org/10.3390/en15030717.
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Mandatory regulations are published worldwide for the efficiency of line-operated electric motors. The small-sized single-phase induction motors (SPIMs) will not be off the hook in terms of efficiency, since new regulations are scheduled to be introduced regarding them no later than July 2023. By doing so, the efficiency of capacitor-run SPIMs will be forced to exceed the (currently) typical ratings and comply with the requirements of the IE3 (i.e., premium) efficiency class. Since this task is challenging, the already published research works investigated several design, control, and manufacturing aspects. Nevertheless, less attention has been devoted to the study of the rotor bar’s shape impact, both on the SPIMs’ efficiency and starting capability. This gap is filled in this work by examining rotor squirrel-cage configurations with eight different bar shapes for the case of a four-pole/1.0 HP capacitor-run SPIM. A sensitivity analysis, which involves the simultaneous variation of the bar’s cross-sectional area, run-capacitor value, and auxiliary to main winding turns ratio, is performed. The motor’s electromagnetic behavior is estimated through finite element analysis. Through the acquired results, useful directions toward the SPIMs’ efficiency enhancement are provided, while simultaneously conclusions—not found elsewhere—are drawn concerning performance quantities, such as the motor’s starting current, currents shift angle, particular losses, breakdown torque, etc.
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Tsallis, Constantino. "Beyond Boltzmann–Gibbs–Shannon in Physics and Elsewhere." Entropy 21, no. 7 (July 15, 2019): 696. http://dx.doi.org/10.3390/e21070696.
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The pillars of contemporary theoretical physics are classical mechanics, Maxwell electromagnetism, relativity, quantum mechanics, and Boltzmann–Gibbs (BG) statistical mechanics –including its connection with thermodynamics. The BG theory describes amazingly well the thermal equilibrium of a plethora of so-called simple systems. However, BG statistical mechanics and its basic additive entropy S B G started, in recent decades, to exhibit failures or inadequacies in an increasing number of complex systems. The emergence of such intriguing features became apparent in quantum systems as well, such as black holes and other area-law-like scenarios for the von Neumann entropy. In a different arena, the efficiency of the Shannon entropy—as the BG functional is currently called in engineering and communication theory—started to be perceived as not necessarily optimal in the processing of images (e.g., medical ones) and time series (e.g., economic ones). Such is the case in the presence of generic long-range space correlations, long memory, sub-exponential sensitivity to the initial conditions (hence vanishing largest Lyapunov exponents), and similar features. Finally, we witnessed, during the last two decades, an explosion of asymptotically scale-free complex networks. This wide range of important systems eventually gave support, since 1988, to the generalization of the BG theory. Nonadditive entropies generalizing the BG one and their consequences have been introduced and intensively studied worldwide. The present review focuses on these concepts and their predictions, verifications, and applications in physics and elsewhere. Some selected examples (in quantum information, high- and low-energy physics, low-dimensional nonlinear dynamical systems, earthquakes, turbulence, long-range interacting systems, and scale-free networks) illustrate successful applications. The grounding thermodynamical framework is briefly described as well.
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Al-Mezeini, Nawal Khamis, Abdulrahim M. Al-Ismaili, and Said M. Tabook. "Evaluation of Greenhouse Cucumber Production Sustainability in Terms of Energy Use Efficiency." Journal of Agricultural and Marine Sciences [JAMS] 24 (February 10, 2020): 24. http://dx.doi.org/10.24200/jams.vol24iss0pp24-29.
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Sustainable agricultural production could be assessed through energy-use efficiency (EUE). Thus, this paper aims to evaluate the EUE for cucumber greenhouse production in Oman. Data were obtained by interviewing farmers (face-to-face). Result indicated that total energy inputs (e.g. electricity, water, fertilizers and agrochemicals) and total energy output (cucumber yield) were 1159726.0 MJ ha-1 and 89942.9 MJ ha-1, respectively. The highest energy consuming input in the greenhouse production was electricity, consuming 88% of total energy input. This indicates that electricity had again the highest impact in cucumber greenhouse production and 99% of electricity goes for cooling the greenhouse. When all energy inputs were classified into its forms; direct (D) and indirect (ID), and renewable (R) and non-renewable (NR), the highest portion of total energy forms in greenhouse cucumber production was for D and NR energy. The EUE and energy productivity (EP) were found to be 0.07 and 0.10 kg MJ-1, respectively. Energy use in greenhouse cucumber production was inefficient and solar energy need to be implemented to improve cucumber greenhouse sustainability production.
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Perane, Pranit B., Swapnil S. Loni, Sanjana U. Chavan, and H. D. Aiwale. "Zero Energy Building." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 172–76. http://dx.doi.org/10.22214/ijraset.2022.42129.
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Abstract: Decarbonizing the building sector is extremely important to mitigating climate change as the sector contributes 40% of the overall energy consumption and 36% of the total greenhouse gas emissions in the world. Net-zero energy buildings are one of the promising decarbonization attempts due to their potential of decreasing the use of energy and increasing the total share of renewable energy. To achieve a net-zero energy building, it is necessary to decrease the energy demand by applying efficiency enhancement measures and using renewable energy sources. Net zero energy buildings can be classified into four models (Net-Zero Site Energy buildings, Net Zero Emissions buildings, Net-Zero Source Energy buildings, and Net-Zero Cost Energy buildings). A variety of technical, financial, and environmental factors should be considered during the decision-making process of net-zero energy building development, justifying the use of multi-criteria decision analysis methods for the design of net-zero energy buildings. This paper also discussed the contributions of renewable energy generation (hydropower, wind energy, solar, heat pumps, and bioenergy) to the development of net-zero energy buildings and reviewed its role in tackling the decarbonization challenge. Costbenefit analysis and life cycle assessment of net-zero energy building designs and their challenges were reviewed to shape the priorities of future development. It is important to develop a universal decision instrument for optimum design and operation of net-zero energy buildings Keywords: Zero Energy Building, Energy Efficiency, Greenhouse gases, Renewable Energy, Grid
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Hohne, Percy Andrew, Kanzumba Kusakana, and Bubele Papy Numbi. "Improving Energy Efficiency of Thermal Processes in Healthcare Institutions: A Review on the Latest Sustainable Energy Management Strategies." Energies 13, no. 3 (January 24, 2020): 569. http://dx.doi.org/10.3390/en13030569.
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Healthcare institutions consume large amounts of energy, ranking the second highest energy-intensive buildings in the commercial sector. Within developed countries, the energy consumption of healthcare institutions may account for up to 18% of the overall energy usage in commercial sectors. Within developing countries, such as South Africa, the energy consumption of healthcare institutions is observed to be a close second to the food service sector. Energy consumption of healthcare institutions per bed typically range from 43–92 kWh per day. In this paper, the largest energy consumers in South African healthcare institutions are identified and appropriate energy-efficiency (EE) initiatives are proposed, in terms of performance, operation, equipment and technology efficiency (POET). Two main thermal energy consumers are identified as heating, ventilation and air conditioning (HVAC) and water-heating systems. These systems are critical to patient health and may be classified as non-deferrable loads. Therefore, several initiatives are suggested to improve the energy efficiency and demand-side management capability of these systems. These initiatives are subdivided into different levels: the conceptual level, active level, technical and further improvement level, as defined in the POET framework. At each level, energy-efficiency initiatives are introduced based on potential energy savings and the effort required to achieve these savings. In addition, model predictive control (MPC) approaches are discussed and reviewed as part of the further improvement section. Average possible energy savings ranged from 50%–70% at the conceptual level, while energy savings of 15%–30% may be expected for energy-efficiency initiatives at the active level. EE activities at the technical level and the further improvement level may result in savings of 50%–70% and 5%–10%, respectively.
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Küpper, Hans-Dieter, Alessandro Pianetti, and Samer Saab. "A2L low GWP HFO based refrigerant solutions in heat pump applications to drive energy efficiency, safety, and sustainability even in building restoration." E3S Web of Conferences 343 (2022): 04002. http://dx.doi.org/10.1051/e3sconf/202234304002.
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Driven by energy efficiency requirements and legal restrictions like F-Gas Regulation Heat Pump OEM supplier are looking for alternative refrigerant solutions. HFO based low GWP refrigerants can help increasing the system efficiency, expanding the operating temperature range while reducing CO2 emissions. For building restoration in particular, high flow temperatures (for existing hydronic heating system) are essential for convenient and cost-and energy-efficient replacements of fossil fuel boilers. A2L classified refrigerants provide extended application range at highest safety level versus A3 classified refrigerants, but R-32 still carries a Global Warming Potential (GWP) of 675 making it a transitional solution. This paper compares different relevant parameters and points out the advantages provided by HFO A2L low GWP refrigerants (like R-454B and R-454C) for a wide capacity range of air to water and brine to water heat pumps. A special focus is put on the application of building restoration.
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Mustapha, Muslizainun, Ahmad Fudholi, Chan Hoy Yen, Mohd Hafidz Ruslan, and Kamaruzzaman Sopian. "Review on Energy and Exergy Analysis of Air and Water Based Photovoltaic Thermal (PVT) Collector." International Journal of Power Electronics and Drive Systems (IJPEDS) 9, no. 3 (September 1, 2018): 1366. http://dx.doi.org/10.11591/ijpeds.v9.i3.pp1366-1373.
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<p class="AEuroAbstract">In photovoltaic thermal hybrid (PV/T) collectors, the electricity and thermal energy are produce simultaneously. PV/T technology has been proven in previous studies where it could give benefits for high energy demand supplementary. For example, in space heating, domestic water heating and also drying. The PVT collectors can be classified into air-based PVT, water-based PVT and dual-fluid (air+water) PVT collector. In this paper, the analysis of energy and exergy efficiency of PVT collectors are compiled and reviewed. This study has found that generally the energy and exergy efficiency are range from 40%-70% and 5%-20%, respectively.</p>
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Mustapha, Muslizainun, Ahmad Fudholi, Chan Hoy Yen, Mohd Hafidz Ruslan, and Kamaruzzaman Sopian. "Review on Energy and Exergy Analysis of Air and Water Based Photovoltaic Thermal (PVT) Collector." International Journal of Power Electronics and Drive Systems (IJPEDS) 9, no. 3 (September 1, 2018): 1367. http://dx.doi.org/10.11591/ijpeds.v9.i3.pp1367-1373.
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<p class="AEuroAbstract">In photovoltaic thermal hybrid (PV/T) collectors, the electricity and thermal energy are produce simultaneously. PV/T technology has been proven in previous studies where it could give benefits for high energy demand supplementary. For example, in space heating, domestic water heating and also drying. The PVT collectors can be classified into air-based PVT, water-based PVT and dual-fluid (air+water) PVT collector. In this paper, the analysis of energy and exergy efficiency of PVT collectors are compiled and reviewed. This study has found that generally the energy and exergy efficiency are range from 40%-70% and 5%-20%, respectively.</p>
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Žičkienė, Agnė, Mangirdas Morkunas, Artiom Volkov, Tomas Balezentis, Dalia Streimikiene, and Indre Siksnelyte-Butkiene. "Sustainable Energy Development and Climate Change Mitigation at the Local Level through the Lens of Renewable Energy: Evidence from Lithuanian Case Study." Energies 15, no. 3 (January 28, 2022): 980. http://dx.doi.org/10.3390/en15030980.
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The penetration of renewable energy is one of the main challenges for sustainable energy development. Local governments across the European Union commit to development and implementation of the Sustainable Energy (and Climate) Action Plan. This paper focuses on the case of Lithuania—a Central and Eastern European country. Almost one-third of Lithuanian municipalities have joined the Covenant of Mayors and prepared the plans that include SWOT analysis. However, there is a lack of information on how those plans contribute to climate change mitigation and sustainable energy development. This study identifies the links between key policy financial instruments, increasing energy efficiency. The Strategic Action Plans aimed at reducing GHG emissions and energy consumption in Lithuanian municipalities are analyzed. The challenges in promoting the renewable energy generation in Lithuanian rural regions are discussed. Moreover, the importance of strengths, weaknesses, opportunities, and threats identified is elicited at the local level. The study uses a combination of methods, such as expert surveys and SWOT analysis, that complements the tools used for regional energy climate planning and allows for overarching analysis. The expert survey shows that priority is given for renovation of buildings and modernization of energy infrastructure, making them more sustainable and more energy efficient. The results also show that, in the case of Lithuania (and possibly elsewhere in the post-Soviet countries), conditions and opportunities should be created beforehand to increase energy efficiency. Once this is achieved, the policies should focus on energy transition by switching to sustainable energy resources.
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Yuan, Yupeng, Xiaoyu Wang, Liang Tong, Rui Yang, and Boyang Shen. "Research on Multi-Objective Energy Efficiency Optimization Method of Ships Considering Carbon Tax." Journal of Marine Science and Engineering 11, no. 1 (January 3, 2023): 82. http://dx.doi.org/10.3390/jmse11010082.
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Various measures have been taken to improve ship energy efficiency while decreasing CO2 emissions. In this work, the navigation environment between Wuhan and Shanghai in China has been classified based on an improved K-means algorithm in order to realize route division. A fuel consumption prediction model considering the navigation environment factors has been established. Consequently, speed optimization models with multiple different optimization objectives have been constructed and tested based on an actual case using an artificial fish swarm algorithm. Finally, sensitivity analysis has been carried out focusing on the navigation time, fuel price, charter rate, free carbon credits, and carbon tax rate. The results show that the total shipping cost and CO2 emissions could be reduced by 0.94% and 0.38%, respectively, after the optimization. Considering a carbon tax policy with a tax rate of roughly 1300 RMB/t, the optimization result (including the carbon tax cost) is close to the compromised solution of multi-objective optimization, and the corresponding carbon tax rate can provide a useful reference for policymakers.
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KAWAMURA, MASAKO. "EFFICIENCY OF SWIMMING OF MICRO-ORGANISM AND SINGULARITY IN SHAPE SPACE." Modern Physics Letters A 11, no. 24 (August 10, 1996): 1961–69. http://dx.doi.org/10.1142/s0217732396001958.
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Micro-organisms can be classified into three different types according to their sizes. We study the efficiency of the swimming of micro-organism in two-dimensional fluid as a device for helping the explanation of this hierarchy in terms of size. We show that the efficiency of flagellate becomes unboundedly large, whereas that of ciliate has the upper bound. The unboundedness is related to the curious feature of the shape space, that is, a singularity at the basic shape of flagellate.
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Farooq, Muhammad Usman, Abdul Ahad, Zeeshan Maqsood, Niranjan Devkota, and Syed Naqi Raza. "The relationship between the energy efficiency of buildings and occupants: A review." Engineering and Applied Science Letters 4, no. 4 (December 30, 2021): 5–16. http://dx.doi.org/10.30538/psrp-easl2021.0076.
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Green buildings are supposed to provide a sustainable solution for energy usage, but their low performance raised some questions in the literature. The researchers determine that occupants are the key factor for this energy deficiency. In the last two decades, a stream of research focuses on the greening of occupants, but a synthesis of findings and results are absent in the literature. In this study, we reviewed the literature on green buildings and occupants. Based on the findings we classified four classes. The first class consists of green occupants and green buildings, which is the ideal solution for high-energy efficiency. The second class is of brown occupants and green buildings and is the prime reason behind outperformed green buildings and yields negative-medium level efficiency. The third class comprises green occupants and brown buildings and yields positive-medium level efficiency, which helps to start the journey towards sustainability. The fourth class is the combination of brown buildings and brown occupants and has the lowest efficiency and worst impact on the environment throughout the lifecycle. Further, we link these classes with the energy-saving efficiency of buildings and finally recommended an efficient solution for second and third world countries. The study contributes to green building literature and packed with managerial implications to gain the maximum benefits of green buildings.
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Johansen, Katinka. "A Brief History of District Heating and Combined Heat and Power in Denmark: Promoting Energy Efficiency, Fuel Diversification, and Energy Flexibility." Energies 15, no. 24 (December 7, 2022): 9281. http://dx.doi.org/10.3390/en15249281.
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The World Energy Council ranks the Danish energy system among best in the world judging by the energy trilemma criteria: energy security, energy equity, and sustainability. District heating (DH) and CHPs are pivotal for this ranking. This brief historical account illustrates how a mix of historical events, collective societal experiences, cultural and political values inform the Danish history of DH and CHPs. After the global energy crisis in the 1970s, public and political sentiment called for energy independence, alternatives to imported fuels, and alternatives to nuclear power. National-scale collective heat infrastructure planning initiatives targeted the energy policy objectives: energy independence, fuel diversification, and energy efficiency, and a political culture of broad coalition agreements made the necessary long-term planning possible. In the following decades, growing environmental awareness and concern called for renewable energy resources as alternatives to fossil fuels. Research considered the role of collective memories and temporal distance (i.e., time) for this sociotechnical journey; it notes the innovative thinking, re-use/re-cycling and energy efficiency focus that still characterize the Danish DH communities today, and it suggests that the intangible, yet reliable nature of heat could lead to the rebound effect in end-user heat-consumption behaviours. The methodological question of how, and to what extent, historical insights and lessons learnt may be translated across contexts is raised and discussed. Although sociotechnical trajectories may have granted the Danish energy system a head-start in the global race towards low-carbon energy transitions, perhaps the route was less direct than popularly portrayed. The Danish DH sector currently faces challenges of growing biomass import dependency, but also the potentials of sector coupling and energy flexibility. Energy efficiency and energy flexibility potential may be harvested via DH and district cooling solutions in future ‘smart’ energy systems globally. Hopefully, insights and lessons learnt from this brief history of Danish DH and CHPs prove informative elsewhere.
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Irfan, Muhammad Arief. "Evaluasi Tingkat Efisiensi Penggunaan Energi Kajian Ex Post Facto Penerapan Standar Green Building Gedung A ITSB." PLANNERS INSIGHT : URBAN AND REGIONAL PLANNING JOURNAL 2, no. 1 (May 20, 2019): 043–50. http://dx.doi.org/10.36870/insight.v2i1.29.
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In Indonesia, until 2016, there were only 11 building units that were successfully certified by green building by the Green Building Council Indonesia (GBCI). The eleven buildings are classified as new building and claimed to be 43% efficient. The issue of energy efficiency in buildings is increasingly becoming a real action. As the first campus in Indonesia to be certified green building with the title of gold, Building A Bandung Institute of Technology and Science (ITSB), located in Cikarang, is expected to be an environmentally friendly pilot building and also a building capable of achieving energy efficiency targets. The building, which began construction in 2009 and completed in 2011, is one of the new building categories that is very well used as an evaluation object. Since its operation in 2012, the ITSB building has never been the object of study regarding the level of efficiency in energy use. The research carried out using the energy audit method for the ITSB building shows that there are levels of energy efficiency, especially electricity use, in the period of 2013 to 2017. From this period data, studies of building performance can be carried out with energy efficiency opportunities in the future. future.
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Walther, Jessica, and Matthias Weigold. "A Systematic Review on Predicting and Forecasting the Electrical Energy Consumption in the Manufacturing Industry." Energies 14, no. 4 (February 12, 2021): 968. http://dx.doi.org/10.3390/en14040968.
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In the context of the European Green Deal, the manufacturing industry faces environmental challenges due to its high demand for electrical energy. Thus, measures for improving the energy efficiency or flexibility are applied to address this problem in the manufacturing industry. In order to quantify energy efficiency or flexibility potentials, it is often necessary to predict or forecast the energy consumption. This paper presents a systematic review of state-of-the-art of existing approaches to predict or forecast the energy consumption in the manufacturing industry. Seventy-two articles are classified according to the defined categories System Boundary, Modelling Technique, Modelling Focus, Modelling Horizon, Modelling Perspective, Modelling Purpose and Model Output. Based on the reviewed articles future research activities are derived.
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Fukata, Naoki, and Wipakorn Jevasuwan. "(Invited, Digital Presentation) Photovoltaic Applications Using Energy Transfer Characteristics from Quantum Dots." ECS Meeting Abstracts MA2022-02, no. 20 (October 9, 2022): 919. http://dx.doi.org/10.1149/ma2022-0220919mtgabs.
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Silicon-related materials are most commonly used in solar cells and become now an invaluable material. However, a reported maximum energy conversion efficiency of Si solar cell is close to reaching its theoretical limits. To further improve the cell performance and create new functions, it will become increasingly important to functionalize Si materials using nanostructures. One- and zero-dimensional Si nanostructures called Si nanowires (SiNWs) and Si quantum dots (Si QDs) are increasingly being used as new solar cell materials. Our group has shown that the conversion efficiency of solar cells can be increased by the non-radiation energy transfer (NRET) from Si QDs [1]. Recently, research has been developed on compound semiconductor QDs and perovskite QDs, and the conversion efficiency has been successfully increased [3-7]. n-type SiNW arrays were fabricated by electroless etching and Bosch & nanoimprint lithography followed by CVD process. The CVD process was performed to form p-type Si layer for pn homojunction. Hybrid heterojunction cells of PEDOT:PSS and n-SiNWs were also fabricated. Passivation by ozone and hydrogen were applied to improve the solar cell properties [2]. After the cell fabrications, the solar cells were coated with Si QDs, CdZnS/ZnS QDs, CdZnSe/ZnS QDs and perovskite QDs. The fabrication methods and conditions of QDs have been reported elsewhere [1-7] Energy transfer effects such as NRET are new ways of increasing solar cell efficiency. To effectively use the NRET effect, the surface of Si QDs should be fully passivated by ligand molecules. The NRET process is a highly distance-dependent phenomenon, and its dependence on the length of the passivation ligands clearly showed this. NRET efficiency was increased by shortening the ligand length from 1-octadecene to 1-octene, resulting in higher JSC, ultimately providing higher energy conversion efficiency. The efficiency was increased about 1-2 % by adding SiQDs. We also observed the same effect for CdZnS/ZnS QDs, CdZnSe/ZnS QDs and perovskite CsPbCl3 QDs. In these cases, in addition to the NRET effect, the radiative energy transfer (RET) effect also contributes to the increase in conversion efficiency. References: [1] M. Dutta et al, ACS Nano 2015, 9, 6891 (2015). [2] M. Dutta et al, Nano Energy 2015, 11, 219. [3] N. Fukata et al., Small 2017, 13, 1701713. [4] J. Chen et al., Nano Energy 2019, 56, 604. [5] M. F. Abdelbar et al., Nano Energy 2020, 77, 105163. [6] M. Abdelhameed et al., Nano Energy 2020, 82, 105728. [7] M. F. Abdelbar et al., Nano Energy 2021, 89, 106470.
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Xi, Qiao, Weifan Long, and Qingsong Ma. "Research of flat plate solar air collector in drying." E3S Web of Conferences 248 (2021): 02015. http://dx.doi.org/10.1051/e3sconf/202124802015.
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Solar drying technology has been widely used in engineering fields such us chemical drying because of its low cost and low pollution advantages. In this review, the structural forms, materials and coatings of the heat-absorbing panels of flat plate solar air collector are classified, and the experimental and theoretical results of the performance level of the solar air flat panel collector are summarized. In indoor tests, the energy efficiency of flat plate solar air collector is 30% to 79%, and the energy efficiency of flat plate solar air collector in drying applications is 28% to 62%.
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Halima Adetoro, Sylvia. "Liberalisation of the Energy Sector – Is It Reserved for Countries with Overcapacity?" European Energy and Environmental Law Review 18, Issue 3 (June 1, 2009): 185–90. http://dx.doi.org/10.54648/eelr2009014.
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It is the year 2009! The question of whether to or not to liberalise the energy industry would actually sound absurd in most fora. The usual query when raised is centred on the most effective form suited for a particular country. Liberalisation in its most basic form can be defined as the removal of monopoly rights and introduction of competition and choice. Experience has shown that efficiency in any system cannot be sustained in the absence of choice, hence the universal inclination towards it. In discussing liberalisation, countries are classified into two main groupings on the basis of their resource quotient or access to same; one group with overcapacity and the other with insufficient capacity. The emphasis of this paper is the electricity industry. This paper explores the possibility of countries with insufficient capacity having an opportunity to liberalise their energy markets and the options available to them. It argues that maximum benefits are derivable from the embrace of this world-wide trend and that liberalisation is a welcome option for economies at different levels of development. Finally, it concludes that liberalisation is not just about availability of capacity but should focus on efficiency capacity production and allocative efficiency.
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Ilomets, Simo, Dariusz Heim, Ivan Chodak, Dariusz Czarny, and Targo Kalamees. "A method to develop energy activated ETICS." E3S Web of Conferences 172 (2020): 21006. http://dx.doi.org/10.1051/e3sconf/202017221006.
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We propose a method for developing an Energy Activated External Thermal Insulation Composite System (En-ActivETICS) for smart building envelopes that guarantees the required performance, durability, and service life of the building. The En-ActivETICS combines the traditional ETICS with phase change material (PCM) and flexible photovoltaics (FPV). These combined materials will become multifunctional, playing the roles of thermal insulator, heat accumulator, and energy generator with PCM lowering the temperature of FPV and therefore, increasing their efficiency. The En-ActivETICS is a new step in the development of building facade technology enabling to achieve a component that is classified as a functional material. The main result reported in the paper is the proposed method, which improves the existing technical approval guidelines for ETICS, entitled ETAG 004, when thermally activated components are added to the system. The method proposes research activities necessary to determine whether the novel wall system is in line with the essential requirements set to a building by the Construction Products Regulation. When tested according to the proposed method, a wall system should be comprehensively tested and technically documented active thermal insulation system that is aimed to give better building performance in terms of indoor environment, energy efficiency, and aesthetics.
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Estevao, Joao. "An Analysis of the Impact of the 2030 Agreement on R&D Intensity in the Energy Sector." International Journal of Energy Economics and Policy 12, no. 4 (July 19, 2022): 204–16. http://dx.doi.org/10.32479/ijeep.13219.
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European Union countries signed the 2030 Climate and Energy Framework Agreement on October 24, 2014. This framework brings with it changes in the expectations of energy consumers and producers that has opened new avenues of research. Because the 2030 Agreement imposed targets to be achieved by 2030, energy companies could increase their R&D expenditures as they search for increased efficiency through a reduction of carbon dioxide emissions and stronger base in renewable sources that promotes innovation. In addition, the risks that arise from climate change can compromise the successful achievement of the targets, such as 27% renewable energy consumption, reduction in emissions of carbon dioxide by at least 40% and to improve energy efficiency. In this study, I conduct an evaluation of the behavior of R&D intensity in this sector. It analyze the behavior of companies related to the electricity sector in two different moments, before and after the 2030 Agreement, by using panel data and comparing the listed companies with headquarters in European Union countries with companies headquartered elsewhere in Europe. The results show that the 2030 Agreement had no effect on R&D intensity in companies in the electricity sector in the countries of the European Union.
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Ulu, Meltem, and Zeynep Durmuş Arsan. "Retrofit Strategies for Energy Efficiency of Historic Urban Fabric in Mediterranean Climate." Atmosphere 11, no. 7 (July 13, 2020): 742. http://dx.doi.org/10.3390/atmos11070742.
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Energy-efficient retrofitting of historic housing stock requires methodical approach, in-depth analysis and case-specific regulatory system, yet only limited efforts have been realized. In large scale rehabilitation projects, it is essential to develop a retrofit strategy on how to decide energy-efficient solutions for buildings providing the most energy saving in a short time. This paper presents a pilot study conducted at a neighborhood scale, consisting of 22 pre-, early-republican and contemporary residential buildings in a historic urban fabric in the Mediterranean climate. This study aims to develop an integrated approach to describe case-specific solutions for larger scale historic urban fabric. It covers the building performance simulation (BPS) model and numerical analysis to determine the most related design parameters affecting annual energy consumption. All the case buildings were classified into three main groups to propose appropriate retrofit solutions in different impact categories. Retrofit solutions were gathered into two retrofit packages, Package 1 and 2, and separately, three individual operational solutions were determined, considering a five-levelled assessment criteria of EN 16883:2017 Standard. Energy classes of case buildings were calculated based on National Building Energy Regulations. Changes in building classes were evaluated considering pre- and post-retrofit status of the buildings. For the integrated approach, the most related design parameters on annual energy consumption were specified through Pearson correlation analysis. The approach indicated that three buildings, representing each building group, can initially be retrofitted. For all buildings, while maximum energy saving was provided by Package 2 with 48.57%, minimum energy saving was obtained from Package 1 with 19.8%.
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Kelagadi, Hemantaraj M., and Priyatam Kumar. "Distributed Topology Control Techniques for Wireless Sensor Networks: An Overview." International Journal of Advanced Research in Computer Science and Software Engineering 7, no. 7 (October 2, 2017): 425. http://dx.doi.org/10.23956/ijarcsse/v7i7/0225.
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The recent technological innovations and development like the Internet of Things (IoT), Smart Grids and Smart Environment applications tend to enhance the scalability, self-organizing capability of the mesh networks as well as the wireless sensor networks. As the wireless sensor network have limited energy resources, there is a need of utilizing these limitations in an efficient way in order to accomplish such advanced energy efficiency and better lifetime can be taken care by the operation of topology control methods. In this survey the issue of energy efficiency is formed upon and a comprehensive study of topology control technologies that can be used for enhancement of battery lifetime in WSNs is presented. An insight of how energy efficiency can be achieved by design is provided by review of the significant topology control algorithms based on the energy conservation approach adopted, those algorithms are classified further and evaluated on the basis of communication so as to aid the designer to select best suitable techniques for their applications. A number of open research issues for achieving the energy efficiency by means of controlling topology are identified based on the survey conducted.
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Ackshaya Varshini, K. S., Alenkar K. Aswin, H. Rajan, and K. S. Maanav Charan. "Concept design and numerical analysis of hybrid solar–wind turbine." IOP Conference Series: Earth and Environmental Science 850, no. 1 (November 1, 2021): 012032. http://dx.doi.org/10.1088/1755-1315/850/1/012032.
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Abstract A wind turbine is a device that converts wind energy to electrical energy. External factors such as wind speed and direction shift, as well as turbine blade design considerations, cause a significant amount of energy to be wasted throughout the conversion process. Considering all these losses, a turbine’s average efficiency is roughly 45 percent. The blades of a wind turbine are one of the most crucial factors in determining the turbine’s efficiency. The design and geometry of the blades have a direct impact on performance since it determines how much kinetic energy from the wind is converted into mechanical energy. Many concepts and technologies are being used to improve the efficiency of wind turbines while lowering their maintenance costs. Wind turbines based on their axis orientation are classified as vertical axis and horizontal axis. Vertical axis wind turbines are not as widespread as their horizontal-axis counterparts due to their lower efficiency. In this study, we will use a Savonius vertical axis wind turbine to investigate a way of enhancing its efficiency by installing solar panels on its vertical blades and determining the best performance angle at which the turbine should be kept achieving maximum efficiency. Computation fluid dynamic analysis and thermal and structural analysis has been performed to check the efficiency of the designed blade. As a result, an optimized wind turbine design has been developed.
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Noor-ul-huda, Muhammad, Samabia Tehsin, Sairam Ahmed, Fuad A. K. Niazi, and Zeerish Murtaza. "Retinal images benchmark for the detection of diabetic retinopathy and clinically significant macular edema (CSME)." Biomedical Engineering / Biomedizinische Technik 64, no. 3 (May 27, 2019): 297–307. http://dx.doi.org/10.1515/bmt-2018-0098.
Full textAbstract:
Abstract Diabetes mellitus is an enduring disease related with significant morbidity and mortality. The main pathogenesis behind this disease is its numerous micro- and macrovascular complications. In developing countries, diabetic retinopathy (DR) is one of the major sources of vision impairment in working age population. DR has been classified into two categories: proliferative diabetic retinopathy (PDR) and non-proliferative diabetic retinopathy (NPDR). NPDR is further classified into mild, moderate and severe, while PDR is further classified into early PDR, high risk PDR and advanced diabetic eye disease. DR is a disease caused due to high blood glucose levels which result in vision loss or permanent blindness. High-level advancements in the field of bio-medical image processing have speeded up the automated process of disease diagnoses and analysis. Much research has been conducted and computerized systems have been designed to detect and analyze retinal diseases through image processing. Similarly, a number of algorithms have been designed to detect and grade DR by analyzing different symptoms including microaneurysms, soft exudates, hard exudates, cotton wool spots, fibrotic bands, neovascularization on disc (NVD), neovascularization elsewhere (NVE), hemorrhages and tractional bands. The visual examination of the retina is a vital test to diagnose DR-related complications. However, all the DR computer-aided diagnostic systems require a standard dataset for the estimation of their efficiency, performance and accuracy. This research presents a benchmark for the evaluation of computer-based DR diagnostic systems. The existing DR benchmarks are small in size and do not cover all the DR stages and categories. The dataset contains 1445 high-quality fundus photographs of retinal images, acquired over 2 years from the records of the patients who presented to the Department of Ophthalmology, Holy Family Hospital, Rawalpindi. This benchmark provides an evaluation platform for medical image analysis researchers. Furthermore, it provides evaluation data for all the stages of DR.