Optimum autonomous stand-alone photovoltaic system design on the basis of energy pay-back analysis

International Nuclear Information System (INIS)

Kaldellis, J.K.; Zafirakis, D.; Kondili, E.

2009-01-01

Stand-alone photovoltaic (PV) systems comprise one of the most promising electrification solutions for covering the demand of remote consumers. However, such systems are strongly questioned due to extreme life-cycle (LC) energy requirements. For similar installations to be considered as environmentally sustainable, their LC energy content must be compensated by the respective useful energy production, i.e. their energy pay-back period (EPBP) should be found less than their service period. In this context, an optimum sizing methodology is currently developed, based on the criterion of minimum embodied energy. Various energy autonomous stand-alone PV-lead-acid battery systems are examined and two different cases are investigated; a high solar potential area and a medium solar potential area. By considering that the PV-battery (PV-Bat) system's useful energy production is equal to the remote consumer's electricity consumption, optimum cadmium telluride (CdTe) based systems yield the minimum EPBP (15 years). If achieving to exploit the net PV energy production however, the EPBP is found less than 20 years for all PV types. Finally, the most interesting finding concerns the fact that in all cases examined the contribution of the battery component exceeds 27% of the system LC energy requirements, reflecting the difference between grid-connected and stand-alone configurations.

Energy Payback Time Calculation for a Building Integrated Semitransparent Thermal (BISPVT) System with Air Duct

OpenAIRE

Kanchan Mudgil; Deepali Kamthania

2013-01-01

This paper evaluates the energy payback time (EPBT) of building integrated photovoltaic thermal (BISPVT) system for Srinagar, India. Three different photovoltaic (PV) modules namely mono crystalline silicon (m-Si), poly crystalline silicon (p-Si), and amorphous silicon (a-Si) have been considered for calculation of EPBT. It is found that, the EPBT is lowest in m-Si. Hence, integration of m-Si PV modules on the roof of a room is economical.

A systematic evaluation of payback of publicly funded health and health services research in Hong Kong

Directory of Open Access Journals (Sweden)

Chong Doris SY

2007-07-01

Full Text Available Abstract Background The Health and Health Services Research Fund (HHSRF is dedicated to support research related to all aspects of health and health services in Hong Kong. We evaluated the fund's outcomes and explored factors associated with the translation of research findings to changes in health policy and provider behaviour. Methods A locally suitable questionnaire was developed based on the "payback" evaluation framework and was sent to principal investigators of the completed research projects supported by the fund since 1993. Research "payback" in six outcome areas was surveyed, namely knowledge production, use of research in the research system, use of research project findings in health system policy/decision making, application of the research findings through changed behaviour, factors influencing the utilization of research, and health/health service/economic benefits. Results Principal investigators of 178 of 205 (87% completed research projects returned the questionnaire. Investigators reported research publications in 86.5% (mean = 5.4 publications per project, career advancement 34.3%, acquisition of higher qualifications 38.2%, use of results in policy making 35.4%, changed behaviour in light of findings 49.4%, evidence of health service benefit 42.1% and generated subsequent research in 44.9% of the projects. Payback outcomes were positively associated with the amount of funding awarded. Multivariate analysis found participation of investigators in policy committees and liaison with potential users were significantly associated with reported health service benefit (odds ratio [OR]participation = 2.86, 95% confidence interval [CI] 1.28–6.40; ORliaison = 2.03, 95% CI 1.05–3.91, policy and decision-making (ORparticipation = 10.53, 95% CI 4.13–26.81; ORliaison = 2.52, 95% CI 1.20–5.28, and change in behavior (ORparticipation = 3.67, 95% CI 1.53–8.81. Conclusion The HHSRF has produced substantial outcomes and compared

Payback time for soil carbon and sugar-cane ethanol

Science.gov (United States)

Mello, Francisco F. C.; Cerri, Carlos E. P.; Davies, Christian A.; Holbrook, N. Michele; Paustian, Keith; Maia, Stoécio M. F.; Galdos, Marcelo V.; Bernoux, Martial; Cerri, Carlos C.

2014-07-01

The effects of land-use change (LUC) on soil carbon (C) balance has to be taken into account in calculating the CO2 savings attributed to bioenergy crops. There have been few direct field measurements that quantify the effects of LUC on soil C for the most common land-use transitions into sugar cane in Brazil, the world's largest producer . We quantified the C balance for LUC as a net loss (carbon debt) or net gain (carbon credit) in soil C for sugar-cane expansion in Brazil. We sampled 135 field sites to 1 m depth, representing three major LUC scenarios. Our results demonstrate that soil C stocks decrease following LUC from native vegetation and pastures, and increase where cropland is converted to sugar cane. The payback time for the soil C debt was eight years for native vegetation and two to three years for pastures. With an increasing need for biofuels and the potential for Brazil to help meet global demand, our results will be invaluable for guiding expansion policies of sugar-cane production towards greater sustainability.

Carbon Debt Payback Time for a Biomass Fired CHP Plant—A Case Study from Northern Europe

Directory of Open Access Journals (Sweden)

Kristian Madsen

2018-03-01

Full Text Available The European Union (EU has experienced a large increase in the use of biomass for energy in the last decades. In 2015, biomass used to generate electricity, heat, and to a limited extent, liquid fuels accounted for 51% of the EU’s renewable energy production. Bioenergy use is expected to grow substantially to meet energy and climate targets for 2020 and beyond. This development has resulted in analyses suggesting the increased use of biomass for energy might initially lead to increased greenhouse gas (GHG emissions to the atmosphere, a so-called carbon debt. Here, we analyze carbon debt and payback time of substituting coal with forest residues for combined heat and power generation (CHP. The analysis is, in contrast to most other studies, based on empirical data from a retrofit of a CHP plant in northern Europe. The results corroborate findings of a carbon debt, here 4.4 kg CO2eq GJ−1. The carbon debt has a payback time of one year after conversion, and furthermore, the results show that GHG emissions are reduced to 50% relative to continued coal combustion after about 12 years. The findings support the use of residue biomass for energy as an effective means for climate change mitigation.

Techno-economic optimization for the design of solar chimney power plants

International Nuclear Information System (INIS)

Ali, Babkir

2017-01-01

Highlights: • Chimney height and collector area of different designs were optimized. • Simple actual and minimum payback periods were developed. • Comparative assessment was conducted for different designs configuration. • Effects of uncertain parameters on the payback period were studied. - Abstract: This paper aims to propose a methodology for optimization of solar chimney power plants taking into account the techno-economic parameters. The indicator used for optimization is the comparison between the actual achieved simple payback period for the design and the minimum possible (optimum) simple payback period as a reference. An optimization model was executed for different twelve designs in the range 5–200 MW to cover reinforced concrete chimney, sloped collector, and floating chimney. The height of the chimney was optimized and the associated collector area was calculated accordingly. Relationships between payback periods, electricity price, and the peak power capacity of each power plant were developed. The resulted payback periods for the floating chimney power plants were the shortest compared to the other studied designs. For a solar chimney power plant with 100 MW at electricity price 0.10 USD/kWh, the simple payback period for the reference case was 4.29 years for floating chimney design compared to 23.47 and 16.88 years for reinforced concrete chimney and sloped collector design, respectively. After design optimization for 100 MW power plant of each of reinforced concrete, sloped collector, and floating chimney, a save of 19.63, 2.22, and 2.24 million USD, respectively from the initial cost of the reference case is achieved. Sensitivity analysis was conducted in this study to evaluate the impacts of varied running cost, solar radiation, and electricity price on the payback periods of solar chimney power plant. Floating chimney design is still performing after applying the highest ratio of annual running cost to the annual revenue. The

Output Performance and Payback Analysis of a Residential Photovoltaic System in Colorado: Preprint

Energy Technology Data Exchange (ETDEWEB)

Johnston, S.

2012-06-01

Cost of installation and ownership of a 9.66-kilowatt (kW) residential photovoltaic system is described, and the performance of this system over the past 3 years is shown. The system is located in Colorado at 40 degrees latitude and consists of arrays on two structures. Two arrays are installed on a detached garage, and these are each composed of 18 Kyocera 130-W modules strung in series facing south at an angle of 40 degrees above horizontal. Each 18-panel array feeds into a Xantrex/Schneider Electric 2.8-kW inverter. The other two arrays are installed on the house and face south at an angle of 30 degrees. One of these arrays has twelve 205-W Kyocera panels in series, and the other is made up of twelve 210-Kyocera panels. Each of these arrays feeds into Xantrex/Schneider Electric 3.3-kW inverters. Although there are various shading issues from trees and utility poles and lines, the overall output resembles that which is expected from PVWatts, a solar estimate program. The array cost, which was offset by rebates from the utility company and federal tax credits, was $1.17 per watt. Considering measured system performance, the estimated payback time of the system is 9 years.

Energy Payback Time of a Solar Photovoltaic Powered Waste Plastic Recyclebot System

Directory of Open Access Journals (Sweden)

Shan Zhong

2017-06-01

Full Text Available The growth of both plastic consumption and prosumer 3-D printing are driving an interest in producing 3-D printer filaments from waste plastic. This study quantifies the embodied energy of a vertical DC solar photovoltaic (PV powered recyclebot based on life cycle energy analysis and compares it to horizontal AC recyclebots, conventional recycling, and the production of a virgin 3-D printer filament. The energy payback time (EPBT is calculated using the embodied energy of the materials making up the recyclebot itself and is found to be about five days for the extrusion of a poly lactic acid (PLA filament or 2.5 days for the extrusion of an acrylonitrile butadiene styrene (ABS filament. A mono-crystalline silicon solar PV system is about 2.6 years alone. However, this can be reduced by over 96% if the solar PV system powers the recyclebot to produce a PLA filament from waste plastic (EPBT is only 0.10 year or about a month. Likewise, if an ABS filament is produced from a recyclebot powered by the solar PV system, the energy saved is 90.6–99.9 MJ/kg and 26.33–29.43 kg of the ABS filament needs to be produced in about half a month for the system to pay for itself. The results clearly show that the solar PV system powered recyclebot is already an excellent way to save energy for sustainable development.

An economic optimization of evaporator and air collector area in a solar assisted heat pump drying system

International Nuclear Information System (INIS)

Rahman, S.M.A.; Saidur, R.; Hawlader, M.N.A.

2013-01-01

Highlights: • The optimum combination will provide around 89% of the total load. • The system has a savings during the life cycle with least payback period of 4.37 year. • The optimal system is insensitive to the variation in fuel inflation and discount rate. - Abstract: This paper presents an economic optimization of evaporator and air collector area of a solar assisted heat pump drying system. Economic viability of solar heating systems is usually made by comparing the cost flows recurring throughout the lifetime of the solar and conventional alternative systems. Therefore, identification of optimum variables by using a simulation program and an economic analysis based on payback period of the system are presented in this paper. FORTRAN language is used to run the simulation. Effect of load and different economic variables on payback period is also investigated. Economic analysis reveals that system has sufficient amount of savings during the life cycle with a minimum payback period of about 4 years

76 FR 56413 - Building Energy Codes Cost Analysis

Science.gov (United States)

2011-09-13

... intends to calculate three metrics. Life-cycle cost. Simple payback period. Cash flow. Life-cycle cost... exceed costs) will be considered cost effective. The payback period and cash flow analyses provide... of LCC analysis is the summing of costs and benefits over multiple years, it requires that cash flows...

Survey evidence on the willingness of U.S. consumers to pay for automotive fuel economy

International Nuclear Information System (INIS)

Greene, David L.; Evans, David H.; Hiestand, John

2013-01-01

Prospect theory holds that human beings faced with a risky bet will tend to value potential losses about twice as much as potential gains. Previous research has demonstrated that prospect theory could be sufficient to explain an energy paradox in the market for automotive fuel economy. This paper analyzes data from questions added to four commercial, multi-client surveys of 1000 U.S. households each in 2004, 2011, 2012 and 2013. Households were asked about willingness to pay for future fuel savings as well as the annual fuel savings necessary to justify a given upfront payment. Payback periods inferred from household responses are generally consistent over time and across different formulations of questions. Mean calculated payback periods are about 3 years, but there is substantial dispersion among individual responses. The calculated payback periods do not appear to be correlated with the attributes of respondents. Respondents were able to quantitatively describe their uncertainty about both vehicle fuel economy and future fuel prices. Simulation of loss averse behavior based on respondents’ stated uncertainty illustrates how loss aversion could lead consumers to substantially undervalue future fuel savings relative to their expected value. - Highlights: • Payback periods were calculated from stated willingness to pay for fuel savings in 4 US surveys. • US car buyers expect payback in 3 years in order to pay more for increased fuel economy. • Respondents’ payback periods are uncorrelated with their socio-economic attributes. • Survey respondents consider fuel economy ratings and future fuel prices highly uncertain. • The survey results are consistent with the behavioral economic principle of loss aversion

Multi-Objective Optimization of Building Energy Design to Reconcile Collective and Private Perspectives: CO2-eq vs. Discounted Payback Time

Directory of Open Access Journals (Sweden)

Mohamed Hamdy

2017-07-01

Full Text Available Building energy design is a multi-objective optimization problem where collective and private perspectives conflict each other. For instance, whereas the collectivity pursues the minimization of environmental impact, the private pursues the maximization of financial viability. Solving such trade-off design problems usually involves a big computational cost for exploring a huge solution domain including a large number of design options. To reduce that computational cost, a bi-objective simulation-based optimization algorithm, developed in a previous study, is applied in the present investigation. The algorithm is implemented for minimizing the CO2-eq emissions and the discounted payback time (DPB of a single-family house in cold climate, where 13,456 design solutions including building envelope and heating system options are explored and compared to a predefined reference case. The whole building life is considered by assuming a calculation period of 30 years. The results show that the type of heating system significantly affects energy performance; notably, the ground source heat pump leads to the highest reduction in CO2-eq emissions, around 1300 kgCO2-eq/m2, with 17 year DPB; the oil fire boiler can provide the lowest DPB, equal to 8.5 years, with 850 kgCO2-eq/m2 reduction. In addition, it is shown that using too high levels of thermal insulation is not an effective solution as it causes unacceptable levels of summertime overheating. Finally a multi-objective decision making approach is proposed in order to enable the stakeholders to choice among the optimal solutions according to the weight given to each objective, and thus to each perspective.

Birth to death analysis of the energy payback ratio and CO2 gas emission rates from coal, fission, wind, and DT-fusion electrical power plants

International Nuclear Information System (INIS)

White, Scott W.; Kulcinski, Gerald L.

2000-01-01

The amount of electrical energy produced over the lifetime of coal, LWR fission, UP fusion, and wind power plants is compared to the total amount of energy required to procure the fuel, build, operate, and decommission the power plants. The energy payback ratio varies from a low of 11 for coal plants to a high of 27 for DT-fusion plants. The magnitude of the energy investment and the source of the various energy inputs determine the CO 2 emission factor. This number varies from a low of 9 to a high of 974 tonnes of CO 2 per GW e h for DT-fusion and coal plants, respectively

Net Energy Payback and CO2 Emissions from Three Midwestern Wind Farms: An Update

International Nuclear Information System (INIS)

White, Scott W.

2006-01-01

This paper updates a life-cycle net energy analysis and carbon dioxide emissions analysis of three Midwestern utility-scale wind systems. Both the Energy Payback Ratio (EPR) and CO 2 analysis results provide useful data for policy discussions regarding an efficient and low-carbon energy mix. The EPR is the amount of electrical energy produced for the lifetime of the power plant divided by the total amount of energy required to procure and transport the materials, build, operate, and decommission the power plants. The CO 2 analysis for each power plant was calculated from the life-cycle energy input data.A previous study also analyzed coal and nuclear fission power plants. At the time of that study, two of the three wind systems had less than a full year of generation data to project the life-cycle energy production. This study updates the analysis of three wind systems with an additional four to eight years of operating data.The EPR for the utility-scale wind systems ranges from a low of 11 for a two-turbine system in Wisconsin to 28 for a 143-turbine system in southwestern Minnesota. The EPR is 11 for coal, 25 for fission with gas centrifuge enriched uranium and 7 for gaseous diffusion enriched uranium. The normalized CO 2 emissions, in tonnes of CO 2 per GW e h, ranges from 14 to 33 for the wind systems, 974 for coal, and 10 and 34 for nuclear fission using gas centrifuge and gaseous diffusion enriched uranium, respectively

Net energy payback and CO2 emissions from three midwestern wind farms: An update

Science.gov (United States)

White, S.W.

2006-01-01

This paper updates a life-cycle net energy analysis and carbon dioxide emissions analysis of three Midwestern utility-scale wind systems. Both the Energy Payback Ratio (EPR) and CO2 analysis results provide useful data for policy discussions regarding an efficient and low-carbon energy mix. The EPR is the amount of electrical energy produced for the lifetime of the power plant divided by the total amount of energy required to procure and transport the materials, build, operate, and decommission the power plants. The CO2 analysis for each power plant was calculated from the life-cycle energy input data. A previous study also analyzed coal and nuclear fission power plants. At the time of that study, two of the three wind systems had less than a full year of generation data to project the life-cycle energy production. This study updates the analysis of three wind systems with an additional four to eight years of operating data. The EPR for the utility-scale wind systems ranges from a low of 11 for a two-turbine system in Wisconsin to 28 for a 143-turbine system in southwestern Minnesota. The EPR is 11 for coal, 25 for fission with gas centrifuge enriched uranium and 7 for gaseous diffusion enriched uranium. The normalized CO2 emissions, in tonnes of CO2 per GW eh, ranges from 14 to 33 for the wind systems, 974 for coal, and 10 and 34 for nuclear fission using gas centrifuge and gaseous diffusion enriched uranium, respectively. ?? Springer Science+Business Media, LLC 2007.

Payback Period for Emissions Abatement Alternatives: Role of Regulation and Fuel Prices

DEFF Research Database (Denmark)

Zis, Thalis; Angeloudis, Panagiotis; Bell, Michael G. H.

2016-01-01

As of January 2015, the new maximum limit of fuel sulfur content for ships sailing within emission control areas has been reduced to 0.1%. A critical decision for ship owners in advance of the new limits was the selection of an abatement method that complies with the regulations. Two main options...... exist: investing in scrubber systems that remove sulfur dioxide emissions from the exhaust and switching to low-sulfur fuel when sailing in regulated waters. The first option would involve significant capital costs, while the latter would lead to operating cost increases because of the higher price...

Uncertainty and sensitivity analyses of ballast life-cycle cost and payback period

Energy Technology Data Exchange (ETDEWEB)

McMahon, James E.; Liu, Xiaomin; Turiel, Ike; Hakim, Sajid; Fisher, Diane

2000-06-01

The paper introduces an innovative methodology for evaluating the relative significance of energy-efficient technologies applied to fluorescent lamp ballasts. The method involves replacing the point estimates of life cycle cost of the ballasts with uncertainty distributions reflecting the whole spectrum of possible costs, and the assessed probability associated with each value. The results of uncertainty and sensitivity analyses will help analysts reduce effort in data collection and carry on analysis more efficiently. These methods also enable policy makers to gain an insightful understanding of which efficient technology alternatives benefit or cost what fraction of consumers, given the explicit assumptions of the analysis.

Uncertainty and sensitivity analyses of ballast life-cycle cost and payback period

OpenAIRE

Mcmahon, James E.

2000-01-01

The paper introduces an innovative methology for evaluating the relative significance of energy-efficient technologies applied to fluorescent lamp ballasts. The method involves replacing the point estimates of life cycle cost of the ballasts with uncertainty distributions reflecting the whole spectrum of possible costs, and the assessed probability associated with each value. The results of uncertainty and sensitivity analyses will help analysts reduce effort in data collection and carry on a...

Energetic and Economic Assessment of Pipe Network Effects on Unused Energy Source System Performance in Large-Scale Horticulture Facilities

Directory of Open Access Journals (Sweden)

Jae Ho Lee

2015-04-01

Full Text Available As the use of fossil fuel has increased, not only in construction, but also in agriculture due to the drastic industrial development in recent times, the problems of heating costs and global warming are getting worse. Therefore, the introduction of more reliable and environmentally-friendly alternative energy sources has become urgent and the same trend is found in large-scale horticulture facilities. In this study, among many alternative energy sources, we investigated the reserves and the potential of various different unused energy sources which have infinite potential, but are nowadays wasted due to limitations in their utilization. This study investigated the effects of the distance between the greenhouse and the actual heat source by taking into account the heat transfer taking place inside the pipe network. This study considered CO2 emissions and economic aspects to determine the optimal heat source. Payback period analysis against initial investment cost shows that a heat pump based on a power plant’s waste heat has the shortest payback period of 7.69 years at a distance of 0 km. On the other hand, the payback period of a heat pump based on geothermal heat showed the shortest payback period of 10.17 year at the distance of 5 km, indicating that heat pumps utilizing geothermal heat were the most effective model if the heat transfer inside the pipe network between the greenhouse and the actual heat source is taken into account.

Economic analysis of the daylight-linked lighting control system in office buildings

Energy Technology Data Exchange (ETDEWEB)

Yang, In-Ho; Nam, Eun-Ji [Department of Architectural Engineering, College of Engineering, Dongguk University, 26-3, Pil-dong, Chung-gu, Seoul 100-715 (Korea)

2010-08-15

The objective of this study is to perform an economic analysis of the daylight-linked automatic on/off lighting control system installed for the purpose of energy savings in office buildings. For this, a building was chosen as a typical example, and the energy cost was calculated by using the daylight and building energy analysis simulation. When the lighting control was utilized, an economic analysis was performed using a payback period that was calculated by comparing the initial cost of installing the lighting control system with the annual energy cost which was reduced thanks to the application of the lighting control. The results showed that the lighting energy consumption, when the lighting control was applied, was reduced by an average of 30.5% compared with the case that there was not lighting control applied. Also, the result for total energy consumption showed that, when lighting control was applied, this was reduced by 8.5% when the glazing ratio was 100%, 8.2% for 80%, and 7.6% for 60% when compared to non-application. The payback period was analyzed in terms of the number of floors in a building; 10 floors, 20 floors, 30 floors, and 40 floors. Hence, the building with 40 floors and glazing ratio 100% resulted in the shortest payback period of 8.8 years, the building with 10 floors and glazing ratio 60% resulted in the longest period of 12.7 years. In other words, the larger the glazing ratio and the number of building floors are, the shorter the payback period is. (author)

Evaluation and comparison of return of investment for proposed use of solar systems in the Czech and Slovak Republic

Directory of Open Access Journals (Sweden)

E. Weiss

2012-07-01

Full Text Available The aim of the paper is to evaluate return of investment (ROI and cost savings from proposed use of solar systems for residents funded by government grants. The paper deals with proposals for solar energy systems for various use, simple calculations of payback periods of solar systems financed with subsidy and without subsidy. Apart from climatic conditions, chemical composition the of the absorber and structural elements that are made of copper, respectively aluminum and Al-Mg alloy play an important role in assessing the payback period of the investment in solar panels.

The Economic Pre-feasibility Study of Madura Nuclear Desalination System

International Nuclear Information System (INIS)

Djoko-Birmanto, Moch; Suparman

2004-01-01

The feasibility study is needed in the planning of construction of NPPs SMART type coupled with desalination technology of MED tpe to produce clean water in Madura island. One important part of the feasibility study is the economical and financial analysis. The feasibility criteria of nuclear desalination project is analyzed by using the general parameters that is commonly used in evaluating a project, which is Financial Net Present Value (FNPV), Financial Internal Rate of Return (FIRR) and Payback Period. The calculation result shows that with the electricity selling price of 54.17 mills/KWh, for entirely project funded by the foreign loan, local loan and equity, it could be obtained FIRR 12.73 %, FNPV US$ 75.29 million and Payback Period is 8 years. By seeing from the project feasibility criteria, this nuclear desalination project can be feasible and the investment aspect shows that this project is beneficial because the capital return rate is rather high, the benefit in the end of the economic life-time is rather big and the capital payback period is fast. (author)

Life cycle assessment and evaluation of energy payback time on high-concentration photovoltaic power generation system

International Nuclear Information System (INIS)

Nishimura, A.; Hayashi, Y.; Tanaka, K.; Hirota, M.; Kato, S.; Ito, M.; Araki, K.; Hu, E.J.

2010-01-01

In this study, the environmental load of photovoltaic power generation system (PV) during its life cycle and energy payback time (EPT) are evaluated by LCA scheme. Two hypothetical case studies in Toyohashi, Japan and Gobi dessert in China have been carried out to investigate the influence of installation location and PV type on environmental load and EPT. The environmental load and EPT of a high-concentration photovoltaic power generation system (hcpV) and a multi-crystalline silicon photovoltaic power generation system (mc-Si PV) are studied. The study shows for a PV of 100 MW size, the total impacts of the hcpV installed in Toyohashi is larger than that of the hcpV installed in Gobi desert by 5% without consideration of recycling stage. The EPT of the hcpV assumed to be installed in Gobi desert is shorter than EPT of the hcpV assumed to be installed in Toyohashi by 0.64 year. From these results, the superiority to install PV in Gobi desert is certificated. Comparing with hcpV and mc-Si PV, the ratio of the total impacts of mc-Si PV to that of hcpV is 0.34 without consideration of recycling stage. The EPT of hcpV is longer than EPT of mc-Si PV by 0.27 year. The amount of global solar radiation contributing to the amount of power generation of mc-Si PV is larger than the amount of direct solar radiation contributing to the amount of power generation of hcpV by about 188 kW h/(m 2 year) in Gobi desert. Consequently, it appears that using mc-Si PV in Gobi desert is the best option.

The economic and financing viability of the OPR-1000 construction at Muria Peninsula

International Nuclear Information System (INIS)

Moch Djoko Birmano; Mochamad Nasrullah

2005-01-01

The study of the economic and financing viability of the OPR-1000 construction at Muria Peninsula have been done. This study is carried out with steps as follows: updating of newest OPR-1000 technical and economic data; survey of financing sources; the calculation of electricity generation cost, electricity tariff, construction cost of OPR-1000; and calculation of OPR-1000 financing viability by using feasibility criteria such as Net Present Value (NPV), Internal Rate of Return (IRR) and capital payback period. The calculation of generation cost, electricity tariff, construction cost and financing viability criteria (IRR, NPV, Payback Period)by using KEPCO Spread Sheet. From the results of calculations how that the electricity generation cost is 4.0866 cent/kWh, while the electricity tariff is 6.6399 cent/kWh(after Value Added Tax). The total construction cost of OPR-1000 is US $4,092.09 million (included interest and financial fee, excluded initial nuclear fuel). The calculation of financing viability in base case obtained that value of IRR, NPV and Payback Period for total investment is 10.37%. US$90.52 million and 12.11 years respectively. From these results can be concluded that with the electricity tariff of 6.640 cent/kWh or 0.0664 US$/kWh, basically this project of OPR-1000 construction is very feasible and beneficial. From investment side, this project can attract investor because the rate of capital return is high enough, profit in the end of economic life is big enough and payback period is short. (author)

Technical and economical assessment of the utilization of photovoltaic systems in residential buildings: The case of Jordan

International Nuclear Information System (INIS)

Al-Salaymeh, A.; Al-Hamamre, Z.; Sharaf, F.; Abdelkader, M.R.

2010-01-01

This paper studies the feasibility of utilizing photovoltaic systems in a standard residential apartment in Amman city in Jordan. Data on solar radiation, sunshine duration and the ambient temperature has been recorded in Amman city. An apartment in Amman was chosen as a case study to conduct energy and economic calculations. The electrical power needs and cost were calculated for the apartment. The component design and cost of PV system required to supply required energy was calculated and the payback period for the suggested stand-alone PV system in this paper was estimated in a constant inflation rate in electricity price similar to that of interest rate. The calculated payback period was high in a stand-alone system, to decrease payback period a grid-connected PV system is suggested. Considering an annual increase of 3% in electricity price, 15% of payback period was decreased in a stand-alone PV system and 21% in a grid-connected PV system. The output results of this study show that installation of PV system in a residential flat in Jordan may not be economically rewarding owing to the high cost of PV system compared to the cost of grid electricity. A feed-in tariff law of solar electricity may help to reduce PV system cost like the case of Germany. Additional conclusions are PV systems may be economically rewarding in Jordan if applied in locations far from electrical grid or in remote large scale PV power installations to overcome economical limitations of PV technology.

DESIGN AND DEVELOPMENT OF A LARGE SIZE NON-TRACKING SOLAR COOKER

Directory of Open Access Journals (Sweden)

N. M. NAHAR

2009-09-01

Full Text Available A large size novel non-tracking solar cooker has been designed, developed and tested. The cooker has been designed in such a way that the width to length ratio for reflector and glass window is about 4 so that maximum radiation falls on the glass window. This has helped in eliminating azimuthal tracking that is required in simple hot box solar cooker towards the Sun every hour because the width to length ratio of reflector is 1. It has been found that stagnation temperatures were 118.5oC and 108oC in large size non-tracking solar cooker and hot box solar cooker respectively. It takes about 2 h for soft food and 3 h for hard food. The cooker is capable of cooking 4.0 kg of food at a time. The efficiency of the large size non-tracking solar cooker has been found to be 27.5%. The cooker saves 5175 MJ of energy per year. The cost of the cooker is Rs. 10000.00 (1.0 US$ = Rs. 50.50. The payback period has been calculated by considering 10% annual interest, 5% maintenance cost and 5% inflation in fuel prices and maintenance cost. The payback period is least, i.e. 1.58 yr., with respect to electricity and maximum, i.e. 4.89 yr., with respect to kerosene. The payback periods are in increasing order with respect to fuel: electricity, coal, firewood, liquid petroleum gas, and kerosene. The shorter payback periods suggests that the use of large size non-tracking solar cooker is economical.

Power balance provision through co-ordinated control of modern storage heater load

OpenAIRE

Qazi, Hassan Wajahat; Flynn, Damian

2013-01-01

Operational inflexibility due to wind variability at high penetration levels can be mitigated through flexible demand. However, most flexible loads entail a subsequent short-term higher energy payback and aggregated load coincidence. Storage heaters operating on a dual tariff, that typically charge during a fixed time window, can be considered as distributed thermal storage without an associated energy payback period. Modern storage heaters have improved heat retention, the capability to esti...

Technoeconomic Evaluation for an Installed Small-Scale Photovoltaic Power Plant

Directory of Open Access Journals (Sweden)

Bulent Yaniktepe

2017-01-01

Full Text Available Solar energy production and economic evaluation are analyzed, in this study, by using daily solar radiation and average temperature data which are measured for 3 years in the Osmaniye province in Turkey. Besides, this study utilizes the photovoltaic- (PV- based grid connected to a power plant which has an installed capacity of 1 MW investment in electricity production. Economic values show that the net present value (NPV, the first economic method in the research, is about 111941 USD, which is greater than zero. Therefore, the payback year of this investment is approximately 8.3. The second one of these methods, the payback period of the simple payback period (PBP, is 6.27 years. The last method, which is the mean value of the internal rate of return (IRR, is 10.36%. The results of this study show that Osmaniye is a considerable region for the PV investment in electricity production. As a result, investment of a PV system in Osmaniye can be applicable.

JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis

Science.gov (United States)

Gaffin, W. O.; Webb, D. E.

1979-01-01

JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation.

Performance evaluation of photovoltaic-thermosyphon system for subtropical climate application

Energy Technology Data Exchange (ETDEWEB)

Chow, T.T.; He, W.; Chan, A.L.S. [Division of Building Science and Technology, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong SAR (China); Ji, J. [Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Anhui (China)

2007-01-15

The rapid development and sales volume of photovoltaic (PV) modules has created a promising business environment in the foreseeable future. However, the current electricity cost from PV is still several times higher than from the conventional power generation. One way to shorten the payback period is to bring in the hybrid photovoltaic-thermal (PVT) technology, which multiplies the energy outputs from the same collector surface area. In this paper, the performance evaluation of a new water-type PVT collector system is presented. The thermal collection making use of the thermosyphon principle eliminates the expense of pumping power. Experimental rigs were successfully built. A dynamic simulation model of the PVT collector system was developed and validated by the experimental measurements, together with two other similar models developed for PV module and solar hot-water collector. These were then used to predict the energy outputs and the payback periods for their applications in the subtropical climate, with Hong Kong as an example. The numerical results show that a payback period of 12 year for the PVT collector system is comparable to the side-by-side system, and is much shorter than the plain PV application. This is a great encouragement in marketing the PVT technology. (author)

Performance evaluation of photovoltaic-thermosyphon system for subtropical climate application

International Nuclear Information System (INIS)

Chow, T.T.; He, W.; Chan, A.L.S.; Ji, J.

2007-01-01

The rapid development and sales volume of photovoltaic (PV) modules has created a promising business environment in the foreseeable future. However, the current electricity cost from PV is still several times higher than from the conventional power generation. One way to shorten the payback period is to bring in the hybrid photovoltaic-thermal (PVT) technology, which multiplies the energy outputs from the same collector surface area. In this paper, the performance evaluation of a new water-type PVT collector system is presented. The thermal collection making use of the thermosyphon principle eliminates the expense of pumping power. Experimental rigs were successfully built. A dynamic simulation model of the PVT collector system was developed and validated by the experimental measurements, together with two other similar models developed for PV module and solar hot-water collector. These were then used to predict the energy outputs and the payback periods for their applications in the subtropical climate, with Hong Kong as an example. The numerical results show that a payback period of 12 year for the PVT collector system is comparable to the side-by-side system, and is much shorter than the plain PV application. This is a great encouragement in marketing the PVT technology. (author)

Investigation of existing financial incentive policies for solar photovoltaic systems in U.S. regions

Directory of Open Access Journals (Sweden)

Jian Zhang

2017-12-01

Full Text Available This paper analyzes some of the existing incentives for solar photovoltaic (PV energy generation in the U.S. Four types of buildings (e.g., hospitals, large offices, large hotels, and secondary schools located in five different U.S. states, each having their own incentives, are selected and analyzed for the PV incentive policies. The payback period of the PV system is chosen as an indicator to analyze and critique the effectiveness of each incentive by comparing the payback periods before and after taking the incentive into consideration. Then a parametric analysis is conducted to determine the influence of the variation in key parameters, such as PV system capacity, capital cost of PV, sell back ratio and the performance-based incentive rate, on the performance of the PV system. The results show how the existing incentives can be effectively used to promote the PV systems in the U.S. and how variations of the parameters can impact the payback period of the PV systems. Through the evaluation of the existing incentive policies and the parametric study, this paper demonstrates that the type and level of incentives should be carefully determined in policy-making processes to effectively promote the PV systems.

Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason Aaron; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory J.; Yeakel, Skip; Adelman, Steven; Luo, Zhiming; Zehme, John

2016-04-05

Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

An Economic Evaluation of Binary Cycle Geothermal Electricity Production

National Research Council Canada - National Science Library

Fitzgerald, Crissie

2003-01-01

.... Variables such as well flow rate, geothermal gradient and electricity prices were varied to study their influence on the economic payback period for binary cycle geothermal electricity production...

Long-Haul Truck Sleeper Heating Load Reduction Package for Rest Period Idling: Preprint

Energy Technology Data Exchange (ETDEWEB)

Lustbader, Jason; Kekelia, Bidzina; Tomerlin, Jeff; Kreutzer, Cory; Adelman, Steve; Yeakel, Skip; Luo, Zhiming; Zehme, John

2016-03-24

Annual fuel use for sleeper cab truck rest period idling is estimated at 667 million gallons in the United States, or 6.8% of long-haul truck fuel use. Truck idling during a rest period represents zero freight efficiency and is largely done to supply accessory power for climate conditioning of the cab. The National Renewable Energy Laboratory's CoolCab project aims to reduce heating, ventilating, and air conditioning (HVAC) loads and resulting fuel use from rest period idling by working closely with industry to design efficient long-haul truck thermal management systems while maintaining occupant comfort. Enhancing the thermal performance of cab/sleepers will enable smaller, lighter, and more cost-effective idle reduction solutions. In addition, if the fuel savings provide a one- to three-year payback period, fleet owners will be economically motivated to incorporate them. For candidate idle reduction technologies to be implemented by original equipment manufacturers and fleets, their effectiveness must be quantified. To address this need, several promising candidate technologies were evaluated through experimentation and modeling to determine their effectiveness in reducing rest period HVAC loads. Load reduction strategies were grouped into the focus areas of solar envelope, occupant environment, conductive pathways, and efficient equipment. Technologies in each of these focus areas were investigated in collaboration with industry partners. The most promising of these technologies were then combined with the goal of exceeding a 30% reduction in HVAC loads. These technologies included 'ultra-white' paint, advanced insulation, and advanced curtain design. Previous testing showed more than a 35.7% reduction in air conditioning loads. This paper describes the overall heat transfer coefficient testing of this advanced load reduction technology package that showed more than a 43% reduction in heating load. Adding an additional layer of advanced insulation

Assessment of the Carbon Footprint, Social Benefit of Carbon Reduction, and Energy Payback Time of a High-Concentration Photovoltaic System

Directory of Open Access Journals (Sweden)

Allen H. Hu

2016-12-01

Full Text Available Depleting fossil fuel sources and worsening global warming are two of the most serious world problems. Many renewable energy technologies are continuously being developed to overcome these challenges. Among these technologies, high-concentration photovoltaics (HCPV is a promising technology that reduces the use of expensive photovoltaic materials to achieve highly efficient energy conversion. This reduction process is achieved by adopting concentrating and tracking technologies. This study intends to understand and assess the carbon footprint and energy payback time (EPBT of HCPV modules during their entire life cycles. The social benefit of carbon reduction is also evaluated as another indicator to assess the energy alternatives. An HCPV module and a tracker from the Institute of Nuclear Energy Research (INER were applied, and SimaPro 8.0.2 was used for the assessment. The functional unit used in this study was 1 kWh, which is produced by HCPV, and inventory data was sourced from Ecoinvent 3.0 and the Taiwan carbon footprint calculation database. The carbon footprint, EPBT, and social benefit of carbon reduction were evaluated as 107.69 g CO2eq/kWh, 2.61 years, and 0.022 USD/kWh, respectively. Direct normal irradiation (DNI, life expectancy, and the degradation rate of HCPV system were subjected to sensitivity analysis. Results show that the influence of lifetime assumption under a low DNI value is greater than those under high DNI values. Degradation rate is also another important factor when assessing the carbon footprint of HCPV under a low DNI value and a long lifetime assumption. The findings of this study can provide several insights for the development of the Taiwanese solar industry.

Economic and Environmental Optimization of an Airport Terminal Building’s Wall and Roof Insulation

Directory of Open Access Journals (Sweden)

Mehmet Kadri Akyüz

2017-10-01

Full Text Available HVAC systems use the largest share of energy consumption in airport terminal buildings. Thus, the efficiency of the HVAC system and the performance of the building envelope have great importance in reducing the energy used for heating and cooling purposes. In this study, the application of thermal insulation on the walls and roof of the Hasan Polatkan Airport terminal building was investigated from energy, environment and cost aspects. This study determined the optimum insulation thickness and assessed its effects on environmental performance based on energy flows. Environmental payback periods were calculated depending on the optimum insulation thickness. The life cycle assessment (LCA method was used to assess whether the decrease in energy consumption after applying the insulation balanced the environmental effects during the period between the production and application of the thermal insulation material. The global warming potential (GWP based on IPCC100, and the effects on human health (HH, the ecosystem and natural resources were evaluated according to the ReCiPe method. LCA results were obtained by processing data taken from ecoinvent 3 database present in the Sima Pro 8.3.0.0 software. Applying thermal insulation on the walls and roof of the terminal building was found to decrease heat loss by 48% and 56%, respectively. In addition, the analyses showed that the environmental payback periods for the thermal insulation were shorter than the economic payback periods.

Energy efficient biological air cleaning for farm stable ventilation; Energieffektiv biologisk luftrensning til staldventilation

Energy Technology Data Exchange (ETDEWEB)

Groenborg Nicolaisen, C.; Hansen, Mads P.R. [Teknologisk Institut, Aarhus (Denmark); Stroem, J.; Soerensen, Keld [DXT. Danish Exergy Technology A/S, Skoerping (Denmark); Goetke, C. [Lokalenergi Aarhus, Viby J. (Denmark); Morsing, S.; Soerensen, Lars C. [SKOV A/S, Roslev (Denmark); Ladegaerd Jensen, T.; Pedersen, Poul [Videncenter for svineproduktion, Copenhagen (Denmark)

2013-05-01

The project has been designed to reduce energy consumption for air purification by 30% while having a payback period of maximum 3 years. The project has achieved very significant results which are far above the target. Particularly satisfying is the wide range of new components that are launched in late 2012. By implementing the newly developed system at 100% cleaning (LPC 13 ventilators and Dynamic multistep control) in relation to Best Practice (SKOV's original system with DA600 fans) in a concrete pigsty, a saving of 61% and a simple payback of 1.7 years is achieved. Similarly, it is found that the energy used for pump operation can be reduced by 37% with the new Dynamic sprinkling control. At 20% cleaning a potential saving of 15% per year and a payback period of between 0 and 5 years was found, which is dependent on the desired performance as the capacities in the bio-filter's upper capacity range between 26 thousand to 30 thousand m3 / h entails costs for an additional extraction unit in the new solution. Furthermore, the newly developed components proved highly suitable for standard installations without air cleaning where a savings potential is 53% and the payback period 1.5 years. Product-wise, the project formed the basis for the development of: 1. New energy-efficient ventilation units (LPC11, 12,13) that are suitable for air purification; 2. A new energy-saving control principle (Dynamic Multi-Step) which is particularly suitable for low-energy ventilators; 3. A new energy-saving flow measurement system for ventilating ducts (Dynamic air to the central exhaust); 4. An energy-saving pressure control in common ducts (pressure control as a function of outside temperature); 5. Proposal for a new energy-saving pump operation for sprinkling of biological filters (Dynamic sprinkling). (LN)

Economic assessment of biogas-to-electricity generation system with H2S removal by activated carbon in small pig farm

International Nuclear Information System (INIS)

Pipatmanomai, Suneerat; Kaewluan, Sommas; Vitidsant, Tharapong

2009-01-01

This study was conducted to assess the economic feasibility of electricity generation from biogas in small pig farms with and without the H 2 S removal prior to biogas utilisation. The 2% potassium iodide (KI) impregnated activated carbon selected as H 2 S adsorbent was introduced to a biogas-to-electricity generation system in a small pig farm in Thailand as a case study. With the average inlet H 2 S concentration of about 2400 ppm to the adsorption unit, the H 2 S removal efficiency could reach 100% with the adsorption capacity of 0.062 kg of H 2 S/kg of adsorbent. Under the reference scenario (i.e., 45% subsidy on digester installation and fixed electricity price at 0.06 Euro/kWh) and based on an assumption that the biogas was fully utilised for electricity generation in the system, the payback period for the system without H 2 S removal was about 4 years. With H 2 S removal, the payback period was within the economic life of digester but almost twice that of the case without H 2 S removal. The impact of electricity price could be clearly seen for the case of treated biogas. At the electricity price fixed at 0.07 Euro/kWh, the payback period for the case of treated biogas was reduced to about 5.5 years, with a trend to decrease at higher electricity prices. For both treated and untreated biogas, the governmental subsidy was the important factor determining the economics of the biogas-to-electricity systems. Without subsidy, the payback period increased to almost 7 years and about 11 years for the case of untreated and treated biogas, respectively, at the reference electricity price. Although the H 2 S removal added high operation cost to the system, it is still highly recommended not only for preventing engine corrosion but also for the environment benefit in which air pollution by H 2 S/SO 2 emission and impact on human health could be potentially reduced. (author)

A Greenhouse Gas and Soil Carbon Model for Estimating the Carbon Footprint of Livestock Production in Canada

Science.gov (United States)

Vergé, Xavier P.C.; Dyer, James A.; Worth, Devon E.; Smith, Ward N.; Desjardins, Raymond L.; McConkey, Brian G.

2012-01-01

Simple Summary We developed a model to estimate the carbon footprint of Canadian livestock production. To include long term soil carbon storage and loss potential we introduced a payback period concept. The model was tested by reallocating 10% only of the protein production from a ruminant to a non ruminant source to minimize the risk of including rangeland or marginal lands. This displacement generated residual land which was found to play a major role in the potential mitigation of GHG emissions. The model will allow land use policies aimed at reducing the agricultural GHG emissions to be assessed. Abstract To assess tradeoffs between environmental sustainability and changes in food production on agricultural land in Canada the Unified Livestock Industry and Crop Emissions Estimation System (ULICEES) was developed. It incorporates four livestock specific GHG assessments in a single model. To demonstrate the application of ULICEES, 10% of beef cattle protein production was assumed to be displaced with an equivalent amount of pork protein. Without accounting for the loss of soil carbon, this 10% shift reduced GHG emissions by 2.5 TgCO2e y−1. The payback period was defined as the number of years required for a GHG reduction to equal soil carbon lost from the associated land use shift. A payback period that is shorter than 40 years represents a net long term decrease in GHG emissions. Displacing beef cattle with hogs resulted in a surplus area of forage. When this residual land was left in ungrazed perennial forage, the payback periods were less than 4 years and when it was reseeded to annual crops, they were equal to or less than 40 years. They were generally greater than 40 years when this land was used to raise cattle. Agricultural GHG mitigation policies will inevitably involve a trade-off between production, land use and GHG emission reduction. ULICEES is a model that can objectively assess these trade-offs for Canadian agriculture. PMID:26487032

Aquaponics Cultivation of Ipome Aquatica and the Peasant Financial Income of Cirata Cistern

Directory of Open Access Journals (Sweden)

Abel Gandhy

2016-08-01

Full Text Available The research paper analyzes the financial income of a poor community living around the Cirata cistern, in West Java, Indonesia, before and after the community employed the aquaponics strategy of planting ipomoea aquatica. Data are gathered from observation, interviews and statistical analysis of the incomes of community members. In addition, analysis of the data applies Net Present Value (NPV, Internal Rate of Return (IRR, and Payback Period (PP. The findings clearly demonstrate an increased annual income of more than 1.117.296 rupiah among those community members using the aquaponics strategy. Once the community has adjusted to professionally implementing this aquaponics strategy, it would be practically useful to invite investors to invest their capital to develop this area.   Keywords: aquaponics, financial income, West Java, internal rate of return, payback period

Energy analysis of solar photovoltaic module production in India

International Nuclear Information System (INIS)

Prakash, R.; Bansal, N.K.

1995-01-01

The objective of this article is to evaluate the energy consumption in solar photovoltaic (SPV) module production in India and examine its implications for large-scale introduction of SPV plants in the country. Data on energy used in SPV production were collected from existing manufacturing facilities in the country. The energy payback period turns out to be approximately 4 years. This is comparable to energy payback periods of similar modules produced internationally. However, if an ambitious program of introducing SPV power production is undertaken to contribute substantially to the power scenario in the country, an annual growth rate beyond 21% will render the program an energy sink rather than an energy source, as borne out by dynamic energy analysis. Policy implications are also discussed in light of this analysis

Economic viability of a residential building integrated photovoltaic generator in South Africa

Energy Technology Data Exchange (ETDEWEB)

Ziuku, Sosten; Meyer, Edson L. [Fort Hare Institute of Technology, University of Fort Hare, Private Bag X1314, Alice 5700 (South Africa)

2012-07-01

A photovoltaic (PV) generator was integrated onto the north facing roof of an energy efficient house in South Africa. The building integrated photovoltaic generator (BIPV) supplies power to the household loads and the grid and is also the roof facade. This paper presents an economic evaluation of the viability of the BIPV system using methods of investment analysis. The capital cost and life cycle cost of energy were found to be ZAR 52 631-58/kWp and ZAR 1-94/kWh respectively. The payback period was 8 years and adjusted internal rate of return 9.3%. Parametric sensitivity analysis revealed that a 50% decrease in module price results in a 29% reduction in life cycle cost of energy and more than 50% reduction in payback period.

Viabilidade econômica da produção de eucalipto no interior de São Paulo = Economic viability of eucalyptus production in the countryside of São Paulo

Directory of Open Access Journals (Sweden)

Helder Roberto Dota Janoselli

2016-04-01

culture in the city of São João da Boa Vista, countryside of the state of Sao Paulo. Hence, the cash flow was elaborated within a period of 14 years obtaining the indicators: Net Present Value [NPV]; Internal Rate of Return [IRR]; Payback period (Simple and Discounted, as well as sensitivity analysis. The economic indicators show that the establishment of eucalyptus cultivation, as proposed, with stump removal and the opportunity cost of land, proved to be unfeasible and not profitable for the investor. The NPV was R$ 40,808.70, but negative, IRR was 3.41% and the recovery time for the capital invested by simple payback was in 7.82 years and discounted payback in eight years. The same project with a different way of management, not removing the stumps, with the possibility of planting again, became feasible, with a positive NPV of R$ 6.802,85, IRR at 4.55% and the recovery time for the capital invested by simple payback in 7.82 years and discounted payback in eight years.

Stockbridge Munsee Community Health and Wellness Center and the Mohican Family Center Renewable Energy and Energy Efficiency Feasibility Study

Energy Technology Data Exchange (ETDEWEB)

DeRocher, Andy [Stockbridge-Munsee Health and Wellness Center, Bowler, WI (United States); Barrnett, Michael [Stockbridge-Munsee Health and Wellness Center, Bowler, WI (United States)

2014-03-14

The results of the Renewable Energy and Energy Efficiency Feasibility Study of Stockbridge Munsee Community’s Health and Wellness Center (HWC) indicate that a variety of renewable energy options and energy conservation measures (ECMs) exist for the facility. A requirement of the Request for Proposal for this study was to assess renewable energy options that could offset 30 to 100 percent of the HWC’s energy use. This study identifies that a geothermal system is the most cost effective renewable energy option available to decrease the HWC’s energy consumption by 30 to 100 percent. Currently the HWC performs in the lowest 8 percent of buildings in its building category, as scored in the EPA portfolio manager benchmarking tool. Multiple ECM opportunities have been identified with paybacks of less than five years to yield an estimated 25-percent decrease in annual energyconsumption. The ECMs within this payback period are estimated to save $26,800 per year with an implementation cost of just $4,650 (0.2 year payback). For the Mohican Family Center document: The results of the Renewable Energy and Energy Efficiency Feasibility Study of Stockbridge Munsee Community’s Mohican Family Center (MFC) indicate that a variety of renewable energy options and energy conservation measures (ECMs) exist for the facility. A requirement of the Request for Proposal for this study was to assess renewable energy options that could offset 30 to 100 percent of the MFC’s energy use. This study identifies that a geothermal system is the most cost effective renewable energy option available to decrease the MFC’s energy consumption by 30 to 100 percent. Currently the MFC performs better than 80 percent of buildings in its building category, as scored in the EPA portfolio manager benchmarking tool. Multiple ECM opportunities have been identified with short term paybacks to yield an estimated 13-percent decrease in energy consumption. The ECMs within this payback period are estimated

Viabilidade econômica do cultivo de videira Niágara Rosada = Economic feasibility of grapevine Niagara Rosada production

Directory of Open Access Journals (Sweden)

Meyriele Pires de Camargo

2017-04-01

Full Text Available O estado de São Paulo é o terceiro maior produtor de uvas do Brasil e o maior produtor nacional de uvas de mesa, sendo a variedade Niágara Rosada (Vitis labrusca a mais plantada no estado. O objetivo do trabalho foi verificar a viabilidade econômica do cultivo de Niágara Rosada. O projeto foi dimensionado para uma área de três hectares implantada no município de Piracicaba, SP. As plantas foram conduzidas no sistema em espaldeira em uma densidade de 5000 plantas ha-1. O fluxo de caixa foi dimensionado para um período de 13 anos. Estimaram-se os custos para implantação e manutenção do vinhedo, financiamento bancário, pagamento do Fundo de Apoio ao Trabalhador Rural [Funrural] e o custo de oportunidade da terra. A taxa mínima de atratividade [TMA] foi fixada em 11,45% e os indicadores econômicos calculados foram Valor Presente Líquido [VPL], Taxa Interna de Retorno [TIR], payback simples, payback descontado e relação benefício-custo. Obtiveram-se valores positivos de VPL (R$ 398.951,36 e relação custo-benefício (1,81. A TIR foi estimada em 27,34%, superior à TMA. Os valores de payback simples e descontado foram de cinco anos e de seis anos, respectivamente, indicando que o tempo de retorno do capital inicial investido foi inferior ao período do projeto. Os indicadores econômicos estimados constataram a viabilidade financeira do empreendimento em análise. = São Paulo State is the third largest grapevine producer in Brazil and the largest national producer of table grapes. Niagara Rosada (Vitis labrusca is the most planted cultivar in the State. This study aimed to verify the economic feasibility of Niagara Rosada production. The project was designed for an area of tree hectares to be implemented in Piracicaba, SP. Plants were conducted in vertical trellis system with 5000 plants ha-1. The cash flow was dimensioned for a period of 13 years. Costs with implantation and maintenance of the vineyard, bank financing, payment

APPRAISAL OF ECONOMICAL EFFICIENCY OF APPLICATION OF FIBROUS LINING IN THERMAL GASPLASMA FURNACES AND FURNACES OF RESISTANCE OF MACHINE-BUILDING PRODUCTION

Directory of Open Access Journals (Sweden)

V. I. Timoshpolskij

2011-01-01

Full Text Available The carried out calculations showed that partial modernization of thermal furnaces of machine building production by means of replacement of chamotte by fibrous fettling is economically reasonable and has rather short period of payback.

Analyse technico-économique et évaluation de l’impact environnemental de la cuisson solaire directe au Maroc

Directory of Open Access Journals (Sweden)

Ndiaga MBODJI

2017-09-01

Full Text Available The objective of this study is to present a design methodology, carry out economic analysis and evaluate the environmental impact of direct solar cooking systems in Morocco. To satisfy the energy needs of a 5 people household, consuming a 3 kg meal at noon for a cooking time of 2.5 hours, a parabolic concentrator having a diameter of 1.4 m (useful area of 1.6 m² is required. At the household level, the economic analysis revealed that the payback period of a direct solar cooker compared to butane varies from 4 to 10 years, depending on the rate of public subsidy. Where firewood is used, the payback period varies from 0.6 to 10 years, depending on the stove performance and the firewood price. At the national level, a 50% subsidy of direct solar cookers with a penetration rate of 50% in rural areas requires a budget of 1.61 billion dirhams (1$US=10 Dirhams. This investment will allow the government to save 185 million dirhams a year in butane subsidies reduction, which corresponds to a payback period of about 8.7 years and a total profit of 1.45 billion dirhams over the cookers 15-year lifetime. On the ecological aspect, the area of forest saved would be about 10 000 ha/year, and the annual amount of CO2 emissions avoided would be 1.08 Mt/year.

A Greenhouse Gas and Soil Carbon Model for Estimating the Carbon Footprint of Livestock Production in Canada

Directory of Open Access Journals (Sweden)

Brian G. McConkey

2012-09-01

Full Text Available To assess tradeoffs between environmental sustainability and changes in food production on agricultural land in Canada the Unified Livestock Industry and Crop Emissions Estimation System (ULICEES was developed. It incorporates four livestock specific GHG assessments in a single model. To demonstrate the application of ULICEES, 10% of beef cattle protein production was assumed to be displaced with an equivalent amount of pork protein. Without accounting for the loss of soil carbon, this 10% shift reduced GHG emissions by 2.5 TgCO₂e y⁻¹. The payback period was defined as the number of years required for a GHG reduction to equal soil carbon lost from the associated land use shift. A payback period that is shorter than 40 years represents a net long term decrease in GHG emissions. Displacing beef cattle with hogs resulted in a surplus area of forage. When this residual land was left in ungrazed perennial forage, the payback periods were less than 4 years and when it was reseeded to annual crops, they were equal to or less than 40 years. They were generally greater than 40 years when this land was used to raise cattle. Agricultural GHG mitigation policies will inevitably involve a trade-off between production, land use and GHG emission reduction. ULICEES is a model that can objectively assess these trade-offs for Canadian agriculture.

Techno-economic analysis of lipase enzyme production from agro-industry waste with solid state fermentation method

Science.gov (United States)

Hidayatullah, I. M.; Arbianti, R.; Utami, T. S.; Suci, M.; Sahlan, M.; Wijanarko, A.; Gozan, M.; Hermansyah, H.

2018-03-01

Needs for this kind of catalyst derived from biological raw materials (biocatalysts) has increased along with development of products based on eco-friendly. To achieve the needs of biocatalyst (enzyme), large production is necessary. This study aimed to get the best conditions and design equipment to produce lipase enzyme based on solid state fermentation using SuperPro Designer v9.0. Several equipment such as Tray Bioreactor, Mixing Tank 1, Filter Press, centrifuge, Mixing Tank 2, and a dryer have been improved during the simulation. Economic analysis in the form of NPV, IRR, Payback Period, and the Benefit Cost Ratio was evaluated respectively. The result showed that production of 10 kg enzyme with NPV Rp112.796.147.423,00; IRR 54.20%; Payback Period 1.95 years; and Benefit Cost Ratio of 3.36 was more advantageous.

Comparative technical-economical analysis of solar systems with liquid absorbent

International Nuclear Information System (INIS)

Kaloyanov, N.; Popova, I.

2005-01-01

An analyses of solar water heating systems with two types liquid absorbent is presented. A system with classic collector design is used for comparison. The dependence between the value of the collectors active area and the absorbent type, collectors slope and design parameters is discussed. Two economic indexes (payback period and index of actual net value, based on the electricity price) are used for comparison of the different variants of the system. The presented results shown that: 1) the payback period can be reduced twice if the collectors with liquid absorbent are used; 2) the index of actual net value of the systems using the collectors with fluid absorbent is about four times higher than this one with classic collectors; 3) the systems using distilled water like a liquid absorbent can not fulfil the requirements for the positive economic indicators

Feasibility study of a hybrid renewable energy system with geothermal and solar heat sources for residential buildings in South Korea

International Nuclear Information System (INIS)

Kim, Young Ju; Woo, Nam Sub; Jang, Sung Cheol; Choi, Jeong Ju

2013-01-01

This study investigates the economic feasibility of a hybrid renewable energy system (HRES) that uses geothermal and solar heat sources for water heating, space heating, and space cooling in a residential building in Korea. A small-scale HRES consists of a geothermal heat pump for heating and cooling, solar collectors for hot water, a gas-fired backup boiler, and incidental facilities. To determine whether the Hares will produce any economic benefits for homeowners, an economic analysis is conducted to compare the Hares with conventional methods of space heating and cooling in Korea. The payback period of a small-scale Hares is predicted as a maximum of 9 yrs by life cycle costing based on a performance index compared with conventional systems. However, the payback period of large-scale HRES above 400 RT is 6 yrs to 7 yrs.

A Method for Estimating Potential Energy and Cost Savings for Cooling Existing Data Centers

Energy Technology Data Exchange (ETDEWEB)

Van Geet, Otto

2017-04-24

NREL has developed a methodology to prioritize which data center cooling systems could be upgraded for better efficiency based on estimated cost savings and economics. The best efficiency results are in cool or dry climates where 'free' economizer or evaporative cooling can provide most of the data center cooling. Locations with a high cost of energy and facilities with high power usage effectiveness (PUE) are also good candidates for data center cooling system upgrades. In one case study of a major cable provider's data centers, most of the sites studied had opportunities for cost-effective cooling system upgrades with payback period of 5 years or less. If the cable provider invested in all opportunities for upgrades with payback periods of less than 15 years, it could save 27% on annual energy costs.

Feasibility study of a hybrid renewable energy system with geothermal and solar heat sources for residential buildings in South Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Young Ju; Woo, Nam Sub [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Jang, Sung Cheol [Mechatronics Department of the Korea Aviation Polytechnic College, Sacheon (Korea, Republic of); Choi, Jeong Ju [Dong-A University, Busan (Korea, Republic of)

2013-08-15

This study investigates the economic feasibility of a hybrid renewable energy system (HRES) that uses geothermal and solar heat sources for water heating, space heating, and space cooling in a residential building in Korea. A small-scale HRES consists of a geothermal heat pump for heating and cooling, solar collectors for hot water, a gas-fired backup boiler, and incidental facilities. To determine whether the Hares will produce any economic benefits for homeowners, an economic analysis is conducted to compare the Hares with conventional methods of space heating and cooling in Korea. The payback period of a small-scale Hares is predicted as a maximum of 9 yrs by life cycle costing based on a performance index compared with conventional systems. However, the payback period of large-scale HRES above 400 RT is 6 yrs to 7 yrs.

Approaches to economic analysis of profitability of forestry enterprises

Directory of Open Access Journals (Sweden)

O.M. Dzyubenko

2018-03-01

Full Text Available The article substantiates the directions of adaptation of existing analytical procedures for assessing the profitability to specific activities of forestry enterprises, which is an integral part of evaluating financial potential of enterprises of the investigated branch. In particular, the author identifies the following analytical procedures that make it possible to assess the performance of forestry enterprises and determine its financial potential: the return on equity (assets on net profit, the return on equity, the return on assets, the return on sales of profits from operating activities, the profitability of sold products at net profit, reinvestment factor, the economic growth sustainability ratio, the period of payback capital, the payback period of equity capital. On the basis of these indicators, the current state of profitability of forestry enterprises was substantiated and their critical points were determined.

Modes of governance for municipal energy efficiency services - the case of LED street lighting in Germany

NARCIS (Netherlands)

Polzin, F.H.J.; von Flotow, Paschen; Nolden, Colin

2016-01-01

Energy efficiency retrofits are often impeded by high perceived investment risks, long payback periods and a lack of skills. At the municipal level these issues are particularly pronounced as procuring, implementing, and managing retrofits can exceed existing municipal governance capacities. The

OUT Success Stories: Transpired Solar Collectors

International Nuclear Information System (INIS)

Clyne, R.

2000-01-01

Transpired solar collectors are a reliable, low-cost technology for preheating building ventilation air. With simple payback periods ranging from 3 to 12 years and an estimated 30-year life span, transpired collector systems offer building owners substantial cost savings

Annual performance investigation and economic analysis of heating systems with a compression-assisted air source absorption heat pump

International Nuclear Information System (INIS)

Wu, Wei; Shi, Wenxing; Wang, Baolong; Li, Xianting

2015-01-01

Highlights: • Optimal compression ratio of CASAHP is obtained for the maximum energy saving rate. • Annual performance is improved by 10–20% compared to ASAHP without compression. • Energy saving rate is 17.7–29.2% and investment is reduced to 30–60% for CASAHP. • Both compression and partial-design enhance the economy with given energy saving. • Payback time is reduced from 12–32 to 3–6 years by compression and partial-design. - Abstract: The compression-assisted air source absorption heat pump (CASAHP) is a promising alternative heating system in severe operating conditions. In this research, parameter studies on the annual performance under various compression ratios (CRs) and source temperatures are performed to achieve the maximum energy saving rates (ESRs). Economic analyses of the CASAHP under different CRs and partial-design ratios are conducted to obtain an optimal design that considers both energy savings and economy improvements. The results show that the optimal CR becomes higher in colder regions and with lower heat source temperatures. For a source temperature of 130 °C, the optimal CR values in all of the cities are within 2.0. For source temperatures from 100 to 130 °C, the maximum ESR is in the range of 17.7–29.2% in the studied cities. The efficiency improvement rate (EIR) caused by compression in a severe source condition can reach 10.0–20.0%. From the viewpoint of economy, the relative investment of CASAHP is reduced to 30–60% with a CR of 2.0–3.0. With a 2–6% sacrifice in ESR, the payback period can be reduced from 12–32 to 5–9 years using compression. Partial-design of the CASAHP can further reduce the payback period to 3–6 years with a partial-design ratio of 50% and a CR of 2.8. Additionally, CRs and partial-design ratios are designed comprehensively by seeking the maximum ESR for a given acceptable payback period

ANALISIS KELAYAKAN EKONOMI DAN KEUANGAN USAHA IKAN LELE ASAP DI PEKANBARU

Directory of Open Access Journals (Sweden)

Indo Yama Nasarudin

2015-09-01

Full Text Available This research is to analyze the feasibility of economic and financial on smoked catfish business in Pekanbaru. The methods analysis that used in this research are B/C ratio, NPV, payback period, profitability index, and IRR. Economic Performance for business of smoked lele fish was very good for marketing aspect and good enough for production, management and human resource aspect. While seen from finance aspect assess the Benefit cost ratio (BCR equal to 1,39, Value of Payback Period is 2,44 years,  below time specified 10 years. Positive valuable Net Present Value equal is Rp 739.508.134, Value of profitability index equal to 6,35. Rate of return (IRR equal to 53,09% Pursuant to measurement financial as a whole indicate that the effort competent poultry to be continued.DOI: 10.15408/etk.v12i2.1915

Cost-benefit analysis of retrofit of high-intensity discharge factory lighting with energy-saving alternatives

Energy Technology Data Exchange (ETDEWEB)

Preston, D.J. [Alabama Industrial Assessment Center, The University of Alabama, 1530 W. Tremont St, Allentown, PA 18102 (United States); Woodbury, K.A. [Alabama Industrial Assessment Center, The University of Alabama, 290 Hardaway Hall, Box 870276, Tuscaloosa, AL 35487-0276 (United States)

2013-05-15

Due to increased concern about overall energy costs and the appearance of efficient and inexpensive lighting system alternatives, factories and plants with high-intensity discharge (HID) lighting are forced to consider retrofit with more modern, energy-efficient lighting. The decision is complicated from an economic perspective, and there is a lack of information readily available on the topic. This study provides an analysis of the replacement by retrofit of common probe-start metal halide and high-pressure sodium industrial lighting systems. Retrofit options considered include the more recent pulse-start metal halide lamps and a range of T5 high output and T8 fluorescent lamp configurations. Recent data on lighting system pricing, labor and energy costs, and time required for tasks are reported. The results generated include savings, payback period, and net present value for many retrofit options, as well as the change in energy consumption, carbon footprint, and lumen output for each retrofit. Effects of varying rate of return and daily duration of operation are considered. Based on change in lumen output, payback period, net present value, and comparison of lighting quality, one or two options are recommended from the overall retrofit options considered. A fluorescent retrofit is recommended for each of the HID initial scenarios considered. The payback period is no more than 3 years in any recommended case. The focus of this study is on the potential energy and cost savings, and some proposed solutions may, or may not, be acceptable due to lack of illuminance uniformity.

Post-evaluation of a ground source heat pump system for residential space heating in Shanghai China

Science.gov (United States)

Lei, Y.; Tan, H. W.; Wang, L. Z.

2017-11-01

Residents of Southern China are increasingly concerned about the space heating in winter. The chief aim of the present work is to find a cost-effective way for residential space heating in Shanghai, one of the biggest city in south China. Economic and energy efficiency of three residential space heating ways, including ground source heat pump (GSHP), air source heat pump (ASHP) and wall-hung gas boiler (WHGB), are assessed based on Long-term measured data. The results show that the heat consumption of the building is 120 kWh/m2/y during the heating season, and the seasonal energy efficiency ratio (SEER) of the GSHP, ASHP and WHGB systems are 3.27, 2.30, 0.88 respectively. Compared to ASHP and WHGB, energy savings of GSHP during the heating season are 6.2 kgce/(m2.y) and 2.2 kgce/(m2.y), and the payback period of GSHP are 13.3 and 7.6 years respectively. The sensitivity analysis of various factors that affect the payback period is carried out, and the results suggest that SEER is the most critical factor affecting the feasibility of ground source heat pump application, followed by building load factor and energy price factor. These findings of the research have led the author to the conclusion that ground source heat pump for residential space heating in Shanghai is a good alternative, which can achieve significant energy saving benefits, and a good system design and operation management are key factors that can shorten the payback period.

PRODUCTIVITY AND ECONOMIC ANALYSIS OF THE INDIAN OCEAN LONGLINE FISHERY LANDED AT BENOA PORT BALI INDONESIA

Directory of Open Access Journals (Sweden)

Fathur Rochman

2014-12-01

and feasible with payback periods (year-3, month - 2 and day- 18, internal rate of return (53%, average rate of return (61.24% and net present value between Rp 1.709.897.950,- (first year and Rp 85.331.099.211,- (at the end of 25 years.

Economic Efficiency and Investment Implementation in Energy Saving Projects

Directory of Open Access Journals (Sweden)

Venelin Terziev

2017-09-01

Full Text Available Investment in building thermoinsulation is a subject to appraisal for efficiency from the position of discounted cash flows taken specifically by energy saving. The appraisal of investment as optimal is attended by achieving the shortest term for investment implementation, the lowest investment outlays, the maximum total net value of energy savings, the shortest investment payback period. The complex application of the dynamic methods for appraising economic efficiency of an investment – net present value, internal rate of return, profitability index and discounted payback period, involves drawing of particular values which comparison definitely will show if this kind of investment is practically “attractive”. However, the question for significance weight of each of these indicators above in decision making for implementation a particular real investment still remains unsolved. This requires working out a system of criteria, priorities that can determine which of the indicators for economic efficiency of specific investment project will have the highest significance.

A comparison of two low grade heat recovery options

International Nuclear Information System (INIS)

Walsh, Conor; Thornley, Patricia

2013-01-01

Low grade heat (LGH) recovery is one way of increasing industrial energy efficiency and reducing associated greenhouse gas emissions. The organic Rankine cycle (ORC) and condensing boiler are two options that can be used to recover low grade heat ( 2 annually, but the high carbon intensity of the coking process means this has a negligible influence (<1%) on the overall process lifecycle impacts. However, if the electricity generated offsets the external purchasing of electricity this results in favourable economic payback periods of between 3 and 6 years. The operation of a condensing boiler within a woodchip boiler reduces the fuel required to achieve an increased thermal output. The thermal efficiency gains reduce the lifecycle impacts by between 11 and 21%, and reflect payback periods as low as 1.5–2 years, depending on the condenser type and wood supply chain. The two case studies are used to highlight the difficulty in identifying LGH recovery solutions that satisfy multiple environmental, economic and wider objectives

Energetic-environmental-economic assessment of the biogas system with three utilization pathways: Combined heat and power, biomethane and fuel cell.

Science.gov (United States)

Wu, Bin; Zhang, Xiangping; Shang, Dawei; Bao, Di; Zhang, Suojiang; Zheng, Tao

2016-08-01

A typical biogas system with three utilization pathways, i.e., biogas upgrading, biogas combined heat and power (CHP), biogas solid oxide fuel cells (SOFCs) were designed. It was assessed from the viewpoint of energy, environment and economy by using energy efficiency, green degree and net present value index respectively. The assessment considered the trade-off relationships among these indexes, which is more comprehensive than previous systematic evaluation work only included single or two of the pathway(s) by using one or two of the index(es). Assessment results indicated that biogas upgrading pathway has the highest systematic energy efficiency (46.5%) and shortest payback period (8.9year) with the green degree production is the lowest (9.29gd/day). While for biogas SOFC pathway, although the green degree production is the highest (21.77gd/day), the payback period is longer (14.5year) and the energy efficiency is 13.6% lower than the biogas upgrading pathway. Copyright © 2016 Elsevier Ltd. All rights reserved.

An economic evaluation of photovoltaic grid connected systems (PVGCS) in Flanders for companies: A generic model

International Nuclear Information System (INIS)

Audenaert, Amaryllis; De Boeck, Liesje; De Cleyn, Sven; Lizin, Sebastien; Adam, Jean-Francois

2010-01-01

In this paper an economic evaluation of photovoltaic grid connected systems (PVGCS) for companies situated in Flanders (Belgium) is conducted by using a generic Excel model. The model is unique in that it includes the dimension of taxation. This inclusion is required, otherwise the fiscal benefit of using solar panels is not accounted for. The model uses the cash flow projection method. This technique allows the calculation of the following classical evaluation criteria: net present value, internal rate of return, payback period, discounted payback period, profitability index, yield unit cost, yield unit revenue and break-even turnkey cost. Their outcome makes it possible to answer the question whether installing a PVGCS in Flanders is a responsible financial investment for companies. Furthermore, the paper estimates whether the corporate environment is ready for a subsidy legislation change. This change has recently been announced and as such it is possible to gauge whether the current market situation is profitable given future legislation. (author)

Assessing the economic aspects of solar hot water production in Greece

International Nuclear Information System (INIS)

Haralambopoulos, D.; Kovras, H.

1997-01-01

The long-term performance of various systems was determined and the economic aspects of solar hot water production were investigated in this work. The effect of the collector inclination angle, collector area and storage volume was examined for all systems, and various climatic conditions and their payback period was calculated. It was found that the collector inclination angle does not have a significant effect on system performance. Large collector areas have a diminishing effect on the system's overall efficiency. The increase in storage volume has a detrimental effect for small daily load volumes, but a beneficial one when there is a large daily consumption. Solar energy was found to be truly competitive when the conventional fuel being substituted is electricity, and it should not replace diesel oil on pure economic grounds. Large daily load volumes and large collector areas are in general associated with shorter payback periods. Overall, the systems are oversized and are economically suitable for large daily hot water load volumes. (Author)

An innovative design of small low head hydropower units for low cost decentralized production

International Nuclear Information System (INIS)

Holmen, E.; Dennehy, T.

1991-01-01

Design allowing turbine operation at heads as low as 1m and operating at a rotational speed of 500 RPM at a flow of 2.6m 3 /s and a runner diameter of 700 mm. This eliminates the need for a gear box and helps in achieving efficiency of 60% in the case of a 21 kW installation at a 1m head site and 85% with a 69 kW 3.2m head site. Present turbine designs for such low head sites are very expensive to produce and have a low efficiency. The design uses an all plastic waterway, guide vane assembly and reinforced plastic runner blades. There will be a short pay-back period, for example 4.5 years in the case of a 21 kW unit and 2.0 years in case of the 69 kW unit. These payback periods assume a cost per kW of 0.00 ECU. Design is attractive for decentralized production. 3 figs

Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

Energy Technology Data Exchange (ETDEWEB)

Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Abhyankar, Nikit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Diddi, Saurabh [Bureau of Energy Efficiency, Government of India (India); Ahuja, Deepanshu [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Mukherjee, P. K. [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Walia, Archana [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States)

2016-06-01

Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant,and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one-star level) should be evaluated rigorously considering significant benefits to consumers, energy security, and environment

An economic analysis comparison of stationary and dual-axis tracking grid-connected photovoltaic systems in the US Upper Midwest

Science.gov (United States)

Choi, Wongyu; Pate, Michael B.; Warren, Ryan D.; Nelson, Ron M.

2018-05-01

This paper presents an economic analysis of stationary and dual-axis tracking photovoltaic (PV) systems installed in the US Upper Midwest in terms of life-cycle costs, payback period, internal rate of return, and the incremental cost of solar energy. The first-year performance and energy savings were experimentally found along with documented initial cost. Future PV performance, savings, and operating and maintenance costs were estimated over 25-year assumed life. Under the given assumptions and discount rates, the life-cycle savings were found to be negative. Neither system was found to have payback periods less than the assumed system life. The lifetime average incremental costs of energy generated by the stationary and dual-axis tracking systems were estimated to be 0.31 and 0.37 per kWh generated, respectively. Economic analyses of different scenarios, each having a unique set of assumptions for costs and metering, showed a potential for economic feasibility under certain conditions when compared to alternative investments with assumed yields.

Investigation into life-cycle costing as a comparative analysis approach of energy systems

CSIR Research Space (South Africa)

Mokheseng, B

2010-08-31

Full Text Available selection based on a simple payback period. Due to life-cycle stages, often the real costs of the project or equipment, either to the decision maker or the cost bearer, are not reflected by the upfront capital costs. In this paper, the life-cycle costing...

Techno-economic studies on hybrid energy based cooling system for milk preservation in isolated regions

International Nuclear Information System (INIS)

Edwin, M.; Joseph Sekhar, S.

2014-01-01

Highlights: • Performance studies on biomass and biogas based milk cooling systems in remote areas. • Economic analysis of milk cooling system operated with locally available renewable energy sources. • Payback period for replacing conventional milk cooling systems with renewable energy based cooling system. • Identification of the suitable combination of locally available renewable energy sources for milk cooling. • Hybrid energy based milk cooling system for regions that have rubber and paddy cultivation, in India. - Abstract: In developing countries like India, about 70% of the population is engaged in the production of milk, fruits and vegetables. Due to the lack of proper storage and transit facilities, the agricultural produce, in remote areas loses its value. This spoilage could be prevented at the local village level, by providing cooling units for short term preservation. In this paper, the possibility of a hybrid energy based thermally operated cold storage has been considered to meet the cooling needs of the villages in the southern parts of India, where biomass, biogas and gobar gas are available in abundance. A milk cooling system that uses various combinations of locally available renewable energy sources to operate an aqua ammonia vapour absorption cooling system has been analysed using the Matlab software. The impact of various combinations of renewable energy sources on the Coefficient of Performance (COP), Net Present Value (NPV) and payback period of the total cooling system has been studied. The analysis shows that the COP and payback period of the proposed hybrid renewable energy based milk cooling system are 0.16–0.23 and 4–6 years respectively

Techno-economic and sensitivity analysis for grid-connected renewable energy electric boat charging station in Terengganu

Directory of Open Access Journals (Sweden)

Salleh N. A. S.

2017-01-01

Full Text Available In order to encourage the eco-friendly technologies in transportation sector, the reliance on fuel need to be reduced and the use of renewable energy (RE technology as energy source are widely explored by researchers. Thus, this study focus on the feasibility of developing grid-connected renewable energy electric boat charging station for the fishermen in Terengganu using simulation-based method by HOMER software. Five year solar radiation and wind speed data were collected at Universiti Sultan Zainal Abidin (UNISZA weather station. For load profile, the information about fishing activities and the amount of subsidy spent by the government were obtained from the interview session with the fishermen and validated with Lembaga Kemajuan Ikan Malaysia (LKIM. The results acquired are compared between grid-only and grid-connected RE systems in term of net present cost (NPC, operational cost and payback period. A sensitivity analysis is done to find the minimal Feed-in Tariff (FiT rate that can be implemented in order to encourage the use of RE system in this sector. Then, the relationship between FiT and NPC, payback period and emission of pollutants are analyzed. At current FiT rates RM 0.813/kWh, hybrid grid-PV system manages to achieve its optimal in generating high income from selling the power to the grid with convincing amount of electricity production and short payback period. It is concluded at minimum RM 0.56/kWh of FiT, the grid-connected RE system is possible to be developed because its performance shows better outcome compared to the grid-only system.

Trade-offs between forest carbon stocks and harvests in a steady state - A multi-criteria analysis.

Science.gov (United States)

Pingoud, Kim; Ekholm, Tommi; Sievänen, Risto; Huuskonen, Saija; Hynynen, Jari

2018-03-15

This paper provides a perspective for comparing trade-offs between harvested wood flows and forest carbon stocks with different forest management regimes. A constant management regime applied to a forest area with an even age-class distribution leads to a steady state, in which the annual harvest and carbon stocks remain constant over time. As both are desirable - carbon stocks for mitigating climate change and harvests for the economic use of wood and displacing fossil fuels - an ideal strategy should be chosen from a set of management regimes that are Pareto-optimal in the sense of multi-criteria decision-making. When choosing between Pareto-optimal alternatives, the trade-off between carbon stock and harvests is unavoidable. This trade-off can be described e.g. in terms of carbon payback times or carbon returns. As numerical examples, we present steady-state harvest levels and carbon stocks in a Finnish boreal forest region for different rotation periods, thinning intensities and collection patterns for harvest residues. In the set of simulated management practices, harvest residue collection presents the most favorable trade-off with payback times around 30-40 years; while Pareto-optimal changes in rotation or thinnings exhibited payback times over 100 years, or alternatively carbon returns below 1%. By extending the rotation period and using less-intensive thinnings compared to current practices, the steady-state carbon stocks could be increased by half while maintaining current harvest levels. Additional cases with longer rotation periods should be also considered, but were here excluded due to the lack of reliable data on older forest stands. Copyright © 2018 Elsevier Ltd. All rights reserved.

A decision support assessment of cogeneration plant for a community energy system in Korea

International Nuclear Information System (INIS)

Chung, Mo; Park, Chuhwan; Lee, Sukgyu; Park, Hwa-Choon; Im, Yong-Hoon; Chang, Youngho

2012-01-01

We have undertaken a case study of a Combined Heat and Power (CHP) plant applied to a mixture of buildings comprising residential premises, offices, hospitals, stores, and schools in Korea. We proposed five Plans for grouping buildings in the complex and estimated the annual 8760-hourly demands for electricity, cooling, heating, and hot water. For each Plan, we built about ten Scenarios for system construction. Then, we simulated the operation of the system to find the fuel consumption, electricity purchase, and heat recovery. Applying the local rates to the amounts of fuel and electricity, we estimated the operating costs. Combining the operating cost with the initial cost associated with the purchase and construction of the system, we calculated the payback periods for the scenarios. We found that the payback period can be as short as two years for smartly grouped buildings with a generator capacity of around 50% of the peak electricity demand. A progressive electricity rate that applies only to residential premises currently plays a key role in the economic merits. We recommend extending a sound progressive system to other types of building in Korea to promote distributed power production and enhance energy saving practices in general. - Highlights: ►We case-studied cogeneration plants for a residential complex in Korea. ►We estimated the annual 8760-hourly demands for electricity, heating, and cooling. ► We simulated the operation of CHP and estimated the fuel and electricity costs. ► We found payback periods that were shorter than two years for well-planned systems. ► A progressive electricity tariff plays a key role in the economic merits.

Technical support document: Energy efficiency standards for consumer products: Room air conditioners, water heaters, direct heating equipment, mobile home furnaces, kitchen ranges and ovens, pool heaters, fluorescent lamp ballasts and television sets. Volume 2, Fluorescent lamp ballasts, television sets, room air conditioners, and kitchen ranges and ovens

Energy Technology Data Exchange (ETDEWEB)

1993-11-01

This document is divided into ``volumes`` B through E, dealing with individual classes of consumer products. Chapters in each present engineering analysis, base case forecasts, projected national impacts of standards, life-cycle costs and payback periods, impacts on manufacturers, impacts of standards on electric utilities, and environmental effects. Supporting appendices are included.

Can biofuels be a solution to climate change? The implications of land use change-related emissions for policy

Science.gov (United States)

Khanna, Madhu; Crago, Christine L.; Black, Mairi

2011-01-01

Biofuels have gained increasing attention as an alternative to fossil fuels for several reasons, one of which is their potential to reduce the greenhouse gas (GHG) emissions from the transportation sector. Recent studies have questioned the validity of claims about the potential of biofuels to reduce GHG emissions relative to the liquid fossil fuels they are replacing when emissions owing to direct (DLUC) and indirect land use changes (ILUC) that accompany biofuels are included in the life cycle GHG intensity of biofuels. Studies estimate that the GHG emissions released from ILUC could more than offset the direct GHG savings by producing biofuels and replacing liquid fossil fuels and create a ‘carbon debt’ with a long payback period. The estimates of this payback period, however, vary widely across biofuels from different feedstocks and even for a single biofuel across different modelling assumptions. In the case of corn ethanol, this payback period is found to range from 15 to 200 years. We discuss the challenges in estimating the ILUC effect of a biofuel and differences across biofuels, and its sensitivity to the assumptions and policy scenarios considered by different economic models. We also discuss the implications of ILUC for designing policies that promote biofuels and seek to reduce GHG emissions. In a first-best setting, a global carbon tax is needed to set both DLUC and ILUC emissions to their optimal levels. However, it is unclear whether unilateral GHG mitigation policies, even if they penalize the ILUC-related emissions, would increase social welfare and lead to optimal emission levels. In the absence of a global carbon tax, incentivizing sustainable land use practices through certification standards, government regulations and market-based pressures may be a viable option for reducing ILUC. PMID:22482030

Comparison of swimming pools alternative passive and active heating systems based on renewable energy sources in Southern Europe

International Nuclear Information System (INIS)

Katsaprakakis, Dimitris Al.

2015-01-01

This article examines different passive and active heating systems for swimming pools. The passive systems introduced in this article are: * The swimming pools' enclosure. * The placement of floating insulating covers on the pools' surfaces whenever they are not used. The examined active systems in this article are: * A biomass heater. * A biomass heater and solar collectors combi-system. * Vertical geothermal heat exchangers (GHE) co-operating with geothermal heat pumps (GHP). The methodology employed for the introduced systems' evaluation is the arithmetic computational simulation of the swimming pools' annual heating, using annual time series of averaged hourly values for the available solar radiation and the calculated pools' thermal power demand (heating loads). The dimensioning of the active systems aims at the maximisation of the heating production from R.E.S. (renewable energy sources). and the optimisation of the corresponding investments' economic indexes. The examined systems are evaluated technically and economically versus fundamental criteria. It is proved that significant reduction of the heating loads is achieved with the introduced passive systems. The reduced swimming pools' heating loads can be successfully covered by the proposed R.E.S. active systems. The fossil fuels consumption is eliminated. The corresponding investments' payback periods can be lower than 5 years. - Highlights: • The passive solar systems reduce the swimming pools heating loads more than 90%. • The examined active heating system exhibit payback periods lower than 3.5 years. • The energy saving is maximised with a biomass heater – solar collectors system. • Single biomass heaters exhibits the shortest payback period. • GHE–GHP can be used in cases of low solar radiation and lack of biomass fuels

Phantom taxes: The big payback

International Nuclear Information System (INIS)

Wise, D.M.

1996-01-01

This article is a discussion of Accumulated Deferred Federal Income Taxes (AFDITs) associated with the stranded investments in nuclear facilities. The amounts are in the tens of billions of dollars and may rival the sum of recoverable stranded costs. The example is given of LILCO's Shoreham Nuclear Power Plant. Prior to cancellation, LILCO had capitalized the cost of the project for rate purposes and had generated income for rate purposes. For tax purposes, however, their accounting system produced a substantial loss, resulting in the collection of more than $1B in federal tax-expense reimbursements over and above actual tax expenses. These additional monies were retained by LILCO. The author argues that these monies should be used to offset standed recoverable costs

Italian Residential Buildings: Economic Assessments for Biomass Boilers Plants

Directory of Open Access Journals (Sweden)

Maurizio Carlini

2013-01-01

Full Text Available Biomass is increasingly used for energy generation since it represents a useful alternative to fossil fuel in order to face the pollutions and the global warming problem. It can be exploited for heating purposes and for supplying domestic hot water. The most common applications encompass wood and pellet boilers. The economic aspect is becoming an important issue in order to achieve the ambitious targets set by the European Directives on Renewable Sources. Thus, the present paper deals with the economic feasibility of biomass boiler plants with specific regard to an existing residential building. An Italian case study is further investigated, focusing the attention on European and national regulations on energy efficiency and considering the recent public incentives and supporting measures. The main thermoclimatic parameters—that is, heating degree days (HDDs, building thermal insulation and thermal needs—are taken into account. Moreover, the following economic indicators are calculated: cumulative cash flow, discounted cumulative cash flow, payback period (PP, net present value (NPV, Internal rate of return (IRR, discounted payback period (DPP, and profit index (PI.

ASSESSMENT OF EFFICIENCY OF APPLICATION OF A NEW BUILDING MATERIAL

Directory of Open Access Journals (Sweden)

Gumba Huta Msuratovich

2012-10-01

Full Text Available Methodical approaches and procedures of implementation of official provisions of Methodical Recommendations are considered in article. Upon completion of analysis of a number of factors, the authors suggest using the option of assessment of efficiency of application of a new construction material through the application of Methodical Recommendations for Assessment of Efficiency of Investment Projects. As for the assimilation of new materials by building companies engaged in construction operations, the recommendation is to assess the business project efficiency upon introduction of each new construction material, and capital investments are the main indicators of efficiency of construction materials, let alone net discounted profit and the payback period. Upon consideration of a number of conditions that underlie the mathematical and economic model that substantiates decision-making in terms of implementation of innovative projects, the project efficiency can be assessed on the basis of an integrated indicator - maximal return on capital investments. The proposed model also takes account of the payback period, although the efficiency of new construction materials does not take account of any positive social effect of their introduction.

Parametric Investigation of Optimum Thermal Insulation Thickness for External Walls

Directory of Open Access Journals (Sweden)

Omer Kaynakli

2011-06-01

Full Text Available Numerous studies have estimated the optimum thickness of thermal insulation materials used in building walls for different climate conditions. The economic parameters (inflation rate, discount rate, lifetime and energy costs, the heating/cooling loads of the building, the wall structure and the properties of the insulation material all affect the optimum insulation thickness. This study focused on the investigation of these parameters that affect the optimum thermal insulation thickness for building walls. To determine the optimum thickness and payback period, an economic model based on life-cycle cost analysis was used. As a result, the optimum thermal insulation thickness increased with increasing the heating and cooling energy requirements, the lifetime of the building, the inflation rate, energy costs and thermal conductivity of insulation. However, the thickness decreased with increasing the discount rate, the insulation material cost, the total wall resistance, the coefficient of performance (COP of the cooling system and the solar radiation incident on a wall. In addition, the effects of these parameters on the total life-cycle cost, payback periods and energy savings were also investigated.

Cost-Benefit of Improving the Efficiency of Room Air Conditioners (Inverter and Fixed Speed) in India

Energy Technology Data Exchange (ETDEWEB)

Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Abhyankar, Nikit [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Division; Diddi, Saurabh [Government of India, New Delhi (India). Bureau of Energy Efficiency; Ahuja, Deepanshu [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Mukherjee, P. K. [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States); Walia, Archana [Collaborative Labeling and Appliance Standards Program (CLASP), Washington, DC (United States)

2016-06-30

Improving efficiency of air conditioners (ACs) typically involves improving the efficiency of various components such as compressors, heat exchangers, expansion valves, refrigerant and fans. We estimate the incremental cost of improving the efficiency of room ACs based on the cost of improving the efficiency of its key components. Further, we estimate the retail price increase required to cover the cost of efficiency improvement, compare it with electricity bill savings, and calculate the payback period for consumers to recover the additional price of a more efficient AC. We assess several efficiency levels, two of which are summarized below in the report. The finding that significant efficiency improvement is cost effective from a consumer perspective is robust over a wide range of assumptions. If we assume a 50% higher incremental price compared to our baseline estimate, the payback period for the efficiency level of 3.5 ISEER is 1.1 years. Given the findings of this study, establishing more stringent minimum efficiency performance criteria (one star level) should be evaluated rigorously considering significant benefits to consumers, energy security and environment.

Feasibility of wind power generation in Ghana | Ayensu | Journal of ...

African Journals Online (AJOL)

For payback period of 10 years, the projected cost of the energy produced by a single turbine was estimated to be GHC 0.30 (~ 20 cents) per kWh (compared to 14 cents/kWh for photovoltaic generation and 10 cents/kWh for solar thermal), which therefore makes large scale optimized wind power generation competitive in ...

EFFICIENCY OF THE USE OF HEAT PUMPS ON THE CHP PLANTS

Directory of Open Access Journals (Sweden)

Juravleov A.A.

2007-04-01

Full Text Available The work is dedicated to the calculus of the efficiency of the use of heat pumps on the CHP plants. There are presented the interdependences between the pay-back period and NPV of heat pump and the price of 1 kWt of thermal power of heat pump and of the tariff of electricity.

Techno-economic evaluation of a ventilation system assisted with exhaust air heat recovery, electrical heater and solar energy

OpenAIRE

Özyoğurtçu, Gamze; Mobedi, Moghtada; Özerdem, Barış

2014-01-01

The energy consumed to condition fresh air is considerable, particularly for the buildings such as cinema, theatre or gymnasium saloons. The aim of the present study is to design a ventilation system assisted with exhaust air heat recovery unit, electrical heater and stored solar energy, then to make an economical analysis based on life cycle cost (LCC) to find out its payback period. The system is able to recover thermal energy of exhaust air, store solar energy during the sunlight period an...

Early action to reduce greenhouse gas emissions before the commitment period of the Kyoto protocol: advantages and disadvantages.

Science.gov (United States)

Michaelowa, A; Rolfe, C

2001-09-01

Current "business as usual" projections suggest greenhouse gas emissions from industrialized nations will grow substantially over the next decade. However, if it comes into force, the Kyoto Protocol will require industrialized nations to reduce emissions to an average of 5% below 1990 levels in the 2008-2012 period. Taking early action to close this gap has a number of advantages. It reduces the risks of passing thresholds that trigger climate change "surprises." Early action also increases future generations' ability to choose greater levels of climate protection, and it leads to faster reductions of other pollutants. From an economic sense, early action is important because it allows shifts to less carbon-intensive technologies during the course of normal capital stock turnover. Moreover, many options for emission reduction have negative costs, and thus are economically worthwhile, because of paybacks in energy costs, healthcare costs, and other benefits. Finally, early emission reductions enhance the probability of successful ratification and lower the risk of noncompliance with the protocol. We discuss policy approaches for the period prior to 2008. Disadvantages of the current proposals for Credit for Early Action are the possibility of adverse selection due to problematic baseline calculation methods as well as the distributionary impacts of allocating a part of the emissions budget already before 2008. One simple policy without drawbacks is the so-called baseline protection, which removes the disincentive to early action due to the expectation that businesses may, in the future, receive emission rights in proportion to past emissions. It is particularly important to adopt policies that shift investment in long-lived capital stock towards less carbon-intensive technologies and to encourage innovation and technology development that will reduce future compliance costs.

Round-bale feeder design affects hay waste and economics during horse feeding.

Science.gov (United States)

Martinson, K; Wilson, J; Cleary, K; Lazarus, W; Thomas, W; Hathaway, M

2012-03-01

Many horse owners find round bales convenient, less labor intensive, and more affordable than other hay types, but report an inability to control horse BW gain and excessive hay waste. The objectives were to compare hay waste, hay intake, and payback of 9 round-bale feeders and a no-feeder control when used during horse feeding. Nine round-bale feeders were tested: Cinch Net, Cone, Covered Cradle, Hayhut, Hay Sleigh, Ring, Tombstone, Tombstone Saver, and Waste Less. Each feeder design was placed on the ground in a dirt paddock. Five groups of 5 horses were fed in rotation for a 4-d period with each feeder. Every fourth day, groups were rotated among paddocks and a new round bale was placed in each feeder. In the 5 paddocks used, 5 feeders were installed for d 1 through 20, and the remaining 4 feeders and no-feeder control were installed for d 21 through 40. Groups of horses were sequentially assigned to feeders using two 5 × 5 Latin squares, the first for d 1 through 20, the second for d 21 through 40. Horse groups of similar age, BW, breed, and sex were formed from 25 Quarter Horse and Thoroughbred geldings and open mares (means: 11 yr; 541 kg of BW). Hay on the ground surrounding the feeder was collected daily, dried, and weighed. The total amount of hay removed around each feeder for a 4-d period was considered waste. Dry matter intake was estimated as the difference between hay disappearance and waste. Number of months for the reduction in waste to repay feeder cost (payback) were calculated using hay valued at $110/t, and improved feeder efficiency over the control. Feeder design did not affect hay intake (P > 0.05); all feeders resulted in an estimated hay intake of 2.0 to 2.4% BW; the no-feeder control resulted in a reduced intake of 1.3% BW (P = 0.001). Mean percentage of hay waste differed among feeders (P feeder control, 57%. Feeder design also affected payback (P feeder design affected hay waste and payback, but not estimated hay intake or BW change

Comparative Evaluation of Integrated Waste Heat Utilization Systems for Coal-Fired Power Plants Based on In-Depth Boiler-Turbine Integration and Organic Rankine Cycle

Directory of Open Access Journals (Sweden)

Shengwei Huang

2018-01-01

Full Text Available To maximize the system-level heat integration, three retrofit concepts of waste heat recovery via organic Rankine cycle (ORC, in-depth boiler-turbine integration, and coupling of both are proposed, analyzed and comprehensively compared in terms of thermodynamic and economic performances. For thermodynamic analysis, exergy analysis is employed with grand composite curves illustrated to identify how the systems are fundamentally and quantitatively improved, and to highlight key processes for system improvement. For economic analysis, annual revenue and investment payback period are calculated based on the estimation of capital investment of each component to identify the economic feasibility and competitiveness of each retrofit concept proposed. The results show that the in-depth boiler-turbine integration achieves a better temperature match of heat flows involved for different fluids and multi-stage air preheating, thus a significant improvement of power output (23.99 MW, which is much larger than that of the system with only ORC (6.49 MW. This is mainly due to the limitation of the ultra-low temperature (from 135 to 75 °C heat available from the flue gas for ORC. The thermodynamic improvement is mostly contributed by the reduction of exergy destruction within the boiler subsystem, which is eventually converted to mechanical power; while the exergy destruction within the turbine system is almost not changed for the three concepts. The selection of ORC working fluids is performed to maximize the power output. Due to the low-grade heat source, the cycle with R11 offers the largest additional net power generation but is not significantly better than the other preselected working fluids. Economically, the in-depth boiler-turbine integration is the most economic completive solution with a payback period of only 0.78 year. The ORC concept is less attractive for a sole application due to a long payback time (2.26 years. However, by coupling both

An experimental study on energy generation with a photovoltaic (PV)-solar thermal hybrid system

International Nuclear Information System (INIS)

Erdil, Erzat; Ilkan, Mustafa; Egelioglu, Fuat

2008-01-01

A hybrid system, composed of a photovoltaic (PV) module and a solar thermal collector is constructed and tested for energy collection at a geographic location of Cyprus. Normally, it is required to install a PV system occupying an area of about 10 m 2 in order to produce electrical energy; 7 kWh/day, required by a typical household. In this experimental study, we used only two PV modules of area approximately 0.6 m 2 (i.e., 1.3x0.47 m 2 ) each. PV modules absorb a considerable amount of solar radiation that generate undesirable heat. This thermal energy, however, may be utilized in water pre-heating applications. The proposed hybrid system produces about 2.8 kWh thermal energy daily. Various attachments that are placed over the hybrid modules lead to a total of 11.5% loss in electrical energy generation. This loss, however, represents only 1% of the 7 kWh energy that is consumed by a typical household in northern Cyprus. The pay-back period for the modification is less than 2 years. The low investment cost and the relatively short pay-back period make this hybrid system economically attractive

Optimization and Economic Analysis of Grid-Photovoltaic Electric Boat Charging Station in Kuala Terengganu

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Salleh N.A. S.

2016-01-01

Full Text Available This study evaluates the feasibility of developing grid-photovoltaic electric boat charging station in Kuala Terengganu using simulation-based method. The main focus is on reducing the dependency on subsidy spent by the government in fisheries sector and encouraging green technology in commercial sector. All data such as solar radiation, amount of subsidy received by fishermen, and fishing activities were collected for the selected area. Economic analyses of the proposed system are discussed based on payback period and net present cost (NPC. The comparison between the proposed system and the grid-only system is done based on the production and consumption of electricity per year, the NPC and emission of pollutant. The system also generates high income from selling energy to the grid with tariff rates RM 1.49/kWh. It is concluded that the proposed system is feasible to be developed in the selected area with the payback period and the NPC are 8.2 years and RM 759,098, respectively. The results also show that the performance of the proposed system is better than grid-only system in all the interested parameters.

Comparative performance of fluorescent iron-core ballasts and electronic ballasts. Rendement comparatif des ballasts a noyau de fer et des ballasts electroniques pour eclairage fluorescent

Energy Technology Data Exchange (ETDEWEB)

Pasini, I

1987-01-01

Commercially available one- and two-lamp fluorescent luminaires were tested, and a number of electrical parameters were measured using varying combinations of lamps and either iron-core or electronic ballasts. Comprehensive photometric tests and thermal measurements were also conducted. The test results were tabulated and compared. The performance of the iron-core ballasts was found to be sufficiently close to nominally rated values to not raise concerns. Results from testing the electronic ballasts showed that the user has to be careful when selecting these ballasts, as they far exceed standard specification limits for current and voltage crest factors. All other electrical, photometric and thermal parameters are within accepted levels. An economic analysis was undertaken to determine cost benefits and payback periods for using electronic ballasts, the use of which will result in higher efficiency and lower power consumption. A project life of 20 years was assumed, and analysis was run for a power cost of $0.04/kWh. A unit made by Fyrnetics showed the lowest total annual owning and operating costs and had a payback period of 12.1 years. 13 figs., 13 tabs.

Financial Profitability and Sensitivity Analysis of Palm Oil Plantation in Indonesia

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Tereza Svatoňová

2015-01-01

Full Text Available Oil palm cultivation in Indonesia is increasing. This study investigates the financial and economic aspects of establishing an oil palm plantation using data collected in 2014. The financial case study is undertaken from the perspective of company in North Sumatra, Indonesia. A spreadsheet model was used to develop and calculate the net present value (NPV, return of investment (ROI, internal rate of return (IRR and payback period (PP. Sensitivity analysis of the NPV to the default discount rate (10% was included. A 8,000 ha plantation over 25 years was estimated to result in a positive NPV of USD 10,670 with a ROI 73.50% and an IRR at 14.83% and payback period of 6.75 years. Establishing an oil palm plantation seems to be very profitable investment on the basis of the assumptions made. System is tested on sensitivity in different capital and recurrent costs and in selling price of raw material, while change in selling price of FFB is more sensitive to NPV than change in investment and recurrent costs Discount rate is also one of the factors affecting NPV and system is tested between 5–15% change in discount rate.

The Identification of Financing Strategy for the Construction of NPP Type Opr-1000 at Muria Peninsula

International Nuclear Information System (INIS)

Moch-Djoko Birmano

2006-01-01

The study for identification of financing strategy for the construction of OPR-1000 at Muria Peninsula have been done. This study is continuation of previous study with title T he Economic and Financing Viability of the OPR-1000 Construction at Muria Peninsula . In the previous study have been the economic and financing viability of OPR-1000 construction. The economic viability was known by obtained the generation cost, electricity tariff and construction cost. The meanwhile, the financing viability was known by obtained Net Present Value (NPV), Internal Rate of Return (IRR) and Payback Period (P) by using KEPCO Spread Sheet. From the calculation of economic and financing viability in base case, have been obtained the result of electricity tariff, IRR, FNPV and Payback Period for total investment is 6.640 cent/kWh (after Value Added Tax), 10.37%, US$ 90.52 million and 12.11 years, respectively. From this result of economic and financing viability in base case, have been carried out sensitivity analysis to technical parameter (capacity factor) and economic parameter (discount rate). The result of sensitivity analysis to be used for identifying financing strategy in order to obtain the best and optimal economic and financing viability. (author)

Is HAPS Viable for the Next-Generation Telecommunication Platform in Korea?

Directory of Open Access Journals (Sweden)

Jonghwa Kim

2008-07-01

Full Text Available HAPS is a promising technology capable of providing broadband multimedia services as an alternative to the satellite communication system or terrestrial network. In this study, economic aspects of HAPS service are analyzed, HAPS services are defined, and revenues from the defined services are forecasted assuming nine scenarios. Capital expenditure as well as operating expenditure is estimated. To evaluate the profitability of HAPS service, the net present value (NPV, payback period, and the internal rate of return (IRR are calculated. The results show that HAPS is economically justifiable in all the scenarios. Assuming that ARPU for the service is $35 per month in the average scenario, NPV is calculated as $2964 million, IRR becomes 31.9%, and payback occurs in 2017, which implies that HAPS service is profitable in Korea. In addition, the results of the sensitivity analysis show that the results are fairly robust.

Is HAPS Viable for the Next-Generation Telecommunication Platform in Korea?

Directory of Open Access Journals (Sweden)

Lee Deokjoo

2008-01-01

Full Text Available Abstract HAPS is a promising technology capable of providing broadband multimedia services as an alternative to the satellite communication system or terrestrial network. In this study, economic aspects of HAPS service are analyzed, HAPS services are defined, and revenues from the defined services are forecasted assuming nine scenarios. Capital expenditure as well as operating expenditure is estimated. To evaluate the profitability of HAPS service, the net present value (NPV, payback period, and the internal rate of return (IRR are calculated. The results show that HAPS is economically justifiable in all the scenarios. Assuming that ARPU for the service is $35 per month in the average scenario, NPV is calculated as $2964 million, IRR becomes 31.9%, and payback occurs in 2017, which implies that HAPS service is profitable in Korea. In addition, the results of the sensitivity analysis show that the results are fairly robust.

Effectiveness of duct sealing and duct insulation in multi-family buildings. Final report

Energy Technology Data Exchange (ETDEWEB)

Karins, N.H.; Tuluca, A.; Modera, M.

1997-07-01

This research investigated the cost-effectiveness of sealing and insulating the accessible portions of duct systems exposed to unconditioned areas in multifamily housing. Airflow and temperature measurements were performed in 25 apartments served by 10 systems a 9 multi-family properties. The measurements were performed before and after each retrofit, and included apartment airflow (supply and return), duct system temperatures, system fan flow and duct leakage area. The costs for each retrofit were recorded. The data were analyzed and used to develop a prototypical multifamily house. This prototype was used in energy simulations (DOE-2.1E) and air infiltration simulations (COMIS 2.1). The simulations were performed for two climates: New York City and Albany. In each climate, one simulation was performed assuming the basement was tight, and another assuming the basement was leaky. Simulation results and average retrofit costs were used to calculate cost-effectiveness. The results of the analysis indicate that sealing leaks of the accessible ductwork is cost-effective under all conditions simulated (simple payback was between 3 and 4 years). Insulating the accessible ductwork, however, is only cost-effective for buildings with leaky basement, in both climates (simple paybacks were less than 5 years). The simple payback period for insulating the ducts in buildings with tight basements was greater than 10 years, the threshold of cost-effectiveness for this research. 13 refs., 5 figs., 27 tabs.

Can energy conservation and religion mix

Energy Technology Data Exchange (ETDEWEB)

Fox, J

1987-08-01

Many churches share problems of inefficient heating systems, drafty windows, high ceilings, and poor insulation. The author has devised a four-stage method to evaluate the energy efficiency of a religious building and to develop recommendations for improvement. The suggested payback period is four years or less. This article describes the proposed method and highlights a successful project in Oshawa, Ontario as an example.

Caribic EEG. A new regulation speeds up the solar power market in the Dominical Republic; Karibik-EEG. Eine neue Richtlinie belebt den Solarstrommarkt in der Dominikanischen Republik

Energy Technology Data Exchange (ETDEWEB)

Rosell, Alejandro Diego

2011-09-15

In spite of its sunny weather conditions, the Dominican Republic so far has only solar systems with a total of 500 kW. But a new law came into force that permits backward current meters. Those who generate more power than they consume will even get a reimbursement. With additional tax exemptions, the payback period of solar systems will be only a few years.

Parameter analysis and optimization of the energy and economic performance of solar-assisted liquid desiccant cooling system under different climate conditions

International Nuclear Information System (INIS)

Qi, Ronghui; Lu, Lin; Huang, Yu

2015-01-01

Highlights: • Operation conditions significantly affect energy & economic performance of SLDCS. • Control parameters in three areas were optimized by Multi-Population Genetic Algorithm. • Solar collector area showed the greatest effect on system performance for humid areas. • Desiccant concentration showed greatest effect on system performance for dry areas. • Requirement of collector area, heating water and desiccant flow rates for humid areas is highest. - Abstract: Operation conditions significantly affect the energy and economic performance of solar-assisted liquid desiccant cooling systems. This study optimized the system control parameters for buildings in different climates, i.e., Singapore (hot and humid), Beijing (moderate) and Boulder (hot and dry), with a multi-parameter optimization based on the Multi-Population Genetic Algorithm to obtain optimal system performance in terms of relatively maximum electricity saving rate with a minimum cost payback period. The results indicated that the selection of operation parameters is significantly influenced by climatic conditions. The solar collector installation area exhibited the greatest effect on both energy and economic performance in humid areas, and the heating water flow rate was also important. For dry areas, a change in desiccant concentration had the largest effect on system performance. Although the effect of the desiccant flow rate was significant in humid cities, it appeared to have little influence over buildings in dry areas. Furthermore, the requirements of the solar collector installation area in humid areas were much higher. The optimized area was up to 70 m"2 in Singapore compared with 27.5 m"2 in Boulder. Similar results were found for the flow rates of heating water and the desiccant solution. Applying the optimization, humid cities could achieve an electricity saving of more than 40% with a six-year payback period. The optimal performance for hot and dry areas of a 38% electricity

The cost-effectiveness of household photovoltaic systems in reducing greenhouse gas emissions in Australia: Linking subsidies with emission reductions

International Nuclear Information System (INIS)

Burtt, D.; Dargusch, P.

2015-01-01

Highlights: • Payback period for Australian household PV fell to four years in 2011 and 2012. • PV became attractive due to high feed-in tariffs and declining PV costs. • Cost was AU$200/t CO 2 e in 2010, expected to be AU$65 to AU$100/t CO 2 e by 2020. • PV resulted in greenhouse gas emissions reducing by 3.7 million t CO 2 e in 2013. • PV expected to reduce greenhouse gas emissions by 8 million t CO 2 e in 2020. - Abstract: This paper examines the cost-effectiveness of subsidies (feed-in tariffs and renewable energy credits) paid for by electricity consumers to support the uptake of roof top photovoltaic (PV) systems by households in Australia. We estimate annual payback periods, and then regress these against the actual uptake of household PV and associated emission reductions, creating a relationship not apparent in other research. Sensitivity analysis reveals that the declining cost of PV panels had most impact on PV uptake followed by feed-in tariffs, renewable energy credits and the increasing cost of household electricity tariffs. Our modelling shows that feed-in tariffs were higher than necessary to achieve the resultant levels of PV uptake and that the low cost of PV panels and comparatively high electricity tariffs are likely to result in a continuing strong uptake of household PV in Australia. Our modelling shows that subsidies peaked in 2011 and 2012, with payback periods of three to four years, having since increased to five to six years. Emission reduction costs are expected to reduce from over AU$200 per t CO 2 e in 2013 to between AU$65 and AU$100 per t CO 2 e in 2020. Household PV reduced Australia’s emissions by 3.7 million t CO 2 e in 2013 (1.7% of Australia’s total emissions) and is expected to reach eight million tonnes (3.7% of Australia’s total emissions) by 2020

A Cost to Benefit Analysis of a Next Generation Electric Power Distribution System

Science.gov (United States)

Raman, Apurva

This thesis provides a cost to benefit analysis of the proposed next generation of distribution systems- the Future Renewable Electric Energy Distribution Management (FREEDM) system. With the increasing penetration of renewable energy sources onto the grid, it becomes necessary to have an infrastructure that allows for easy integration of these resources coupled with features like enhanced reliability of the system and fast protection from faults. The Solid State Transformer (SST) and the Fault Isolation Device (FID) make for the core of the FREEDM system and have huge investment costs. Some key features of the FREEDM system include improved power flow control, compact design and unity power factor operation. Customers may observe a reduction in the electricity bill by a certain fraction for using renewable sources of generation. There is also a possibility of huge subsidies given to encourage use of renewable energy. This thesis is an attempt to quantify the benefits offered by the FREEDM system in monetary terms and to calculate the time in years required to gain a return on investments made. The elevated cost of FIDs needs to be justified by the advantages they offer. The result of different rates of interest and how they influence the payback period is also studied. The payback periods calculated are observed for viability. A comparison is made between the active power losses on a certain distribution feeder that makes use of distribution level magnetic transformers versus one that makes use of SSTs. The reduction in the annual active power losses in the case of the feeder using SSTs is translated onto annual savings in terms of cost when compared to the conventional case with magnetic transformers. Since the FREEDM system encourages operation at unity power factor, the need for installing capacitor banks for improving the power factor is eliminated and this reflects in savings in terms of cost. The FREEDM system offers enhanced reliability when compared to a

A systematic approach to find the best road map for enhancement of a power plant with dew point inlet air pre-cooling of the air compressor

International Nuclear Information System (INIS)

Sohani, Ali; Farasati, Yashar; Sayyaadi, Hoseyn

2017-01-01

Highlights: • Dew-point cooler was proposed in order to enhance a power plant. • A systematic method to find the best road map was offered. • Investigation was done considering four optimization scenarios and different investment plans. • Payback period of the final plan was 2.67 years. • Annual net power and steam generation’s capability were improved 6.02% and 8.92%. - Abstract: Dimensional characteristics and operating parameters of the optimized Maisotsenko indirect evaporative cooler for pre-cooling of the compressor’s inlet air and consequently enhancement of the gas-turbine power generation system as well as the best investment strategy for it were found for an in-operation combined cycle power plant through a systematic approach. Four optimization scenarios were proposed considering different combinations of annual average of net power of the gas-turbine power generation system, payback period time and enthalpy difference of exhaust gases compared to the reference state of each gas-turbine power generation system as objective functions. In each scenario, optimization was conducted for different possible percentages of investment allocated to the research and development of the project. After that, analytical hierarchy process was used to find the best percentage of investment allocated to the research and development of the project of each scenario and the final selected one. Having introduced the approach, it was implemented for Montazer-Ghaem combined cycle power plant in Iran. The results showed for that case study, the analytical hierarchy process selected an optimization scenario in which the annual average of the net power and the enthalpy difference of the exhaust gases compared to the reference state were the objective functions and 15% of the total profit of the gas-turbine power generation system sold electricity was dedicated to the improvement project. This optimization had the payback period time of 2.67 years and it also improved

Energetic, exergetic and economic analysis of an innovative Solar CombiSystem (SCS) producing thermal and electric energies: Application in residential and tertiary households

International Nuclear Information System (INIS)

Hazami, Majdi; Mehdaoui, Farah; Naili, Nabiha; Noro, Marco; Lazzarin, Renato; Guizani, AmenAllah

2017-01-01

Highlights: • The present work studies the potential of using innovative SCS in Tunisia. • In cold months the SCS provide about 50–75% of the total exergy provides. • The SCS produces between 70–150% of electric energy needs. • The SCS payback period (Pb) based on electric water heater was 10.2 years. • The SCS payback period (Pb) based on gas/gas town was about and 8.7 years. - Abstract: The endeavor of this paper is to study of the potential offered by the expenditure of an innovative Solar CombiSystem, SCS, used for the space heating load, the domestic hot water supply and the electric energy production. The investigation achieved in this work was based on an experimental and a simulation studies. A TRNSYS simulation program was achieved in order to evaluate the SCS monthly/annual thermal and electric performances. It was found that the proposed SCS covered between 20 and 45% of the SH energy needs by considering only solar energy. The result shows also that the SCS provided from 40 to 70% of the total DHW needs. It was also found that the SCS electric production ranged between 32 and 225 MJ/m 2 with a gain factor varying between 49 and 125%. An economic appraisal was also achieved to appraise the SCS feasibility. The results of the economic analysis show that the annual energy saved (ARE) and the payback period (Pb) based on electric water heater were respectively equal to 7618.3 kW h/year and 10.2 years. It was found that ARE and Pb based on gas/gas town were about 5825 m 3 and 8.7 years, respectively. The results of the economic analysis shows that the adoption of the SCS saves about 48% of electric energy and about 46% of gas/gas town kept back by the conventional system.

Evolution of periodicity in periodical cicadas.

Science.gov (United States)

Ito, Hiromu; Kakishima, Satoshi; Uehara, Takashi; Morita, Satoru; Koyama, Takuya; Sota, Teiji; Cooley, John R; Yoshimura, Jin

2015-09-14

Periodical cicadas (Magicicada spp.) in the USA are famous for their unique prime-numbered life cycles of 13 and 17 years and their nearly perfectly synchronized mass emergences. Because almost all known species of cicada are non-periodical, periodicity is assumed to be a derived state. A leading hypothesis for the evolution of periodicity in Magicicada implicates the decline in average temperature during glacial periods. During the evolution of periodicity, the determinant of maturation in ancestral cicadas is hypothesized to have switched from size dependence to time (period) dependence. The selection for the prime-numbered cycles should have taken place only after the fixation of periodicity. Here, we build an individual-based model of cicadas under conditions of climatic cooling to explore the fixation of periodicity. In our model, under cold environments, extremely long juvenile stages lead to extremely low adult densities, limiting mating opportunities and favouring the evolution of synchronized emergence. Our results indicate that these changes, which were triggered by glacial cooling, could have led to the fixation of periodicity in the non-periodical ancestors.

KAJIAN FINANSIAL ISOLASI CITRONELLAL DAN RHODINOL PADA INDUSTRI bERBASIS SENYAWA TURUNAN MINYAK SEREH WANGI

Directory of Open Access Journals (Sweden)

Retno Sri Endah Lestari

2016-11-01

Full Text Available Isolation components of Citronellal and  Rhodinol in citronella oil can be applied to the industry to increase the added value and develop intermediate industries of citronella oil. To determine the feasibility of implementation, financial analysis is required to process such isolation. Feasibility of investment in new industrial establishment or development of NPV seen citronella oil  industry, BEP, PBP, Net B / C and IRR can describe whether the project is still attractive to be realized. On the establishment of new industries, the NPV value of Rp11, 844,269,430.12, an IRR of 47%. The payback period (PBP is achieved over a period of 2.79 years. Net value of B / C is 2.75 and the production break-even point (BEP is obtained on the sale value of Rp. 5,217,742,676.09. While the development of citronella oil industry, the NPV of the industrial development of Rp 12,348,032,363.16. IRR value for industrial development with 600 kg Input / process is 89%. The payback period (PBP industrial development achieved during the period of 4.41 years. Net value of B / C obtained from the establishment Factory is 6.30. Production break-even point (BEP is obtained on the sale value of Rp 20,912,029,225.35. This suggests that the establishment of new industries and the development of scented citronella oil industry that already exist, worthy to be realized

KINERJA INVESTASI JASA PENGUJIAN TABLEWARE UNTUK PRODUK KREATIF KERAMIK PADA BTIKK-BPPT

Directory of Open Access Journals (Sweden)

I Nyoman Normal

2017-05-01

Full Text Available The aims of this research was to analize the tableware testing service investment especially on ceramic glaze for eating and drinking equipments at BTIKK-BPPT. The analysis techniques used were payback period, net present value, profitability index, internal rate of return, and break even point. The research results shew that the expansion investment of tableware testing service of ceramic on glaze for eating and drinking equipments qualified by BSN according to SNI 7275:2008 was feasible to be acted or applicated because they fulfilled the criteria of investment feasibility valuation, namely: payback period analysis result was 4,65 years, in which its value was shorter than range time of investment that was 10 years; net present value analysis result was IDR.206.043.764,69, in which it was the positive value; profitability index analysis result was 1,41, in which its value was over than 1,00; internal rate of return analysis result was 18,93%, in which its value was over than 10,00%; and break even point analysis resulted 2.567,56 samples unit or IDR.256.911.104,11, in which it was smaller than 6.300,00 samples unit or IDR.783.000.000,00. For all criteria, the analysis of testing service investment (appearance, glazur hardness, temperature frightened tenacity, water absorption, Cd & Pb solubility, glaze crack tenacity, and strike sturdy was feasible to continue. Penelitian ini bertujuan untuk menganalisis jasa pengujian produk kreatif keramik tableware, khususnya keramik berglasir untuk alat makan dan minum keramik di BTIKK-BPPT. Teknik analisis yang digunakan adalah payback period, net present value, profitability index, internal rate of return, dan break even point. Hasil penelitian menunjukkan bahwa perluasan investasi jasa pengujian peralatan makan dari keramik berglasir untuk alat makan dan minum berkualifikasi BSN sesuai dengan SNI 7275:2008 adalah layak untuk dilanjutkan atau diaplikasikan karena telah memenuhi kriteria penilaian

Custom design of a hanging cooling water power generating system applied to a sensitive cooling water discharge weir in a seaside power plant: A challenging energy scheme

International Nuclear Information System (INIS)

Tian, Chuan Min; Jaffar, Mohd Narzam; Ramji, Harunal Rejan; Abdullah, Mohammad Omar

2015-01-01

In this study, an innovative design of hydro-electricity system was applied to an unconventional site in an attempt to generate electricity from the exhaust cooling water of a coal-fired power plant. Inspired by the idea of micro hydro, present study can be considered new in three aspects: design, resource and site. This system was hung at a cooling water discharge weir, where all sorts of civil work were prohibited and sea water was used as the cooling water. It was designed and fabricated in the university's mechanical workshop and transported to the site for installation. The system was then put into proof run for a three-month period and achieved some success. Due to safety reasons, on-site testing was prohibited by the power plant authority. Hence, most data was acquired from the proof run. The driving system efficiency was tested in the range of 25% and 45% experimentally while modeling results came close to experimental results. Payback period for the system is estimated to be about 4.23 years. Result obtained validates the feasibility of the overall design under the sensitive site application. - Highlights: • Challenging energy scheme via a hanging cooling water power generating system. • Driving system efficiency was tested in the range of 25% and 45%. • Payback period for the system is estimated to be about 4.2 years

Analysis Of Investment Feasibility Of Batching Plant Development In Tanjung Redeb Talisayan Highway Km 102 In Biatan District Berau Regency

Directory of Open Access Journals (Sweden)

Ali Rosit

2017-12-01

Full Text Available This research is a feasibility study of Batching Plant development on Tanjung Redeb - Talisayan Highway Km 102 Biatan District Berau Regency which aims to know whether the development project can be built in terms of technical and economic aspects and to analyze the sensitivity with 3 types of economic situation. The data from this field study are analyzed using Present Value Net Present Value NPV Internal Rate of Return IRR Benefit Cost Ratio BCR and Payback Periods PBP. The results of the analysis show that Batching Plant Development on Tanjung Redeb Talisayan Highway Km 102 in Biatan District Berau Regency is quite feasible to be implemented with the assumption of 10 years investment period. Based on the calculation of Net Present Value NPV of IDR 11.499.703.942 positive Internal Rate of Return 1727 12 Benefit Cost Ratio 2309 1 with Payback Period is 5 years 7 months from the sensitivity analysis results the condition of the initial investment cost rate run up reaches to 127 the state of interest rates rose to 1454 due to uncertainty in the national and international economies and the circumstances when cash flows fell as a result of the decrease in revenues to 1684 where the circumstances state that the project which is about to be affected is not feasible or break event.

Users enlist consultants to calculate costs, savings

Energy Technology Data Exchange (ETDEWEB)

1982-05-24

Consultants who calculate payback provide expertise and a second opinion to back up energy managers' proposals. They can lower the costs of an energy-management investment by making complex comparisons of systems and recommending the best system for a specific application. Examples of payback calculations include simple payback for a school system, a university, and a Disneyland hotel, as well as internal rate of return for a corporate office building and a chain of clothing stores. (DCK)

ANALISIS KELAYAKAN FINANSIAL PROYEK NARROWNECK PRESS AND BLOW UNTUK PROSES PRODUKSIBOTOL MINUMAN BERENERGI DI PT. ABC

Directory of Open Access Journals (Sweden)

Toni MT Munthe

2015-08-01

Full Text Available PT. ABC merupakan salah satu pabrik yang memproduksi botol kemasan kaca. Penelitian ini bertujuan untuk mengetahui layak atau tidaknya rencana investasi pada proyek Narrow Neck Press and Blow secara finansial di PT. ABC pada periode bulan April 2014 hingga bulan Juni 2014. Analisis kelayakan finansial proyek Narrow Neck Press and Blow, menggunakan metode analisis Net Present Value, Internal Rate of Return, Payback Period dan Sensitivity Analysis. Perbedaan antara nilai sekarang dari semua kas masuk dengan nilai sekarang dari semua kas keluar dari suatu proyek atau suatu investasi diperoleh dengan metode NPV, sedangkan untuk mencari tingkat bunga yang menyamakan nilai sekarang dari aliran kas bersih dan investasi diperoleh dengan metode IRR. Metode analisis yang dapat digunakan untuk mengetahui berapa lamakah waktu yang diperlukan untuk menutup dana yang dikeluarkan untuk suatu proyek dapat diperoleh dengan metode Payback Period. Setelah itu, dilakukan pengujian menggunakan sensitivitas analisis untuk mengetahui tingkat sensitivitas untuk tiap-tiap parameter terhadap persentase kenaikan dan penurunan. Dari hasil analisis data diperoleh nilai NPV sebesar Rp. 1.179.728.649.900,06, nilai IRR sebesar 56,36% dan periode pengembalian terletak pada 2 tahun 2 bulan 9 hari. Dengan menggunakan analisis sensitivitas dapat diketahui bahwa proyek ini sangat sensitif terhadap penurunan volume produksi. Berdasarkan hasil perhitungan, titik impas akan dicapai apabila volume produksi 213.403.267 unit per tahun atau 88,92% dari volume produksi awal. Nilai ini menunjukkan bahwa apabila volume produksi pada suatu periode mengalami penurunan lebih dari 11,08% dari volume produksi awal, maka investasi tersebut akan merugikan.

Supervisory selection and development yields payback

International Nuclear Information System (INIS)

Rubino, E.A.

1991-01-01

The selection and development of first line supervisors is a critical factor in a strategic effort to bring about organizational change, to improve performance and productivity and to enhance professionalism in the work force. Candidates for first line supervisory positions at Philadelphia Electric Company are no longer promoted purely on the basis of seniority. A Supervisory Selection Assessment Center permits candidates to demonstrate leadership potential. Successful candidates then attend an eight week Supervisory Development Academy, away from the work place. On successful completion of the Academy, the supervisor assembles his or her work team and, with training and leadership, shapes a performance based work team ready to plan, execute and assess its own work. Since this radically different program was initiated in September, 1989, results have been highly acclaimed by management. Contractor support has been sharply reduced, budgets have been met and reduced more work has been accomplished and fewer overtime hours have been needed. Workers attend training with no loss of team productivity. Each SDA graduate and his team sets goals to improve quality, increase productivity, increase efficiency, maintain ALARA, improve safety and effect cultural change while improving job satisfaction and morale

Predictors of return rate discrimination in slot machine play.

Science.gov (United States)

Coates, Ewan; Blaszczynski, Alex

2014-09-01

The purpose of this study was to investigate the extent to which accurate estimates of payback percentages and volatility combined with prior learning, enabled players to successfully discriminate between multi-line/multi-credit slot machines that provided differing rates of reinforcement. The aim was to determine if the capacity to discriminate structural characteristics of gaming machines influenced player choices in selecting 'favourite' slot machines. Slot machine gambling history, gambling beliefs and knowledge, impulsivity, illusions of control, and problem solving style were assessed in a sample of 48 first year undergraduate psychology students. Participants were subsequently exposed to a choice paradigm where they could freely select to play either of two concurrently presented PC-simulated slot machines programmed to randomly differ in expected player return rates (payback percentage) and win frequency (volatility). Results suggest that prior learning and cognitions (particularly gambler's fallacy) but not payback, were major contributors to the ability of a player to discriminate volatility between slot machines. Participants displayed a general tendency to discriminate payback, but counter-intuitively placed more bets on the slot machine with lower payback percentage rates.

Life cycle cost analysis of single slope hybrid (PV/T) active solar still

International Nuclear Information System (INIS)

Kumar, Shiv; Tiwari, G.N.

2009-01-01

This paper presents the life cycle cost analysis of the single slope passive and hybrid photovoltaic (PV/T) active solar stills, based on the annual performance at 0.05 m water depth. Effects of various parameters, namely interest rate, life of the system and the maintenance cost have been taken into account. The comparative cost of distilled water produced from passive solar still (Rs. 0.70/kg) is found to be less than hybrid (PV/T) active solar still (Rs. 1.93/kg) for 30 years life time of the systems. The payback periods of the passive and hybrid (PV/T) active solar still are estimated to be in the range of 1.1-6.2 years and 3.3-23.9 years, respectively, based on selling price of distilled water in the range of Rs. 10/kg to Rs. 2/kg. The energy payback time (EPBT) has been estimated as 2.9 and 4.7 years, respectively. (author)

On Adaptive Extended Different Life Cycle of Product Design Strategy

Science.gov (United States)

Wenwen, Jiang; Zhibin, Xie

The article uses research ways of following the whole lifespan of product and enterprise's development course to research strategy of company's product design and development. It announces enterprises of different nature, enterprises at different developing stage will adopt different mode strategy. It also announces close causality between development course of company and central technology and product. The result indicated in different developing stages such as company development period, crisis predicament period, lasting steadies period, improving by payback period, issues steadies secondary period, declining go and live period, enterprise should pursue different mode product tactics of research and development such as shrinking strategy, consolidating strategy, innovation keeping forging ahead strategy. Enterprise should break regular management mode to introduce different research and development mode to promote enterprise's competitiveness effectively.

Is HAPS Viable for the Next-Generation Telecommunication Platform in Korea?

OpenAIRE

Jonghwa Kim; Deokjoo Lee; Jaekyoung Ahn; Do-Seob Ahn; Bon-Jun Ku

2008-01-01

Abstract HAPS is a promising technology capable of providing broadband multimedia services as an alternative to the satellite communication system or terrestrial network. In this study, economic aspects of HAPS service are analyzed, HAPS services are defined, and revenues from the defined services are forecasted assuming nine scenarios. Capital expenditure as well as operating expenditure is estimated. To evaluate the profitability of HAPS service, the net present value (NPV), payback period,...

Outcome-Driven Service Provider Performance under Conditions of Complexity and Uncertainty, Defense Acquisition in Transition, Volume 2, 13-14 May 2009.

Science.gov (United States)

2009-04-22

bandwidth and response times. Forrester Research uses the analogy of a consumer using an automated teller machine to explain how technical SLAs should...be crafted. “It’s not enough that you put your card and Personal Identification Number (PIN) [in the machine ] and request to withdraw cash...IRR) Net Present Value (NPV) Other Relevant Metrics Payback Period Cost/Benefit Ratio Cost, Economic, and/or Financial Analysis Yes Yes Yes

Electric heating of a unit for uranium trioxide production

International Nuclear Information System (INIS)

Faron, R.; Striff, A.

1985-01-01

Ammonium diuranate U 2 O 7 (NH 4 ) 2 containing about 50% of water is dried and transformed by calcination in uranium trioxide UO 3 . Drying and calcination was obtained by air heated by two burners using domestic fuel. In 1984 the plant was transformed for utilization of electric heating improving maintenance cost, decreasing heat losses and by energy saving the payback period on investment is of 2.6 years [fr

Managerial preferences in relation to financial indicators regarding the mitigation of global change.

Science.gov (United States)

Maroušek, Josef; Hašková, Simona; Zeman, Robert; Vaníčková, Radka

2015-02-01

Biochar is a soil-improving substrate made from phytomass pyrolysis. In Southeast Asia, its application decreases due to the long-term growth of biochar cost and thus caused further prolongation of the payback period. In the Euro-American civilization the biochar application is already almost forgotten once it has been much earlier recognized that the crop yields can be increased much faster with higher doses of nutrients and other agrochemicals. The payback period can be expected in decades. Such a long-time investment into soil fertility raises also many ethical questions. The final decision combines issues of social responsibility, risk and other financial indicators as well as personal preferences and more. The attitudes of Western and Central European decision makers in the agriculture business segment were analyzed on the basis of electronic questionnaire survey and a subsequent interview through their local unions. According to the data, most of them did not know about the possibilities of a more environmentally friendly approach to soil enhancement based on the addition of a fertilizer in the form of biochar. Among others, the collected data also shows that the decision makers from Western Europe have a much different ethical approach to the land and financial indicators than the Central Europeans.

A Demonstration System for Capturing Geothermal Energy from Mine Waters beneath Butte, Montana

Energy Technology Data Exchange (ETDEWEB)

Blackketter, Donald [Montana Tech of the Univ. of Montana, Butte, MT (United States)

2015-06-01

Executive Summary An innovative 50-ton ground-source heat pump (GSHP) system was installed to provide space heating and cooling for a 56,000 square foot (5,200 square meter) building in Butte Montana, in conjunction with its heating and chiller systems. Butte is a location with winter conditions much colder than the national average. The GSHP uses flooded mine waters at 78F (25C) as the heat source and heat sink. The heat transfer performance and efficiency of the system were analyzed using data from January through July 2014. This analysis indicated that for typical winter conditions in Butte, Montana, the GSHP could deliver about 88% of the building’s annual heating needs. Compared with a baseline natural-gas/electric system, the system demonstrated at least 69% site energy savings, 38% source energy savings, 39% carbon dioxide emissions reduction, and a savings of $17,000 per year (40%) in utility costs. Assuming a $10,000 per ton cost for installing a production system, the payback period at natural gas costs of $9.63/MMBtu and electricity costs of $0.08/kWh would be in the range of 40 to 50 years. At higher utility prices, or lower installation costs, the payback period would obviously be reduced.

Experimental investigation on a semi-circular trough-absorber solar still with baffles for fresh water production

International Nuclear Information System (INIS)

Sathyamurthy, Ravishankar; Nagarajan, P.K.; El-Agouz, S.A.; Jaiganesh, V.; Sathish Khanna, P.

2015-01-01

Highlights: • Experiments are carried out to analyze the performance. • Baffles are placed in the absorber to increase the residence time of water with solar intensity. • Yield of fresh water from present solar still is 16.66% more than a conventional solar still. • Payback period of the present model is quicker. - Abstract: The main objective of this research is to increase the contact time of water in the basin to enhance yield of fresh water by using a semicircular absorber solar still with baffles. An experimental as well as theoretical investigation is carried out. The productivity and efficiency of present still are analyzed with the influence of the number baffles and the water flow rate. A good agreement between the experimental and theoretical results is observed. The results indicate that, the daily yield of present solar still is higher than that for conventional still approximately by 16.66%. The outlet water temperature present solar still is high subsequently, it can be coupled with multi-state of solar stills to increase productivity. Therefore, the present solar still can be sufficiently extended for other continuous solar desalination systems. Economic analysis concluded that, the payback period of the present model solar still is quicker while comparing it with other solar still

A novel process for small-scale pipeline natural gas liquefaction

International Nuclear Information System (INIS)

He, T.B.; Ju, Y.L.

2014-01-01

Highlights: • A novel process was proposed to liquefy natural gas by utilizing the pressure exergy. • The process is zero energy consumption. • The maximum liquefaction rate of the process is 12.61%. • The maximum exergy utilization rate is 0.1961. • The economic analysis showed that the payback period of the process is quit short. - Abstract: A novel process for small-scale pipeline natural gas liquefaction is designed and presented. The novel process can utilize the pressure exergy of the pipeline to liquefy a part of natural gas without any energy consumption. The thermodynamic analysis including mass, energy balance and exergy analysis are adopted in this paper. The liquefaction rate and exergy utilization rate are chosen as the objective functions. Several key parameters are optimized to approach the maximum liquefaction rate and exergy utilization rate. The optimization results showed that the maximum liquefaction rate is 12.61% and the maximum exergy utilization rate is 0.1961. What is more, the economic performances of the process are also discussed and compared by using the maximum liquefaction rate and exergy utilization rate as indexes. In conclusion, the novel process is suitable for pressure exergy utilization due to its simplicity, zero energy consumption and short payback period

Optimized MBR for greywater reuse systems in hotel facilities.

Science.gov (United States)

Atanasova, Natasa; Dalmau, Montserrat; Comas, Joaquim; Poch, Manel; Rodriguez-Roda, Ignasi; Buttiglieri, Gianluigi

2017-05-15

Greywater is an important alternative water source, particularly in semi-arid, touristic areas, where the biggest water demand is usually in the dry period. By using this source wisely, tourist facilities can substantially reduce the pressure to scarce water resources. In densely urbanized touristic areas, where space has high value, compact solutions such as MBR based greywater reuse systems appear very appropriate. This research focuses on technical and economical evaluation of such solution by implementing a pilot MBR to a hotel with separated grey water. The pilot was operated for 6 months, with thorough characterisation of the GW performed, its operation was monitored and its energy consumption was optimized by applying a control system for the air scour. Based on the pilot operation a design and economic model was set to estimate the feasibility (CAPEX, OPEX, payback period of investment) of appropriate scales of MBR based GW systems, including separation of GW, MBR technology, clean water storage and disinfection. The model takes into account water and energy prices in Spain and a planning period of 20 years. The results demonstrated an excellent performance in terms of effluent quality, while the energy demand for air-scour was reduced by up to 35.2%, compared to the manufacturer recommendations. Economical evaluation of the entire MBR based GW reuse system shows its feasibility for sizes already at 5 m 3 /day (60 PE). The payback period of the investment for hotels like the demonstration hotel, treating 30 m 3 /day is 3 years. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solar Drying in Hot and Dry Climate of Jaipur

OpenAIRE

Parikh, Darshit; Agrawal, G. D.

2016-01-01

Objective of the present study was to design, develop and to carry out detail experimentation and then analyze solar cabinet dryer. For these various types of solar dryer, their principles and design methods, modeling, drying temperature, efficiency, utilization of dryer and payback period were reviewed. In the present study, solar cabinet dryer is constructed at Mechanical Engineering Department, M.N.I.T, Jaipur, latitude (26.01° N). The measurement of solar intensity, temperatures, relative...

Diminishing Manufacturing Sources and Material Shortages (DMSMS) Guidebook

Science.gov (United States)

2006-11-01

www.dau.mil/registrar/enroll.aspx DoD Acquisition, Technology, and Logistics (AT&L) Integrated Framework Chart (IFC) lifecycle activities and...ROI) and Break Even Point ( BEP ). Two analysts could look at the same data and generate different outcomes if they use different assumptions or...principal output of the BCA is the Break Even Point ( BEP ), which shows the payback period of an alternative. It is found from a plot of the

Hybrid PV and solar-thermal systems for domestic heat and power provision in the UK: Techno-economic considerations

International Nuclear Information System (INIS)

Herrando, María; Markides, Christos N.

2016-01-01

Highlights: • Renewable heat and power generation in UK homes with PVT systems studied. • PVT/w generation: 2.3 MW_e h/yr (51% of demand) and 1.0 MW_t_h h/yr (36% hot water). • Optimised PVT/w system has 9–11 year payback periods (PV-only: 6.8 years). • Same system allows 16.0-t CO_2 reduction and 14-t primary fossil-fuel saving. • With a ∼2:1 support (£/W_e h:£/W_t_h h), PVT and PV have similar payback periods. - Abstract: A techno-economic analysis is undertaken to assess hybrid PV/solar-thermal (PVT) systems for distributed electricity and hot-water provision in a typical house in London, UK. In earlier work (Herrando et al., 2014), a system model based on a PVT collector with water as the cooling medium (PVT/w) was used to estimate average year-long system performance. The results showed that for low solar irradiance levels and low ambient temperatures, such as those associated with the UK climate, a higher coverage of total household energy demands and higher CO_2 emission savings can be achieved by the complete coverage of the solar collector with PV and a relatively low collector cooling flow-rate. Such a PVT/w system demonstrated an annual electricity generation of 2.3 MW h, or a 51% coverage of the household’s electrical demand (compared to an equivalent PV-only value of 49%), plus a significant annual water heating potential of to 1.0 MW h, or a 36% coverage of the hot-water demand. In addition, this system allowed for a reduction in CO_2 emissions amounting to 16.0 tonnes over a life-time of 20 years due to the reduction in electrical power drawn from the grid and gas taken from the mains for water heating, and a 14-tonne corresponding displacement of primary fossil-fuel consumption. Both the emissions and fossil-fuel consumption reductions are significantly larger (by 36% and 18%, respectively) than those achieved by an equivalent PV-only system with the same peak rating/installed capacity. The present paper proceeds further, by

Energy conservation in industry; Energibesparelser i erhvervslivet

Energy Technology Data Exchange (ETDEWEB)

Johanson, M. (Dansk Energi Analyse A/S (Denmark)); Maagoee Petersen, P. (Viegand and Maagoee ApS (Denmark))

2010-02-15

The report describes the completed survey and the methodology used for the analysis of energy saving opportunities and potentials for processing technologies and equipment in the industry. The report also includes a total of fourteen technology descriptions, of which eleven relate to end use of energy, while the three descriptions are for cross-technologies. The technology descriptions analyse any significant savings opportunities in the processing technologies concerned and work out the potentials of 'here and now' cost savings, with 2, 4 and 10-year payback time, respectively. The survey makes it possible to prioritize the instruments with the shortest payback times. The total savings potential for the eleven end-use technologies is estimated to be 10% at 2 years of payback time, 15% at four year payback time, and 32% at the 10 year payback time. The percentage potential is somewhat greater for the end-use technologies using electricity than the end-use which mainly uses fuel. That the potential is less for fuel-based end-use technologies may be explained by the fact that they are key processes that are regularly upgraded to increase product quality, to reduce production time and waste, etc. Such improvements also help to save energy and means that further improvements are relatively expensive. (ln)

Solar water heating systems feasibility for domestic requests in Tunisia: Thermal potential and economic analysis

International Nuclear Information System (INIS)

Hazami, Majdi; Naili, Nabiha; Attar, Issam; Farhat, Abdelhamid

2013-01-01

Highlights: • The present work studies the potential of using Domestic Solar Water Heating systems. • The payback period is between 8 and 7.5 years. • The annual savings in electrical energy is between 1316 and 1459 kW h/year. • The savings by using the solar systems is about 3969–4400.34 $. • The annual GHG emission per house is reduced by 27,800 tCO 2 . - Abstract: The main goal of the present work is to study the energetic and the economic potential of the deployment of Domestic Solar Water Heating systems (DSWHs) instead of using electric/gas/town gas water heaters. A case study related to Tunisian scenario was performed according to a typical Tunisian households composed of 4–5 persons. In this scenario we evaluated the performance and the life cycle perspective of the two most popular DSWHs over the recent years (i.e. DSWH with flat-plate solar collector, FPC, and DSWHs with evacuated-tube solar collector, ETC). The dynamic behavior of DSWHs according to Tunisian data weather was achieved by means of TRNSYS simulation. The Results showed that the FPC and ETC provide about 8118 and 12032 kW h/year of thermal energy. The economic potential of DSWHs in saving electricity and reducing carbon dioxide emissions was also investigated. Results showed that the annual savings in electrical energy relatively to the FPC and ETC are about 1316 and 1459 kW h/year, with a payback period of around 8 and 10 years, respectively. Based on gas/town gas water heater, the FPC and ETC save about 306 m 3 and 410 m 3 of gas/town gas with a payback period about 6 and 7.5 years, respectively. We found that the life cycle savings by installing the solar system instead of buying electricity to satisfy hot water needs are about $3969 (FPC) and $4400 (ETC). We establish also that the use of the DSWHs instead of installing gas/town gas water heaters save about $1518 (FPC) and $2035 (ETC). From an environmental point of view the annual GHG emission per house is reduced by 27800

Optimized baking processes

Energy Technology Data Exchange (ETDEWEB)

Tentler, H.; Kessel, H.W.

1987-11-01

Details are given on measures helping to reduce unprofitable power peaks which are known to be the result of heating several electric baker's oven at a time. The measures referred to include the installation of electronic clock timers and an up to three hours extension of heating phases. Variable turn/slide switch load shedding systems allow for a threshold adjustment of the maximum values to be controlled. Payback periods do not exceed one year. (BWI).

Generation of electric power through wind-diesel hybrid system for a hospital; Geracao de energia eletrica atraves de sistema hibrido diesel-eolico para um hospital

Energy Technology Data Exchange (ETDEWEB)

Almeida, Silvio Carlos Anibal de; Freire, Raphael Lopes [Universidade Federal do Rio de Janeiro (DEM/UFRJ), RJ (Brazil). Dept. de Engenharia Mecanica], e-mail: silvioa@gmail.com, e-mail: raphaellfreire@gmail.com

2008-07-01

This paper presents a wind-diesel hybrid power simulation using the software Homer. The model is applied to the case study of Hospital das Clinicas da UNICAMP Analysis of several alternative energy facilities like wind, photovoltaic (PV), and connection of the isolated system with the grid is done. The costs used in the simulation indicated that the best results were obtained with the wind-diesel system. The payback period for the investment in the system is 8 years. (author)

Thin layer drying characteristics of curry leaves (Murraya koenigii in an indirect solar dryer

Directory of Open Access Journals (Sweden)

Vijayan Selvaraj

2017-01-01

Full Text Available In this work, the thin layer drying characteristics of curry leaves (Murraya koenigii has been studied in an indirect forced convection solar dryer with constant air mass flow rate of 0.0636 kg/s. Twelve thin layer drying models were tested for its suitability to describe the drying characteristics of curry leaves. The dryer has reduced the initial moisture content of curry leaves from 67.3% (wet basis to the final moisture content of 4.75% (wet basis in 3.5 hours. The pickup efficiency of indirect solar dryer for drying curry leaves was varied between 4.9% and 23.02%. Based on the statistical parameters, the Modified Henderson and Pabis model and Wang and Singh model were selected for predicting the drying characteristics of curry leaves. The payback period for the solar dryer was evaluated as 8 months, which is found to be much lower when compared with the entire life span of 15 years. The payback evaluation confirms that the solar dryer is economically viable in rural applications.

Extraction of astaxanthin from microalgae: process design and economic feasibility study

Science.gov (United States)

Zgheib, Nancy; Saade, Roxana; Khallouf, Rindala; Takache, Hosni

2018-03-01

In this work, the process design and the economic feasibility of natural astaxanthin extraction fromHaematococcus pluvialisspecies have been reported. Complete process drawing of the process was first performed, and then the process was designed including five main steps being the harvesting process, the cell disruption, the spray drying, the supercritical CO2extraction and the anaerobic digestion. The major components of the facility would include sedimentation tanks, a disk stack centrifuge, a bed miller, a spray dryer, a multistage compressor, an extractor, a pasteurizer and a digester. All units have been sized assuming a 10 kg/h of dried biomass as a feedstock to produce nearly 2592 kg of astaxanthin per year. The investment payback time and the return on investment were all estimated for different market prices of astaxanthin. Based on the results the production process was found to become economically feasible for a market price higher than 1500/Kg. Also, a payback period of 1 year and an ROI equal to 113% was estimated for an astaxanthin market price equal to 6000/Kg.

Economic assessment of electric energy storage for load shifting in positive energy building

DEFF Research Database (Denmark)

Dumont, Olivier; Do Carmo, Carolina Madeira Ramos; Georges, Emeline

2017-01-01

Net zero energy buildings and positive energy buildings are gaining more and more interest. This paper evaluates the impact of the integration of a battery in a positive energy building used to increase its self-consumption of electricity. Parametric studies are carried out by varying the buildin...... and a 3.7 kWh battery. Finally, simple correlations (based on the feed-in tariff, the annual electrical consumption and production) to predict the optimal size of battery and the lowest payback period are proposed.......Net zero energy buildings and positive energy buildings are gaining more and more interest. This paper evaluates the impact of the integration of a battery in a positive energy building used to increase its self-consumption of electricity. Parametric studies are carried out by varying the building...... envelope characteristics, the power supply system, the climate, the lighting and appliances profiles, the roof tilt angle, the battery size and the electricity tariffs, leading to 3200 cases. The analysis is performed on an annual basis in terms of self-consumption and self-production rate and payback...

A dedicated pollution tax: The motor for change

International Nuclear Information System (INIS)

Stoyke, E.; Stoyke, G.

1992-01-01

Carbon taxes coming into effect around the world are predicted to reduce greenhouse gas emissions by 1-6%. Using the punitive approach alone, such taxes will not be sufficiently effective in fighting global climate change. A dedicated pollution tax is proposed in which moderate fees on greenhouse gases and other polluting emissions are balanced by financial incentives for energy efficient retrofitting or non-polluting substitutions. These incentives will vastly accelerate conversion to energy efficient technologies by reducing payback periods to acceptable levels and will lead to a 50-80% reduction in fossil fuel consumption at a profit. Estimated environmental costs of pollutant emissions from coal and natural gas are presented, and the internalization of external costs into energy prices is discussed. Demand reduction provides more environmental benefits than scrubbing of fossil emissions, at less cost. Examples of potential lighting savings in a classroom are presented, and simple payback and savings for a variety of lighting energy efficiency measures are tabulated. The effects of different pollution tax levels on Alberta's coal fired electricity generation are tabulated. 5 refs., 6 figs., 4 tabs

Fiscal 1999 basic survey report for promotion of joint implementation. Plan for repowering Ashuganji thermal power station; 1999 nendo Ashuganji karyoku hatsudensho no repowering keikaku chosa hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-03-01

A study is conducted of a plan to repower the Ashuganji thermal power station, the People's Republic of Bangladesh, with the plan to be connected to the clean development mechanism (CDM). For conversion of the existing No. 3, No. 4, and No. 5 generators (each outputting 150MW) into full fired heat recovery combined cycle generators, 31MW gas turbines are added, one to each of the three. The construction cost is calculated to be 14,000-million yen. Fuel (natural gas) will be saved by 28kt/year/generator, the three saving 2.1-million tons in total in 25 years. There will be a CO2 reduction of 77kt/year/generator, the total reduction to be 5.8-million tons in 25 years for the three generators. Then payback is assessed. In the main case (with the repowering-created increase in output to be used to cover the current power supply shortage), where the internal rate of return of 8.09% is much lower than the discount rate of 15.5% during the 10-year period for payback in case of financing by private funds, the discounted present worth is predicted to be negative and then the project is not feasible. Since there will be no problems about the repayment of borrowed money, however, it is hoped that low-interest special yen credit will be granted for the elimination of chronic power shortage. When it comes to international emission trading (550 yen/ton of CO2), payback is again found to be impossible. (NEDO)

Desiccant-Based Preconditioning Market Analysis

Energy Technology Data Exchange (ETDEWEB)

Fischer, J.

2001-01-11

A number of important conclusions can be drawn as a result of this broad, first-phase market evaluation. The more important conclusions include the following: (1) A very significant market opportunity will exist for specialized outdoor air-handling units (SOAHUs) as more construction and renovation projects are designed to incorporate the recommendations made by the ASHRAE 62-1989 standard. Based on this investigation, the total potential market is currently $725,000,000 annually (see Table 6, Sect. 3). Based on the market evaluations completed, it is estimated that approximately $398,000,000 (55%) of this total market could be served by DBC systems if they were made cost-effective through mass production. Approximately $306,000,000 (42%) of the total can be served by a non-regenerated, desiccant-based total recovery approach, based on the information provided by this investigation. Approximately $92,000,000 (13%) can be served by a regenerated desiccant-based cooling approach (see Table 7, Sect. 3). (2) A projection of the market selling price of various desiccant-based SOAHU systems was prepared using prices provided by Trane for central-station, air-handling modules currently manufactured. The wheel-component pricing was added to these components by SEMCO. This resulted in projected pricing for these systems that is significantly less than that currently offered by custom suppliers (see Table 4, Sect. 2). Estimated payback periods for all SOAHU approaches were quite short when compared with conventional over-cooling and reheat systems. Actual paybacks may vary significantly depending on site-specific considerations. (3) In comparing cost vs benefit of each SOAHU approach, it is critical that the total system design be evaluated. For example, the cost premium of a DBC system is very significant when compared to a conventional air handling system, yet the reduced chiller, boiler, cooling tower, and other expense often equals or exceeds this premium, resulting in a

MARGARET ATWOOD'S NON-FICTION ABOUT FICTION: PAYBACK

Directory of Open Access Journals (Sweden)

Igor Maver

2015-10-01

Full Text Available Margaret Atwood's provocative recent book of non-fiction contains many literary references, which help to effectively highlight her points about such a topical matter as debt, debt as a philosophical, politico-economic, religious, and historical issue over the centuries. In the central chapters of the book she looks at the Protestant Reformation and the introduction of interest on loans and in this light analyzes the novels by Dickens, Irving, Thackeray and G. Eliot. Her final statement in the book is, however, about the ecological debt we all have to pay to Earth in order to ensure our existence.

Economic analysis of solar assisted absorption chiller for a commercial building

Science.gov (United States)

Antonyraj, Gnananesan

Dwindling fossil fuels coupled with changes in global climate intensified the drive to make use of renewable energy resources that have negligible impact on the environment. In this attempt, the industrial community produced various devices and systems to make use of solar energy for heating and cooling of building space as well as generate electric power. The most common components employed for collection of solar energy are the flat plate and evacuated tube collectors that produce hot water that can be employed for heating the building space. In order to cool the building, the absorption chiller is commonly employed that requires hot water at high temperatures for its operation. This thesis deals with economic analysis of solar collector and absorption cooling system to meet the building loads of a commercial building located in Chattanooga, Tennessee. Computer simulations are employed to predict the hourly building loads and performance of the flat plate and evacuated tube solar collectors using the hourly weather data. The key variables affecting the economic evaluation of such system are identified and the influence of these parameters is presented. The results of this investigation show that the flat plate solar collectors yield lower payback period compared to the evacuated tube collectors and economic incentives offered by the local and federal agencies play a major role in lowering the payback period.

A multi-objective optimization model for energy-efficiency building envelope retrofitting plan with rooftop PV system installation and maintenance

International Nuclear Information System (INIS)

Fan, Yuling; Xia, Xiaohua

2017-01-01

Highlights: • A multi-objective optimization model for building envelope retrofit is presented. • Facility performance degradation and maintenance is built into the model. • A rooftop PV system is introduced to produce electricity. • Economic factors including net present value and payback period are considered. - Abstract: Retrofitting existing buildings with energy-efficient facilities is an effective method to improve their energy efficiency, especially for old buildings. A multi-objective optimization model for building envelope retrofitting is presented. Envelope components including windows, external walls and roofs are considered to be retrofitted. Installation of a rooftop solar panel system is also taken into consideration in this study. Rooftop solar panels are modeled with their degradation and a maintenance scheme is studied for sustainability of energy and its long-term effect on the retrofitting plan. The purpose is to make the best use of financial investment to maximize energy savings and economic benefits. In particular, net present value, the payback period and energy savings are taken as the main performance indicators of the retrofitting plan. The multi-objective optimization problem is formulated as a non-linear integer programming problem and solved by a weighted sum method. Results of applying the designed retrofitting plan to a 50-year-old building consisting of 66 apartments demonstrated the effectiveness of the proposed model.

Comparative economic assessment of the energy performance of air-conditioning within the Mexican residential sector

Directory of Open Access Journals (Sweden)

Ivan Oropeza-Perez

2016-11-01

Full Text Available This work shows a sensitivity analysis of the economic impact of different energy performances of air-conditioning within the Mexican housing sector. For this purpose, a cooling-load calculator program in function of the indoor temperature is developed. The program also calculates the electricity consumption along with the expenditure with the different residential rates of the Mexican Federal Commission of Electricity (CFE, initials in Spanish set according to the season of the year and zone of the country. After the results onto the national-scale scenario are validated with the literature, a sensitivity analysis is carried out by changing three parameters that are considered as influential on the consumption and which can be considered as energy saving strategies. With these strategies, it is found that the indoor temperature decrease due to the use of a passive cooling system is the most important characteristic to take into account followed by the coefficient of performance (COP of the air-conditioning and the increase of the comfort temperature set-point, respectively. Thereby, an economic analysis is carried out, finding an annual saving up to 770 USD within a single air-conditioned dwelling having a payback period of 3 years for using a combination of passive cooling techniques and increasing the comfort temperature set-point; or a 2 years payback period if the air-conditioning is changed by a high-efficient equipment.

Thermoeconomic Evaluation of Modular Organic Rankine Cycles for Waste Heat Recovery over a Broad Range of Heat Source Temperatures and Capacities

Directory of Open Access Journals (Sweden)

Markus Preißinger

2017-02-01

Full Text Available Industrial waste heat recovery by means of an Organic Rankine Cycle (ORC can contribute to the reduction of CO2 emissions from industries. Before market penetration, high efficiency modular concepts have to be developed to achieve appropriate economic value for industrial decision makers. This paper aims to investigate modularly designed ORC systems from a thermoeconomic point of view. The main goal is a recommendation for a suitable chemical class of working fluids, preferable ORC design and a range of heat source temperatures and thermal capacities in which modular ORCs can be economically feasible. For this purpose, a thermoeconomic model has been developed which is based on size and complexity parameters of the ORC components. Special emphasis has been laid on the turbine model. The paper reveals that alkylbenzenes lead to higher exergetic efficiencies compared to alkanes and siloxanes. However, based on the thermoeconomic model, the payback periods of the chemical classes are almost identical. With the ORC design, the developed model and the boundary conditions of this study, hexamethyldisiloxane is a suitable working fluid and leads to a payback period of less than 5 years for a heat source temperature of 400 to 600 °C and a mass flow rate of the gaseous waste heat stream of more than 4 kg/s.

Forest industries energy research

Energy Technology Data Exchange (ETDEWEB)

Scott, G. C.

1977-10-15

Data on energy use in the manufacturing process of the wood products industry in 1974 are tabulated. The forest industries contributed 10% of New Zealand's factory production and consumed 25% of all industrial energy (including that produced from self-generated sources such as waste heat liquors and wood wastes) in that year. An evaluation of the potential for savings in process heat systems in existing production levels is shown to be 3% in the short, medium, and long-term time periods. The industry has a high potential for fuel substitution in all sectors. The payback periods for the implementation of the conservation measures are indicated.

Dimensioning of Solar Thermal Systems for Multi-Family Buildings in Lithuania: an Optimisation Study

OpenAIRE

Valančius, Rokas; Jurelionis, Andrius; Vaičiūnas, Juozas; Perednis, Eugenijus

2017-01-01

Small-scale solar thermal domestic hot water (DHW) systems in Lithuania can produce up to 523 kWh per year per one square meter of solar collector area. It is therefore one of the most common solar thermal applications in the country with the expected payback period of approximately 10 years. However, the number of solar water heating systems (SWH) installed in the renovated multi-family buildings is quite limited. On the other hand, the potential of integrating solar thermal systems in these...

Periodic feedback stabilization for linear periodic evolution equations

CERN Document Server

Wang, Gengsheng

2016-01-01

This book introduces a number of recent advances regarding periodic feedback stabilization for linear and time periodic evolution equations. First, it presents selected connections between linear quadratic optimal control theory and feedback stabilization theory for linear periodic evolution equations. Secondly, it identifies several criteria for the periodic feedback stabilization from the perspective of geometry, algebra and analyses respectively. Next, it describes several ways to design periodic feedback laws. Lastly, the book introduces readers to key methods for designing the control machines. Given its coverage and scope, it offers a helpful guide for graduate students and researchers in the areas of control theory and applied mathematics.

An analysis of switching and non-switching slot machine player behaviour.

Science.gov (United States)

Coates, Ewan; Blaszczynski, Alex

2013-12-01

Learning theory predicts that, given the repeated choice to bet between two concurrently available slot machines, gamblers will learn to bet more money on the machine with higher expected return (payback percentage) or higher win probability per spin (volatility). The purpose of this study was to investigate whether this occurs when the two machines vary orthogonally on payback percentage and volatility. The sample comprised 52 first year psychology students (mean age = 20.3 years, 20 females, 32 males) who had played a gaming machine at least once in the previous 12 months. Participants were administered a battery of questionnaires designed to assess level of knowledge on the characteristics and operation of poker machines, frequency of poker machine play in the past 12 months, personality traits of impulsivity and capacity for cognitive reflection, and gambling beliefs. For the experimental task, participants were instructed to play on two PC-simulated electronic gaming machines (EGMs or slot machines) that differed on payback percentage and volatility, with the option of freely switching between EGMs after a practice phase. Results indicated that participants were able to easily discriminate between machines and manifested a preference to play machines offering higher payback or volatility. These findings diverged from previous findings of no preference for play on higher payback/volatility machines, potentially due to of the current study's absence of the option to make multi-line and multi-credit bets. It was concluded that return rate parameters like payback percentage and volatility strongly influenced slot machine preference in the absence of betting options like multi-line bets, though more research is needed to determine the effects of such betting options on player distribution of money between multiple EGMs.

Viabilidade econômica da implantação de um banco de capacitores em unidade armazenadora de grãos = Economic feasibility of the installation of capacitor banks in a grain storage

Directory of Open Access Journals (Sweden)

Gustavo Veloso

2017-07-01

,772.03. The investment presented a NPV of R$ 7,228.63. IRR was 9.34% p.s., higher than the MARR (4.46% p.s.. Payback period was three years and four months. Based on the results obtained from NPV, IRR and Payback, the investment proved to be economically viable and attractive.

The early design stage for building renovation with a novel loop-heat-pipe based solar thermal facade (LHP-STF) heat pump water heating system: Techno-economic analysis in three European climates

International Nuclear Information System (INIS)

Zhang, Xingxing; Shen, Jingchun; Adkins, Deborah; Yang, Tong; Tang, Llewellyn; Zhao, Xudong; He, Wei; Xu, Peng; Liu, Chenchen; Luo, Huizhong

2015-01-01

Highlights: • LHP-STF was evaluated from both technical and economic aspects for three EU climates. • The impact of LHP-STF on the overall building socio-energy performance was explored. • A dedicated business model was developed to study the economic feasibility of LHP-STF. • Three fundamental methods for financial measurement of LHP-STF were analysed. • Four investment options were considered in this business model. - Abstract: Most of the building renovation plans are usually decided in the early design stage. This delicate phase contains the greatest opportunity to achieve the high energy performance buildings after refurbishment. It is therefore important to provide the pertinent energy performance information for the designers or decision-makers from multidisciplinary and comparative points of view. This paper investigates the renovation concept of a novel loop-heat-pipe based solar thermal facade (LHP-STF) installed on a reference residential building by technical evaluation and economic analysis in three typical European climates, including North Europe (represented by Stockholm), West Europe (represented by London) and South Europe (represented by Madrid). The aim of this paper is firstly to explore the LHP-STF’s sensitivity with regards to the overall building socio-energy performance and secondly to study the LHP-STF’s economic feasibility by developing a dedicated business model. The reference building model was derived from the U.S. Department of Energy (DOE) commercial buildings research, in which the energy data for the building models were from the ASHRAE codes and other standard practices. The financial data were collected from the European statistic institute and the cost of system was based on the manufactured prototype. Several critical financial indexes were applied to evaluate the investment feasibility of the LHP-STF system in building renovation, such as Payback Period (PP), Net Present Value (NPV), and the modified internal

An application of trigeneration and its economic analysis

Energy Technology Data Exchange (ETDEWEB)

Temir, Galip; Bilge, Durriye; Emanet, Ozlem [Yildiz Technical Univ., Mechanical Engineering Dept., Istanbul (Turkey)

2004-07-15

Trigeneration can be described as the production of three different forms of energy - power, heat, and coldness together. Trigeneration increases the productivity and the services provided by cogeneration installations. Consequently, the production costs of the systems related with energy consumption become lower. For this purpose, a trigeneration application has been carried out based on the data of a currently active insulated pipe production plant situated in Istanbul, Turkey. In the feasibility study made after calculations, the profitability and payback period have been calculated. (Author)

Chaos to periodicity and periodicity to chaos by periodic perturbations in the Belousov-Zhabotinsky reaction

International Nuclear Information System (INIS)

Li Qianshu; Zhu Rui

2004-01-01

A three-variable model of the Belousov-Zhabotinsky reaction system subject to external sinusoidal perturbations is investigated by means of frequency spectrum analysis. In the period-1 window of the model, the transitions from periodicity to chaos are observed; in the chaotic window, the transitions from chaos to periodicity are found. The former might be understood by the circle map of two coupled oscillators, and the latter is partly explained by the resonance between the main frequency of the chaos and the frequency of the external periodic perturbations

Encouraging Combined Heat and Power in California Buildings

Energy Technology Data Exchange (ETDEWEB)

Stadler, Michael [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Groissbock, Markus [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cardoso, Goncalo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Muller, Andreas [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lai, Judy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2013-02-01

Governor Brown’s research priorities include an additional 6.5 GW of combined heat and power (CHP) by 2030. As of 2009, roughly 0.25 GW of small natural gas and biogas fired CHP is documented by the Self-Generation Incentive Program (SGIP) database. The SGIP is set to expire, and the anticipated grid de-carbonization based on the development of 20 GW of renewable energy will influence the CHP adoption. Thus, an integrated optimization approach for this analysis was chosen that allows optimizing the adoption of distributed energy resources (DER) such as photovoltaics (PV), CHP, storage technologies, etc. in the California commercial sector from the building owners’ perspective. To solve this DER adoption problem the Distributed Energy Resources Customer Adoption Model (DER-CAM), developed by the Lawrence Berkeley National Laboratory and used extensively to address the problem of optimally investing and scheduling DER under multiple settings, has been used. The application of CHP at large industrial sites is well known, and much of its potential is already being realized. Conversely, commercial sector CHP, especially those above 50 to 100 kW peak electricity load, is widely overlooked. In order to analyze the role of DER in CO₂ reduction, 147 representative sites in different climate zones were selected from the California Commercial End Use Survey (CEUS). About 8000 individual optimization runs, with different assumptions for the electric tariffs, natural gas costs, marginal grid CO₂ emissions, and nitrogen oxide treatment costs, SGIP, fuel cell lifetime, fuel cell efficiency, PV installation costs, and payback periods for investments have been performed. The most optimistic CHP potential contribution in this sector in 2020 will be 2.7 GW. However, this result requires a SGIP in 2020, 46% average electric efficiency for fuel cells, a payback period for investments of 10 years, and a CO₂ focused approach of the building owners. In

Energy performance of solar-assisted liquid desiccant air-conditioning system for commercial building in main climate zones

International Nuclear Information System (INIS)

Qi, Ronghui; Lu, Lin; Huang, Yu

2014-01-01

Highlights: • Simulation of solar liquid desiccant AC system in four climate regions was conducted. • System performance was determined by relationship of sensible and latent cooling load. • For humid area, saving amount is large by handling latent load with solar energy. • For dry area, electricity saving rate is considerable due to the high COP of chillers. • For buildings with mild SHR, the system performance was not as good as others. - Abstract: Liquid desiccant air-conditioning (LDAC) system, which consists of a liquid desiccant ventilation system for dehumidification and an air-handling unit for cooling, has become a promising alternative for conventional technology. To evaluate its feasibility and applicability, the simulation of solar-assisted LDAC (SLDAC) in commercial buildings in five cities of four main climate regions were conducted, including Singapore in Tropical, Houston and Beijing in Temperate, Boulder in Arid and Los Angeles in Mediterranean. Results showed that the system’s performance was seriously affected by the ratios of building’s sensible and latent cooling load. For buildings located in humid areas with low sensible-total heat ratio (SHR), the electricity energy reduction of SLDAC was high, about 450 MW h in Houston and Singapore, which accounted for 40% of the total energy consumption in cooling seasons. The cost payback period was as short as approximately 7 years. The main reason is that the energy required for handling the moisture could be saved by liquid desiccant dehumidification, and the regeneration heat could be covered by solar collectors. For buildings in dry climate with high SHR, the total cooling load was low, but up to 45% electricity of AC system could be saved in Boulder because the chiller COP could be significantly improved during more than 70% operation time. The cost payback period was around 22 years, which was acceptable. However, for the buildings with mild SHR, such as those in Beijing and Los

Architecturally sensitive retrofitting of PV to a residential block in Greece to reduce its carbon footprint

Science.gov (United States)

Panopoulou, Ismini

Photovoltaic power is a unique energy source, with wide distribution potential, which can be integrated within the fabric of individual buildings, transforming the power generation in a less large-scale and regionally located issue. As a result, photovoltaic power is a free, clean and silent electrical supply that can be introduced into cities and residential areas. Over the past years, grid-connected, distributed photovoltaic power systems have become an explosively growing sector worldwide. This trend is expected to be continued in the future and solar systems may become a common building element of building construction. In Greece, where the main focus of the project is concentrated, the extended sunshine and the incentives of the new Renewable Energy Sources law of 2006, give a different perspective in photovoltaic investments. In the case study of Vera Water Residence complex in Athens, the viability of an architecturally sensitive retrofitting of PV was examined, from both financial and environmental aspects. The project was concentrated in one of the complex's buildings which was modelled in TAS simulator in order for the annual heating and cooling loads to be estimated. A closer to the reality estimation of electricity demand was made through the annual electricity bills of the building. The proposed building integrated photovoltaic system was designed in terms of following and respecting the aesthetics of the existing architecture of the complex while being as efficient as possible. The annual energy output and C02 emissions reductions were then calculated through RETScreen software analysis according to the location of the project and the characteristics of the PV system. Finally, an economic analysis has been included to the study, considering the installation cost, the annual savings and the embodied energy of the system, in order for the payback period of the investment to be determined. Finally, a small sensitivity analysis concerning the effect of

Impact of external longwave radiation on optimum insulation thickness in Tunisian building roofs based on a dynamic analytical model

International Nuclear Information System (INIS)

Daouas, Naouel

2016-01-01

Highlights: • An efficient tool is proposed for a rigorous energy analysis of building envelope. • The longwave radiation has an important impact on the energy requirements. • Optimum insulation thickness for roofs is rigorously determined in a cost analysis. • The present method is more accurate than the sol–air degree hours method. • The proposed model is applicable to the study of the efficiency of cool roofs. - Abstract: In Tunisia, the building sector is considered as a major issue of energy consumption. A special attention should be drawn to improve the thermal quality of the building envelope with real consideration of the Tunisian climate specificity. One of the most effective measures is the roof insulation. Therefore, the present study is concerned with the determination of the optimum insulation thickness and the resulting energy savings and payback period for two typical roof structures and two types of insulation materials. An efficient analytical dynamic model based on the Complex Finite Fourier Transform (CFFT) is proposed and validated in order to handle the nonlinear longwave radiation (LWR) exchange with the sky. This model provides a short computational time solution of the transient heat transfer through multilayer roofs, which could be a good alternative to some numerical methods. Both heating and cooling annual loads are rigorously estimated and used as inputs to a life-cycle cost analysis. Among the studied cases, the most economical one is the hollow terracotta-based roof insulated with rock wool, where the optimum insulation thickness is estimated to be 7.9 cm, with a payback period of 6.06 years and energy savings up to 58.06% of the cost of energy consumed without insulation. The impact of the LWR exchange component is quantified and the results show its important effect on the annual transmission loads and, consequently, on optimum insulation thickness. A sensitivity analysis shows the efficiency of cool roofs in the Tunisian

High efficiency novel window air conditioner

International Nuclear Information System (INIS)

Bansal, Pradeep

2015-01-01

Highlights: • Use of novel refrigerant mixture of R32/R125 (85/15% molar conc.) to reduce global warming and improve energy efficiency. • Use of novel features such as electronically commuted motor (ECM) fan motor, slinger and sub-merged sub-cooler. • Energy savings of up to 0.1 Quads per year in USA and much more in Asia/Middle East where WACs are used in large numbers. • Payback period of only 1.4 years of the novel efficient WAC. - Abstract: This paper presents the results of an experimental and analytical evaluation of measures to raise the efficiency of window air conditioners (WAC). In order to achieve a higher energy efficiency ratio (EER), the original capacity of a baseline R410A unit was reduced by replacing the original compressor with a lower capacity but higher EER compressor, while all heat exchangers and the chassis from the original unit were retained. Subsequent major modifications included – replacing the alternating current fan motor with a brushless high efficiency electronically commutated motor (ECM) motor, replacing the capillary tube with a needle valve to better control the refrigerant flow and refrigerant set points, and replacing R410A with a ‘drop-in’ lower global warming potential (GWP) binary mixture of R32/R125 (85/15% molar concentration). All these modifications resulted in significant enhancement in the EER of the baseline WAC. Further, an economic analysis of the new WAC revealed an encouraging payback period

A support strategy for the promotion of photovoltaic uses for residential houses in Korea

International Nuclear Information System (INIS)

Oh, Si-Doek; Lee, Yeji; Yoo, Yungpil; Kim, Jinoh; Kim, Suyong; Song, Seung Jin; Kwak, Ho-Young

2013-01-01

Various policies such as feed-in tariffs, quota obligations and capital subsides were enacted to expand the uses of renewable energy (RE) in many countries. This study examined whether capital subsidies are cost effective in relation to the installation of solar photovoltaic (PV) facility. To do this, the capacity factor, which is one of the crucial factors for determining the unit cost of electricity from a solar PV system, was estimated from the monthly average clearness index data collected at various cities in Korea. Thermoeconomic analysis was applied to calculate the unit cost of electricity based on the calculated capacity factor of the solar PV system. Instead of subsidizing the same percent of the capital cost of each PV system installation, it is reasonable for the government to adopt a measure to match the subsidy paid to the payback period of the initial investment for all 5 million potential solar PV users in Korea. - Highlights: ► The unit cost of electricity from solar PV depends crucially on its capacity factor. ► We calculated the capacity factor of solar PV at various cities from the clearness index. ► We estimated the unit cost of electricity from solar PV using thermoeconomic analysis. ► We examined whether the capital subsidy program in Korea to solar PV is cost effective. ► This study determined that a measure based on the same payback period is better policy.

Specifying residential retrofit packages for 30 % reductions in energy consumption in hot-humid climate zones

Energy Technology Data Exchange (ETDEWEB)

Burgett, J.M.; Chini, A.R.; Oppenheim, P. [University of Florida, 573 Rinker Hall, Newell Drive, Gainesville, FL 32611 (United States)

2013-08-15

The purpose of this research was to demonstrate the application of energy simulation as an effective tool for specifying cost-effective residential retrofit packages that will reduce energy consumption by 30 %. Single-family homes in the hot-humid climate type of the Southeastern USA were used to demonstrate the application. US census data from both state and federal studies were used to create 12 computer simulation homes representing the most common characteristics of single-family houses specific to this area. Well-recognized energy efficiency measures (EEMs) were simulated to determine their cumulative energy reduction potential. Detailed cost estimates were created for cost-to-benefit analysis. For each of the 12 simulated homes, 4 packages of EEMs were created. The four packages provided home owners options for reducing their energy by 30 % along with the estimated up-front cost and simple payback periods. The simple payback period was used to determine how cost-effective a measure was. The packages are specific to a geographic area to provide a higher degree of confidence in the projected cost and energy savings. The study provides a generic methodology to create a similar 30 % energy reduction packages for other locations and a detailed description of a case study to serve as an example. The study also highlights the value that computer simulation models can have to develop energy efficiency packages cost-effectively and specific to home owner's location and housing type.

Revised feed-in tariff for solar photovoltaic in the United Kingdom: A cloudy future ahead?

International Nuclear Information System (INIS)

Muhammad-Sukki, Firdaus; Ramirez-Iniguez, Roberto; Munir, Abu Bakar; Mohd Yasin, Siti Hajar; Abu-Bakar, Siti Hawa; McMeekin, Scott G.; Stewart, Brian G.

2013-01-01

The United Kingdom (UK) started implementing a national Feed-In Tariff (FiT) mechanism on the 1 April 2010, which included specific payment tariffs for solar photovoltaic (PV) installations. However, a revised FiT rate has been put in place starting from 1 April 2012, applicable to any installations with an eligibility date of on or after 3 March 2012. This paper presents, first, an overview of solar PV installation in the UK. This followed by a general concept of the FiT in the UK before analyzing the financial impact of the new FiT rate on the consumers. Similar financial analysis is conducted with selected countries in Europe. The financial analysis investigates the total profit, the average rate of return and the payback period. It is found that the new FiT rate generates very low profit, minimum rate of return and a longer payback period, suggesting a downward trend of solar PV uptake in the future. - Highlight: ► Overview of solar PV installation in the UK until present time is discussed. ► Financial analysis is presented using previous, new and degression FiT tariff. ► Comparative analysis with other European countries is evaluated. ► The new FiT rate in the UK generates very low return than other countries. ► This could suggest a downward trend of UK's solar PV uptake in the future

Feasibility of biomass heating system in Middle East Technical University, Northern Cyprus Campus

Directory of Open Access Journals (Sweden)

Samuel Asumadu-Sarkodie

2016-12-01

Full Text Available Global interest in using biomass feedstock to produce heat and power is increasing. In this study, RETScreen modelling software was used to investigate the feasibility of biomass heating system in Middle East Technical University, Northern Cyprus Campus. Weiss Kessel Multicratboiler system with 2 MW capacity using rice straw biomass as fuel and 10 units of RBI® CB0500 boilers with 144 kW capacity using natural gas as fuel were selected for the proposed biomass heating system. The total cost of the biomass heating project is US$ 786,390. The project has a pre-tax and after tax internal rate of return (IRR of 122.70%, simple payback period of 2.54 years, equity payback period of 0.83 year, a net present value of US$ 3,357,138.29, an annual lifecycle savings of US$ 262,617.91, a benefit-cost ratio of 21.83, an electricity cost of $0/kWh and a GHG reduction cost of −204.66 $/tCO₂. The annual GHG emission reduction is 1,283.2 tCO₂, which is equivalent to 118 hectares of forest absorbing carbon. The development and adoption of this renewable energy technology will save costs on buying conventional type of heating system and result in a large technical and economic potential for reducing greenhouse gas emissions which will satisfy the sustainable development goals.

Energy and economic analysis of a building enclosure outfitted with a phase change material board (PCMB)

International Nuclear Information System (INIS)

Sun, Xiaoqin; Zhang, Quan; Medina, Mario A.; Lee, Kyoung Ok

2014-01-01

Highlights: • Phase change material boards (PCMBs) were simulated in building enclosures. • Energy and economic savings for these buildings were estimated. • The buildings were located in five cities with different climatic conditions. • The energy savings ratio was 100% when a cold energy source was used. • A mean electricity savings ratio of 13.1% was obtained. - Abstract: This paper presents energy and economic analyses related to the application of phase change materials boards (PCMBs) in building enclosures during the cooling season. A heat transfer model was developed, which was implemented via a computer program. Simulations were carried out using weather data files from five cities located in five different climate regions in China. Energy savings from using a natural cold source (e.g., outdoor air) and electricity savings from a reduction in electricity by air conditioning systems were evaluated. The energy savings ratio (ESR) and simple payback period (SPP) were used to assess the application of PCMBs in building enclosures. The selection of optimum phase transition temperatures for the PCMs for the various climates was made using indoor and outdoor air temperatures, as well as SPP. For space cooling purposes, it was suggested that phase transition temperatures should be at least 3 °C higher than the mean outdoor air temperature. Simple payback period suggested the possibility of the cost effective use of PCMBs in occupied buildings for moderate temperature climates

Appraisal of thermal premium in green building practice at urban scale. Methodological preview

Directory of Open Access Journals (Sweden)

Antonino Barbalace

2012-03-01

Full Text Available Research objective is to conceive, design and experiment a strategy at wide city scale to contribute facing the global ecological and energy crises of the Planet. This should be done through structural cut-down of fossil fuel consumption for settlements, i.e. by adopting the lowest cost energy: the not-consumed one! According to the Green Building Practices there are goals that can be achieved mainly through building passivation connected to: application of state-of-the-art sustainable technologies; alternative energy sources; diffusion of zero-mile decentralized solar energy production; fostering-up of solar feeding for summer air-conditioning, i.e. one of the most demanding energy consumers of the world. Owners, investors, contractors, occupants, tenants ask for more information and better quantification of energy saving magnitude in Green Buildings, as well as further appraisal of pay-back period i.e the length of time required for the return or re-payment of the additional larger initial investment. Research tries to conceive a methodology to assess in physical and monetary terms the energy saving and to define in financial terms the initial investment pay-back period at a reasonable rate. Proposed methodology has been tested in a first Case Study set-up at urban level and performed on a urban blocks of a Mediterranean medium size town including real world prototype yard, i.e. chantier, integrating passivation with the adoption of key frontier technologies such as sun chiller and solar cooling.

ANALISIS KELAYAKAN TEKNIS DAN FINANSIAL DARI INVESTASI PENGADAAN TRAY DRYER BERBAHAN BAKAR BIOMASSA PADA USAHA ARANG TEMPURUNG KELAPA BERBASIS EKSPOR (Studi Kasus di Tropica Nucifera Industry – Yogyakarta

Directory of Open Access Journals (Sweden)

Fanny Widadie

2013-11-01

Full Text Available The purpose of the study is to assess the technical and financial feasibility of procurement investment Tray Dryer fueled biomass to operations of coconut shell charcoal briquette in PT. Tropica Nucifera Industry. The result showed that investment-Tray Dryer on cocnut shell charcoal briquette bussiness was highly feasibile both the technical and financial aspects. The technical aspect was seen that the quantity-production capabilities of coconut shell charcoal briquettes using a dryer-Tray Dryer could be increased 15 percent compared the previous consdition-used of solar energy. While the quality of the charcoal briquettes produced from Tray Dryer was a much butter quality, moisture content (6.39%; ash (2.65%; carbon-bound (85.83%, compared to using sunlight, water content (15.89; ash (2.57% and carbon-bound (77.32%.The financial aspects of procurement Tray Dryer investment that its value was more feasible than previous, nothing Tray Dryer. Coconut shell charcoal briquet enterprises without using Tray Dryer was feasible to be done with NPV 1,058,928.12, IRR 63%, Payback Period 1 year and 9 moths, Net B/C 2.25 and analysis of swicthcing value reached 20 percent. And after the business using Tray Drayer, the financial analysis was much more feasible with NPV 2,285,500,498.12, IRR 113%, Payback Period 11 months, Net B/C 3.5 and analysis of switching value reached 50 percent.

Solar thermal–photovoltaic powered potato cold storage – Conceptual design and performance analyses

International Nuclear Information System (INIS)

Basu, Dipankar N.; Ganguly, A.

2016-01-01

Highlights: • Loss of food crop is a huge problem in India due to the shortage of cold storage. • Conceptual design of a power system using solar energy for a potato cold storage. • Integration of flat plate collector and SPV module with suitable operating strategy. • System provides a net energy surplus of about 36 MW h over a calendar year. • Rudimentary economic analysis found payback period of less than four years. - Abstract: Wastage of food crops due to the dearth of proper cold storage facilities is a huge problem in underdeveloped and developing countries of the world. Conceptual design of a potato cold storage is presented here, along with performance appraisal over a calendar year. The microclimate inside the cold storage is regulated using a water–lithium bromide absorption system. Proposed system utilizes both solar thermal and photovoltaic generated electrical energy for its operation. A suitable operation strategy is devised and the performance of the integrated system is analyzed from energy and exergy point of view to identify the required numbers of thermal collectors and photovoltaic modules. The proposed system is found to provide a net surplus of about 36 MW h energy over a calendar year, after meeting the in-house requirements. A rudimentary economic analysis is also performed to check the financial viability of the proposed system. Both the thermal and photovoltaic components are found to have payback periods less than four years.

Photolysis of Periodate and Periodic Acid in Aqueous Solution

DEFF Research Database (Denmark)

Sehested, Knud; Kläning, U. K.

1978-01-01

The photochemistry of periodate and periodic acid in aqueous solution was studied (i) by quantum yield measurements at low light intensity (ii) by flash photolysis, and (iii) by photolysis of glassy samples at 77 K. The photochemical studies were supplemented with pulse radiolysis studies...... of aqueous periodate solutions and with kinetic studies using stopped-flow technique. In strongly alkaline solution the photodecomposition of periodate proceeds via formation of O– and IVI. At pH solution O3 P is formed in a small...

Compact-immersed-tube bath heating for anodizing aluminum sections; Le chauffage de bains par tubes immerges compacts pour l`anodisation de profiles aluminium

Energy Technology Data Exchange (ETDEWEB)

Bouillet, B. [Societe Alusuisse (France); Lhomme, P.J. [Gaz de France (GDF), 75 - Paris (France)

1996-12-31

The compact-immersed-tube system is composed of a burner, a combustor (where natural gas is burned) and a heat exchanger tube (where combustion heat is released to the surrounding bath); its compact configuration is designed for a direct implementation in an industrial process vessel. Natural gas is thus directly used at the utilization location, without any vapour stage and distribution heat losses. Temperature regulation, efficiency, corrosion issues and power requirements are discussed. An application example with the bath heating for aluminum anodization, is presented: energy savings and payback periods are discussed

Rule-based Energy Management System in an Experimental Microgrid with the Presence of Time of Use Tariffs

Directory of Open Access Journals (Sweden)

Moghimi Mojtaba

2016-01-01

Full Text Available This paper aims to investigate a method of peak load shaving through the utilization of solar PV and battery energy storage whilst creating a cost effective Energy Management System (EMS. This is achieved by utilizing a rule-sets to manage and optimize a scheduling system with a forecasting algorithm. As Time of Use (ToU tariffs change throughout the day, a cost benefit can be achieved when a smart energy storage system is appropriately employed. The EMS operation is tested on an experimental microgrid with commercial load considering payback period calculation.

Air conditioning with methane: Efficiency and economics optimization parameters

International Nuclear Information System (INIS)

Mastrullo, R.; Sasso, M.; Sibilio, S.; Vanoli, R.

1992-01-01

This paper presents an efficiency and economics evaluation method for methane fired cooling systems. Focus is on direct flame two staged absorption systems and alternative engine driven compressor sets. Comparisons are made with conventional vapour compression plants powered by electricity supplied by the national grid. A first and second law based thermodynamics analysis is made in which fuel use coefficients and exergy yields are determined. The economics analysis establishes annual energy savings, unit cooling energy production costs, payback periods and economics/efficiency optimization curves useful for preliminary feasibility studies

Berg River Textiles - Cleaner Production Option Report

DEFF Research Database (Denmark)

Wenzel, Henrik; Schneider, Zsig

schematics on the various wet treatment operations in the dyehouse, and water and energy balances were made to the extent data allowed. A number of options for saving water, energy and chemicals were identified. The potentials monetary savings and necessary investments were estimated, and a list of priority...... projects including milestone plans for their implementation was made. A saving potential of around 3 mill. R was identified with a pay-back period of around 0.2 years as average of the identified options. The company implemented a large number of the options right away....

A methodology for financial evaluation of biogas technology in India using cost functions

International Nuclear Information System (INIS)

Rubab, S.; Kandpal, T.C.

1996-01-01

A methodology for financial evaluation of biogas technology for domestic use in India using recently developed cost functions is reported. Analytical expressions for the unit cost of biogas and cost per unit of useful energy delivered by a biogas plant in combination with other suitable technologies have been developed. Net present value and discounted pay-back period have been calculated. The sensitivity of the unit cost of biogas, the cost per unit of useful energy, and the net present value with respect to a number of variables is also reported. (author)

Vacuum boilers developed heating surfaces technic and economic efficiency evaluation

Science.gov (United States)

Slobodina, E. N.; Mikhailov, A. G.; Semenov, B. A.

2018-01-01

The vacuum boilers as manufacturing proto types application analysis was carried out, the possible directions for the heating surfaces development are identified with a view to improving the energy efficiency. Economic characteristics to evaluate the vacuum boilers application efficiency (Net Discounted Income (NDI), Internal Rate of Return (IRR), Profitability Index (PI) and Payback Period) are represented. The given type boilers application technic and economic efficiency criteria were established. NDI changing curves depending on the finning coefficient and operating pressure were obtained as a result of the conducted calculation studies.

Pollution prevention in the oil and soap industry: a case study

International Nuclear Information System (INIS)

Abou-Elela, S.I.; Zaher, F.

1998-01-01

Industrial audit of a complex oil and soap factory has been carried out. The factory produces edible oils, fatty acids, soap, crude, industrial and pharmaceutical glycerin, powdered detergents, animal fodder, sodium and potassium silicates, sodium hypochlorite and hypochloric acid. The audit shows that there were a wide range of pollution prevention opportunities which could be implemented with significant financial advantages for the factory as well as reducing environmental pollution. Cost benefits for the recommended environmental improvements have been estimated. Many of the improvements had short payback periods. (author)

Practical energy auditing

Energy Technology Data Exchange (ETDEWEB)

Jones, C. D.E.

1979-07-01

Graphs are shown depicting energy consumption over a period to illustrate the impact various factors have on energy consumption. Some recommendations are made to improve consumption including weatherization of the building; proper operation of equipment; and insulating pipelines, etc. Formulas are given from which can be determined the factors (seasonal variations, heat losses, etc.) causing fuel consumption variations. Electric power usage for space HVAC systems and for processes is dealt with separately and can usually be audited separately. Some payback times for specific conservation measures are given. (MCW)

Pollution prevention in the oil and soap industry: a case study

Energy Technology Data Exchange (ETDEWEB)

Abou-Elela, S.I. [National Research Center, Gizza (Egypt). Water Pollution Control Dept.; Zaher, F. [National Research Center, Gizza (Egypt). Fats and Oil Dept.

1998-12-31

Industrial audit of a complex oil and soap factory has been carried out. The factory produces edible oils, fatty acids, soap, crude, industrial and pharmaceutical glycerin, powdered detergents, animal fodder, sodium and potassium silicates, sodium hypochlorite and hypochloric acid. The audit shows that there were a wide range of pollution prevention opportunities which could be implemented with significant financial advantages for the factory as well as reducing environmental pollution. Cost benefits for the recommended environmental improvements have been estimated. Many of the improvements had short payback periods. (author)

Capital planning for clinical integration.

Science.gov (United States)

Grauman, Daniel M; Neff, Gerald; Johnson, Molly Martha

2011-04-01

When assessing the financial implications of a physician alignment and clinical integration initiative, a hospital should measure the initiative's potential ROI, perhaps best using a combination of net present value and payback period. The hospital should compare its own historical and projected performance with rating agency median benchmarks for key financial indicators of profitability, debt service, capital and cash flow, and liquidity. The hospital should also consider potential indirect benefits, such as retained outpatient/ancillary revenue, increased inpatient revenue, improved cost control, and improved quality and reporting transparency.

Simulation of an autonomous power supply system based on lithium-iron-phosphate (LiFePO4

Directory of Open Access Journals (Sweden)

Popov Mikhail

2017-01-01

Full Text Available Optimization of equipment composition and operation mode of power supply systems with renewable energy sources is an important and urgent task. As a result of the study, graphs of generation and consumption of electrical energy, charge-discharge characteristics of electric energy storage devices were constructed, the type and capacity of storage batteries were selected, the solar power plant scheme was developed and the main equipment was selected in accordance with the scheme, the economic efficiency of the solar power plant project was estimated and the payback period was determined.

Energy indicators for electricity production : comparing technologies and the nature of the indicators Energy Payback Ratio (EPR), Net Energy Ratio (NER) and Cumulative Energy Demand (CED). [Oestfoldforskning AS

Energy Technology Data Exchange (ETDEWEB)

Raadal, Hanne Lerche [Ostfold research, Fredrikstad (Norway); Modahl, Ingunn Saur [Ostfold research, Fredrikstad (Norway); Bakken, Tor Haakon [SINTEF Energy, Trondheim (Norway)

2012-11-01

CEDREN (Centre for Environmental Design of Renewable Energy) is founded by The Research Council of Norway and energy companies and is one of eight centres that were part of the scheme Centre for Environment-friendly Energy Research (FME) when the scheme was launched in 2009. The main objective of CEDREN is to develop and communicate design solutions for transforming renewable energy sources to the desired energy products, and at the same time address the environmental and societal challenges at local, regional, national and global levels. CEDREN's board initiated in 2011 a pilot project on the topics 'Energy Pay-back Ratio (EPR)', 'Ecosystem services' and 'multi-criteria analysis (MCA)' in order to investigate the possible use of these concepts/indices in the management of regulated river basins and as tools to benchmark strategies for the development of energy projects/resources. The energy indicator part (documented in this report) has aimed at reviewing the applicability of different energy efficiency indicators, as such, in the strategic management and development of energy resources, and to compare and benchmark technologies for production of electricity. The main findings from this pilot study is also reported in a policy memo (in Norwegian), that is available at www.cedren.no. The work carried out in this project will be continued in the succeeding research project EcoManage, which was granted by the Research Council of Norway's RENERGI programme in December 2011. Energy indicators: Several energy indicators for extraction and delivery of an energy product (e.g. transport fuel, heat, electricity etc.) exist today. The main objective of such indicators is to give information about the energy efficiency of the needed extraction and transforming processes throughout the value chain related to the delivered energy product. In this project the indicators Energy Payback Ratio (EPR), Net Energy Ration (NER) and Cumulative

Determining appropriate feed-in tariff rates to promote biomass-to-electricity generation in Eastern Ontario, Canada

International Nuclear Information System (INIS)

Moore, Steven; Durant, Vincent; Mabee, Warren E.

2013-01-01

On-site data collection, interviews, and financial models were used to determine the feed-in tariff (FIT) rate required to encourage investment in the generation of electricity from currently unused biomass from the Eastern Ontario forest industry. A financial model was adapted and run to determine the net present value, internal rate of return, and payback period associated with a 15 MW biomass-to-electricity facility. The analysis suggests that Ontario should consider a stronger incentive than the recently-offered CDN$ 0.13 kW −1 h −1 for biomass-to-electricity. If no customer for heat generated from the plant can be found, FIT rates between CDN$ 0.17–0.22 kW −1 h −1 are necessary to achieve a 15% internal rate of return and a simple payback of approximately 5 yr; achieving a price of CDN$ 0.013 kW −1 of thermal output still requires elevated FIT rates between CDN$ 0.15–0.21 kW −1 h −1 to meet economic performance criteria. Other barriers, particularly regulations regarding the use of operating engineers in steam plants, should also be addressed to facilitate development of biomass-to-electricity. Without these changes, it is likely that biomass will be significantly under-used and will not contribute to the renewable energy goals of Ontario. - Highlights: • Economic performance of biomass-to-electricity generation in Ontario is assessed. • Feed-in tariffs needed to meet industrial payback and IRR targets are determined. • Existing feed-in tariff rates for biomass must be raised to meet industrial targets. • Incentives that adjust feedstock price might be explored to increase biomass use

A techno-economic analysis of cost savings for retrofitting industrial aerial coolers with variable frequency drives

International Nuclear Information System (INIS)

Miller, Patrick; Olateju, Babatunde; Kumar, Amit

2012-01-01

Highlights: ► Techno-economic models were developed to assess the retrofitting of aerial coolers. ► The IRR for retrofitting with VFDs exceeds 10% for motor sizes above 20 hp. ► The IRR reaches a maximum of 220% for a cooler with fifty, 250 hp motors. ► The simple payback becomes less than 1 year for motors larger than 120 hp. ► Ambient temperature and location affects the profitability of VFD investment. - Abstract: A techno-economic model was created in order to develop curves that show the typical annual energy savings, rate of return, and payback for retrofitting aerial coolers with variable frequency drives (VFDs) for up to 50 motors, motor sizes from 4 to 186 kW (5–250 hp), and varying climate conditions. The cost savings due to installing a VFD depends on the reduction in energy used, as well as the reduction in power demand, the capital cost of the VFD, installation cost of the VFD, change in operating cost, and cost of electricity. The geographic locations examined in this report were Fort McMurray, Calgary, Vancouver, and Thunder Bay. This study found that the IRR increases rapidly with motor size, becomes greater than 10% at a motor size of approximately 15 kW, and may be as high as 220% (for the case of fifty, 186 kW motors). The IRR is sensitive to the number of fan motors retrofitted with VFDs, however the sensitivity rapidly declines as the number of motors is increased beyond five. The simple payback period becomes less than 1 year and nearly independent of number of motors and motor size for motors larger than 90 kW. Ambient temperature and geographic location affect the profitability of the investment, although the IRR only changes by approximately 4%.

Viabilidade econômica de uma clínica veterinária no interior de São Paulo = Economic viability of a veterinary clinic in the countryside of São Paulo state

Directory of Open Access Journals (Sweden)

Helder Roberto Dota Janoselli

2016-07-01

objective of this study was to assess the costs and analyze the economic viability of starting a complete veterinary clinic, in conformity with standards of a veterinary hospital, able to perform basic and advanced medical procedures all in the same place, in the city of São João da Boa Vista, countryside of São Paulo state. For that, a survey of required investments to start the clinic was performed, as well as the fixed and variable costs, and revenues. The cash flow was projected for a five year period and the economic viability analysis was done using the indicators: Net Present Value [NPV], Internal Rate of Return [IRR] and payback period (simple and discounted. Sensitivity analysis was also used to assess how changes in the investments, revenues and interest rates affect the NPV of the project. The results showed that the project of starting a complete pet veterinary clinic is economically feasible. The project had a positive NPV of R$ 152.049,33, IRR of 12,68%, and simple and discounted payback period of 4.13 and 4.38 years, respectively. The NPV calculation was very sensitive to changes in revenue, followed by the investments, whose increase negatively affected the NPV. Lower sensitivity was observed for changes in interest rates.

Positive periodic solutions of delayed periodic Lotka-Volterra systems

International Nuclear Information System (INIS)

Lin Wei; Chen Tianping

2005-01-01

In this Letter, for a general class of delayed periodic Lotka-Volterra systems, we prove some new results on the existence of positive periodic solutions by Schauder's fixed point theorem. The global asymptotical stability of positive periodic solutions is discussed further, and conditions for exponential convergence are given. The conditions we obtained are weaker than the previously known ones and can be easily reduced to several special cases

From Periodic Properties to a Periodic Table Arrangement

Science.gov (United States)

Besalú, Emili

2013-01-01

A periodic table is constructed from the consideration of periodic properties and the application of the principal components analysis technique. This procedure is useful for objects classification and data reduction and has been used in the field of chemistry for many applications, such as lanthanides, molecules, or conformers classification.…

Renewable energy production support schemes for residential-scale solar photovoltaic systems in Nordic conditions

International Nuclear Information System (INIS)

Hirvonen, Janne; Kayo, Genku; Cao, Sunliang; Hasan, Ala; Sirén, Kai

2015-01-01

The objective of this study was to examine the effect of production-based support schemes on the economic feasibility of residential-scale PV systems (1–10 kW) in Finland. This was done by calculating the payback time for various sizes of newly installed PV systems for a Finnish detached house with district heating. Three types of economic support schemes (guaranteed selling price, fixed premiums and self-consumption incentives) were tested in an hourly simulation. The load of the building was based on real-life measurements, while PV output was simulated with TRNSYS software. The energy results were post-processed with economic data in MATLAB to find the payback time. Hourly electricity prices from the Nordic energy market were used with PV system prices from Finnish companies. Unsubsidised residential PV systems in Finland had payback times of more than 40 years. The production-based support for PV generation needs to be two to three times the buying price of electricity, to make it possible to pay back the initial investment in 20 years. Low capacity systems with more than 50% self-consumption (under 3 kW) were favoured by self-consumption incentives, while high capacity systems with less than 40% self-consumption (over 5 kW) were favoured by the FIT-type support schemes. - Highlights: • Unsubsidised residential PV is uneconomical in Finland. • Support rate must be 2 times the electricity price for reasonable payback time. • Even using all electricity on-site is not profitable enough without support. • Assumed real interest rate had great influence on payback time. • Hourly electricity prices are much lower than average values from Finnish statistics

Losses Disguised as Wins Affect Game Selection on Multiline Slots.

Science.gov (United States)

Graydon, Candice; Stange, Madison; Dixon, Mike J

2018-05-05

Multiline slots are exciting games that contain features which make them alluring. One such feature is a loss disguised as a win (LDW); wherein, players win less than they wager (e.g., bet 2 dollars, win back 50 cents), but this net loss is disguised by flashing graphics and winning sounds. Research to date concludes that LDWs are both rewarding and reinforcing. Here, we investigated whether LDWs affect players' game selection. Thirty-two undergraduate students with experience playing slot machines played 100 spins on four games-two had positive payback percentages (115%) and two had negative payback percentages (85%) after 100 spins. For each payback percentage condition, there was a game with no LDWs and a game with a moderate number of LDWs. For the 100 spins, players could choose to play whichever game they wished. They then rated their preference for each game following the 100-spins and chose a game to continue playing. The majority of players preferred playing the positive payback percentage game with LDWs and chose to continue playing this game over the three other games. We conclude that in addition to LDWs being reinforcing and rewarding, LDWs do in fact influence game selection. We conclude that responsible gambling initiatives should educate players about LDWs.

Bounded and Periodic Solutions of Semilinear Impulsive Periodic System on Banach Spaces

Directory of Open Access Journals (Sweden)

Wei W

2008-01-01

Full Text Available Abstract A class of semilinear impulsive periodic system on Banach spaces is considered. First, we introduce the -periodic PC-mild solution of semilinear impulsive periodic system. By virtue of Gronwall lemma with impulse, the estimate on the PC-mild solutions is derived. The continuity and compactness of the new constructed Poincaré operator determined by impulsive evolution operator corresponding to homogenous linear impulsive periodic system are shown. This allows us to apply Horn's fixed-point theorem to prove the existence of -periodic PC-mild solutions when PC-mild solutions are ultimate bounded. This extends the study on periodic solutions of periodic system without impulse to periodic system with impulse on general Banach spaces. At last, an example is given for demonstration.

Low temperature desalination using solar collectors augmented by thermal energy storage

International Nuclear Information System (INIS)

Gude, Veera Gnaneswar; Nirmalakhandan, Nagamany; Deng, Shuguang; Maganti, Anand

2012-01-01

Highlights: ► A new low temperature desalination process using solar collectors was investigated. ► A thermal energy storage tank (TES) was included for continuous process operation. ► Solar collector area and TES volumes were optimized by theoretical simulations. ► Economic analysis for the entire process was compared with and without TES tank. ► Energy and emission payback periods for the solar collector system were reported. -- Abstract: A low temperature desalination process capable of producing 100 L/d freshwater was designed to utilize solar energy harvested from flat plate solar collectors. Since solar insolation is intermittent, a thermal energy storage system was incorporated to run the desalination process round the clock. The requirements for solar collector area as well as thermal energy storage volume were estimated based on the variations in solar insolation. Results from this theoretical study confirm that thermal energy storage is a useful component of the system for conserving thermal energy to meet the energy demand when direct solar energy resource is not available. Thermodynamic advantages of the low temperature desalination using thermal energy storage, as well as energy and environmental emissions payback period of the system powered by flat plate solar collectors are presented. It has been determined that a solar collector area of 18 m 2 with a thermal energy storage volume of 3 m 3 is adequate to produce 100 L/d of freshwater round the clock considering fluctuations in the weather conditions. An economic analysis on the desalination system with thermal energy storage is also presented.

Energetic and financial investigation of a stand-alone solar-thermal Organic Rankine Cycle power plant

International Nuclear Information System (INIS)

Tzivanidis, Christos; Bellos, Evangelos; Antonopoulos, Kimon A.

2016-01-01

Highlights: • A stand-alone solar driven Organic Rankine Cycle is optimized parametrically. • The system is optimized energetically and financially. • Nine working fluids are tested with cyclohexane to be the most suitable. • A collecting area of 25,000 m"2 parabolic trough collectors is the optimum solution. • The maximum IRR is 13.46% and the payback period is about 9 years. - Abstract: The use of solar thermal energy for electricity production is a clean and sustainable way to cover the increasing energy needs of our society. The most mature technology for capturing solar energy in high temperature levels is the parabolic trough collectors (PTC). In this study, an Organic Rankine Cycle (ORC) coupled with PTC is analyzed parametrically in order to be optimized financially and energetically. The first step is the thermodynamic investigation of the ORC by using various working fluids. The second step is the energetic and financial investigation of the total system which includes the solar field, the storage tank and the ORC module. By testing many combinations of collecting areas and storage tank volumes, finally cyclohexane proved to be the most suitable working fluid for producing 1 MW_e_l with PTC. Specifically, in the optimum situation a solar field of 25,000 m"2 with storage tank of about 300 m"3 leads to a payback period of 9 years and to an internal rate of return (IRR) equal to 13.46%. Moreover, an economic comparison for different commercial collectors is presented, with Eurotrough ET-150 being the financially optimum solution for this case study.

The potential energy conservation of the Dutch industrial, business and service sector

International Nuclear Information System (INIS)

Van der Werff, R.L.; Opschoor, J.B.

1992-01-01

The database ICARUS has been used as a starting point to estimate the economical potential for energy conservation in different sectors of the Dutch society. ICARUS is based on research on real energy consuming processes and applications in a number of sub-sectors of the Dutch economy. The present energy conservation potential in the Netherlands is based on energy conservation studies in the Netherlands and other countries. For this article the economical efficient energy conservation potentials in 1992 have been investigated for the Dutch sectors, which do not supply energy. The potentials are determined on the basis of the technical energy conservation potentials for the year 2000, according to the database ICARUS. Two methods were used to extract the economic potential from the technical potential: the method of the Net Market Value and the method of the payback period. From the ICARUS analysis it appears that the technical potential for energy conservation is 479 PJ, which is 28.8% of the primary energy consumption of 1664 PJ in 1985. The economic energy conservation potential is 262 PJ for a payback period of less than five years, which is 17% of the 1985 primary energy consumption. Next to the above-mentioned analysis policy-aimed simulations were carried out for three scenarios to determine economical energy conservation potentials. In one scenario doubled energy prices were used in comparison with the 1991 prices. Another scenario uses the Net Market Value method with a 5% discount rate, and the third scenario uses both parameters

Sustainable urban energy: Development of a mesoscale assessment model for solar reflective roof technologies

International Nuclear Information System (INIS)

Jo, J.H.; Carlson, J.; Golden, J.S.; Bryan, H.

2010-01-01

Buildings and other engineered structures that form cities are responsible for a significant portion of the global and local impacts of climate change. Consequently, the incorporation of building design strategies and materials such as the use of reflective roof materials, or 'cool' roofs, are being widely investigated. However, although their benefits for individual buildings have been studied, as yet there is little understanding of the potential benefits of urban scale implementation of such systems. Here we report the development of a new methodology for assessing the potential capacity and benefits of installing reflective roofs in an urbanized area. The new methodology combines remote sensing image data with a building energy computer simulation to quantify the current rooftop reflectivity and predict the potential benefits of albedo improvement. In addition to the direct electricity savings, cool roof systems reduce peak electrical demand in the month of August when the peak demand is at its highest in the case study area. Environmental benefits associated with lowering greenhouse-gas emissions are also substantial. The new methodology allows the calculation of payback periods to assist planners to evaluate the potential economic benefits of the widespread installation of cool roof systems. - Research highlights: →Integrated remote sensing technique into building energy simulation quantifies rooftop reflectivity and predicts the potential benefits of albedo improvement. →70% buildings can improve rooftop reflectivity. →Cool roof application can reduce the study area's electrical demand by 4.3%. →Payback period will be 7-11 years depending on low and high-end cool roof cost assumptions.

Sensitivity analysis of floating offshore wind farms

International Nuclear Information System (INIS)

Castro-Santos, Laura; Diaz-Casas, Vicente

2015-01-01

Highlights: • Develop a sensitivity analysis of a floating offshore wind farm. • Influence on the life-cycle costs involved in a floating offshore wind farm. • Influence on IRR, NPV, pay-back period, LCOE and cost of power. • Important variables: distance, wind resource, electric tariff, etc. • It helps to investors to take decisions in the future. - Abstract: The future of offshore wind energy will be in deep waters. In this context, the main objective of the present paper is to develop a sensitivity analysis of a floating offshore wind farm. It will show how much the output variables can vary when the input variables are changing. For this purpose two different scenarios will be taken into account: the life-cycle costs involved in a floating offshore wind farm (cost of conception and definition, cost of design and development, cost of manufacturing, cost of installation, cost of exploitation and cost of dismantling) and the most important economic indexes in terms of economic feasibility of a floating offshore wind farm (internal rate of return, net present value, discounted pay-back period, levelized cost of energy and cost of power). Results indicate that the most important variables in economic terms are the number of wind turbines and the distance from farm to shore in the costs’ scenario, and the wind scale parameter and the electric tariff for the economic indexes. This study will help investors to take into account these variables in the development of floating offshore wind farms in the future

Energy and fuel efficient parallel mild hybrids for urban roads

International Nuclear Information System (INIS)

Babu, Ajay; Ashok, S.

2016-01-01

Highlights: • Energy and fuel savings depend on battery charge variations and the vehicle speed parameters. • Indian urban conditions provide lot of scope for energy and fuel savings in mild hybrids. • Energy saving strategy has lower payback periods than the fuel saving one in mild hybrids. • Sensitivity to parameter variations is the least for energy saving strategy in a mild hybrid. - Abstract: Fuel economy improvements and battery energy savings can promote the adoption of parallel mild hybrids for urban driving conditions. The aim of this study is to establish these benefits through two operating modes: an energy saving mode and a fuel saving mode. The performances of a typical parallel mild hybrid using these modes were analysed over urban driving cycles, in the US, Europe, and India, with a particular focus on the Indian urban conditions. The energy pack available from the proposed energy-saving operating mode, in addition to the energy already available from the conventional mode, was observed to be the highest for the representative urban driving cycle of the US. The extra energy pack available was found to be approximately 21.9 times that available from the conventional mode. By employing the proposed fuel saving operating mode, the fuel economy improvement achievable in New York City was observed to be approximately 22.69% of the fuel economy with the conventional strategy. The energy saving strategy was found to possess the lowest payback periods and highest immunity to variations in various cost parameters.

Measuring buildings for sustainability: Comparing the initial and retrofit ecological footprint of a century home – The REEP House

International Nuclear Information System (INIS)

Bin, Guoshu; Parker, Paul

2012-01-01

Highlights: ► Life cycle energy, carbon and ecological footprints of a century home are studied. ► The operational impact accounts for most of the total lifecycle impact. ► Sourcing energy-intensive materials locally only reduces embodied impacts a little. ► Deep energy retrofits (80% savings) achieved substantial environmental benefits. ► The environmental payback period of major energy retrofits is less than 2 years. - Abstract: The residential sector is recognized as a major energy consumer and thus a significant contributor to climate change. Rather than focus only on current energy consumption and the associated emissions, there is a need to broaden sustainability research to include full life cycle contributions and impacts. This paper looks at houses from the perspective of the ecological footprint (EF), a well-known sustainability indicator. Exemplifying single-detached houses of the early 20th century, the century-old REEP House (downtown Kitchener, Canada), together with its high performance energy retrofits, is examined in detail. This research combines material, energy and carbon emission studies. Its scope covers the life cycle of the house, including the direct and indirect consumption of material and energy, and concomitant carbon emissions during its stages of material extraction, transportation, construction, operation, and demolition. It is revealed that the REEP House had a typical impact on the environment when it was built, and, even though the renovations to improve energy efficiency by 80% introduce additional embodied environmental impacts, they are environmentally sound activities because the environmental payback period is less than 2 years.

Optimal investment and scheduling of distributed energy resources with uncertainty in electric vehicle driving schedules

International Nuclear Information System (INIS)

Cardoso, G.; Stadler, M.; Bozchalui, M.C.; Sharma, R.; Marnay, C.; Barbosa-Póvoa, A.; Ferrão, P.

2014-01-01

The large scale penetration of electric vehicles (EVs) will introduce technical challenges to the distribution grid, but also carries the potential for vehicle-to-grid services. Namely, if available in large enough numbers, EVs can be used as a distributed energy resource (DER) and their presence can influence optimal DER investment and scheduling decisions in microgrids. In this work, a novel EV fleet aggregator model is introduced in a stochastic formulation of DER-CAM [1], an optimization tool used to address DER investment and scheduling problems. This is used to assess the impact of EV interconnections on optimal DER solutions considering uncertainty in EV driving schedules. Optimization results indicate that EVs can have a significant impact on DER investments, particularly if considering short payback periods. Furthermore, results suggest that uncertainty in driving schedules carries little significance to total energy costs, which is corroborated by results obtained using the stochastic formulation of the problem. - Highlights: • This paper introduces a new EV aggregator model in the DER-CAM model and expands it with a stochastic formulation. • The model is used to analyze the impact of EVs in DER investment decisions in a large office building. • The uncertainty in EV driving patterns is considered through scenarios based on data from a daily commute driving survey. • Results indicate that EVs have a significant impact in optimal DER decisions, particularly when looking at short payback periods. • Furthermore, results indicate that uncertainty in EV driving schedules has little impact on DER investment decisions

ANALISA PERBANDINGAN BIAYA PENGGUNAAN NUTRUNNER MANUAL DAN OTOMATIS MENGGUNAKAN METODE COST & BENEFITS ANALYSIS

Directory of Open Access Journals (Sweden)

Ucok Mulyo Sugeng

2017-10-01

Full Text Available In a situation of increasingly fierce competition in every manufacturing company, PT SZI supposedly able to apply concepts and production strategies well as improve product quality. Thus the need for the selection of the right nutrunner as an investment in the assembly process. The assembly process is the part that greatly affects the quantity and quality of production in the manufacturing industry, the faster the process of assembling the more units are produced. Likewise with the production quality, the better the nutrunner is used it will be less risk of rejection unit which will incur additional costs. Nutrunner is a tool used for tightening bolts / nuts that are powered by wind energy or electricity. The different types of energy use in nutrunner that is the term naming nutrunner automatic and manual will be compared based on several aspects that will be selected which are more efficient in the production process. In search results of the comparison, cost calculation will use the application Desoutter Rightway. After known perbandinagn some aspects costs (energy costs, productivity costs, calibraton cost, maintenance cost, and quality cost then the analysis will be continued use Cost & Benefits Analysis to get some of the goals of this research, which is a long period of return on investment or breakeven on the project this nutrunner with Payback Period method. Besides the cost analysis is also used to find the value of benefits in order to determine whether the project is feasible and acceptable methods Return on Investment. After the data were analyzed using the method of cost and benefit analysis then obtained a long period of payback or breakeven for automatic nutrunner investment is 1.22 years and 14.63 months. As for the value of the benefits of 146%, this means that the project is acceptable because it provides the advantages of the total investment cost.

Entropy method of measuring and evaluating periodicity of quasi-periodic trajectories

Science.gov (United States)

Ni, Yanshuo; Turitsyn, Konstantin; Baoyin, Hexi; Junfeng, Li

2018-06-01

This paper presents a method for measuring the periodicity of quasi-periodic trajectories by applying discrete Fourier transform (DFT) to the trajectories and analyzing the frequency domain within the concept of entropy. Having introduced the concept of entropy, analytical derivation and numerical results indicate that entropies increase as a logarithmic function of time. Periodic trajectories typically have higher entropies, and trajectories with higher entropies mean the periodicities of the motions are stronger. Theoretical differences between two trajectories expressed as summations of trigonometric functions are also derived analytically. Trajectories in the Henon-Heiles system and the circular restricted three-body problem (CRTBP) are analyzed with the indicator entropy and compared with orthogonal fast Lyapunov indicator (OFLI). The results show that entropy is a better tool for discriminating periodicity in quasiperiodic trajectories than OFLI and can detect periodicity while excluding the spirals that are judged as periodic cases by OFLI. Finally, trajectories in the vicinity of 243 Ida and 6489 Golevka are considered as examples, and the numerical results verify these conclusions. Some trajectories near asteroids look irregular, but their higher entropy values as analyzed by this method serve as evidence of frequency regularity in three directions. Moreover, these results indicate that applying DFT to the trajectories in the vicinity of irregular small bodies and calculating their entropy in the frequency domain provides a useful quantitative analysis method for evaluating orderliness in the periodicity of quasi-periodic trajectories within a given time interval.

Potential application of a centralized solar water-heating system for a high-rise residential building in Hong Kong

International Nuclear Information System (INIS)

Chow, T.T.; Fong, K.F.; Chan, A.L.S.; Lin, Z.

2006-01-01

There is a growing, government-led trend of applying renewable energy in Hong Kong. One area of interest lies in the wider use of solar-energy systems. The worldwide fast development of building-integrated solar technology has prompted the design alternative of fixing the solar panels on the external facades of buildings. In Hong Kong, high-rise buildings are found everywhere in the urban districts. How to make full use of the vertical facades of these buildings to capture the most solar radiation can be an important area in the technology promotion. In this numerical study, the potential application of a centralized solar water-heating system in high-rise residence was evaluated. Arrays of solar thermal collectors, that occupied the top two-third of the south and west facades of a hypothetical high-rise residence, were proposed for supporting the domestic hot-water system. Based on typical meteorological data, it was found that the annual efficiency of the vertical solar collectors could reach 38.4% on average, giving a solar fraction of 53.4% and a payback period of 9.2 years. Since the solar collectors were able to reduce the heat transmission through the building envelope, the payback was in fact even shorter if the energy saving in air-conditioner operation was considered

Energy Refurbishment of an Office Building with Hybrid Photovoltaic System and Demand-Side Management

Directory of Open Access Journals (Sweden)

Giovani Almeida Dávi

2017-08-01

Full Text Available On-site photovoltaic (PV and battery systems intend to improve buildings energy performance, however battery costs and monetary incentives are a major drawback for the introduction of these technologies into the electricity grids. This paper proposes an energy refurbishment of an office building based on multi-objective simulations. An innovative demand-side management approach is analyzed through the PV and battery control with the purpose of reducing grid power peaks and grid imported energy, as well as improving the project economy. Optimization results of load matching and grid interaction parameters, complemented with an economic analysis, are investigated in different scenarios. By means of battery use, the equivalent use of the grid connection is reduced by 12%, enhancing the grid interaction potential, and 10% of load matching rates can be increased. Project improvements indicate the grid connection capacity can be reduced by 13% and significant savings of up to 48% are achieved on yearly bills. The economy demonstrates the grid parity is only achieved for battery costs below 100 €/kWh and the payback period is large: 28 years. In the case with only PV system, the grid parity achieves better outcomes and the payback time is reduced by a half, making this a more attractive option.

Demonstration Assessment of Light-Emitting Diode (LED) Roadway Lighting on Lija Loop in Portland, OR

International Nuclear Information System (INIS)

Kinzey, Bruce R.; Myer, Michael

2009-01-01

This report describes the process and results of a demonstration of solid-state lighting (SSL) technology in a residential street lighting application, under the U.S. Department of Energy GATEWAY Solid-State Lighting Technology Demonstration Program. In this project, eight 100W (nominal) high-pressure sodium cobra head fixtures were replaced with a like number of LED street light luminaires manufactured by Leotek, Inc. The Leotek product achieved an estimated payback in the Lija Loop installation of about 20 years for replacement scenarios and a much shorter 7.6 years for new installations. Much of the associated energy savings (55%) supporting these payback periods, however, were achieved by reducing average horizontal photopic illuminance a similar amount (53%). Examined from a different perspective, the measured performance suggests that the Leotek product is at approximate parity with the HPS cobra head in terms of average delivered photopic illumination for a given power consumption. HPS comprises the second most efficacious street lighting technology available, exceeded only by low pressure sodium (LPS). LPS technology is not considered suitable for most street lighting applications due to its monochromatic spectral output and poor color rendering ability; therefore, this LED product is performing at an efficiency level comparable to its primary competition in this application.

Vertebrate fauna of the Roman period, migrations period and Medieval period in Vojvodina (Serbia

Directory of Open Access Journals (Sweden)

Radmanović Darko P.

2014-01-01

Full Text Available Based on current published and unpublished research results, a total of 16 vertebrate species members of mammal (Mammalia, bird (Aves and osteichthyes (Osteichthyes classes have been registered at 11 archaeological sites from the Roman Period in Vojvodina. Mammals dominate with 12 species and one genus, birds are present with 3 species, and osteichthyes with one. From the Migration Period, at 9 sites, 22 vertebrate species have been registered, of which 13 species and one genus of mammals, 4 species and one genus of birds, and 5 species from the Osteichthyes class. At 8 sites from the Medieval Period, 16 vertebrate species have been registered. Mammals are the most numerous class with 10 species and one genus, while birds are present with 4 species and one genus. Furthermore, two species of osteichthyes have also been registered.

Commuting periodic operators and the periodic Wigner function

International Nuclear Information System (INIS)

Zak, J

2004-01-01

Commuting periodic operators (CPO) depending on the coordinate x-hat and the momentum p-hat operators are defined. The CPO are functions of the two basic commuting operators exp(i x-hat 2π/a) and exp(i/h p-hat a), with a being an arbitrary constant. A periodic Wigner function (PWF) w(x, p) is defined and it is shown that it is applicable in a normal expectation value calculation to the CPO, as done in the original Wigner paper. Moreover, this PWF is non-negative everywhere, and it can therefore be interpreted as an actual probability distribution. The PWF w(x, p) is shown to be given as an expectation value of the periodic Dirac delta function in the phase plane. (letter to the editor)

Forward Period Analysis Method of the Periodic Hamiltonian System.

Directory of Open Access Journals (Sweden)

Pengfei Wang

Full Text Available Using the forward period analysis (FPA, we obtain the period of a Morse oscillator and mathematical pendulum system, with the accuracy of 100 significant digits. From these results, the long-term [0, 1060] (time unit solutions, ranging from the Planck time to the age of the universe, are computed reliably and quickly with a parallel multiple-precision Taylor series (PMT scheme. The application of FPA to periodic systems can greatly reduce the computation time of long-term reliable simulations. This scheme provides an efficient way to generate reference solutions, against which long-term simulations using other schemes can be tested.

Modeling Stochastic Energy and Water Consumption to Manage Residential Water Uses

Science.gov (United States)

Abdallah, A. M.; Rosenberg, D. E.; Water; Energy Conservation

2011-12-01

and energy use, potential savings, and payback periods to install efficient water end-use appliances and fixtures. Stochastic model results show the distributions among households for (i) water end-use, (ii) energy consumed to use water, and (iii) financial payback periods. Compared to deterministic analysis, stochastic modeling results show that hot water fractions for appliances follow normal distributions with high standard deviation and reveal pronounced variations among households that significantly affect energy savings and payback period estimates. These distributions provide an important tool to select and size water conservation programs to simultaneously meet both water and energy conservation goals. They also provide a way to identify and target a small fraction of customers with potential to save large water volumes and energy from appliance retrofits. Future work will embed this household scale stochastic model in city-scale models to identify win-win water management opportunities where households save money by conserving water and energy while cities avoid costs, downsize, or delay infrastructure development.

Cogeneration through small and medium sized gas turbines in Italy: Marketing survey

International Nuclear Information System (INIS)

Bianchi, A.; Schieppati, P.

1992-01-01

In Italy, the use of cogeneration systems by private industrial concerns has greatly increased in the early 90's. The successful technological development of highly efficient low and medium sized gas turbines and the successful application of cogenerated power to a number of industrial processes, favourable legislation and financial incentives on the part of the Italian Government, especially interested in promoting energy conservation and the use of natural gas as an alternative to petroleum, as well as, fast payback periods for such investments are amongst the major regions for the growing demand for this type of power system alternative in Italy

Heat pumps; Synergy of high efficiency and low carbon electricity

Energy Technology Data Exchange (ETDEWEB)

Koike, Akio

2010-09-15

Heat pump is attracting wide attention for its high efficiency to utilize inexhaustible and renewable ambient heat in the environment. With its rapid innovation and efficiency improvement, this technology has a huge potential to reduce CO2 emissions by replacing currently widespread fossil fuel combustion systems to meet various heat demands from the residential, commercial and industrial sectors. Barriers to deployment such as low public awareness and a relatively long pay-back period do exist, so it is strongly recommended that each country implement policies to promote heat pumps as a renewable energy option and an effective method to combat global warming.

Geothermal Retrofit of Illinois National Guard's State headquarters Building

Energy Technology Data Exchange (ETDEWEB)

Lee, Mark

2015-04-27

The goal of this project was to assess the feasibility of utilizing mine water as a heat sink for a geothermal heat pump system to heat and cool the 74,000 sq. ft. Illinois National Guard State Headquarters’ building in Springfield Illinois. If successful, this type of system would be less expensive to install than a traditional closed loop geothermal (ground source) heat pump system by significantly reducing the size of the well field, thus shortening or eliminate the payback period compared to a conventional system. In the end, a conventional ground loop was used for the project.

Modernization of two gas-fired shaft annealing furnaces

Energy Technology Data Exchange (ETDEWEB)

Barthof, G.; Porst, G.; Raczek, S.

1986-04-01

The objective was to modernize two existing shaft-type annealing furnaces used for the heat treatment of grey iron castings with the aim of reducing the consumption of gaseous fuel, minimize the formation of scale, decrease maintenance expense and apply more automatic control to the annealing process. This was to be achieved by an optimum combination of new types of construction materials and advanced firing and control equipment. The author describes the furnace in its condition prior to and after reconstruction. The operating results obtained after reconstruction were found to justify the costs incurred. The payback period is roughly one year.

Trigeneration System Based on Municipal Waste Gasification, Fuel Cell and an Absorption Chiller

DEFF Research Database (Denmark)

Katsaros, Giannis; Nguyen, Tuong-Van; Rokni, Masoud

2016-01-01

of a specific building is also investigated and the system can fully meet the electricity and cooling demands, whereas the heat needs can be satisfied only up to 55%. Moreover, assuming 20 years of operation, the payback period is 4.3 years and the net present value exceeds 5 MEUR.......The present work focuses on the design of a novel tri-generation system based on municipal solid wastes gasification, solid oxide fuel cell and an ammonia-water absorption chiller. Trigeneration systems can be implemented in buildings such as hospitals, where there is a continuous and large demand...

A small capacity co generative gas-turbine plant in factory AD 'Komuna' - Skopje (Macedonia)

International Nuclear Information System (INIS)

Dimitrov, Konstantin; Armenski, Slave; Tashevski, Done

2000-01-01

The factory AD 'Komuna' -Skopje (Macedonia), has two steam block boilers, type ST 800 for steam production for process and space heating. The factory satisfies the electricity needs from the national grid. By the use of natural gas like fuel it is possible to produce electrical energy in its own co generative gas turbine plant. In this article, a co generative plant with small-scale gas turbine for electricity production is analyzed . The gas from gas turbine have been introduce in the steam block boiler. Also, a natural gas consumption, the electricity production, total investment and payback period of investment are determined. (Authors)

The Periodic Pyramid

Science.gov (United States)

Hennigan, Jennifer N.; Grubbs, W. Tandy

2013-01-01

The chemical elements present in the modern periodic table are arranged in terms of atomic numbers and chemical periodicity. Periodicity arises from quantum mechanical limitations on how many electrons can occupy various shells and subshells of an atom. The shell model of the atom predicts that a maximum of 2, 8, 18, and 32 electrons can occupy…

Middle Helladic Period

DEFF Research Database (Denmark)

Sarri, Kalliopi

1999-01-01

and their quality was improved considerably toward the end of this period. The profound cultural innovations of the Middle Helladic period were initially interpreted as a result of violent population movement and troubles provoked by the coming of the first Indo-European races. However, this matter does no more...... Helladic period is considered as a period of economic and social decline it was the time during which the mainland features merged with the insular influence, that is all the Aegean elements which led to the creation of the Mycenaean civilization were mixed in a creative way....

Periodicity and quasi-periodicity for super-integrable hamiltonian systems

International Nuclear Information System (INIS)

Kibler, M.; Winternitz, P.

1990-01-01

Classical trajectories are calculated for two Hamiltonian systems with ring shaped potentials. Both systems are super-integrable, but not maximally super-integrable, having four globally defined single-valued integrals of motion each. All finite trajectories are quasi-periodical; they become truly periodical if a commensurability condition is imposed on an angular momentum component

PERIOD ESTIMATION FOR SPARSELY SAMPLED QUASI-PERIODIC LIGHT CURVES APPLIED TO MIRAS

Energy Technology Data Exchange (ETDEWEB)

He, Shiyuan; Huang, Jianhua Z.; Long, James [Department of Statistics, Texas A and M University, College Station, TX (United States); Yuan, Wenlong; Macri, Lucas M., E-mail: lmacri@tamu.edu [George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States)

2016-12-01

We develop a nonlinear semi-parametric Gaussian process model to estimate periods of Miras with sparsely sampled light curves. The model uses a sinusoidal basis for the periodic variation and a Gaussian process for the stochastic changes. We use maximum likelihood to estimate the period and the parameters of the Gaussian process, while integrating out the effects of other nuisance parameters in the model with respect to a suitable prior distribution obtained from earlier studies. Since the likelihood is highly multimodal for period, we implement a hybrid method that applies the quasi-Newton algorithm for Gaussian process parameters and search the period/frequency parameter space over a dense grid. A large-scale, high-fidelity simulation is conducted to mimic the sampling quality of Mira light curves obtained by the M33 Synoptic Stellar Survey. The simulated data set is publicly available and can serve as a testbed for future evaluation of different period estimation methods. The semi-parametric model outperforms an existing algorithm on this simulated test data set as measured by period recovery rate and quality of the resulting period–luminosity relations.

Periodic Solutions and S-Asymptotically Periodic Solutions to Fractional Evolution Equations

Directory of Open Access Journals (Sweden)

Jia Mu

2017-01-01

Full Text Available This paper deals with the existence and uniqueness of periodic solutions, S-asymptotically periodic solutions, and other types of bounded solutions for some fractional evolution equations with the Weyl-Liouville fractional derivative defined for periodic functions. Applying Fourier transform we give reasonable definitions of mild solutions. Then we accurately estimate the spectral radius of resolvent operator and obtain some existence and uniqueness results.

On complex periodic motions and bifurcations in a periodically forced, damped, hardening Duffing oscillator

International Nuclear Information System (INIS)

Guo, Yu; Luo, Albert C.J.

2015-01-01

In this paper, analytically predicted are complex periodic motions in the periodically forced, damped, hardening Duffing oscillator through discrete implicit maps of the corresponding differential equations. Bifurcation trees of periodic motions to chaos in such a hardening Duffing oscillator are obtained. The stability and bifurcation analysis of periodic motion in the bifurcation trees is carried out by eigenvalue analysis. The solutions of all discrete nodes of periodic motions are computed by the mapping structures of discrete implicit mapping. The frequency-amplitude characteristics of periodic motions are computed that are based on the discrete Fourier series. Thus, the bifurcation trees of periodic motions are also presented through frequency-amplitude curves. Finally, based on the analytical predictions, the initial conditions of periodic motions are selected, and numerical simulations of periodic motions are carried out for comparison of numerical and analytical predictions. The harmonic amplitude spectrums are also given for the approximate analytical expressions of periodic motions, which can also be used for comparison with experimental measurement. This study will give a better understanding of complex periodic motions in the hardening Duffing oscillator.

Theoretical growth rates, periods, and pulsation constants for long-period variables

International Nuclear Information System (INIS)

Fox, M.W.; Wood, P.R.

1982-01-01

Theoretical values of the growth rate, period, and pulsation constant for the first three radial pulsation modes in red giants (Population II and galactic disk) and supergiants have been derived in the linear, nonadiabatic approximation. The effects of altering the surface boundary conditions, the effective temperature (or mixing length), and the opacity in the outer layers have been explored. In the standard models, the Q-value for the first overtone can be much larger (Q 1 1 roughly-equal0.04); in addition, the Q-value for the fundamental mode is reduced from previous values, as is the period ratio P 0 /P 1 . The growth rate for the fundamental mode is found to increase with luminosity on the giant branch while the growth rate for the first overtone decreases. Dynamical instabilities found in previous adiabatic models of extreme red giants do not occur when nonadiabatic effects are included in the models. In some massive, luminous models, period ratios P 0 /P 1 approx.7 occur when P 0 approx.2000--5000 days; it is suggested that the massive galactic supergiants and carbon stars which have secondary periods Papprox.2000--7000 days and primary periods Papprox.300--700 days are first-overtone pulsators in which the long secondary periods are due to excitation of the fundamental mode. Some other consequences of the present results are briefly discussed, with particular emphasis on the mode of pulsation of the Mira variables. Subject headings: stars: long-period variables: stars: pulsation: stars: supergiants

Quasi-periodic solutions of nonlinear beam equations with quintic quasi-periodic nonlinearities

Directory of Open Access Journals (Sweden)

Qiuju Tuo

2015-01-01

Full Text Available In this article, we consider the one-dimensional nonlinear beam equations with quasi-periodic quintic nonlinearities $$ u_{tt}+u_{xxxx}+(B+ \\varepsilon\\phi(tu^5=0 $$ under periodic boundary conditions, where B is a positive constant, $\\varepsilon$ is a small positive parameter, $\\phi(t$ is a real analytic quasi-periodic function in t with frequency vector $\\omega=(\\omega_1,\\omega_2,\\dots,\\omega_m$. It is proved that the above equation admits many quasi-periodic solutions by KAM theory and partial Birkhoff normal form.

Minimum period and the gap in periods of Cataclysmic binaries

International Nuclear Information System (INIS)

Paczynski, B.; Sienkiewicz, R.

1983-01-01

The 81 minute cutoff to the orbital periods of hydrogen-rich cataclysmic binaries is consistent with evolution of those systems being dominated by angular momentum losses due to gravitational radiation. Unfortunately, many uncertainties, mainly poorly known atmospheric opacities below 2000 K, make is physically impossible to verify the quadrupole formula for gravitational radiation by using the observed cutoff at 81 minutes. The upper boundary of the gap in orbital periods observed at about 3 hours is almost certainly due to enhanced angular momentum losses from cataclysmic binaries which have longer periods. The physical mechanism of those losses is not identified, but a possible importance of stellar winds is pointed out. The lower boundary of the gap may be explained with the oldest cataclysmic binaries, whose periods evolved past the minimum at 81 minutes and reached the value of 2 hours within about 12 x 10 9 years after the binary had formed. Those binaries should have secondary components of only 0.02 solar masses, and their periods could be used to estimate ages of the oldest cataclysmic stars, and presumably the age of Galaxy. An alternative explanation for the gap requires that binaries should be detached while crossing the gap. A possible mechanism for this phenomenon is discussed. It requires the secondary components to be about 0.2 solar masses in the binaries just below the gap

Economic Comparison of Two Business Models for Implementation of Small Integrated PV Systems

International Nuclear Information System (INIS)

Matak, N.; Krajacic, G.; Jerkic, E.; Duic, N.

2016-01-01

We compared two different models for the implementation of small photovoltaic solar systems in the Croatia. The new prosumer model presented in the new Croatian law on the Renewable Energy Sources and Highly Efficient Cogeneration (OG 100/15) and PV ESCO model which is similar to net metering. The PV ESCO model is developed from authors to determine possibility to raise payback period of small integrated PV systems. The comparison was done on a 15-minute basis and there were compared values of Simple Payback Period (SPP) for different locations and systems size considering electricity demand and market prices. Internal Rate of Return (IRR) and Net Present Value (NPV) were compared for 4 different cases. Conducted comparison showed that PV ESCO model is always more favourable for the owner of PV system in terms of lower SPP and higher IRR and NPV. It has been noticed that for systems higher than 5 kWp use of PV ESCO model is recommended. For smaller systems it is not always clear which model should be used, since some losses are generated in the system on the side of the electricity supply company. For smaller systems from 2 to 5 kWp, PV ESCO model has SPP from 7.5 to 13 years and SPP value for the prosumer model is 8.7 to 15 years. This difference is higher when comparing PV system from 6 to 10 kWp. SPP for PV ESCO model, in that case, is from 10 to 13 years and in the prosumer model is from 17.5 to 28 years.(author).

Life cycle assessment of the offshore wind farm alpha ventus

International Nuclear Information System (INIS)

Wagner, Hermann-Josef; Baack, Christoph; Eickelkamp, Timo; Epe, Alexa; Lohmann, Jessica; Troy, Stefanie

2011-01-01

Due to better wind conditions at sea, offshore wind farms have the advantage of higher electricity production compared to onshore and inland wind farms. In contrast, a greater material input, leading to increased energy consumptions and emissions during the production phase, is required to build offshore wind farms. These contrary effects are investigated for the first German offshore wind farm alpha ventus in the North Sea. In a life cycle assessment its environmental influence is compared to that of Germany's electricity mix. In comparison to the mix, alpha ventus had better indicators in nearly every investigated impact category. One kilowatt-hour electricity, generated by the wind farm, was burdened with 0.137 kWh Primary Energy-Equivalent and 32 g CO 2 -Equivalent, which represented only a small proportion of the accordant values for the mix. Furthermore, the offshore foundations as well as the submarine cable were the main energy intensive components. The energetic and greenhouse gas payback period was less than one year. Therefore, offshore wind power, even in deep water, is compatible with the switch to sustainable electricity production relying on renewable energies. Additional research, taking backup power plants as well as increasingly required energy storage systems into account, will allow further calculation. -- Highlights: → Offshore wind energy represents an environmentally friendly way of power generation. → The offshore foundations and the submarine cable are energy intensive components. → Alpha ventus emits 30 g CO 2 per kWh electricity over the entire life cycle. → Less specific emissions occur in comparison to the existing German electricity grid. → The energetic and greenhouse gas payback periods are less than one year.

Thermoeconomic analysis of a novel zero-CO{sub 2}-emission high-efficiency power cycle using LNG coldness

Energy Technology Data Exchange (ETDEWEB)

Liu, Meng [China National Institute of Standardization, Beijing 100088 (China); Lior, Noam [Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104-6315 (United States); Zhang, Na; Han, Wei [Institute of Engineering Thermophysics, Chinese Academy of Sciences, P.O. Box 2706, Beijing 100190 (China)

2009-11-15

This paper presents a thermoeconomic analysis aimed at the optimization of a novel zero-CO{sub 2} and other emissions and high-efficiency power and refrigeration cogeneration system, COOLCEP-S (Patent pending), which uses the liquefied natural gas (LNG) coldness during its revaporization. It was predicted that at the turbine inlet temperature (TIT) of 900 C, the energy efficiency of the COOLCEP-S system reaches 59%. The thermoeconomic analysis determines the specific cost, the cost of electricity, the system payback period and the total net revenue. The optimization started by performing a thermodynamic sensitivity analysis, which has shown that for a fixed TIT and pressure ratio, the pinch point temperature difference in the recuperator, {delta}T{sub p1}, and that in the condenser, {delta}T{sub p2} are the most significant unconstrained variables to have a significant effect on the thermal performance of novel cycle. The payback period of this novel cycle (with fixed net power output of 20 MW and plant life of 40 years) was {proportional_to}5.9 years at most, and would be reduced to {proportional_to}3.1 years at most when there is a market for the refrigeration byproduct. The capital investment cost of the economically optimized plant is estimated to be about 1000 /kWe, and the cost of electricity is estimated to be 0.34-0.37 CNY/kWh ({proportional_to}0.04 USD/kWh). These values are much lower than those of conventional coal power plants being installed at this time in China, which, in contrast to COOLCEP-S, do produce CO{sub 2} emissions at that. (author)

Thermoeconomic analysis of a novel zero-CO{sub 2}-emission high-efficiency power cycle using LNG coldness

Energy Technology Data Exchange (ETDEWEB)

Liu Meng [China National Institute of Standardization, Beijing 100088 (China)], E-mail: liumeng@cnis.gov.cn; Lior, Noam [Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA 19104-6315 (United States)], E-mail: lior@seas.upenn.edu; Zhang Na; Han Wei [Institute of Engineering Thermophysics, Chinese Academy of Sciences, P.O. Box 2706, Beijing 100190 (China)

2009-11-15

This paper presents a thermoeconomic analysis aimed at the optimization of a novel zero-CO{sub 2} and other emissions and high-efficiency power and refrigeration cogeneration system, COOLCEP-S (Patent pending), which uses the liquefied natural gas (LNG) coldness during its revaporization. It was predicted that at the turbine inlet temperature (TIT) of 900 deg. C, the energy efficiency of the COOLCEP-S system reaches 59%. The thermoeconomic analysis determines the specific cost, the cost of electricity, the system payback period and the total net revenue. The optimization started by performing a thermodynamic sensitivity analysis, which has shown that for a fixed TIT and pressure ratio, the pinch point temperature difference in the recuperator, {delta}T{sub p1}, and that in the condenser, {delta}T{sub p2} are the most significant unconstrained variables to have a significant effect on the thermal performance of novel cycle. The payback period of this novel cycle (with fixed net power output of 20 MW and plant life of 40 years) was {approx}5.9 years at most, and would be reduced to {approx}3.1 years at most when there is a market for the refrigeration byproduct. The capital investment cost of the economically optimized plant is estimated to be about 1000 $/kWe, and the cost of electricity is estimated to be 0.34-0.37 CNY/kWh ({approx}0.04 $/kWh). These values are much lower than those of conventional coal power plants being installed at this time in China, which, in contrast to COOLCEP-S, do produce CO{sub 2} emissions at that.

Energy conservation demonstration potential in the food and beverage industry in New Brunswick

Energy Technology Data Exchange (ETDEWEB)

Juchymenko, A

1985-01-01

Concerns expressed by the Food and Beverage industry in the past few years over energy supply and prices have prompted many plant managers to direct their attention to the efficiency with which energy is being used in producing goods and services. Industry is attempting to hold down the total cost of energy by increasing efficiency. This increased efficiency in energy use is accomplished by many methods, some of which are as follows: improved housekeeping and maintenance, use of new materials or improved and more efficient processes and equipment, recycling of materials, modification of existing equipment, use of cogeneration, reduction of energy losses in boilers, ovens, steam pipes, retorts, recovery of waste heat from industrial processes. Cogeneration Associates Limited were engaged to identify two demonstration projects in the Food and Beverage industry which would be suitable for Conservation and Renewable Energy Demonstration Assistance Program (CREDA) financing, and to assist the selected plants in preparing a proposal. A survey of thirty-two establishments was undertaken by means of a mail questionnaire and plant visits. Nineteen projects were identifed which showed suitable pay-back periods. Two projects, Connors Bros. and Carapec Ltd., were selected for further study and detailed proposals were prepared. Connors Bros. submitted a proposal for funding and was successful in obtaining 65% of the total capital cost of $202,000 as a contribution from the CREDA progream. The Connors project demonstrates hot air recovery, hot water recover, and electricity load management. The total energy saving of the project will be $80,000 year, giving a pay-back period of 2.5 years. 6 figs., 1 tab.

Thermodynamic and economic optimization of a solar-powered Stirling engine for micro-cogeneration purposes

International Nuclear Information System (INIS)

Ferreira, Ana C.; Nunes, Manuel L.; Teixeira, José C.F.; Martins, Luís A.S.B.; Teixeira, Senhorinha F.C.F.

2016-01-01

Micro-cogeneration systems are a promising technology for improving the energy efficiency near the end user, allowing the optimal use of the primary energy sources and significant reductions in carbon emissions. Its use, still incipient, has a great potential for applications in the residential sector. This study aims to develop a methodology for the thermal-economic optimization of micro cogeneration units using Stirling engine as prime mover and concentrated solar energy as the heat source. The thermal-economic optimization was formulated considering the maximization of the annual worth from the system operation, subjected to the nonlinear thermodynamic and economic constraints. The physical model includes the limitations in the heat transfer processes and losses due to the pumping effects and the costing methodology was defined considering a purchase cost equation representative of each system component. Geometric and operational parameters were selected as decision variables. Numerical simulations were developed in MatLab"® programming language and the Generalized Pattern Search optimization algorithm with MADSPositiveBasis2N was used in the determination of the optimal solution. A positive annual worth for the defined input simulation conditions and the economic analysis disclosed a system, economically attractive, with a payback period of approximately 10 years. - Highlights: • Application of optimization methods to model a renewable powered Stirling engine. • The aim is to optimize design of each plant-component for the best economical outcome. • The objective function is the maximization of annual worth of micro-CHP system. • The optimal solution is sensitive to electricity feed-in-tariffs and fuel prices fluctuations. • The optimal solution is economically attractive, with a payback period of ≈10 years.

Parametric analysis of technology and policy tradeoffs for conventional and electric light-duty vehicles

International Nuclear Information System (INIS)

Barter, Garrett E.; Reichmuth, David; Westbrook, Jessica; Malczynski, Leonard A.; West, Todd H.; Manley, Dawn K.; Guzman, Katherine D.; Edwards, Donna M.

2012-01-01

A parametric analysis is used to examine the supply demand interactions between the US light-duty vehicle (LDV) fleet, its fuels, and the corresponding primary energy sources through 2050. The analysis emphasizes competition between conventional internal combustion engine (ICE) vehicles, including hybrids, and electric vehicles (EVs), represented by both plug-in hybrid and battery electric vehicles. We find that EV market penetration could double relative to our baseline case with policies to extend consumers' effective payback period to 7 years. EVs can also reduce per vehicle petroleum consumption by up to 5% with opportunities to increase that fraction at higher adoption rates. However, EVs have limited ability to reduce LDV greenhouse gas (GHG) emissions with the current energy source mix. Alone, EVs cannot drive compliance with the most aggressive GHG emission reduction targets, even if the electricity grid shifts towards natural gas powered sources. Since ICEs will dominate the LDV fleet for up to 40 years, conventional vehicle efficiency improvements have the greatest potential for reductions in LDV GHG emissions and petroleum consumption over this time. Specifically, achieving fleet average efficiencies of 72 mpg or greater can reduce average GHG emissions by 70% and average petroleum consumption by 81%. - Highlights: ► Parametric analysis of the light duty vehicle fleet, its fuels, and energy sources. ► Conventional vehicles will dominate the fleet for up to 40 years. ► Improving gasoline powertrain efficiency is essential for GHG and oil use reduction. ► Electric vehicles have limited leverage over GHG emissions with the current grid mix. ► Consumer payback period extensions can double electric vehicle market share.

Thermoeconomic analysis of a novel zero-CO2-emission high-efficiency power cycle using LNG coldness

International Nuclear Information System (INIS)

Liu, Meng; Lior, Noam; Zhang, Na; Han, Wei

2009-01-01

This paper presents a thermoeconomic analysis aimed at the optimization of a novel zero-CO 2 and other emissions and high-efficiency power and refrigeration cogeneration system, COOLCEP-S (Patent pending), which uses the liquefied natural gas (LNG) coldness during its revaporization. It was predicted that at the turbine inlet temperature (TIT) of 900 C, the energy efficiency of the COOLCEP-S system reaches 59%. The thermoeconomic analysis determines the specific cost, the cost of electricity, the system payback period and the total net revenue. The optimization started by performing a thermodynamic sensitivity analysis, which has shown that for a fixed TIT and pressure ratio, the pinch point temperature difference in the recuperator, (delta)T p1 , and that in the condenser, (delta)T p2 are the most significant unconstrained variables to have a significant effect on the thermal performance of novel cycle. The payback period of this novel cycle (with fixed net power output of 20 MW and plant life of 40 years) was ∝5.9 years at most, and would be reduced to ∝3.1 years at most when there is a market for the refrigeration byproduct. The capital investment cost of the economically optimized plant is estimated to be about 1000 /kWe, and the cost of electricity is estimated to be 0.34-0.37 CNY/kWh (∝0.04 USD/kWh). These values are much lower than those of conventional coal power plants being installed at this time in China, which, in contrast to COOLCEP-S, do produce CO 2 emissions at that. (author)

Energy, economic and environmental analysis of metal oxides nanofluid for flat-plate solar collector

International Nuclear Information System (INIS)

Faizal, M.; Saidur, R.; Mekhilef, S.; Alim, M.A.

2013-01-01

Highlights: • By using nanofluid, smaller and compact solar collector can be produced. • The average value of 220 MJ embodied energy can be saved. • The payback period of using nanofluid solar collector is around 2.4 years. • Around 170 kg less CO 2 emissions in average for nanofluid solar collector. • Environmental damage cost is lower with the nanofluid based solar collector. - Abstract: For a solar thermal system, increasing the heat transfer area can increase the output temperature of the system. However, this approach leads to a bigger and bulkier collector. It will then increase the cost and energy needed to manufacture the solar collector. This study is carried out to estimate the potential to design a smaller solar collector that can produce the same desired output temperature. This is possible by using nanofluid as working fluid. By using numerical methods and data from literatures, efficiency, size reduction, cost and embodied energy savings are calculated for various nanofluids. From the study, it was estimated that 10,239 kg, 8625 kg, 8857 kg and 8618 kg total weight for 1000 units of solar collectors can be saved for CuO, SiO 2 , TiO 2 and Al 2 O 3 nanofluid respectively. The average value of 220 MJ embodied energy can be saved for each collector, 2.4 years payback period can be achieved and around 170 kg less CO 2 emissions in average can be offset for the nanofluid based solar collector compared to a conventional solar collector. Finally, the environmental damage cost can also be reduced with the nanofluid based solar collector

Technical-financial evaluation of rainwater harvesting systems in commercial buildings-case ase studies from Sonae Sierra in Portugal and Brazil.

Science.gov (United States)

Sousa, Vitor; Silva, Cristina Matos; Meireles, Inês C

2017-11-10

Water is an essential and increasingly scarce resource that should be preserved. The evolution of the human population and communities has contributed to the global decrease of potable water availability and the reduction of its consumption is now compulsory. Rainwater harvesting systems (RWHS) are emerging as a viable alternative source for water consumption in non-potable uses. The present study aims to contribute to the promotion of water efficiency, focusing on the application of rainwater harvesting systems in commercial buildings, and comprises four stages: (i) development of a technical evaluation tool to aid the design of RWHS and support their financial evaluation; (ii) validation of the tool using operational data from an existing RWHS installed at Colombo Shopping Center, in Lisbon, Portugal; (iii) assessment of the sensibility of the technical evaluation tool results to the variation of the inputs, namely the precipitation and consumption, through a parametric analysis for the Colombo Shopping Center; and (iv) comparison of the performance and financial feasibility of hypothetical RWHS in two existing commercial buildings. The technical tool was applied to two Sonae Sierra's shopping centers, one in Portugal and one in Brazil. The installation of a 200-m 3 tank is advised for the first case study, allowing non-potable water savings of 60% but a payback period of about 19 years. In the Brazilian shopping, the implementation of a tank with a capacity ranging from 100 to 400 m 3 leads to non-potable savings between 20 and 50%, but with smaller payback period, under 2 years, due to the relatively lower investment costs and higher water fees.

Co-generation potentials of municipal solid waste landfills in Serbia

Directory of Open Access Journals (Sweden)

Bošković Goran B.

2016-01-01

Full Text Available Waste management in the Republic of Serbia is based on landfilling. As a result of such year-long practice, a huge number of municipal waste landfills has been created where landfill gas has been generated. Landfill gas, which is essentially methane (50-55% and carbon dioxide (40-45% (both GHGs, has a great environmental impact which can be reduced by using landfill gas in cogeneration plants to produce energy. The aim of this paper is to determine economic and environmental benefits from such energy production. For that purpose, the database of cogeneration potentials (CP of 51 landfills in the Republic of Serbia (RS was created. Amount of landfill gas generated at each municipal landfill was calculated by applying a first order decay equation which requires the data about solid waste production and composition and about some landfill characteristics. For all landfills, which have over 100,000 m3 each, a techno-economic analysis about building a CHP plant was conducted. The results have shown, that the total investment in 14 CHP plants with payback period of less than 7 years amounts € 11,721,288. The total nominal power of these plants is 7 MW of electrical power and 7.9 MW of thermal power, and an average payback period is about 61 months. In addition, using landfill biogas as energy source in proposed plants would reduce methane emission for 161,000 tons of CO2 equivalent per year. [Projekat Ministarstva nauke Republike Srbije, br. III 42013: Research of cogeneration potential of municipal and industrial energy power plant in Republic of Serbia and opportunities for rehabilitation of existing and construction of new cogeneration plants

What are retail investors' risk-return preferences towards renewable energy projects? A choice experiment in Germany

International Nuclear Information System (INIS)

Salm, Sarah; Hille, Stefanie Lena; Wüstenhagen, Rolf

2016-01-01

Citizens own nearly half the renewable energy generation capacity in Germany and have been important drivers of the country's energy transition. In contrast to citizens' important role in financing renewable energies, the energy policy and economics literature has traditionally focused on other investors, such as incumbent energy firms. To close this gap, this paper reports on a large-scale survey of 1,990 German retail investors. Conducting a choice experiment with the subset of 1,041 respondents who expressed an interest in investing in community renewable energy projects, we present a unique dataset allowing for new insights in risk-return expectations of retail investors. We find that apart from return on investment, respondents are particularly sensitive to the minimum holding period and the issuer of community renewable energy investment offerings. A minimum holding period of 10 years implies a risk premium of 2.76% points. A subsequent segmentation analysis shows that two groups of potential community renewable energy investors with different risk-return expectations can be identified: “local patriots” and “yield investors”. In contrast to professional investors, a majority of retail investors use simple decision rules such as calculating payback time or relying on their gut feeling when making investments. - Highlights: • Out of 1,990 retail investors surveyed, 1,041 express interest to invest in renewables. • Two target segments are identified, “local patriots” and “yield investors”. • “Local patriots” are willing to forgo return on investment in local projects. • Solar photovoltaic is most popular technology, followed by wind and small hydro. • Majority of investors use simple payback calculation or decide intuitively.

The Impacts of Changes to Nevada's Net Metering Policy on the Financial Performance and Adoption of Distributed Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Gagnon, Pieter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sigrin, Ben [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gleason, Mike [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-01-01

As the adoption of distributed photovoltaics (DPV) has continued to rapidly increase, a national conversation has begun about the efficacy of full-retail net metering as a means of achieving the diverse objectives of electricity pricing. This conversation has prompted studies that have primarily focused on the total costs and benefits of DPV. To compliment those studies, we here characterize the potential impacts of tariff design on the customer-economics and adoption of DPV, where recent changes in Nevada are taken as a case study. We show that an increase in fixed charges more strongly impacts the payback period of small systems, and a decrease in credit for exported electricity more strongly impacts the payback period of large systems. We project that these combined changes will reduce DPV adoption in Nevada; total capacity in 2030 was projected to reach up to 363 MW, with 226 MW having already been installed at the end of the second quarter of 2016. In contrast, if full retail net metering had continued, DPV capacity was projected to reach up to 1,280 MW at the end of 2030, which would account for an estimated 6.5% of the total sales of electricity by NV Energy at that time. We project that the DPV systems will decrease the gross revenue from bill collection by $48 million per year under the new tariffs, whereas the decrease in gross revenue could have reached $255 million per year if full retail net metering had been continued. Although these results are given in the context of Nevada, the trends shown are intended to help information similar upcoming decisions in other states.

Water as a sustainable energy source. Recommendations and energy payback periods of eight technologies; Water als duurzame energiebron. Aanbevelingen en energieterugverdientijden van acht technologieen

Energy Technology Data Exchange (ETDEWEB)

Van de Berg, M.; Geurts, F.; Stolk, N. [Ecofys, Utrecht (Netherlands)

2010-02-15

The spatial effects of six energy technologies based on water are described: thermal energy storage, tidal energy, tidal energy based on height of fall, wave energy, aquatic biomass and osmosis energy (blue energy) [Dutch] De omgevingseffecten van zes energietechnologieen met water worden beschreven: warmte-koude opslag, getijdenstroming, getijdenenergie op verval, golfenergie, aquatische biomassa en osmose-energie (blue energy)

Super periodic potential

Science.gov (United States)

Hasan, Mohammd; Mandal, Bhabani Prasad

2018-04-01

In this paper we introduce the concept of super periodic potential (SPP) of arbitrary order n, n ∈I+, in one dimension. General theory of wave propagation through SPP of order n is presented and the reflection and transmission coefficients are derived in their closed analytical form by transfer matrix formulation. We present scattering features of super periodic rectangular potential and super periodic delta potential as special cases of SPP. It is found that the symmetric self-similarity is the special case of super periodicity. Thus by identifying a symmetric fractal potential as special cases of SPP, one can obtain the tunnelling amplitude for a particle from such fractal potential. By using the formalism of SPP we obtain the close form expression of tunnelling amplitude of a particle for general Cantor and Smith-Volterra-Cantor potentials.

34 CFR 263.8 - What are the payback requirements?

Science.gov (United States)

2010-07-01

... participant performs. (Approved by the Office of Management and Budget under control number 1810-0580... for which training was actually received under the Professional Development program. (c) The cash...

SLAVIC LITERATURES IN DALMATIAN PERIODICALS IN THE PERIOD OF CROATIAN MODERNISM

Directory of Open Access Journals (Sweden)

Robert Bacalja

2010-01-01

Full Text Available The paper analyzes translations and mediatorial articles from the Slavic literature published in Dalmatian newspapers and periodicals which contribute most to mediation during the period of Croatian Modernism. While periodicals in Dalmatia traditionally mediates from the Roman literature, especially from the Italian, in the examined corpus can be seen the remarkable reception of Slavic literature, particularly Russian.. The paradigm of the most recognized culture and literature in non Slavic world is desirable identity basis of the Croatian literature as a part of a large Slavic stem from romanticism to modernism. Mediation of Slavic literatures is examined on the corpus of newspapers and periodicals published in Dubrovnik, Split and Zadar (Crvena Hrvatska, Srđ, Sloboda, Jedinstvo/Novo jedinstvo, Novi vijek, Narodni list, Smotra dalmatinska, Iskra, Glasnik Matice dalmatinske, Lovor, etc..

The Discrete Beverton-Holt Model with Periodic Harvesting in a Periodically Fluctuating Environment

Directory of Open Access Journals (Sweden)

Ziyad AlSharawi

2010-01-01

Full Text Available We investigate the effect of constant and periodic harvesting on the Beverton-Holt model in a periodically fluctuating environment. We show that in a periodically fluctuating environment, periodic harvesting gives a better maximum sustainable yield compared to constant harvesting. However, if one can also fix the environment, then constant harvesting in a constant environment can be a better option, especially for sufficiently large initial populations. Also, we investigate the combinatorial structure of the periodic sequence of carrying capacities and its effect on the maximum sustainable yield. Finally, we leave some questions worth further investigations.

Convergence acceleration of quasi-periodic and quasi-periodic-rational interpolations by polynomial corrections

OpenAIRE

Lusine Poghosyan

2014-01-01

The paper considers convergence acceleration of the quasi-periodic and the quasi-periodic-rational interpolations by application of polynomial corrections. We investigate convergence of the resultant quasi-periodic-polynomial and quasi-periodic-rational-polynomial interpolations and derive exact constants of the main terms of asymptotic errors in the regions away from the endpoints. Results of numerical experiments clarify behavior of the corresponding interpolations for moderate number of in...

TECHNO-ECONOMIC ASSESSMENT OF THE USE OF WHEELS OF PERSPECTIVE STRUCTURAL SCHEME FOR RAILWAY VEHICLES

Directory of Open Access Journals (Sweden)

S. A. Semenov

2016-12-01

Full Text Available Purpose. The article is aimed to the definition of technical and economic efficiency from the use of wheels of perspective structural scheme in the undercarriage of the rail vehicles (wagon. Methodology. The use efficiency of wheels of promising design scheme by reducing the motion resistance and wear of the wheel flanges is estimated by calculated values of estimated annual economic effect of implementation and payback period of the costs required for the development and implementation of the proposed wheel. Non-recurring costs include the cost associated with conducting research and development work, as well as the additional costs required for the manufacture of wheels of promising design scheme. Findings. In the course of computation and analysis of the economic efficiency from introductions of wheels of promising design concept, carried out on the basis of the initial data for the South-West railway, it was determined the profit which can be obtained by reducing the following operating costs: cost of returning the wheel flange on wheel sets; cost of fuel and energy resources for train traction; the value of the idle of cars in the current uncoupling repair; cost of repairs and current maintenance of rail track. In addition, it can be additionally released a number of cars by reducing their downtime. The calculation of net discounted income is carried out with the following assumptions: calculation period; estimated increase in the cost of wheel sets with wheels of promising constructive scheme compared to the model, the values of net profit for the accounting period, which was calculated by calculating the average value minus the cost of research, development and manufacturing of wheelset park with wheels of new design scheme. For a given billing period, the calculated value of the net discounted income was obtained and the payback period of the project was determined. Originality. The approaches to the perfection of design scheme of wheels

Implementing a resident lifting system in an extended care hospital. Demonstrating cost-benefit.

Science.gov (United States)

Spiegel, Jerry; Yassi, Analee; Ronald, Lisa A; Tate, Robert B; Hacking, Penny; Colby, Teresa

2002-03-01

1. Implemeting mechanical resident lifting equipment in an extended care facility produced a payback from direct savings alone within 4 years. Payback occurred more quickly when the effect of indirect savings or the trend to rising compensation costs was considered. 2. Combining the observations of the occupational health nurses related to staff well being with relevant cost-benefit data is useful in influencing decision makers and in securing funding for prevention measures. 3. Clear identification of a viewpoint is an important part of an economic evaluation and cost-benefit analysis.

Integration of A Solid Oxide Fuel Cell into A 10 MW Gas Turbine Power Plant

Directory of Open Access Journals (Sweden)

Denver F. Cheddie

2010-04-01

Full Text Available Power generation using gas turbine power plants operating on the Brayton cycle suffers from low efficiencies. In this work, a solid oxide fuel cell (SOFC is proposed for integration into a 10 MW gas turbine power plant, operating at 30% efficiency. The SOFC system utilizes four heat exchangers for heat recovery from both the turbine outlet and the fuel cell outlet to ensure a sufficiently high SOFC temperature. The power output of the hybrid plant is 37 MW at 66.2% efficiency. A thermo-economic model predicts a payback period of less than four years, based on future projected SOFC cost estimates.

Design Configuration And Simulation Of A Multi Effects Evaporator For A Desalination Plant

Directory of Open Access Journals (Sweden)

Ethar Ali

2015-08-01

Full Text Available This research is focused on the economic feasibility of using multi-effect evaporators MEV for the production of potable water for the city of Port Sudan the main port of Sudan. Port Sudan city suffers from chronic shortage of potable water. The study has shown that five effect evaporator plant in Port Sudan can produce 1.41106 m3year at a unit cost of 5m3 with a pay-back period of 7 years. A simulation of the MEV has been performed using Aspen Hysys version 7.3 and produced results were very much similar to these obtained manually.

Congeneration feasibility: Otis Elavator Company and Polychrome Corporation

Science.gov (United States)

Fox, H.

1982-05-01

An investigation of the technical and economic feasibility of cogenerating electric and thermal power at two manufacturing plants (Otis Elevator Company and Polychrome Corporation) located on neighboring properties in Yonkers, NY is discussed. Existing electrical and steam producing equipment and energy consumption date are summarized. Alternative cases examined include electrical energy generation, electrical energy generation with waste heat recovery and a combined cycle case. Also reported are life cycle cost economic evaluations including simple payback period and return on investment indices. While it was concluded that cogeneration of heat and electricity at these industrial plant sites would not be economically viable, this detailed study provides valuable insights.

Heat recovery from shower water; Warmteterugwinning uit douchewater

Energy Technology Data Exchange (ETDEWEB)

Heidemans, J. [Hei-Tech, Emmen (Netherlands)

2011-09-15

With a payback period of several years, heat recovery from shower water in swimming pools but also in, for example, apartment buildings are an attractive form of energy saving. Possible are savings from 30 to 50% on energy, which is tested and proved by measurements in the heat exchanger of showers in a swimming pool in Denmark. [Dutch] Met een terugverdientijd van enkele jaren is warmteterugwinning uit douchewater in zwembaden maar ook in bijvoorbeeld sporthallen en appartementengebouwen een aantrekkelijke vorm van energiebesparing. Er kan een besparing worden gerealiseerd van 30 tot 50% op het energiegebruik van het douchewater. Metingen aan een douchewarmtewisselaar in een zwembad in Denemarken tonen dit aan.

Wind pumps for farms: Economic and environmental feasibility

International Nuclear Information System (INIS)

Piccoli, F.

1992-01-01

The cost and environmental benefits of four different types of water pumps for use on farms are compared. The factors considered in the analysis of the different pumps categorized according to head (7, 30 and 50 m) and energy source (wind energy, electricity, gasoline or fuel oil) include operating and maintenance costs, and payback periods. Particular attention is given to the socio-economic implications of the use of wind pumps in developing countries. In this case, the various aspects taken into account are: wind pump siting requirements, optimum sizing, the feasibility of water pumping-power production with the use of wind turbines, required skill levels of operators, and environmental compatibility

Systems Analysis and Design for Decision Support Systems on Economic Feasibility of Projects

Science.gov (United States)

Balaji, S. Arun

2010-11-01

This paper discuss about need for development of the Decision Support System (DSS) software for economic feasibility of projects in Rwanda, Africa. The various economic theories needed and the corresponding formulae to compute payback period, internal rate of return and benefit cost ratio of projects are clearly given in this paper. This paper is also deals with the systems flow chart to fabricate the system in any higher level computing language. The various input requirements from the projects and the output needed for the decision makers are also included in this paper. The data dictionary used for input and output data structure is also explained.

Improving Motor and Drive System Performance – A Sourcebook for Industry

Energy Technology Data Exchange (ETDEWEB)

None

2014-02-01

This sourcebook outlines opportunities to improve motor and drive systems performance. The sourcebook is divided into four main sections: (1) Motor and Drive System Basics: Summarizes important terms, relationships, and system design considerations relating to motor and drive systems. (2) Performance Opportunity Road Map: Details the key components of well-functioning motor and drive systems and opportunities for energy performance opportunities. (3) Motor System Economics: Offers recommendations on how to propose improvement projects based on corporate priorities, efficiency gains, and financial payback periods. (4) Where to Find Help: Provides a directory of organizations associated with motors and drives, as well as resources for additional information, tools, software, videos, and training opportunities.

Small wind rising? Is the market for building-mounted wind power about to pick up?

International Nuclear Information System (INIS)

Slowe, J.

2006-01-01

The potential market for small roof-mounted wind turbines is discussed. Should the technology prove popular, the market would be enormous. Delta Energy and Environment has prepared a study called, Roof Top Wind Turbines: A Product for Mass Markets? At present, the future for roof-mounted wind turbines is unclear: predictions range from little or no market at all to mass installations with a payback period of as little as five years. Several small roof-top turbines are described. A critical factor influencing the efficiency of a roof-mounted wind turbine is the air flow pattern over the roof which may in turn be affected by neighbouring buildings. (author)

Mean-periodic functions

Directory of Open Access Journals (Sweden)

Carlos A. Berenstein

1980-01-01

Full Text Available We show that any mean-periodic function f can be represented in terms of exponential-polynomial solutions of the same convolution equation f satisfies, i.e., u∗f=0(μ∈E′(ℝn. This extends to n-variables the work of L. Schwartz on mean-periodicity and also extends L. Ehrenpreis' work on partial differential equations with constant coefficients to arbitrary convolutors. We also answer a number of open questions about mean-periodic functions of one variable. The basic ingredient is our work on interpolation by entire functions in one and several complex variables.

Eat now, pay later? Evidence of deferred food-processing costs in diving seals.

Science.gov (United States)

Sparling, Carol E; Fedak, Mike A; Thompson, Dave

2007-02-22

Seals may delay costly physiological processes (e.g. digestion) that are incompatible with the physiological adjustments to diving until after periods of active foraging. We present unusual profiles of metabolic rate (MR) in grey seals measured during long-term simulation of foraging trips (4-5 days) that provide evidence for this. We measured extremely high MRs (up to almost seven times the baseline levels) and high heart rates during extended surface intervals, where the seals were motionless at the surface. These occurred most often during the night and occurred frequently many hours after the end of feeding bouts. The duration and amount of oxygen consumed above baseline levels during these events was correlated with the amount of food eaten, confirming that these metabolic peaks were related to the processing of food eaten during foraging periods earlier in the day. We suggest that these periods of high MR represent a payback of costs deferred during foraging.

38 CFR 3.252 - Annual income; pension; Mexican border period and later war periods.

Science.gov (United States)

2010-07-01

...; Mexican border period and later war periods. 3.252 Section 3.252 Pensions, Bonuses, and Veterans' Relief... Dependency, Income and Estate § 3.252 Annual income; pension; Mexican border period and later war periods. (a) Annual income limitations; old-law pension. Where the right to old-law pension is payable under section...

Nanopublication beyond the sciences: the PeriodO period gazetteer

Directory of Open Access Journals (Sweden)

Patrick Golden

2016-02-01

Full Text Available The information expressed in humanities datasets is inextricably tied to a wider discursive environment that is irreducible to complete formal representation. Humanities scholars must wrestle with this fact when they attempt to publish or consume structured data. The practice of “nanopublication,” which originated in the e-science domain, offers a way to maintain the connection between formal representations of humanities data and its discursive basis. In this paper we describe nanopublication, its potential applicability to the humanities, and our experience curating humanities nanopublications in the PeriodO period gazetteer.

Comparison of Periodized and Non-Periodized Resistance Training on Maximal Strength: A Meta-Analysis.

Science.gov (United States)

Williams, Tyler D; Tolusso, Danilo V; Fedewa, Michael V; Esco, Michael R

2017-10-01

Periodization is a logical method of organizing training into sequential phases and cyclical time periods in order to increase the potential for achieving specific performance goals while minimizing the potential for overtraining. Periodized resistance training plans are proposed to be superior to non-periodized training plans for enhancing maximal strength. The primary aim of this study was to examine the previous literature comparing periodized resistance training plans to non-periodized resistance training plans and determine a quantitative estimate of effect on maximal strength. All studies included in the meta-analysis met the following inclusion criteria: (1) peer-reviewed publication; (2) published in English; (3) comparison of a periodized resistance training group to a non-periodized resistance training group; (4) maximal strength measured by 1-repetition maximum (1RM) squat, bench press, or leg press. Data were extracted and independently coded by two authors. Random-effects models were used to aggregate a mean effect size (ES), 95% confidence intervals (CIs) and potential moderators. The cumulative results of 81 effects gathered from 18 studies published between 1988 and 2015 indicated that the magnitude of improvement in 1RM following periodized resistance training was greater than non-periodized resistance training (ES = 0.43, 95% CI 0.27-0.58; P training status (β = -0.59; P = 0.0305), study length (β = 0.03; P = 0.0067), and training frequency (β = 0.46; P = 0.0123) were associated with a change in 1RM. These results indicate that undulating programs were more favorable for strength gains. Improvements in 1RM were greater among untrained participants. Additionally, higher training frequency and longer study length were associated with larger improvements in 1RM. These results suggest that periodized resistance training plans have a moderate effect on 1RM compared to non-periodized training plans. Variation in training stimuli

Book Reviews in Periodicals.

Science.gov (United States)

Ettelt, Harold J.

All recent issues of periodicals found which contain indexed book reviews are listed in this compilation from Drake Memorial Library at the New York State University at Brockport. The periodicals are listed by 29 subject headings in this informal guide designed to be used at Drake Library. The number of reviews in the periodical in a recent year…

Testing periodically integrated autoregressive models

NARCIS (Netherlands)

Ph.H.B.F. Franses (Philip Hans); M.J. McAleer (Michael)

1997-01-01

textabstractPeriodically integrated time series require a periodic differencing filter to remove the stochastic trend. A non-periodic integrated time series needs the first-difference filter for similar reasons. When the changing seasonal fluctuations for the non-periodic integrated series can be

Design and simulation of a prototype of a small-scale solar CHP system based on evacuated flat-plate solar collectors and Organic Rankine Cycle

International Nuclear Information System (INIS)

Calise, Francesco; D’Accadia, Massimo Dentice; Vicidomini, Maria; Scarpellino, Marco

2015-01-01

Highlights: • A novel small scale solar power plant was designed and simulated. • The system is based on evacuated solar thermal collectors and an ORC system. • An average electric efficiency of 10% was found for the ORC. • The efficiency of solar collectors was found to be high in summer (>50%). • Pay-back periods lower than 5 years were estimated, in case of public funding. - Abstract: This paper presents a dynamic simulation model of a novel prototype of a 6 kW e solar power plant. The system is based on the coupling of innovative solar thermal collectors with a small Organic Rankine Cycle (ORC), simultaneously producing electric energy and low temperature heat. The novelty of the proposed system lies in the solar collector field, which is based on stationary evacuated flat-plate solar thermal collectors capable to achieve the operating temperatures typical of the concentrating solar thermal collectors. The solar field consists of about 73.5 m 2 of flat-plate evacuated solar collectors, heating a diathermic oil up to a maximum temperature of 230 °C. A diathermic oil storage tank is employed in order to mitigate the fluctuations due to the variability of solar energy availability. The hot diathermic oil exiting from the tank passes through an auxiliary gas-fired burner which provides eventual additional thermal energy. The inlet temperature of the diathermic oil entering the ORC system varies as a function of the availability of solar energy, also determining an oscillating response of the ORC. The ORC was simulated in Engineering Equation Solver (EES), using zero-dimensional energy and mass balances. The ORC model was subsequently implemented in a more general TRNSYS model, including all the remaining components of the system. The model was used to evaluate the energy and economic performance of the solar CHP system under analysis, in different climatic conditions. The results show that the efficiency of the ORC does not significantly vary during the

Detecting periodicities with Gaussian processes

Directory of Open Access Journals (Sweden)

Nicolas Durrande

2016-04-01

Full Text Available We consider the problem of detecting and quantifying the periodic component of a function given noise-corrupted observations of a limited number of input/output tuples. Our approach is based on Gaussian process regression, which provides a flexible non-parametric framework for modelling periodic data. We introduce a novel decomposition of the covariance function as the sum of periodic and aperiodic kernels. This decomposition allows for the creation of sub-models which capture the periodic nature of the signal and its complement. To quantify the periodicity of the signal, we derive a periodicity ratio which reflects the uncertainty in the fitted sub-models. Although the method can be applied to many kernels, we give a special emphasis to the Matérn family, from the expression of the reproducing kernel Hilbert space inner product to the implementation of the associated periodic kernels in a Gaussian process toolkit. The proposed method is illustrated by considering the detection of periodically expressed genes in the arabidopsis genome.

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

Energy Technology Data Exchange (ETDEWEB)

Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

2017-03-01

High-performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

Viabilidade financeira da inseminação artificial em tempo fixo de bezerros cruzados Nelore e Aberdeen Angus = Economic feasibility of timed artificial insemination of Nellore and Aberdeen Angus crossbred calves

Directory of Open Access Journals (Sweden)

Nelson Zuchi Neto

2017-07-01

Full Text Available O cruzamento entre taurinos e zebuínos através de Inseminação Artificial em Tempo Fixo [IATF] é uma realidade presente em várias propriedades rurais no Brasil. Visando as vantagens da IATF em conjunto com as vantagens do cruzamento industrial o objetivo foi verificar a viabilidade financeira desta atividade em uma propriedade no município de Nova Lacerda, MT. Para tal, utilizou-se as ferramentas de matemática financeira Valor Presente Líquido [VPL], Taxa Interna de Retorno [TIR] e Payback. O projeto se mostrou viável com um VPL acima de R$ 300 mil, TIR de 23,03% e Payback descontado de aproximadamente oito anos. A venda de descartes e a suplementação dos bezerros em sistema de “creep feeding” se mostraram importantes para a viabilidade deste projeto. = Bos taurus and Bos indicus crossbred through Timed Artificial Insemination [TAI] is present in several farms in Brazil. Aiming the advantages of the TAI together with industrial crossing, the objective was to verify the economic feasibility of this activity on a farm in the city of Nova Lacerda, MT. Financial mathematics tools like Net Present Value [NPV], Internal Rate of Return [IRR] and Payback were used. The project was feasible with a NPV above R$ 300 thousand, an IRR of 23.03% and a Discounted Payback of approximately eight years. The sale of discards matrix and the supplementation of calves in a creep feeding system showed to be important for the viability of this project.

Monitored performance of residential geothermal heat pumps in central Texas and Southern Michigan

Energy Technology Data Exchange (ETDEWEB)

Sullivan, W.N.

1997-11-01

This report summarizes measured performance of residential geothermal heat pumps (GHP`s) that were installed in family housing units at Ft. Hood, Texas and at Selfridge Air National Guard base in Michigan. These units were built as part of a joint Department of Defense/Department of Energy program to evaluate the energy savings potential of GHP`s installed at military facilities. At the Ft. Hood site, the GHP performance was compared to conventional forced air electric air conditioning and natural gas heating. At Selfridge, the homes under test were originally equipped with electric baseboard heat and no air conditioning. Installation of the GHP systems at both sites was straightforward but more problems and costs were incurred at Selfridge because of the need to install ductwork in the homes. The GHP`s at both sites produced impressive energy savings. These savings approached 40% for most of the homes tested. The low cost of energy on these bases relative to the incremental cost of the GHP conversions precludes rapid payback of the GHP`s from energy savings alone. Estimates based on simple payback (no inflation and no interest on capital) indicated payback times from 15 to 20 years at both sites. These payback times may be reduced by considering the additional savings possible due to reduced maintenance costs. Results are summarized in terms of 15 minute, hourly, monthly, and annual performance parameters. The results indicate that all the systems were working properly but several design shortcomings were identified. Recommendations are made for improvements in future installations at both sites.

Measured energy savings and cost-effectiveness of conservation retrofits in commercial buildings

International Nuclear Information System (INIS)

Greely, K.M.; Harris, J.P.; Hatcher, A.M.

1990-01-01

In this study, the authors examine the measured savings and cost-effectiveness of 447 commercial retrofit projects in the US, Canada, and Europe, representing over 1,700 buildings. For these projects, they examine savings and cost-effectiveness by building type and retrofit strategy, savings from individual measures, peak electric demand savings, comparisons of measured vs. predicted savings, and the persistence of savings in the years following a retrofit. Median annual site energy savings amounted to 20 kBtu/ft 2 , or 18% of whole-building usage; median retrofit cost was $0.56/ft 2 (1988 $), the median payback time was 3.1 years, and the median cost of conserved energy was $3.10/site MBtu. When examined by retrofit strategy, they found that projects with only HVAC and/or lighting retrofits had median payback times of one to three years, while those affecting the building shell, either alone or in combination with other types of measures, had payback times of five or more years. Projects in which only maintenance practices were changed typically saved 12% of their pre-retrofit consumption, often using in-house labor. Their research suggests that, despite significant savings and short payback times for the majority of projects, optimum savings are often not being achieved, due to limited owner willingness to invest in all cost-effective measures, as well as to improper retrofit installation and/or maintenance. A comprehensive understanding of energy management as a process is needed, including both inspection and commissioning of installed retrofits and ongoing tracking of energy consumption as an indicator of operating problems

Simple Retrofit High-Efficiency Natural Gas Water Heater Field Test

Energy Technology Data Exchange (ETDEWEB)

Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States)

2017-03-28

High performance water heaters are typically more time consuming and costly to install in retrofit applications, making high performance water heaters difficult to justify economically. However, recent advancements in high performance water heaters have targeted the retrofit market, simplifying installations and reducing costs. Four high efficiency natural gas water heaters designed specifically for retrofit applications were installed in single-family homes along with detailed monitoring systems to characterize their savings potential, their installed efficiencies, and their ability to meet household demands. The water heaters tested for this project were designed to improve the cost-effectiveness and increase market penetration of high efficiency water heaters in the residential retrofit market. The retrofit high efficiency water heaters achieved their goal of reducing costs, maintaining savings potential and installed efficiency of other high efficiency water heaters, and meeting the necessary capacity in order to improve cost-effectiveness. However, the improvements were not sufficient to achieve simple paybacks of less than ten years for the incremental cost compared to a minimum efficiency heater. Significant changes would be necessary to reduce the simple payback to six years or less. Annual energy savings in the range of $200 would also reduce paybacks to less than six years. These energy savings would require either significantly higher fuel costs (greater than $1.50 per therm) or very high usage (around 120 gallons per day). For current incremental costs, the water heater efficiency would need to be similar to that of a heat pump water heater to deliver a six year payback.

Periods and Nori motives

CERN Document Server

Huber, Annette

2017-01-01

This book casts the theory of periods of algebraic varieties in the natural setting of Madhav Nori’s abelian category of mixed motives. It develops Nori’s approach to mixed motives from scratch, thereby filling an important gap in the literature, and then explains the connection of mixed motives to periods, including a detailed account of the theory of period numbers in the sense of Kontsevich-Zagier and their structural properties. Period numbers are central to number theory and algebraic geometry, and also play an important role in other fields such as mathematical physics. There are long-standing conjectures about their transcendence properties, best understood in the language of cohomology of algebraic varieties or, more generally, motives. Readers of this book will discover that Nori’s unconditional construction of an abelian category of motives (over fields embeddable into the complex numbers) is particularly well suited for this purpose. Notably, Kontsevich's formal period algebra represents a to...

Periodic and almost periodic solutions for multi-valued differential equations in Banach spaces

Directory of Open Access Journals (Sweden)

E. Hanebaly

2000-03-01

Full Text Available It is known that for $omega$-periodic differential equations of monotonous type, in uniformly convex Banach spaces, the existence of a bounded solution on ${Bbb R}^+$ is equivalent to the existence of an omega-periodic solution (see Haraux [5] and Hanebaly [7, 10]. It is also known that if the Banach space is strictly convex and the equation is almost periodic and of monotonous type, then the existence of a continuous solution with a precompact range is equivalent to the existence of an almost periodic solution (see Hanebaly [8]. In this note we want to generalize the results above for multi-valued differential equations.

Nonparametric Inference for Periodic Sequences

KAUST Repository

Sun, Ying

2012-02-01

This article proposes a nonparametric method for estimating the period and values of a periodic sequence when the data are evenly spaced in time. The period is estimated by a "leave-out-one-cycle" version of cross-validation (CV) and complements the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both theoretically and by simulation.We also propose a nonparametric test of the null hypothesis that the data have constantmean against the alternative that the sequence of means is periodic. Finally, our methodology is demonstrated on three well-known time series: the sunspots and lynx trapping data, and the El Niño series of sea surface temperatures. © 2012 American Statistical Association and the American Society for Quality.

Periodic waves in nonlinear metamaterials

International Nuclear Information System (INIS)

Liu, Wen-Jun; Xiao, Jing-Hua; Yan, Jie-Yun; Tian, Bo

2012-01-01

Periodic waves are presented in this Letter. With symbolic computation, equations for monochromatic waves are studied, and analytic periodic waves are obtained. Factors affecting properties of periodic waves are analyzed. Nonlinear metamaterials, with the continuous distribution of the dielectric permittivity obtained, are different from the ones with the discrete distribution. -- Highlights: ► Equations for the monochromatic waves in transverse magnetic polarization have been studied. ► Analytic periodic waves for the equations have been obtained. ► Periodic waves are theoretically presented and studied in the nonlinear metamaterials.

Beam-wave interaction in periodic and quasi-periodic structures. 2. ed.

International Nuclear Information System (INIS)

Schaechter, Levi

2011-01-01

The main theme of this book is the interaction of electrons with electromagnetic waves in the presence of periodic and quasi-periodic structures in vacuum, in view of applications in the design and operation of particle accelerators. The first part of the book is concerned with the textbook-like presentation of the basic material, in particular reviewing elementary electromagnetic phenomena and electron dynamics. The second part of the book describes the current models for beam-wave interactions with periodic and quasi-periodic structures. This is the basis for introducing, in the last part of the book, a number of particle and radiation sources that rest on these principles, in particular the free-electron laser, wake-field acceleration schemes and a number of other advanced particle accelerator concepts. This second edition brings this fundamental text up-to-date in view of the enormous advances that have been made over the last decade since the first edition was published. All chapters, as well as the bibliography, have been significantly revised and extended, and the number of end-of-chapter exercises has been further increased to enhance this book's usefulness for teaching specialized graduate courses. (orig.)

The Present and Future of Szigetvár Spa – An Economic Analysis of Geothermal Energy Investment

Directory of Open Access Journals (Sweden)

Judit Pálné Schreiner

2014-09-01

Full Text Available In Hungary, geothermal energy has proved to be an economical source of energy for direct use. It highlights the pros and cons of including renewable energy in the power generation mix of Hungary, and the pros and cons of local application. This paper looks at the operation of Szigetvár Spa from both economic and social aspects. In this study, qualitative analysis is used for the basic economic and social introduction of the Spa, and then real options, based on quantitative methods, are described to identify the long-term financial consequences of the project. In 1966, thermal water was found in Szigetvár. In 1997, this thermal water was certified as medicinal water. The wellhead temperature of Szigetvár thermal water is 62°C in the 790 metres deep thermal well. It is used as so-called domestic hot water in the Szent István housing estate and in Szigetvár Spa. One of the problems with the project is that it is based on single stage thermal water utilization, another problem is that the waste water is too hot. This can be solved by exploiting the heat energy of thermal water more intensively. This way, maximum benefits can be gained from geothermal energy with minimum use of energy. Static and dynamic investment analyses were carried out to examine the spa from a financial aspect. The methods used include static payback period, average rate of return, levelized cost of electricity, net present value, profitability index, dynamic payback period, internal rate of return and real options. By pricing geothermal technology, it is possible to identify the strategic value of flexibility, to quantify what was previously left unquantified, and thus to show that geothermal investments are profitable not only from a social but also from a financial aspect as well.

Optimal Renewable Energy Integration into Refinery with CO2 Emissions Consideration: An Economic Feasibility Study

Science.gov (United States)

Alnifro, M.; Taqvi, S. T.; Ahmad, M. S.; Bensaida, K.; Elkamel, A.

2017-08-01

With increasing global energy demand and declining energy return on energy invested (EROEI) of crude oil, global energy consumption by the O&G industry has increased drastically over the past few years. In addition, this energy increase has led to an increase GHG emissions, resulting in adverse environmental effects. On the other hand, electricity generation through renewable resources have become relatively cost competitive to fossil based energy sources in a much ‘cleaner’ way. In this study, renewable energy is integrated optimally into a refinery considering costs and CO2 emissions. Using Aspen HYSYS, a refinery in the Middle East was simulated to estimate the energy demand by different processing units. An LP problem was formulated based on existing solar energy systems and wind potential in the region. The multi-objective function, minimizing cost as well as CO2 emissions, was solved using GAMS to determine optimal energy distribution from each energy source to units within the refinery. Additionally, an economic feasibility study was carried out to determine the viability of renewable energy technology project implementation to overcome energy requirement of the refinery. Electricity generation through all renewable energy sources considered (i.e. solar PV, solar CSP and wind) were found feasible based on their low levelized cost of electricity (LCOE). The payback period for a Solar CSP project, with an annual capacity of about 411 GWh and a lifetime of 30 years, was found to be 10 years. In contrast, the payback period for Solar PV and Wind were calculated to be 7 and 6 years, respectively. This opens up possibilities for integrating renewables into the refining sector as well as optimizing multiple energy carrier systems within the crude oil industry

Primary energy consumption of the dwelling with solar hot water system and biomass boiler

International Nuclear Information System (INIS)

Berković-Šubić, Mihaela; Rauch, Martina; Dović, Damir; Andrassy, Mladen

2014-01-01

Highlights: • Methodology for determing delivered and primary energy is developed. • Conventional and solar hot water system are analyzed. • Influence of system components, heat losses and energy consumption is explored. • Savings when using solar system in delivered energy is 30% and in primary 75%. • Dwelling with higher Q H,nd has 60% shorter payback period. - Abstract: This paper presents a new methodology, based on the energy performance of buildings Directive related European norms. It is developed to overcome ambiguities and incompleteness of these standards in determining the delivered and primary energy. The available procedures from the present “Algorithm for determining the energy demands and efficiency of technical systems in buildings”, normally used for energy performance certification of buildings, also allow detailed analyzes of the influence of particular system components on the overall system energy efficiency. The calculation example is given for a Croatian reference dwelling, equipped with a solar hot water system, backed up with a biomass boiler for space heating and domestic hot water purposes as a part of the dwelling energy performance certification. Calculations were performed for two cases corresponding to different levels of the dwelling thermal insulation with an appropriate heating system capacity, in order to investigate the influence of the building heat losses on the system design and energy consumption. The results are compared against those obtained for the conventional system with a gas boiler in terms of the primary energy consumption as well as of investment and operating costs. These results indicate great reduction in both delivered and primary energy consumption when a solar system with biomass boiler is used instead of the conventional one. Higher savings are obtained in the case of the dwelling with higher energy need for space heating. Such dwellings also have a shorter payback period than the ones with

Improving energy efficiency of cyclone circuits in coal beneficiation plants by pump-storage systems

International Nuclear Information System (INIS)

Zhang, Lijun; Xia, Xiaohua; Zhang, Jiangfeng

2014-01-01

Highlights: • A pump-storage system (PSS) is introduced in a coal washing plant to reduce energy consumption and cost. • Optimal operation of the PSS under TOU tariff is formulated and solved. Life cycle cost analysis of the design is done. • Simulation results show the effectiveness of energy efficiency improvement and load shifting effect of the proposed approach. • An annual 38% reduction of overall cost of the coal washing plant with 2.86 years payback period is achieved. • Capacity improvement of power plants contracted to the coal mine is expected as less electricity is required to get fuel. - Abstract: A pump storage system (PSS) is introduced to the coal preparation dense medium cyclone (DMC) plants to improve their energy efficiency while maintaining the required medium supply. The DMC processes are very energy intensive and inefficient because the medium supply pumps are constantly over-pumping. The PSS presented is to reduce energy consumption and cost by introducing an addition medium circulation loop. The corresponding pump operation optimization problem in the PSS scheme under time-based electricity tariff is formulated and solved, based on which the financial benefits of the design is investigated using life cycle cost analysis. A case study based on the operation status of a South African coal mine is carried out to verify the effectiveness of the proposed approach. It is demonstrated that the energy cost can be reduced by more than 50% in the studied case by introducing a 160 m 3 storage tank. According to life cycle analysis, the PSS Option 1 yields an annual 38% reduction of the overall cost for the beneficiation plant with a payback period of 2.68 years

Drying of Rhinacanthus nasutus (Linn. Kurz. using a solar dryer incorporated with a backup thermal energy storage from wood combustion

Directory of Open Access Journals (Sweden)

Perapong Tekasakul

2006-05-01

Full Text Available An indirect, natural convection, solar cabinet dryer incorporated with a backup thermal energy storage from wood combustion was designed and tested with the Thai herb, Rhinacanthus nasutus (Linn. Kurz. Most of Thai herbs are widely used as traditional medicine and drying is an initial step in the production process. Solar dryer with a biomass backup heating system is the most feasible solution to drying in Thailand. In this work, a 4 m x 5 m solar collector was used to absorb solar radiation for heating the incoming air during the daytime, while a biomass burner was used to supply heat when solar energy was not possible. Heat from fuelwood combustion was accumulated in the thermal storage system made of bricks, and was used to heat up the incoming air. Results showed that the herb was dried uniformly and the temperature inside the drying cabinet could be maintained above 50ºC for more than 10 hours. Thermal efficiency when using solar energy was 10.5%, but the value was less than 1% when using the heat from biomass burning. This resulted from the low moisture content of the products after being dried by the solar energy. The dryer is beneficial to the operators, particularly in southern Thailand, where continuous drying is required. This dryer is by no means limited to drying of the herb. Currently, four dryers of the same model have been used by farmer groups in southern Thailand for drying bananas, several types of herbs, fish, and other products. In economic consideration, its payback period is 5.5 years when compared with the LPG-equipped dryer. When the total cost and production capacity are considered, its payback period is about 6 years.

The economical production of alcohol fuels from coal-derived synthesis gas. Quarterly technical progress report Number 8, 1 July, 1993--30 September, 1993

Energy Technology Data Exchange (ETDEWEB)

1993-10-01

Task 1, the preparation of catalyst materials, is proceeding actively. At WVU, catalysts based on Mo are being prepared using a variety of approaches to alter the oxidation state and environment of the Mo. At UCC and P, copper-based zinc chromite spinel catalysts will be prepared and tested. The modeling of the alcohol-synthesis reaction in a membrane reactor is proceeding actively. Under standard conditions, pressure drop in the membrane reactor has been shown to be negligible. In Task 2, base case designs had previously been completed with a Texaco gasifier. Now, similar designs have been completed using the Shell gasifier. A comparison of the payback periods or production cost of these plants shows significant differences among the base cases. However, a natural gas only design, prepared for comparison purposes, gives a lower payback period or production cost. Since the alcohol synthesis portion of the above processes is the same, the best way to make coal-derived higher alcohols more attractive economically than natural gas-derived higher alcohols is by making coal-derived syngas less expensive than natural gas-derived syngas. The maximum economically feasible capacity for a higher alcohol plant from coal-derived syngas appears to be 32 MM bbl/yr. This is based on consideration of regional coal supply in the eastern US, coal transportation, and regional product demand. The benefits of economics of scale are illustrated for the base case designs. A value for higher alcohol blends has been determined by appropriate combination of RVP, octane number, and oxygen content, using MTBE as a reference. This analysis suggests that the high RVP of methanol in combination with its higher water solubility make higher alcohols more valuable than methanol.

Storing energy for cooling demand management in tropical climates: A techno-economic comparison between different energy storage technologies

International Nuclear Information System (INIS)

Comodi, Gabriele; Carducci, Francesco; Sze, Jia Yin; Balamurugan, Nagarajan; Romagnoli, Alessandro

2017-01-01

This paper addresses the role of energy storage in cooling applications. Cold energy storage technologies addressed are: Li-Ion batteries (Li-Ion EES), sensible heat thermal energy storage (SHTES); phase change material (PCM TES), compressed air energy storage (CAES) and liquid air energy storage (LAES). Batteries and CAES are electrical storage systems which run the cooling systems; SHTES and PCM TES are thermal storage systems which directly store cold energy; LAES is assessed as a hybrid storage system which provides both electricity (for cooling) and cold energy. A hybrid quantitative-qualitative comparison is presented. Quantitative comparison was investigated for different sizes of daily cooling energy demand and three different tariff scenarios. A techno-economic analysis was performed to show the suitability of the different storage systems at different scales. Three parameters were used (Pay-back period, Savings-per-energy-unit and levelized-cost-of-energy) to analyze and compare the different scenarios. The qualitative analysis was based on five comparison criteria (Complexity, Technology Readiness Level, Sustainability, Flexibility and Safety). Results showed the importance of weighing the pros and cons of each technology to select a suitable cold energy storage system. Techno-economic analysis highlighted the fundamental role of tariff scenario: a greater difference between peak and off-peak electricity tariff leads to a shorter payback period of each technology. - Highlights: • Techno-economic evaluation of energy storage solutions for cooling applications. • Comparison between five energy storage (EES, SHTES, PCM, CAES, LAES) is performed. • Qualitative and quantitative performance parameters were used for the analysis. • LAES/PCM can be valid alternatives to more established technologies EES, SHTES, CAES. • Tariffs, price arbitrage and investment cost play a key role in energy storage spread.

Software for optimal selection of places for installation of balancing devices in 0,4 kV electric power systems loaded with electric motors

Directory of Open Access Journals (Sweden)

Romanova Victoria

2017-01-01

Full Text Available This publication considers the issues of development of the software program for designing of 0,4 kV power supply systems with motor-actuated load under voltage unsymmetry conditions (using the example of the Trans-Baikal Territory. Voltage unsymmetry is practically constant phenomenon in the electric power networks of different voltage types. Voltage unsymmetry effects significantly the electric power consumers, including the supply mains itself. It has especially negative impact on the electrical equipment operation process and its lifetime. The urgency of the problem is confirmed by multiple research on the same topic and by significant number of damages suffered by the electric power consumers staying in service (especially in the Trans-Baikal Territory and in the Far-East regions. Voltage unsymmetry causes economic loss and reduction of the electromagnetic interference value by the voltage unsymmetry coefficient in negative-phase sequence (K2U gives inevitable economic effect accordingly. However, the payback period for the activities aimed at reduction of electromagnetic interference, will vary from some months to several years. The more accurate value of the payback period may be obtained using the developed software program. The developed software design program is implemented by means of the programming language C# in Microsoft Visual Studio environment, using the built-in cross-platform database SQLite. The software program shall allow making quick and accurate calculation of the power losses, to determine the economic feasibility of provision special measures for removal of the voltage unsymmetry, for determination of optimal application and location of the balancing devices. The software implementation in power systems loaded with electric motors will improve reliability and efficiency of asynchronous motors. The software is of interest for developers of projects on power supply systems for regions with non-linear loads.

Three empirical essays on consumer behavior related to climate change and energy

Science.gov (United States)

Jacobsen, Grant Douglas

This dissertation consists of three essays. All of the chapters address a topic in the area of household and consumer behavior related to climate change or energy. The first chapter is titled "The Al Gore Effect: An Inconvenient Truth and Voluntary Carbon Offsets". This chapter examines the relationship between climate change awareness and household behavior by testing whether Al Gore's documentary An Inconvenient Truth caused an increase in the purchase of voluntary carbon offsets. The analysis shows that in the two months following the film's release, zip codes within a 10-mile radius of a zip code where the film was shown experienced a 50 percent relative increase in the purchase of voluntary carbon offsets. The second chapter is titled "Are Building Codes Effective at Saving Energy? Evidence from Residential Billing Data in Florida". The analysis shows that Florida's energy-code change that took effect in 2002 is associated with a 4-percent decrease in electricity consumption and a 6-percent decrease in natural-gas consumption in Gainesville, FL. The estimated private payback period for the average residence is 6.4 years and the social payback period ranges between 3.5 and 5.3 years. The third chapter in this dissertation is titled "Do Environmental Offsets Increase Demand for Dirty Goods? Evidence from Residential Electricity Demand". This study evaluates the relationship between green products and existing patterns of consumer behavior by examining the relationship between household enrollment in a green electricity program and consumption of residential electricity. The results suggest there are two different types of green consumers. One type makes a small monthly donation and partially views the donation as a substitute for a previously existing pattern of green behavior, in this case, energy conservation. The other type makes a larger monthly donation and views the donation as a way to make strictly additional improvements in environmental quality.

Economic Evaluation of Cookie made from blend of Brewers′ Spent Grain (BSG, Groundnut cake and Sorghum Flour

Directory of Open Access Journals (Sweden)

Olawoye Babatunde

2017-08-01

Full Text Available Bakery and pastry products such as cookies are usually produced from wheat flour and as such contribute to high foreign exchange for tropical countries where such cereal is not cultivated. In view of this, we evaluated the engineering economics for the utilization of dried brewers′ spent grain, groundnut cake and sorghum flour in the industrial production of cookies. The production was based on the assumption that the cash flow was uniform over the plant life (i.e. 10 years with no salvage value. The equipment required for the production process was identified and estimates obtained from equipment manufactures. The production of the cookies was based on constant mass flow rate of 90 packets/min. The effects of uncertainties on cookie production were evaluated by varying the operation days (330, 300 and 250 days and also by varying the price of some key variables required for the production processes. The results indicate that the capital cost (fixed and working capital and the annual production cost (APC were US$1.39×106 and US$10.08×106/year, respectively. The after tax annual revenue was US$1.63×106/yr. The return on investment (ROI, single payback period (SPBP, discounted payback period, gross margin and internal rate of return (IRR of the plant were 63%, 1.58 years, 2.08 years, 23% and 77.52%, respectively. The result also showed that the production plant is feasible and could be operated for 330, 300 and 250 days. The difference between operation times lies in the profitability, which decreases as the number of days reduces. Based on the result of this analysis, brewers’ spent grain, groundnut cake, and sorghum flour can be utilized in industrial production of cookies with guaranteed profitability.

A systematic review of occupational safety and health business cases.

Science.gov (United States)

Verbeek, Jos; Pulliainen, Marjo; Kankaanpää, Eila

2009-12-01

Business cases are commonly developed as means to rationalize investment. We systematically reviewed 26 reported cases on occupational safety and health (OSH) interventions to assess if health and productivity arguments make a good business case. To be included in the review, studies had to analyze the costs and benefits, including productivity, of an OSH intervention at the enterprise level. We searched Medline and Embase for studies and used Google search in addition. Two reviewers independently selected studies and extracted data. The intervention profitability was calculated in euros (euro in 2008) as the first year's benefits minus the total intervention costs per worker. The payback period was calculated as the intervention costs divided by the first year's benefits. We found three ex-ante and 23 ex-post cases. In 20 cases, the study design was a before-after comparison without a control group. Generally a 100% reduction of injuries or sickness absence was assumed. In two cases, productivity and quality increases were very large. The main benefit was avoided sick leave. Depreciation or discounting was applied only in a minority of cases. The intervention profitability was negative in seven studies, up to euro 500 per employee in 12 studies and more than euro 500 per employee in seven studies. The payback period was less than half a year for 19 studies. Only a few studies included sensitivity analyses. Few ex-ante business cases for management decisions on OSH are reported. Guidelines for reporting and evaluation are needed. Business cases need more sound assumptions on the effectiveness of interventions and should incorporate greater uncertainty into their design. Ex-post evaluation should be based preferably on study designs that control for trends at a time different from that of the intervention.

Optical Frequency Mixing in Periodically-Patterned and in Quasi-Periodically-Patterned Nonlinear media

International Nuclear Information System (INIS)

Arie, A.

1999-01-01

Nonlinear frequency mixing processes, e.g. second harmonic generation, sum and difference frequency generation, etc., require matching of the phases of the interacting waves. The traditional method to achieve it is by selecting a specific angle of propagation in a birefringent nonlinear crystal. The main limitation of the birefringent phase matching method stems from the fact that for many interesting interactions, the phase matching condition cannot be satisfied in a specific crystal. This obstacle can be removed by the technique of quasi-phase-matching (QPM), where the nonlinear coefficient of the material is modulated at a fixed spatial frequency that equals the wave-vector phase mismatch between the interacting waves. An important development in recent years is the ability to periodically reverse the sign of the nonlinear coefficient in ferroelectric crystals by applying a high electric field through a periodic electrode. Some recent QPM interactions in periodically-poled KTP that were recently achieved at Tel-Aviv University include continuous-wave optical parametric oscillations, as well as generation of tunable mid-infrared radiation by difference frequency generation. Periodic patterning of the nonlinear coefficient enables to phase match only a single interaction. It would be advantageous to further extend the applications of this technique in order to simultaneously satisfy several interactions on a single crystal. This cannot be usually achieved in a periodic pattern, however more sophisticated quasi-periodic structures can be designed in this case. An interesting analogy can be drawn between artificially-made quasi-periodically-patterned nonlinear crystals and quasi-crystals found in nature, in rapidly-cooled metallic alloys

Thyrotoxic periodic paralysis

OpenAIRE

Rojith Karandode Balakrishnan; Suresh Rama Chandran; Geetha Thirumalnesan; Nedumaran Doraisamy

2011-01-01

This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recove...

Nonparametric Inference for Periodic Sequences

KAUST Repository

Sun, Ying; Hart, Jeffrey D.; Genton, Marc G.

2012-01-01

the periodogram, a widely used tool for period estimation. The CV method is computationally simple and implicitly penalizes multiples of the smallest period, leading to a "virtually" consistent estimator of integer periods. This estimator is investigated both

Periodic Table Target: A Game that Introduces the Biological Significance of Chemical Element Periodicity

Science.gov (United States)

Sevcik, Richard S.; McGinty, Ragan L.; Schultz, Linda D.; Alexander, Susan V.

2008-01-01

Periodic Table Target, a game for middle school or high school students, familiarizes students with the form of the periodic table and the biological significance of different elements. The Periodic Table Target game board is constructed as a class project, and the game is played to reinforce the content. Students are assigned several elements…

Periodic instantons and scattering amplitudes

International Nuclear Information System (INIS)

Khlebnikov, S.Yu.; Rubakov, V.A.; Tinyakov, P.G.

1991-04-01

We discuss the role of periodic euclidean solutions with two turning points and zero winding number (periodic instantons) in instanton induced processes below the sphaleron energy E sph . We find that the periodic instantons describe certain multiparticle scattering events leading to the transitions between topologically distinct vacua. Both the semiclassical amplitudes and inital and final states of these transitions are determined by the periodic instantons. Furthermore, the corresponding probabilities are maximal among all states of given energy. We show that at E ≤ E sph , the periodic instantons can be approximated by infinite chains of ordinary instantons and anti-instantons, and they naturally emerge as deformations of the zero energy instanton. In the framework of 2d abelian Higgs model and 4d electroweak theory we show, however, that there is not obvious relation between periodic instantons and two-particle scattering amplitudes. (orig.)

Dissemination of Solar Water Heaters in Taiwan: The Case of Remote Islands

Directory of Open Access Journals (Sweden)

Kung-Ming Chung

2013-10-01

Full Text Available Solar water heaters represent the success story in the development of renewable energy in Taiwan. With increasing public awareness, there are over 0.3 million residential systems in operation. To disseminate solar water heaters in remote islands, economic feasibility and water quality are taken into account in this study. The payback period in Kinmen and Penghu Counties are evaluated, according to effective annual solar energy gain, hot water consumption pattern and cost. Assessment of the scaling and corrosion tendencies for solar water heaters using tap and underground water are also presented. For flat-plate solar collectors with metal components, favorable corrosion resistance and protective anti-corrosion coatings are required.

Techno-economic analysis of a roof-integrated solar air heating system for drying fruit and vegetables

Energy Technology Data Exchange (ETDEWEB)

Sreekumar, A. [Dept. of Physics, Cochin University of Science and Technology, Kochi 682 022 (India)

2010-11-15

The solar air heater was 46 m{sup 2} and recorded a maximum temperature of 76.6 C. The dryer was loaded with 200 kg of fresh pineapple slices 5 mm thick. The initial moisture content of 82% was reduced to the desired level (<10%) within 8 h. The performance of the dryer was analyzed in detail by three methods namely annualized cost, present worth of annual savings, and present worth of cumulative savings. The cost of drying 1 kg pineapple worked out to Rs. 11 which was roughly half of that of an electric dryer. The payback period worked out to 0.54 year, much less than the estimated life of the system (20 years). (author)

STANDALONE PHOTOVOLTAIC SYSTEMS SIZING OPTIMIZATION USING DESIGN SPACE APPROACH: CASE STUDY FOR RESIDENTIAL LIGHTING LOAD

Directory of Open Access Journals (Sweden)

D. F. AL RIZA

2015-07-01

Full Text Available This paper presents a sizing optimization methodology of panel and battery capacity in a standalone photovoltaic system with lighting load. Performance of the system is identified by performing Loss of Power Supply Probability (LPSP calculation. Input data used for the calculation is the daily weather data and system components parameters. Capital Cost and Life Cycle Cost (LCC is calculated as optimization parameters. Design space for optimum system configuration is identified based on a given LPSP value, Capital Cost and Life Cycle Cost. Excess energy value is used as an over-design indicator in the design space. An economic analysis, including cost of the energy and payback period, for selected configurations are also studied.

Data on electrical energy conservation using high efficiency motors for the confidence bounds using statistical techniques.

Science.gov (United States)

Shaikh, Muhammad Mujtaba; Memon, Abdul Jabbar; Hussain, Manzoor

2016-09-01

In this article, we describe details of the data used in the research paper "Confidence bounds for energy conservation in electric motors: An economical solution using statistical techniques" [1]. The data presented in this paper is intended to show benefits of high efficiency electric motors over the standard efficiency motors of similar rating in the industrial sector of Pakistan. We explain how the data was collected and then processed by means of formulas to show cost effectiveness of energy efficient motors in terms of three important parameters: annual energy saving, cost saving and payback periods. This data can be further used to construct confidence bounds for the parameters using statistical techniques as described in [1].

Wind energy assessment and wind farm simulation in Triunfo - Pernambuco, Brazil

Energy Technology Data Exchange (ETDEWEB)

Lima, Laerte; Filho, Celso

2010-09-15

The Triunfo wind's characterization, in Pernambuco state, situated in Brazilian northeast, and wind power potential assessment study shows a average wind speed of 11.27 m / s, predominant Southeast wind direction, average wind power density of 1672 W/m2 and Weibull parameters shape and scale equal to 2,0 and 12,7 m/s. The wind farm was simulated by using 850kW wind turbines (total of 20MW). The simulated shows AEP of 111,4 GWh, Cf of 62% and 5462 hours of operation by year. The economical simulated results, shows Pay-back of 3 years, TIR = 47% and VAN = 85.506kEuro booths @ 20 years time period.

Techno-economic analysis of a roof-integrated solar air heating system for drying fruit and vegetables

International Nuclear Information System (INIS)

Sreekumar, A.

2010-01-01

The solar air heater was 46 m 2 and recorded a maximum temperature of 76.6 deg. C. The dryer was loaded with 200 kg of fresh pineapple slices 5 mm thick. The initial moisture content of 82% was reduced to the desired level (<10%) within 8 h. The performance of the dryer was analyzed in detail by three methods namely annualized cost, present worth of annual savings, and present worth of cumulative savings. The cost of drying 1 kg pineapple worked out to Rs. 11 which was roughly half of that of an electric dryer. The payback period worked out to 0.54 year, much less than the estimated life of the system (20 years).

Congeneration feasibility: Otis Elevator Company and Polychrome Corporation. Final report

Energy Technology Data Exchange (ETDEWEB)

Fox, H.

1982-05-01

This report summarizes an investigation of the technical and economic feasibility of cogenerating electric and thermal power at two manufacturing plants (Otis Elevator Company and Polychrome Corporation) located on neighboring properties in Yonkers, NY. Existing electrical- and steam-producing equipment and energy consumption date are summarized. Alternative cases examined include electrical energy generation, electrical energy generation with waste heat recovery and a combined cycle case. Also reported are life cycle cost economic evaluations including simple payback period and return-on-investment indices. While it was concluded that cogeneration of heat and electricity at these industrial plant sites would not be economically viable, this detailed study provides valuable insight into the types of problems encountered when considering cogeneration feasibility.

Energy and life-cycle cost analysis of a six-story office building

Science.gov (United States)

Turiel, I.

1981-10-01

An energy analysis computer program, DOE-2, was used to compute annual energy use for a typical office building as originally designed and with several energy conserving design modifications. The largest energy use reductions were obtained with the incorporation of daylighting techniques, the use of double pane windows, night temperature setback, and the reduction of artificial lighting levels. A life-cycle cost model was developed to assess the cost-effectiveness of the design modifications discussed. The model incorporates such features as inclusion of taxes, depreciation, and financing of conservation investments. The energy conserving strategies are ranked according to economic criteria such as net present benefit, discounted payback period, and benefit to cost ratio.

Quickscan potential of heat pumps for energy conservation in cultivation with low energy consumption; Quickscan potentie van warmtepompen voor energiebesparing bij teelten met een laag energieverbruik

Energy Technology Data Exchange (ETDEWEB)

De Ruijter, J.A.F.

2012-06-15

In the title quick scan the use of a heat pump has been calculated for two low-energy crops: radish and the cold cultivation of pot plants. With model calculations two types of heat pump are calculated: an electric heat pump and a gas-engine-driven heat pump. The payback period of a heat pump in low-energy crops is too long considering the current market [Dutch] In de quickscan is het gebruik van een warmtepomp doorgerekend voor twee energiearme teelten: radijs en koude teelt van potplanten. Met modelberekeningen zijn twee types warmtepomp beoordeeld, een elektrische en een gasmotorgedreven warmtepomp. De terugverdientijd van een warmtepomp in energiearme teelten is onder de huidige marktomstandigheden te lang.

Cost reduction has priority in solar cell research

International Nuclear Information System (INIS)

Van Zolingen, R.J.C.; Sinke, W.C.

1993-01-01

The main topic in the research and development of photovoltaic cells is cost reduction. Although new materials, improved techniques and increasing efficiency are promising aspects of the clean and sustainable option of a photovoltaic conversion of sunlight to produce electricity at a large scale, the high prices form an obstacle. Photovoltaic conversion is at least a factor three too expensive compared to the conventional power generation techniques by means of fossil fuels. Attention is paid to the theoretical maximum efficiency of photovoltaic conversion, the efficiencies realized sofar, the importance of thin film solar cells, the payback period of photovoltaic modules, the environmental impacts of using photovoltaic cells, and finally the costs. 2 figs., 1 ill., 2 tabs., 6 refs

Integrated alternative energy systems for use in small communities

Science.gov (United States)

Thornton, J.

1982-01-01

This paper summarizes the principles and conceptual design of an integrated alternative energy system for use in typical farming communities in developing countries. A system is described that, utilizing the Sun and methane produced from crop waste, would supply sufficient electric and thermal energy to meet the basic needs of villagers for water pumping, lighting, and cooking. The system is sized to supply enough pumping capacity to irrigate 101 ha (249 acres) sufficiently to optimize annual crop yields for the community. Three economic scenarios were developed, showing net benefits to the community of $3,578 to $15,547 anually, payback periods of 9.5 to 20 years, and benefit-to-cost ratios of 1.1 to 1.9.

Design of solar systems in high-rise buildings

Science.gov (United States)

Kolosov, Alexander; Chudinov, Dmitry; Yaremenko, Sergey

2018-03-01

Nowadays, the renovation program is being implemented in the megapolises of Russia. Innovative high-rise buildings are built instead of morally and physically obsolete houses, where non-traditional renewable energy sources are used to the fullest extent, under the effect of which they are located. The possibility to use solar systems with variation of their design parameters is considered. It is established that solar systems have high technical potential. The share of heat load, that is provided by using solar energy, varies from 4 to 84% depending on the time of the year. Economic indicators restrain the use of such panels. The payback period is about 8 years at the current cost for thermal energy.

Rationalization of Comet Halley's periods

Science.gov (United States)

Belton, Michael J. S.

1990-01-01

The sense of long axis orientation of Comet Halley during the Vega 1 encounter must be reversed from that deduced by Sagdeev et al. (1986) in order to harmonize the comet nucleus' Vega/Giotto-observed orientations with periodicities extracted from time-series brightness data. It is also demonstrated that Vega/Giotto observations can be satisfied by either a 2.2- or 3.7-day long-axis free precession period. A novel Fourier algorithm is used to reanalyze five independent data sets; strong evidence is adduced for periods harmonically related to a 7.4-day period. The preferred candidate models for Halley's nuclear rotation are characterized by a long-axis precession period of 3.7 days.

High-temperature counter-flow recuperator

Science.gov (United States)

Rudloff, F.

1981-05-01

The commercial potential of a helical recuperator design in recovering waste heat from industrial furnaces is reported. The helical recuperator concept consists of a cylindrical column with an interior helical interface which separates the preheat air and the combustion gas. The column operates in a teer flow mode and is formed from modular sections. The material evaluation consisted of exposing material samples to a soda-lime glass furnace environment for a fifteen week period. ECP-3, X-81, and Unichrome were the best suited for use in a soda-lime environment and ECP-3 was the best candidate with respect to manufacturing. Two potential design modifications were identified: a finned design and a double helix design. For materials that showed the greatest potential for use in the glass environment, the double helix design made from ECP-3 was the most economical producing payback periods of 6 to 14 years.

Suppression of period-doubling and nonlinear parametric effects in periodically perturbed systems

International Nuclear Information System (INIS)

Bryant, P.; Wiesenfeld, K.

1986-01-01

We consider the effect on a generic period-doubling bifurcation of a periodic perturbation, whose frequency ω 1 is near the period-doubled frequency ω 0 /2. The perturbation is shown to always suppress the bifurcation, shifting the bifurcation point and stabilizing the behavior at the original bifurcation point. We derive an equation characterizing the response of the system to the perturbation, analysis of which reveals many interesting features of the perturbed bifurcation, including (1) the scaling law relating the shift of the bifurcation point and the amplitude of the perturbation, (2) the characteristics of the system's response as a function of bifurcation parameter, (3) parametric amplification of the perturbation signal including nonlinear effects such as gain saturation and a discontinuity in the response at a critical perturbation amplitude, (4) the effect of the detuning (ω 1 -ω 0 /2) on the bifurcation, and (5) the emergence of a closely spaced set of peaks in the response spectrum. An important application is the use of period-doubling systems as small-signal amplifiers, e.g., the superconducting Josephson parametric amplifier

Iraqi architecture in mogul period

Directory of Open Access Journals (Sweden)

Hasan Shatha

2018-01-01

Full Text Available Iraqi architecture have many periods passed through it until now, each on from these periods have it is architectural style, also through time these styles interacted among us, to creating kind of space forming, space relationships, and architectural elements (detailed treatments, the research problem being from the multi interacted architectural styles causing some of confused of general characteristic to every style, that we could distinguish by it. Research tries to study architecture style through Mogul Conquest to Baghdad. Aim of research follow main characteristic for this architectural style in the Mogul periods on the level of form, elements, and treatments. Research depending on descriptive and analytical all buildings belong to this period, so from analyzing there style by, general form for building, architectural elements, and it architectural treatment, therefore; repeating this procedures to every building we get some similarities, from these similarities we can making conclusion about pure characteristic of the style of these period. Other side, we also discover some Dissimilar in the building periods, these will lead research to make what interacting among styles in this period, after all that we can drew clearly main characteristic of Architectural Style for Mogul Conquest in Baghdad

Problem Periods

Science.gov (United States)

... ovary syndrome. Read our information on PCOS for teens , and see your doctor if you think you may have PCOS. Major weight loss. Girls who have anorexia will often stop having periods. When to see ...

Cost justification of chiller replacement

International Nuclear Information System (INIS)

Baker, T.J.; Baumer, R.A.

1993-01-01

We often hear of products with paybacks that are too good to be true. Just a few weeks ago,a client received a recommendation from a national service company's local office. In the letter the company recommended that open-quotes due to the age and condition of the boiler ... that the school consider replacing the boiler... The cost for the new boiler can usually be recovered by lower fuel bills in 2 to 3 yearsclose quotes. This was for an installation in Southeast Texas where the boiler is only used 4 to 5 months per year. Analysis show the above claims to be nonsense. A new boiler would cost about $47,000 installed. Current total gas bills for the facility are $15,630 per year. They would have to shutoff the gas to the facility to have a three year payback. In fact, only two-thirds of the gas is used to heat the facility so we have only $10, 000 to write off against the new boiler. How much will the greater efficiency save? A 30% savings due to greater efficiency produces $3,000 per year in gas savings to offset the $47,000 cost, a 16 year payback. And much of the efficiency savings can be realized by adjusting the existing boiler. In another care a client wanted to investigate replacement of a twenty year old chiller plant with more efficient equipment. We investigated the project and determined that the payback would be greater than ten years. They did not operate the equipment during the summer and at less than 50% of capacity the balance of the year

Periodic Poisson Solver for Particle Tracking

International Nuclear Information System (INIS)

Dohlus, M.; Henning, C.

2015-05-01

A method is described to solve the Poisson problem for a three dimensional source distribution that is periodic into one direction. Perpendicular to the direction of periodicity a free space (or open) boundary is realized. In beam physics, this approach allows to calculate the space charge field of a continualized charged particle distribution with periodic pattern. The method is based on a particle mesh approach with equidistant grid and fast convolution with a Green's function. The periodic approach uses only one period of the source distribution, but a periodic extension of the Green's function. The approach is numerically efficient and allows the investigation of periodic- and pseudo-periodic structures with period lengths that are small compared to the source dimensions, for instance of laser modulated beams or of the evolution of micro bunch structures. Applications for laser modulated beams are given.

Thyrotoxic periodic paralysis

Directory of Open Access Journals (Sweden)

Rojith Karandode Balakrishnan

2011-01-01

Full Text Available This article aims at highlighting the importance of suspecting thyrotoxicosis in cases of recurrent periodic flaccid paralysis; especially in Asian men to facilitate early diagnosis of the former condition. A case report of a 28 year old male patient with recurrent periodic flaccid paralysis has been presented. Hypokalemia secondary to thyrotoxicosis was diagnosed as the cause of the paralysis. The patient was given oral potassium intervention over 24 hours. The patient showed complete recovery after the medical intervention and was discharged after 24 hours with no residual paralysis. Thyrotoxic periodic paralysis (TPP is a complication of thyrotoxicosis, more common amongst males in Asia. It presents as acute flaccid paralysis in a case of hyperthyroidism with associated hypokalemia. The features of thyrotoxicosis may be subtle or absent. Thus, in cases of recurrent or acute flaccid muscle paralysis, it is important to consider thyrotoxicosis as one of the possible causes, and take measures accordingly.

Holonomic systems for period mappings

Energy Technology Data Exchange (ETDEWEB)

Chen, Jingyue, E-mail: jychen@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States); Huang, An, E-mail: anhuang@math.harvard.edu [Department of Mathematics, Harvard University, Cambridge, MA 02138 (United States); Lian, Bong H., E-mail: lian@brandeis.edu [Department of Mathematics, Brandeis University, Waltham, MA 02454 (United States)

2015-09-15

Period mappings were introduced in the sixties [4] to study variation of complex structures of families of algebraic varieties. The theory of tautological systems was introduced recently [7,8] to understand period integrals of algebraic manifolds. In this paper, we give an explicit construction of a tautological system for each component of a period mapping. We also show that the D-module associated with the tautological system gives rise to many interesting vanishing conditions for period integrals at certain special points of the parameter space.

Scenarios for solar thermal energy applications in Brazil

International Nuclear Information System (INIS)

Martins, F.R.; Abreu, S.L.; Pereira, E.B.

2012-01-01

The Solar and Wind Energy Resource Assessment (SWERA) database is used to prepare and discuss scenarios for solar thermal applications in Brazil. The paper discusses low temperature applications (small and large scale water heating) and solar power plants for electricity production (concentrated solar power plants and solar chimney plants) in Brazil. The results demonstrate the feasibility of large-scale application of solar energy for water heating and electricity generation in Brazil. Payback periods for water heating systems are typically below 4 years if they were used to replace residential electric showerheads in low-income families. Large-scale water heating systems also present high feasibility and many commercial companies are adopting this technology to reduce operational costs. The best sites to set up CSP plants are in the Brazilian semi-arid region where the annual energy achieves 2.2 MW h/m 2 and averages of daily solar irradiation are larger than 5.0 kW h/m 2 /day. The western area of Brazilian Northeastern region meets all technical requirements to exploit solar thermal energy for electricity generation based on solar chimney technology. Highlights: ► Scenarios for solar thermal applications are presented. ► Payback is typically below 4 years for small scale water heating systems. ► Large-scale water heating systems also present high feasibility. ► The Brazilian semi-arid region is the best sites for CSP and chimney tower plants.

Comparative evaluation of three alternative power cycles for waste heat recovery from the exhaust of adiabatic diesel engines

Science.gov (United States)

Bailey, M. M.

1985-01-01

Three alternative power cycles were compared in application as an exhaust-gas heat-recovery system for use with advanced adiabatic diesel engines. The power cycle alternatives considered were steam Rankine, organic Rankine with RC-1 as the working fluid, and variations of an air Brayton cycle. The comparison was made in terms of fuel economy and economic payback potential for heavy-duty trucks operating in line-haul service. The results indicate that, in terms of engine rated specific fuel consumption, a diesel/alternative-power-cycle engine offers a significant improvement over the turbocompound diesel used as the baseline for comparison. The maximum imporvement resulted from the use of a Rankine cycle heat-recovery system in series with turbocompounding. The air Brayton cycle alternatives studied, which included both simple-cycle and compression-intercooled configurations, were less effective and provided about half the fuel consumption improvement of the Rankine cycle alternatives under the same conditions. Capital and maintenance cost estimates were also developed for each of the heat-recovery power cycle systems. These costs were integrated with the fuel savings to identify the time required for net annual savings to pay back the initial capital investment. The sensitivity of capital payback time to arbitrary increases in fuel price, not accompanied by corresponding hardware cost inflation, was also examined. The results indicate that a fuel price increase is required for the alternative power cycles to pay back capital within an acceptable time period.

39 CFR 121.2 - Periodicals.

Science.gov (United States)

2010-07-01

... 39 Postal Service 1 2010-07-01 2010-07-01 false Periodicals. 121.2 Section 121.2 Postal Service UNITED STATES POSTAL SERVICE POST OFFICE SERVICES [DOMESTIC MAIL] SERVICE STANDARDS FOR MARKET-DOMINANT MAIL PRODUCTS § 121.2 Periodicals. (a) End-to-End. (1) For all SCF turnaround Periodicals properly...

On some periodicity effects

DEFF Research Database (Denmark)

Sorokin, Sergey V.

2015-01-01

The talk is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of wave-guide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim o...

Periodically poled silicon

Science.gov (United States)

Hon, Nick K.; Tsia, Kevin K.; Solli, Daniel R.; Khurgin, Jacob B.; Jalali, Bahram

2010-02-01

Bulk centrosymmetric silicon lacks second-order optical nonlinearity χ(2) - a foundational component of nonlinear optics. Here, we propose a new class of photonic device which enables χ(2) as well as quasi-phase matching based on periodic stress fields in silicon - periodically-poled silicon (PePSi). This concept adds the periodic poling capability to silicon photonics, and allows the excellent crystal quality and advanced manufacturing capabilities of silicon to be harnessed for devices based on χ(2)) effects. The concept can also be simply achieved by having periodic arrangement of stressed thin films along a silicon waveguide. As an example of the utility, we present simulations showing that mid-wave infrared radiation can be efficiently generated through difference frequency generation from near-infrared with a conversion efficiency of 50% based on χ(2) values measurements for strained silicon reported in the literature [Jacobson et al. Nature 441, 199 (2006)]. The use of PePSi for frequency conversion can also be extended to terahertz generation. With integrated piezoelectric material, dynamically control of χ(2)nonlinearity in PePSi waveguide may also be achieved. The successful realization of PePSi based devices depends on the strength of the stress induced χ(2) in silicon. Presently, there exists a significant discrepancy in the literature between the theoretical and experimentally measured values. We present a simple theoretical model that produces result consistent with prior theoretical works and use this model to identify possible reasons for this discrepancy.

Evolution of the U.S. energy service company industry: Market size and project performance from 1990–2008

International Nuclear Information System (INIS)

Larsen, Peter H.; Goldman, Charles A.; Satchwell, Andrew

2012-01-01

, especially at K-12 schools. We found that the median simple payback time has increased from 1.9 to 3.2 years in private sector projects since the early-to-mid 1990s and from 5.2 to 10.5 years in public sector projects for the same time period. - Highlights: ► U.S. ESCO industry revenues were ∼$4 billion in 2008 and we estimated accelerated growth for 2011. ► U.S. ESCOs generated ∼$23 billion in direct benefits at projects installed from 1990–2008. ► Industry evolution has implications for customer project economics, especially at K-12 schools. ► Payback times have increased from 1.9 to 3.2 years in private sector projects since 1990. ► Payback times have increased from 5.2 to 10.5 years in public sector projects since 1990.

Periodic precursors of nonlinear dynamical transitions

International Nuclear Information System (INIS)

Jiang Yu; Dong Shihai; Lozada-Cassou, M.

2004-01-01

We study the resonant response of a nonlinear system to external periodic perturbations. We show by numerical simulation that the periodic resonance curve may anticipate the dynamical instability of the unperturbed nonlinear periodic system, at parameter values far away from the bifurcation points. In the presence of noise, the buried intrinsic periodic dynamics can be picked out by analyzing the system's response to periodic modulation of appropriate intensity

Handgun waiting periods reduce gun deaths.

Science.gov (United States)

Luca, Michael; Malhotra, Deepak; Poliquin, Christopher

2017-11-14

Handgun waiting periods are laws that impose a delay between the initiation of a purchase and final acquisition of a firearm. We show that waiting periods, which create a "cooling off" period among buyers, significantly reduce the incidence of gun violence. We estimate the impact of waiting periods on gun deaths, exploiting all changes to state-level policies in the Unites States since 1970. We find that waiting periods reduce gun homicides by roughly 17%. We provide further support for the causal impact of waiting periods on homicides by exploiting a natural experiment resulting from a federal law in 1994 that imposed a temporary waiting period on a subset of states. Copyright © 2017 the Author(s). Published by PNAS.

Long-Period Variability in o Ceti

Science.gov (United States)

Templeton, Matthew R.; Karovska, Margarita

2009-02-01

We carried out a new and sensitive search for long-period variability in the prototype of the Mira class of long-period pulsating variables, o Ceti (Mira A), the closest and brightest Mira variable. We conducted this search using an unbroken light curve from 1902 to the present, assembled from the visual data archives of five major variable star observing organizations from around the world. We applied several time-series analysis techniques to search for two specific kinds of variability: long secondary periods (LSPs) longer than the dominant pulsation period of ~333 days, and long-term period variation in the dominant pulsation period itself. The data quality is sufficient to detect coherent periodic variations with photometric amplitudes of 0.05 mag or less. We do not find evidence for coherent LSPs in o Ceti to a limit of 0.1 mag, where the amplitude limit is set by intrinsic, stochastic, low-frequency variability of approximately 0.1 mag. We marginally detect a slight modulation of the pulsation period similar in timescale to that observed in the Miras with meandering periods, but with a much lower period amplitude of ±2 days. However, we do find clear evidence of a low-frequency power-law component in the Fourier spectrum of o Ceti's long-term light curve. The amplitude of this stochastic variability is approximately 0.1 mag at a period of 1000 days, and it exhibits a turnover for periods longer than this. This spectrum is similar to the red noise spectra observed in red supergiants.

Estimates on the minimal period for periodic solutions of nonlinear second order Hamiltonian systems

International Nuclear Information System (INIS)

Yiming Long.

1994-11-01

In this paper, we prove a sharper estimate on the minimal period for periodic solutions of autonomous second order Hamiltonian systems under precisely Rabinowitz' superquadratic condition. (author). 20 refs, 1 fig

Depression in pregnancy and postpartum period.

Science.gov (United States)

Sood, Mamta; Sood, A K

2003-01-01

This prospective study was carried out in a service hospital, with the aim to study the prevalence and incidence of depression in pregnancy and postpartum period. Eighty Four consecutive patients attending the antenatal outpatient in the Obstetrics & Gynaecology department in their last trimester of pregnancy were recruited for the study. They were assessed on Beck Depression Inventory thrice viz. during third trimester of pregnancy, within 3 days of delivery (early postpartum period) & within 4-8 weeks of delivery (late postpartum period).The prevalence of depression was 8.3%, 20% and 12.8% respectively at three ratings. The incidence was 16% and 10% in the early & late postpartum period respectively. Further analysis revealed that depression in pregnancy correlated significantly with depression in early postpartum period, but not with late postpartum period. Depression in early postpartum period correlated with depression in late postpartum period.These findings have implications for early detection and care of women at risk for developing depression.

Periodic solutions of nonlinear vibrating beams

Directory of Open Access Journals (Sweden)

J. Berkovits

2003-01-01

Full Text Available The aim of this paper is to prove new existence and multiplicity results for periodic semilinear beam equation with a nonlinear time-independent perturbation in case the period is not prescribed. Since the spectrum of the linear part varies with the period, the solvability of the equation depends crucially on the period which can be chosen as a free parameter. Since the period of the external forcing is generally unknown a priori, we consider the following natural problem. For a given time-independent nonlinearity, find periods T for which the equation is solvable for any T-periodic forcing. We will also deal with the existence of multiple solutions when the nonlinearity interacts with the spectrum of the linear part. We show that under certain conditions multiple solutions do exist for any small forcing term with suitable period T. The results are obtained via generalized Leray-Schauder degree and reductions to invariant subspaces.

The Living Periodic Table

Science.gov (United States)

Nahlik, Mary Schrodt

2005-01-01

To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

Orbital periods of recurrent novae

International Nuclear Information System (INIS)

Schaefer, B.E.

1990-01-01

The class of recurrent novae (RN) with thermonuclear runaways contains only three systems (T Pyx, U Sco, and V394 CrA), for which no orbital periods are known. This paper presents a series of photometric observations where the orbital periods for all three systems are discovered. T Pyx is found to have sinusoidal modulation with an amplitude of 0.08 mag and a period of 2.3783 h (with a possible alias of 2.6403 h). U Sco is found to be an eclipsing system with an eclipse amplitude of roughly 1.5 mag and an orbital period of 1.2344 days. V394 CrA is found to have sinusoidal modulation with an amplitude of 0.5 mag and a period of 0.7577 days. Thus two out of three RN with thermonuclear runaways (or five out of six for all RN) have evolved companions. 16 refs

Microprocessor controlled digital period meter

International Nuclear Information System (INIS)

Keefe, D.J.; McDowell, W.P.; Rusch, G.K.

1980-01-01

A microprocessor controlled digital period meter has been developed and tested operationally on a reactor at Argonne National Laboratory. The principle of operation is the mathematical relationship between asymptotic periods and pulse counting circuitry. This relationship is used to calculate and display the reactor periods over a range of /plus or minus/1 second to /plus or minus/999 seconds. The time interval required to update each measurement automatically varies from 8 seconds at the lowest counting rates to 2 seconds at higher counting rates. The paper will describe hardware and software design details and show the advantages of this type of Period Meter over the conventional circuits. 1 ref

Dual-component model of respiratory motion based on the periodic autoregressive moving average (periodic ARMA) method

International Nuclear Information System (INIS)

McCall, K C; Jeraj, R

2007-01-01

A new approach to the problem of modelling and predicting respiration motion has been implemented. This is a dual-component model, which describes the respiration motion as a non-periodic time series superimposed onto a periodic waveform. A periodic autoregressive moving average algorithm has been used to define a mathematical model of the periodic and non-periodic components of the respiration motion. The periodic components of the motion were found by projecting multiple inhale-exhale cycles onto a common subspace. The component of the respiration signal that is left after removing this periodicity is a partially autocorrelated time series and was modelled as an autoregressive moving average (ARMA) process. The accuracy of the periodic ARMA model with respect to fluctuation in amplitude and variation in length of cycles has been assessed. A respiration phantom was developed to simulate the inter-cycle variations seen in free-breathing and coached respiration patterns. At ±14% variability in cycle length and maximum amplitude of motion, the prediction errors were 4.8% of the total motion extent for a 0.5 s ahead prediction, and 9.4% at 1.0 s lag. The prediction errors increased to 11.6% at 0.5 s and 21.6% at 1.0 s when the respiration pattern had ±34% variations in both these parameters. Our results have shown that the accuracy of the periodic ARMA model is more strongly dependent on the variations in cycle length than the amplitude of the respiration cycles

Quantized gauge invariant periodic TDHF solutions

International Nuclear Information System (INIS)

Kan, K.-K.; Griffin, J.J.; Lichtner, P.C.; Dworzecka, M.

1979-01-01

Time-dependent Hartree-Fock (TDHF) is used to study steady state large amplitude nuclear collective motions, such as vibration and rotation. As is well known the small amplitude TDHF leads to the RPA equation. The analysis of periodicity in TDHF is not trivial because TDHF is a nonlinear theory and it is not known under what circumstances a nonlinear theory can support periodic solutions. It is also unknown whether such periodic solution, if they exist, form a continuous or a discrete set. But, these properties may be important in obtaining the energy spectrum of the collective states from the TDHF description. The periodicity and Gauge Invariant Periodicity of solutions are investigated for that class of models whose TDHF solutions depend on time through two parameters. In such models TDHF supports a continuous family of periodic solutions, but only a discrete subset of these is gauge invariant. These discrete Gauge Invariant Periodic solutions obey the Bohr-Summerfeld quantization rule. The energy spectrum of the Gauge Invariant Periodic solutions is compared with the exact eigenergies in one specific example

Periodic and quasiperiodic revivals in periodically driven interacting quantum systems

Science.gov (United States)

Luitz, David J.; Lazarides, Achilleas; Bar Lev, Yevgeny

2018-01-01

Recently it has been shown that interparticle interactions generically destroy dynamical localization in periodically driven systems, resulting in diffusive transport and heating. In this Rapid Communication we rigorously construct a family of interacting driven systems which are dynamically localized and effectively decoupled from the external driving potential. We show that these systems exhibit tunable periodic or quasiperiodic revivals of the many-body wave function and thus of all physical observables. By numerically examining spinless fermions on a one-dimensional lattice we show that the analytically obtained revivals of such systems remain stable for finite systems with open boundary conditions while having a finite lifetime in the presence of static spatial disorder. We find this lifetime to be inversely proportional to the disorder strength.

Discrete symmetries in periodic-orbit theory

International Nuclear Information System (INIS)

Robbins, J.M.

1989-01-01

The application of periodic-orbit theory to systems which possess a discrete symmetry is considered. A semiclassical expression for the symmetry-projected Green's function is obtained; it involves a sum over classical periodic orbits on a symmetry-reduced phase space, weighted by characters of the symmetry group. These periodic orbits correspond to trajectories on the full phase space which are not necessarily periodic, but whose end points are related by symmetry. If the symmetry-projected Green's functions are summed, the contributions of the unperiodic orbits cancel, and one recovers the usual periodic-orbit sum for the full Green's function. Several examples are considered, including the stadium billiard, a particle in a periodic potential, the Sinai billiard, the quartic oscillator, and the rotational spectrum of SF 6

Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

Energy Technology Data Exchange (ETDEWEB)

Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

2017-06-10

Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

International Nuclear Information System (INIS)

Lee, Eve J.; Chiang, Eugene

2017-01-01

Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

A highly specific test for periodicity

International Nuclear Information System (INIS)

Ansmann, Gerrit

2015-01-01

We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series

A highly specific test for periodicity

Energy Technology Data Exchange (ETDEWEB)

Ansmann, Gerrit, E-mail: gansmann@uni-bonn.de [Department of Epileptology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Helmholtz Institute for Radiation and Nuclear Physics, University of Bonn, Nussallee 14–16, 53115 Bonn (Germany); Interdisciplinary Center for Complex Systems, University of Bonn, Brühler Straße 7, 53175 Bonn (Germany)

2015-11-15

We present a method that allows to distinguish between nearly periodic and strictly periodic time series. To this purpose, we employ a conservative criterion for periodicity, namely, that the time series can be interpolated by a periodic function whose local extrema are also present in the time series. Our method is intended for the analysis of time series generated by deterministic time-continuous dynamical systems, where it can help telling periodic dynamics from chaotic or transient ones. We empirically investigate our method's performance and compare it to an approach based on marker events (or Poincaré sections). We demonstrate that our method is capable of detecting small deviations from periodicity and outperforms the marker-event-based approach in typical situations. Our method requires no adjustment of parameters to the individual time series, yields the period length with a precision that exceeds the sampling rate, and its runtime grows asymptotically linear with the length of the time series.

Astrophysical implications of periodicity

International Nuclear Information System (INIS)

Muller, R.A.

1988-01-01

Two remarkable discoveries of the last decade have profound implications for astrophysics and for geophysics. These are the discovery by Alvarez et al., that certain mass extinctions are caused by the impact on the earth of a large asteroid or comet, and the discovery by Raup and Sepkoski that such extinctions are periodic, with a cycle time of 26 to 30 million years. The validity of both of these discoveries is assumed and the implications are examined. Most of the phenomena described depend not on periodicity, but just on the weaker assumption that the impacts on the earth take place primarily in showers. Proposed explanations for the periodicity include galactic oscillations, the Planet X model, and the possibility of Nemesis, a solar companion star. These hypotheses are critically examined. Results of the search for the solar companion are reported. The Deccan flood basalts of India have been proposed as the impact site for the Cretaceous impact, but this hypotheisis is in contradiction with the conclusion of Courtillot et al., that the magma flow began during a period of normal magnetic field. A possible resolution of this contradiction is proposed

Supersymmetrically transformed periodic potentials

OpenAIRE

C, David J. Fernandez

2003-01-01

The higher order supersymmetric partners of a stationary periodic potential are studied. The transformation functions associated to the band edges do not change the spectral structure. However, when the transformation is implemented for factorization energies inside of the forbidden bands, the final potential will have again the initial band structure but it can have bound states encrusted into the gaps, giving place to localized periodicity defects.

Analysis of systems for hot water supply with solar energy utilization

International Nuclear Information System (INIS)

Zlateva, M.

2001-01-01

The results from the analysis of the hot water consumption of a group of hotels in the Black See resort Albena are presented. Structural schemes of hot water solar systems with flat plate collectors have been synthesized. By the synthesis have been analyzed the type of the consumers, the operating period, the existing heating plants, the auxiliary energy source - electricity. The change of the solar fraction by different performance of the system have been investigated. A comparative analysis of the alternative solutions has been fulfilled. The most advantageous solution has been chosen on the basis of the evaluation of the pay-back period, the life cycle savings and the benefit-cost ratio. The effect of the changing economic characteristics on the economic efficiency have been investigated. The risk for the investments has been examined. It had been proved that for the conditions in Bulgarian Black See region the use of solar energy for hot water producing is economic reasonable. (author)

Indoor ice arenas. Humidity caused problems and suggested solutions

Energy Technology Data Exchange (ETDEWEB)

1989-01-01

This report was prepared to assist indoor ice arena managers in Canada to solve common problems related to humidity. These problems typically include leaking roofs, deterioration of roof and insulation, condensation on indoor walls, damages to exterior walls due to condensation on exterior metal parts, rusting metal elements, high energy bills, and long and costly ice-making periods. Recommendations are made for improved roof insulation systems, proper sealing, maintenance, and repair. High energy costs are seen as due to insufficient insulation, air leakage, and heat losses by radiation and convection. Convection can be controlled by dehumidification and shielding the ice from air currents. Radiation losses can be lowered by using a low-emmissivity suspended ceiling; this effectively breaks the flow of radiated heat from the roof toward the ice sheet, and has the additional benefit of lowering of lighting energy demand by acting as a reflector. It is shown that these measures can result in significant energy cost savings with favorable payback periods. 10 figs.

Solar thermal application for the livestock industry in Taiwan

Directory of Open Access Journals (Sweden)

Yi-Mei Liu

2015-09-01

Full Text Available Solar water heating systems have proven reliable and economical. In Taiwan, the cumulative area of installed solar collectors at the end of 2014 was approximately 2.39 million m2 and approximately 98% of those systems were installed in the domestic sector. Preheating water for livestock processing plants is cost-effective since heated water can be used for evisceration, sanitation during processing and for daily cleanup of plant. In this case study, detailed measurements are reported for parallel combined solar thermal and heat pump systems that are installed in a livestock processing plant. These results confirm that the hot water consumption, the mass flow rate and the operation of circulation and heat pumps affect the system's thermal efficiency. The combined operational effect is a factor in system design. The estimated payback period is less than the expected service period of the system, which validates the financial viability.

Efficiency of overhead ceiling lifts in reducing musculoskeletal injury among carers working in long-term care institutions.

Science.gov (United States)

Alamgir, Hasanat; Yu, Shicheng; Fast, Catherine; Hennessy, Stephanie; Kidd, Catherine; Yassi, Annalee

2008-05-01

A longitudinal study was conducted in three long-term care facilities to evaluate the effectiveness and cost benefit of overhead lifts in reducing the risk of musculoskeletal injury among healthcare workers. Analysis of injury trends spanning 6 years before intervention (1996-2001) and 4 years after intervention (2002-2005) found a significant and sustained decrease in workers' compensation claims per number of beds and in working days lost per bed. The payback period was estimated under various assumptions and varied from 6.3 to 6.2 years if only direct claim-cost savings were included, and from 2.06 to 3.20 years when indirect savings were added. The significant reductions in injury rates and compensation claims support intervention with overhead ceiling lifts. A more comprehensive evaluation of such programmes should incorporate in the analysis important variables such as staffing ratios, job stresses, injury reporting systems and compensation policies during the study period.

Economical feasibility study of thermal-photovoltaic concentrators facility in a pig farm of close cycle production; Estudio sobre la viabilidad economica de la instalacion de concentradores termico-fotovoltaicos en una explotacion agropecuaria de ciclo cerrado

Energy Technology Data Exchange (ETDEWEB)

Roca, J.; Ibanez, M.; Rosell, J. I.

2004-07-01

This paper presents an application of an hybrid generation device, where solar energy is converted into both electrical and thermal energy (heating and SDHW). The advantages of a PV/T collector are used in pig's farm of close cycle production. The system proposed is based in a reflector Fresnel concentrator and a PV/T collector which uses water as a cooling fluid. This hybrid generator has been designed and constructed at the University of Lleida. The two-axes sun tracking concentrator has an aperture area of 4,16 m2. It works under 12 suns of concentration. The installation of 12 PV/T units would cover 100% of the electrical demand during 7 months. The output power is 4,4 kW electrical and 24,0 kW thermal. The initial investment to install the PV/T facility is around 47.300 . The payback period is 12 years and the NPV is positive at the end of the, 30 years, lifetime period. (Author)

District heating and cooling systems for communities through power plant retrofit and distribution network. Final report. Volume I. Text

Energy Technology Data Exchange (ETDEWEB)

None

1979-09-15

An analysis was performed investigating the potential of retrofitting Detroit Edison's Conners Creek power plant to supply district heating and cooling to an area surrounding the plant and within the City of Detroit. A detailed analysis was made of the types and ages of the buildings in the service area as a basis for establishing loads. The analysis of the power plant established possible modifications to the turbines to serve the load in the area. Based upon the service area data and plant retrofit schemes, a distribution system was developed incrementally over a 20-y period. An economic analysis of the system was performed to provide cash flows and payback periods for a variety of energy costs, system costs, and escalation rates to determine the economic viability of the system analyzed. The legal and regulatory requirements required of the district heating and cooling system owner in Michigan were also analyzed to determine what conditions must be met to own and operate the system.

Periodic testing in operative action

International Nuclear Information System (INIS)

Larm, T.

2005-01-01

Periodic testing forms a remarkable part of the regular work tasks of the shift crew. Testing is generally carried out beside the daily monitoring and control work. Even remarkable plant related differences may occur in the procedures and routines used in periodic testing. The goal is still always the same, to regularly ensure that the systems and equipment are in working order according to their design. This presentation studies with examples the execution and scope of periodic testing as well as the routines and procedures used in the testing in Loviisa power plant. The presentation is based on the testing procedures of Loviisa power plant and the aim is not to compare them to the procedures of other plants. The scope of periodic testing has increased and the routines and procedures have been developed as the operation experience has increased. The assessment of the need of periodic testing and the consideration of the practical execution possibilities should be a part of the plant's planning phase as a part of the planning process. (orig.)

The redoubtable ecological periodic table

Science.gov (United States)

Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

Promoting energy efficiency investments with risk management decision tools

International Nuclear Information System (INIS)

Jackson, Jerry

2010-01-01

This paper reviews current capital budgeting practices and their impact on energy efficiency investments. The prevalent use of short payback 'rule-of-thumb' requirements to screen efficiency projects for risk is shown to bias investment choices towards 'sure bet' investments bypassing many profitable efficiency investment options. A risk management investment strategy is presented as an alternative to risk avoidance practices applied with payback thresholds. The financial industry risk management tool Value-at-Risk is described and extended to provide an Energy-Budgets-at-Risk or EBaR risk management analysis to convey more accurate energy efficiency investment risk information. The paper concludes with recommendations to expand the use of Value-at-Risk-type energy efficiency analysis.

Positive periodic solutions of periodic neutral Lotka-Volterra system with distributed delays

International Nuclear Information System (INIS)

Li Yongkun

2008-01-01

By using a fixed point theorem of strict-set-contraction, some criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with distributed delays (dx i (t))/(dt) =x i (t)[a i (t)-Σ j=1 n b ij (t)∫ -T ij 0 K ij (θ)x j ( t+θ)dθ-Σ j=1 n c ij (t)∫ -T ij 0 K ij (θ) x j ' (t+θ)dθ],i=1,2,...,n, where a i ,b ij ,c ij element of C(R,R + ) (i, j = 1, 2, ..., n) are ω-periodic functions, T ij ,T ij element of (0,∞) (i, j = 1, 2, ..., n) and K ij ,K ij element of (R,R + ) satisfying ∫ -T ij 0 K ij (θ)dθ=1,∫ -T ij 0 K ij (θ)dθ=1, i, j = 1, 2, ..., n

Energy efficiency and economic feasibility of CCHP driven by stirling engine

International Nuclear Information System (INIS)

Kong, X.Q.; Wang, R.Z.; Huang, X.H.

2004-01-01

This paper deals with the problem of energy efficiency evaluation and economic feasibility analysis of a small scale trigeneration system for combined cooling, heating and power generation (CCHP) with an available Stirling engine. Trigeneration systems have a large potential of energy saving and economical efficiency. The decisive values for energetic efficiency evaluation of such systems are the primary energy rate and comparative primary energy saving (Δq), while the economic feasibility analysis of such systems relates the avoided cost, the total annual saving and payback period. The investigation calculates and compares the energy saving and economic efficiency of trigeneration system with Stirling engine against contemporary conventional independent cooling, heating and power, showing that a CCHP system saves fuel resources and has the assurance of economic benefits

Energy savings and economics of advanced control strategies for packaged air conditioners with gas heat

Energy Technology Data Exchange (ETDEWEB)

Wang, Weimin; Katipamula, Srinivas; Huang, Yunzhi; Brambley, Michael R.

2013-10-01

This paper presents an evaluation of the potential energy savings from adding advanced control to existing packaged air conditioners. Advanced control options include air-side economizer, multi-speed fan control, demand control ventilation and staged cooling. The energy and cost savings from the different control strategies individually and in combination are estimated using the EnergyPlus detailed energy simulation program for four building types, namely, a small office building, a stand-alone retail building, a strip mall building and a supermarket building. For each of the four building types, the simulation was run for 16 locations covering all 15 climate zones in the U.S. The maximum installed cost of a replacement controller that provides acceptable payback periods to owners is estimated.

PULPA CUBA MILL ENERGY ASSESSMENT

Directory of Open Access Journals (Sweden)

Juan Pedro Hernández Touset

2015-10-01

Full Text Available An energy study was performed at Pulpa Cuba Paper Mill, located in Sancti Spiritus, where an energy management system was applied according to NC: ISO 50001, in order to assess the energy system by applying energy management systems for energy and water reduction in the paper mill, in which the current steam generation, distribution and consumption system is diagnosed. The proposal of a modified energy scheme with 1 MW Backpressure Steam Turbine Generator and rehabilitation of the original boiler or installing a lower capacity boiler contributes to save financial resources by the concept of water, fuel and electricity. The implementation of four projects will save 3,095,574 CUC / y and an average payback period of about 1 year is expected.

Energy conservation and saving of materials by means of frequency control of blowers in the drying process of soap. Toerenregeling bij droger bespaart meer op grondstoffen dan op elektriciteit

Energy Technology Data Exchange (ETDEWEB)

Mezger, H.J. (Holec Systemen en Componenten BV, Hengelo (Netherlands))

1992-07-01

A fluidized-bed process is used in a Dutch soap factory to dry soap powder. By means of frequency control of the blower in the dryer a considerable amount of electricity can be saved. Frequency control also results in less loss of material during the start-up and stopping of the production process. The payback period of the frequency control systems is estimated at 1.5 year. Data are presented on the saving of electricity and on the saving of basic material. However, the frequency control system will not yet be implemented in the soap factory. First another drying technique (cooling by means of nitrogen, for which a fluidized-bed is not needed) will be tested. 4 figs., 2 tabs., 1 ref.

High temperature metallic recuperator

Science.gov (United States)

Ward, M. E.; Solmon, N. G.; Smeltzer, C. E.

1981-06-01

An industrial 4.5 MM Btu/hr axial counterflow recuperator, fabricated to deliver 1600 F combustion air, was designed to handle rapid cyclic loading, a long life, acceptable costs, and a low maintenance requirement. A cost benefit anlysis of a high temperature waste heat recovery system utilizing the recurperator and components capable of 1600 F combustion air preheat shows that this system would have a payback period of less than two years. Fifteen companies and industrial associations were interviewed and expressed great interest in recuperation in large energy consuming industries. Determination of long term environmental effects on candidate recuperator tubing alloys was completed. Alloys found to be acceptable in the 2200 F flue gas environment of a steel billet reheat furnace, were identified.

Energy and materials flows in the iron and steel industry

Energy Technology Data Exchange (ETDEWEB)

Sparrow, F.T.

1983-06-01

Past energy-consumption trends and future energy-conservation opportunities are investigated for the nation's iron and steel industry. It is estimated that, in 1980, the industry directly consumed approximately 2.46 x 10/sup 15/ Btu of energy (roughly 3% of total US energy consumption) to produce 111 million tons of raw steel and to ship 84 million tons of steel products. Direct plus indirect consumption is estimated to be about 3.1 x 10/sup 15/ Btu. Of the set of conservation technologies identified, most are judged to be ready for commercialization if and when the industry's capital formation and profitability problems are solved and the gradual predicted increase in energy prices reduces the payback periods to acceptable levels.

Painful menstrual periods

Science.gov (United States)

Menstruation - painful; Dysmenorrhea; Periods - painful; Cramps - menstrual; Menstrual cramps ... into two groups, depending on the cause: Primary dysmenorrhea Secondary dysmenorrhea Primary dysmenorrhea is menstrual pain that ...

PVT Panels. Fully renewable and competitive

International Nuclear Information System (INIS)

Bakker, M.; Strootman, K.J.; Jong, M.J.M.

2003-10-01

A photovoltaic/thermal (PVT) panel is a combination of photovoltaic cells with a solar thermal collector, generating solar electricity and solar heat simultaneously. PVT panels generate more solar energy per unit surface area than a combination of separate PV panels and solar thermal collectors, and share the aesthetic advantage of PV. After several years of research, PVT panels have been developed into a product that is now ready for market introduction. One of the most promising system concepts, consisting of 25 m 2 of PVT panels and a ground coupled heat pump, has been simulated in TRNSYS, and has been found to be able to fully cover both the building related electricity and heat consumption, while keeping the long-term average ground temperature constant. The cost and payback time of such a system have been determined; it has been found that the payback time of this system is approximately two-thirds of the payback time of an identical system but with 21 m 2 of PV panels and 4 m 2 of solar thermal collectors. Finally, by looking at the expected growth in the PV and solar thermal collector market, the market potential for for PVT panels has been found to be very large

Quasi-periodic synchronisation of self-modulation oscillations in a ring chip laser by an external periodic signal

International Nuclear Information System (INIS)

Aulova, T V; Kravtsov, Nikolai V; Lariontsev, E G; Chekina, S N

2011-01-01

The synchronisation of periodic self-modulation oscillations in a ring Nd:YAG chip laser under an external periodic signal modulating the pump power has been experimentally investigated. A new quasi-periodic regime of synchronisation of self-modulation oscillations is found. The characteristic features of the behaviour of spectral and temporal structures of synchronised quasi-periodic oscillations with a change in the external signal frequency are studied. (control of laser radiation parameters)

Periodization of the early postnatal development in the rat with particular attention to the weaning period

Czech Academy of Sciences Publication Activity Database

Ošťádalová, Ivana; Babický, A.

2012-01-01

Roč. 61, Suppl.1 (2012), S1-S7 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) 1M0510; GA ČR(CZ) GAP303/12/1162 Institutional research plan: CEZ:AV0Z50110509 Keywords : rat * ontogenic development * presuckling period * suckling period * weaning period Subject RIV: ED - Physiology Impact factor: 1.531, year: 2012

Manipulating the Cellular Circadian Period of Arginine Vasopressin Neurons Alters the Behavioral Circadian Period.

Science.gov (United States)

Mieda, Michihiro; Okamoto, Hitoshi; Sakurai, Takeshi

2016-09-26

As the central pacemaker in mammals, the circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus is a heterogeneous structure consisting of multiple types of GABAergic neurons with distinct chemical identities [1, 2]. Although individual cells have a cellular clock driven by autoregulatory transcriptional/translational feedback loops of clock genes, interneuronal communication among SCN clock neurons is likely essential for the SCN to generate a highly robust, coherent circadian rhythm [1]. However, neuronal mechanisms that determine circadian period length remain unclear. The SCN is composed of two subdivisions: a ventral core region containing vasoactive intestinal peptide (VIP)-producing neurons and a dorsal shell region characterized by arginine vasopressin (AVP)-producing neurons. Here we examined whether AVP neurons act as pacemaker cells that regulate the circadian period of behavior rhythm in mice. The deletion of casein kinase 1 delta (CK1δ) specific to AVP neurons, which was expected to lengthen the period of cellular clocks [3-6], lengthened the free-running period of circadian behavior as well. Conversely, the overexpression of CK1δ specific to SCN AVP neurons shortened the free-running period. PER2::LUC imaging in slices confirmed that cellular circadian periods of the SCN shell were lengthened in mice without CK1δ in AVP neurons. Thus, AVP neurons may be an essential component of circadian pacemaker cells in the SCN. Remarkably, the alteration of the shell-core phase relationship in the SCN of these mice did not impair the generation per se of circadian behavior rhythm, thereby underscoring the robustness of the SCN network. Copyright © 2016 Elsevier Ltd. All rights reserved.

Special Features In Turbulent Mixing. Comparison between Periodic and Non Periodic Case

Directory of Open Access Journals (Sweden)

Mihai Costescu

2006-12-01

Full Text Available After hundreds of years of stability study, the problems of flow kinematics are far from complete solving. A modern theory appears in this field: the mixing theory. Its mathematical methods and techniques developed the significant relation between turbulence and chaos. The turbulence is an important feature of dynamic systems with few freedom degrees, the so-called far from equilibrium systems. These are widespread between the models of excitable media.Studying a mixing for a flow implies the analysis of successive stretching and folding phenomena for its particles, the influence of parameters and initial conditions. In the previous works, the study of the 3D non-periodic models exhibited a quite complicated behavior, involving some significant events - the so-called rare events. The variation of parameters had a great influence on the length and surface deformations. The 2D (periodic case is simpler, but significant events can also issue for irrational values of the length and surface versors, as was the situation in 3D case.The comparison between 2D and 3D case revealed interesting properties; therefore a modified 2D (periodic model is tested. The numerical simulations were realized in MapleVI, for searching special mathematical events. Continuing this work both from analytical and numeric standpoint would relieve useful properties for the turbulent mixing. A proximal target is to test some special functions for the periodic model, and to study the behavior of the structures realized by the model.

Periodic variations of cosmic ray intensity with period of -37 minute observed on April 25th, 1984

International Nuclear Information System (INIS)

Sakai, Takasuke; Kato, Masahito; Takei, Ryoji; Tamai, Eiji

1985-01-01

Existence of cosmic ray variation with period ranging from a few hours to seconds during geomagnetically quiet and perturb period at different altitude with different detector, was reported previously. As short period variation is thought to be transient with small amplitude fluctuation, consequently high counting rate of cosmic ray and appropriate method for finding short periodicity, is required. Further, there is similar phenomenon in which short variation, followed by storm sudden commencement (SSC) and/or Forbush decrease (FD) occurs. In 1979, Kato et al. used 3 minutes data at Mt. Norikura and obtained -6 x 10 5 count/min, and tried to find out short periodicity of cosmic ray around SSC, but no clear conclusion was obtained. T. Sakai, et al., used plastic scintillation counter of Akeno observatory, following their preceding work. The counter has an area about 154 m 2 . High counting rate of -2 x 10 6 counts/min. was observed at Akeno which revealed the existence of -37 minute periodical oscillation with an amplitude of 0.1 % in p-p during the time period of 1300 - 1900 UT on April 25th 1984, one day before FD. Observed periodical oscillation of cosmic ray counting rate may be the result of the changes in magnetic field. But, it must be noted that there remains possibility of oscillation of cosmic ray intensity in the interplanetary space during the period, independent of geomagnetic field. (author)

Periodic-cylinder vesicle with minimal energy

International Nuclear Information System (INIS)

Xiao-Hua, Zhou

2010-01-01

We give some details about the periodic cylindrical solution found by Zhang and Ou-Yang in [1996 Phys. Rev. E 53 4206] for the general shape equation of vesicle. Three different kinds of periodic cylindrical surfaces and a special closed cylindrical surface are obtained. Using the elliptic functions contained in mathematic, we find that this periodic shape has the minimal total energy for one period when the period–amplitude ratio β ≈ 1.477, and point out that it is a discontinuous deformation between plane and this periodic shape. Our results also are suitable for DNA and multi-walled carbon nanotubes (MWNTs). (cross-disciplinary physics and related areas of science and technology)

47 CFR 22.1035 - Construction period.

Science.gov (United States)

2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Construction period. 22.1035 Section 22.1035 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES PUBLIC MOBILE SERVICES Offshore Radiotelephone Service § 22.1035 Construction period. The construction period (see § 22.142) for...

Periodic Properties and Inquiry: Student Mental Models Observed during a Periodic Table Puzzle Activity

Science.gov (United States)

Larson, Kathleen G.; Long, George R.; Briggs, Michael W.

2012-01-01

The mental models of both novice and advanced chemistry students were observed while the students performed a periodic table activity. The mental model framework seems to be an effective way of analyzing student behavior during learning activities. The analysis suggests that students do not recognize periodic trends through the examination of…

Seismic isolation of two dimensional periodic foundations

International Nuclear Information System (INIS)

Yan, Y.; Mo, Y. L.; Laskar, A.; Cheng, Z.; Shi, Z.; Menq, F.; Tang, Y.

2014-01-01

Phononic crystal is now used to control acoustic waves. When the crystal goes to a larger scale, it is called periodic structure. The band gaps of the periodic structure can be reduced to range from 0.5 Hz to 50 Hz. Therefore, the periodic structure has potential applications in seismic wave reflection. In civil engineering, the periodic structure can be served as the foundation of upper structure. This type of foundation consisting of periodic structure is called periodic foundation. When the frequency of seismic waves falls into the band gaps of the periodic foundation, the seismic wave can be blocked. Field experiments of a scaled two dimensional (2D) periodic foundation with an upper structure were conducted to verify the band gap effects. Test results showed the 2D periodic foundation can effectively reduce the response of the upper structure for excitations with frequencies within the frequency band gaps. When the experimental and the finite element analysis results are compared, they agree well with each other, indicating that 2D periodic foundation is a feasible way of reducing seismic vibrations.

Period, Place and Mental Space: Using Historical Scholarship to Develop Year 7 Pupils' Sense of Period

Science.gov (United States)

Smith, Dan

2014-01-01

What is a sense of period? And how can pupils' sense of period be developed? Questions such as these have troubled history teachers for many years, often revolving around debates over the role played by empathy and imagination in coming to know a period on its own terms. Rather than adopt a comparative approach, Dan Smiths decided in his teaching…

Strategic Issues Facing U.S. Navy Human Systems Integration Professionals

National Research Council Canada - National Science Library

Duehring, Jeremy L

2007-01-01

.... Strategic issues represent relevant challenges and problems facing this community over the next few years, including appropriate pay-back tours from officers receiving master's degrees from the NPS...

Gene Expression Profiling in the Pituitary Gland of Laying Period and Ceased Period Huoyan Geese

Directory of Open Access Journals (Sweden)

Xinhong Luan

2013-07-01

Full Text Available Huoyan goose is a Chinese local breed famous for its higher laying performance, but the problems of variety degeneration have emerged recently, especially a decrease in the number of eggs laid. In order to better understand the molecular mechanism that underlies egg laying in Huoyan geese, gene profiles in the pituitary gland of Huoyan geese taken during the laying period and ceased period were investigated using the suppression subtractive hybridization (SSH method. Total RNA was extracted from pituitary glands of ceased period and laying period geese. The cDNA in the pituitary glands of ceased geese was subtracted from the cDNA in the pituitary glands of laying geese (forward subtraction; the reverse subtraction was also performed. After sequencing and annotation, a total of 30 and 24 up and down-regulated genes were obtained from the forward and reverse SSH libraries, respectively. These genes mostly related to biosynthetic process, cellular nitrogen compound metabolic process, transport, cell differentiation, cellular protein modification process, signal transduction, small molecule metabolic process. Furthermore, eleven genes were selected for further analyses by quantitative real-time PCR (qRT-PCR. The qRT-PCR results for the most part were consistent with the SSH results. Among these genes, Synaptotagmin-1 (SYT1 and Stathmin-2 (STMN2 were substantially over-expressed in laying period compared to ceased period. These results could serve as an important reference for elucidating the molecular mechanism of higher laying performance in Huoyan geese.

27 CFR 70.244 - Payroll period.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Payroll period. 70.244... Excise and Special (Occupational) Tax Limitations § 70.244 Payroll period. For purpose of determining the... established calendar period regularly used by the employer or other person levied upon for payroll or payment...

40 CFR 35.9035 - Budget period.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Budget period. 35.9035 Section 35.9035... ASSISTANCE Financial Assistance for the National Estuary Program § 35.9035 Budget period. An applicant may choose its budget period in consultation with and subject to the approval of the Regional Administrator. ...

On positive periodic solution of periodic competition Lotka-Volterra system with time delay and diffusion

International Nuclear Information System (INIS)

Sun Wen; Chen Shihua; Hong Zhiming; Wang Changping

2007-01-01

A two-species periodic competition Lotka-Volterra system with time delay and diffusion is investigated. Some sufficient conditions of the existence of positive periodic solution are established for the system by using the continuation theorem of coincidence degree theory

Quasi-periodic luminosity variations in dwarf novae

International Nuclear Information System (INIS)

Robinson, E.L.; Nather, R.E.

1979-01-01

We have identified quasi-periodic oscillations in the light curves of five dwarf novae--U Gem, SS Cyg, RU Peg, KT Per, and VW Hyi-- and in the light curve of the quasi-periodic X-ray source Sco X-1. The mean periods of the quasi-periodic oscillations range from 32 s in SS Cyg to 147 s in KT Per and 165 s in Sco X-l. Their amplitudes are typically 0.005--0.0l mag. The properties of the quasi-periodic oscillations are represented well by a second-order autoregressive process. Use of this representation shows that the length of time over which the quasi-periodic oscillations maintain coherence is very short, typically 3--5 cycles of the oscillations. Thus the quasi-periodic oscillations can be distinguished from the short-period coherent oscillations in dwarf novae, which are usually interpreted as white dwarf pulsations, because t the periods of the quasi-periodic oscillations are 3--4 times longer and their coherence time is much shorter. The quasi-periodic oscillations occur in dwarf novae only during their eruptions and occur in Sco X-l only when the system is bright. The presence of the oscillations does not depend on the subclass to which a dwarf nova belongs or on the morphology of the individual eruptions. We argue that their short periods, their short coherence times, and their presence in Sco X-l require that the quasi-periodic oscillations be produced by the accretion disk, and not by the stars or by the boundary between the a accretion disk and its central star

Utilization of oil wells for electricity generation: Performance and economics

International Nuclear Information System (INIS)

Kharseh, Mohamad; Al-Khawaja, Mohammed; Hassani, Ferri

2015-01-01

There is a general agreement that the climate change, which is the most important challenge facing humanity, is anthropogenic and attributed to fossil fuel consumption. Therefore, deploying more renewable energy resources is an urgent issue to be addressed. Geothermal refers to existing heat energy in deep rock and sedimentary basins. Traditionally, geothermal energy has been exploited in places with plentiful hot water at relatively shallow depth. Unfortunately, the high exploration and drilling costs of boreholes is the main barrier to the commerciality of geothermal worldwide. In oil producing countries, such problems can be overcome by utilizing oil or gas wells. The current study presents thermodynamic and economic analyses of a binary geothermal power generation system for commercial electricity generation. Two different source temperatures (100 and 120 °C) and constant sink temperature (29 °C) were considered. The optimal working fluid and optimal design that improve the performance of the plant are determined. For the current costs in Qatar, the economical analysis of 5 MW geothermal plant shows that the levelized cost of electricity for the plant varies from 5.6 to 5.2 ¢/kW. Whereas, the payback period of such plants lies between 5.8 and 4.8 years. - Highlights: • Utilizing oil well makes geothermal plant competitive with other resources. • R32 seems to be the best working fluid. • The levelized cost of electricity for geothermal plant is less than 5.6 ¢/kWh. • The payback time of geothermal plant is less than 6 years.

Regulation and energy conservation. The case of combined heat and power in the European Union. Situation and prospects

International Nuclear Information System (INIS)

Hendriks, C.; Worrell, E.; Blok, K.; Velthuijsen, J.W.

1995-02-01

Policy measures to stimulate the proliferation of combined heat and power generation (CHP) have been motivated because of the energy efficiency potential. In this paper we investigate to what extent the penetration of CHP has taken place in the 12 member states of the European Union (EU-12). Also analyzed is the potential heat demand which can be covered by CHP, and the corresponding amount of capacity for each country. A short overview is given of the goals for CHP capacity for some of the EU-12 member states. We distinguish two different kinds of policy instruments: standard settings and economic instruments. Four different types of standard settings are given. We evaluate a specific standard setting which is applied in the Netherlands in the 1970's and early 1980's. The economic instruments are evaluated in terms of payback time. This payback period can be influenced by for instance an investment grant, tax on the emission of carbon dioxide, a raise of selling electricity to the public grid and lower the price for natural gas for CHP applications. Finally, we give some recommendations how EU policy may stimulate the application of CHP. In section 2 we describe the development of CHP from 1974 to 1990 in the EU-12 member states. and the intentions stated by the national governments. In section 3 we give an overview of the potential capacity of CHP. In section 4 we discuss the regulation instruments: standard settings and economical instruments. In section 5 we give some conclusions especially with regard to EU policy options. 23 refs

49 CFR 236.588 - Periodic test.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Periodic test. 236.588 Section 236.588..., Train Control and Cab Signal Systems Inspection and Tests; Locomotive § 236.588 Periodic test. Except as provided in § 236.586, periodic test of the automatic train stop, train control, or cab signal apparatus...

Periodicity in Age-Resolved Populations

Science.gov (United States)

Esipov, Sergei

We discuss the interplay between the non-linear diffusion and age-resolved population dynamics. Depending on the age properties of collective migration the system may exhibit continuous joint expansion of all ages or continuous expansion with age segregation. Between these two obvious limiting regimes there is an interesting window of periodic expansion, which has been previously used by us in modeling bacterial colonies of Proteus mirabilis. In order to test whether the age-dependent collective migration leads to periodicity in other systems we performed a Fourier analysis of historical data on ethnic expansions and found multiple co-existing periods of activity.

Bi-periodicity evoked by periodic external inputs in delayed Cohen-Grossberg-type bidirectional associative memory networks

Science.gov (United States)

Cao, Jinde; Wang, Yanyan

2010-05-01

In this paper, the bi-periodicity issue is discussed for Cohen-Grossberg-type (CG-type) bidirectional associative memory (BAM) neural networks (NNs) with time-varying delays and standard activation functions. It is shown that the model considered in this paper has two periodic orbits located in saturation regions and they are locally exponentially stable. Meanwhile, some conditions are derived to ensure that, in any designated region, the model has a locally exponentially stable or globally exponentially attractive periodic orbit located in it. As a special case of bi-periodicity, some results are also presented for the system with constant external inputs. Finally, four examples are given to illustrate the effectiveness of the obtained results.

Bi-periodicity evoked by periodic external inputs in delayed Cohen-Grossberg-type bidirectional associative memory networks

International Nuclear Information System (INIS)

Cao Jinde; Wang Yanyan

2010-01-01

In this paper, the bi-periodicity issue is discussed for Cohen-Grossberg-type (CG-type) bidirectional associative memory (BAM) neural networks (NNs) with time-varying delays and standard activation functions. It is shown that the model considered in this paper has two periodic orbits located in saturation regions and they are locally exponentially stable. Meanwhile, some conditions are derived to ensure that, in any designated region, the model has a locally exponentially stable or globally exponentially attractive periodic orbit located in it. As a special case of bi-periodicity, some results are also presented for the system with constant external inputs. Finally, four examples are given to illustrate the effectiveness of the obtained results.

21 CFR 573.240 - Calcium periodate.

Science.gov (United States)

2010-04-01

... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used in...

10 CFR 603.1295 - Periodic audit.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Periodic audit. 603.1295 Section 603.1295 Energy... Used in this Part § 603.1295 Periodic audit. An audit of a participant, performed at an agreed-upon... an audit may cover. A periodic audit of a participant differs from an award-specific audit of an...

Retorno econômico do aproveitamento de resíduos gerados na produção de frutas no semiárido cearense = Economic return of the residues generated in fruit production in the semi-arid region of Ceará

Directory of Open Access Journals (Sweden)

Ariana Carvalho Pinto

2017-10-01

Full Text Available O reaproveitamento dos resíduos plásticos pode se tornar uma atividade agrícola economicamente viável, principalmente na fruticultura localizada no semiárido cearense. Os materiais nos quais eram tidos como lixo nas áreas agrícolas podem ser uma fonte alternativa de geração de capital e empregos para a região, utilizando-se técnicas de reaproveitamento e reciclagem desses materiais. O objetivo deste trabalho foi avaliar a importância e a viabilidade econômica da reutilização dos materiais plásticos empregados diretamente na fruticultura. Os dados foram coletados de uma empresa agrícola de fruticultura e de uma empresa de reciclagem no município de Icapuí, no estado do Ceará. Foram calculados indicadores de viabilidade financeira como Valor Presente Líquido [VPL], Taxa Interna de Retorno [TIR], Payback simples [PB], Payback descontado [PBD]. Os resultados mostraram que a utilização de técnicas e equipamentos de reciclagem em empresas é um caminho que gera muitas oportunidades de reutilização de materiais antes descartados, bem como a viabilidade econômica, confirmada pelos valores obtidos de VPL (R$ 529.777,58 e TIR de 31%. Conforme o cálculo do Payback descontado, serão necessários dois anos e quatro meses para recuperar o investimento dos fluxos líquidos de caixa descontados. Conclui-se que a atividade é sustentável e rentável, trazendo benefícios e lucro ao fruticultor, além de disponibilizar empregos diretos e indiretos. = The reuse of plastic can become an economically viable agricultural activity, mainly in the fruticulture located in the semi-arid region of Ceará. The materials in which they were treated as garbage in the agricultural areas can be an alternative source of capital generation and jobs for the region, using reuse and recycling techniques. The objective of this work was to evaluate the importance and economic viability of the reuse of plastic materials used directly in the fruticulture

Periodic table of elements

International Nuclear Information System (INIS)

Fluck, E.; Heumann, K.G.

1985-01-01

Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF) [de

Scheduling periodic tasks with slack

NARCIS (Netherlands)

Korst, J.H.M.; Aarts, E.H.L.; Lenstra, J.K.

1997-01-01

We consider the problem of nonpreemptively scheduling periodic tasks on a minimum number of identical processors, assuming that some slack is allowed in the time between successive executions of a periodic task. We prove that the problem is NP-hard in the strong sense. Necessary and sufficient

Thyrotoxic periodic paralysis

International Nuclear Information System (INIS)

Ferreiro, J.E.; Arguelles, D.J.; Rams, H. Jr.

1986-01-01

A case of thyrotoxic periodic paralysis is reported in a Hispanic man with an unusual recurrence six weeks after radioactive iodine treatment. Thyrotoxic periodic paralysis has now been well characterized in the literature: it occurs primarily in Orientals with an overwhelming male preponderance and a higher association of specific HLA antigens. Clinical manifestations include onset after high carbohydrate ingestion or heavy exertion, with progressive symmetric weakness leading to flaccid paralysis of the extremities and other muscle groups, lasting several hours. If hypokalemia is present, potassium administration may help abort the attack. Although propranolol can be efficacious in preventing further episodes, the only definitive treatment is establishing a euthyroid state. The pathophysiology is still controversial, but reflects altered potassium and calcium dynamics as well as certain morphologic characteristics within the muscle unit itself

32 CFR 37.1325 - Periodic audit.

Science.gov (United States)

2010-07-01

... 32 National Defense 1 2010-07-01 2010-07-01 false Periodic audit. 37.1325 Section 37.1325 National... TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1325 Periodic audit. An audit of... awards. Appendix C to this part describes what such an audit may cover. A periodic audit of a participant...

Periodization Theory: Confronting an Inconvenient Truth.

Science.gov (United States)

Kiely, John

2018-04-01

Periodization theory has, over the past seven decades, emerged as the preeminent training planning paradigm. The philosophical underpinnings of periodization theory can be traced back to the integration of diverse shaping influences, whereby coaching beliefs and traditions were blended with historically available scientific insights and contextualized against pervading social planning models. Since then, many dimensions of elite preparation have evolved significantly, as driven by a combination of coaching innovations and science-led advances in training theory, techniques, and technologies. These advances have been incorporated into the fabric of the pre-existing periodization planning framework, yet the philosophical assumptions underpinning periodization remain largely unchallenged and unchanged. One particularly influential academic sphere of study, the science of stress, particularly the work of Hans Selye, is repeatedly cited by theorists as a central pillar upon which periodization theory is founded. A fundamental assumption emanating from the early stress research is that physical stress is primarily a biologically mediated phenomenon: a presumption translated to athletic performance contexts as evidence that mechanical training stress directly regulates the magnitude of subsequent 'fitness' adaptations. Interestingly, however, since periodization theory first emerged, the science of stress has evolved extensively from its historical roots. This raises a fundamental question: if the original scientific platform upon which periodization theory was founded has disintegrated, should we critically re-evaluate conventional perspectives through an updated conceptual lens? Realigning periodization philosophy with contemporary stress theory thus presents us with an opportunity to recalibrate training planning models with both contemporary scientific insight and progressive coaching practice.

A Three-period Samuelson-Diamond Growth Model

DEFF Research Database (Denmark)

Blomgren-Hansen, Niels

2005-01-01

Samuelson (1958) analyses a three-period model, whereas Diamod (1965) considers a two-period model. This difference poses the question whether the insights derived by analysing the simple two-period model carry over in the more complicated three-period case. They do. The Samuelson model (no produ...

Establishing contract periods

International Nuclear Information System (INIS)

Huffman, F.C.

1978-01-01

The lead time for executing the Adjustable Fixed-Commitment (AFC) contract and exceptions which may be considered are discussed. The initial delivery period is also discussed. Delays, deferrals, and schedule adjustment charges are finally considered

Period-dependent source rupture behavior of the 2011 Tohoku earthquake estimated by multi period-band Bayesian waveform inversion

Science.gov (United States)

Kubo, H.; Asano, K.; Iwata, T.; Aoi, S.

2014-12-01

Previous studies for the period-dependent source characteristics of the 2011 Tohoku earthquake (e.g., Koper et al., 2011; Lay et al., 2012) were based on the short and long period source models using different method. Kubo et al. (2013) obtained source models of the 2011 Tohoku earthquake using multi period-bands waveform data by a common inversion method and discussed its period-dependent source characteristics. In this study, to achieve more in detail spatiotemporal source rupture behavior of this event, we introduce a new fault surface model having finer sub-fault size and estimate the source models in multi period-bands using a Bayesian inversion method combined with a multi-time-window method. Three components of velocity waveforms at 25 stations of K-NET, KiK-net, and F-net of NIED are used in this analysis. The target period band is 10-100 s. We divide this period band into three period bands (10-25 s, 25-50 s, and 50-100 s) and estimate a kinematic source model in each period band using a Bayesian inversion method with MCMC sampling (e.g., Fukuda & Johnson, 2008; Minson et al., 2013, 2014). The parameterization of spatiotemporal slip distribution follows the multi-time-window method (Hartzell & Heaton, 1983). The Green's functions are calculated by the 3D FDM (GMS; Aoi & Fujiwara, 1999) using a 3D velocity structure model (JIVSM; Koketsu et al., 2012). The assumed fault surface model is based on the Pacific plate boundary of JIVSM and is divided into 384 subfaults of about 16 * 16 km^2. The estimated source models in multi period-bands show the following source image: (1) First deep rupture off Miyagi at 0-60 s toward down-dip mostly radiating relatively short period (10-25 s) seismic waves. (2) Shallow rupture off Miyagi at 45-90 s toward up-dip with long duration radiating long period (50-100 s) seismic wave. (3) Second deep rupture off Miyagi at 60-105 s toward down-dip radiating longer period seismic waves then that of the first deep rupture. (4) Deep

Periodical rocking long period gratings in PANDA fibers for high temperature and refractive index sensing

Science.gov (United States)

Jin, Wa; Bi, Wei-hong; Fu, Xing-hu; Fu, Guang-wei

2017-09-01

We report periodical rocking long period gratings (PR-LPGs) in PANDA fibers fabricated with CO2 laser. The PR-LPGs achieve very high coupling efficiency of 19 dB with 12 periods and a 3.5° twist angle in just one scanning cycle, which is much more effective than the conventional CO2 laser fabrication technique. This type of LPGs exhibits polarization-selective resonance dips which demonstrate different sensitivities to environmental parameters. The high temperature and external refractive index sensitivities are measured simultaneously, so it can be used as a wavelength-selective polarization filter and sensor.

Unstable periodic orbits and chaotic economic growth

International Nuclear Information System (INIS)

Ishiyama, K.; Saiki, Y.

2005-01-01

We numerically find many unstable periodic solutions embedded in a chaotic attractor in a macroeconomic growth cycle model of two countries with different fiscal policies, and we focus on a special type of the unstable periodic solutions. It is confirmed that chaotic behavior represented by the model is qualitatively and quantitatively related to the unstable periodic solutions. We point out that the structure of a chaotic solution is dissolved into a class of finite unstable periodic solutions picked out among a large number of periodic solutions. In this context it is essential for the unstable periodic solutions to be embedded in the chaotic attractor

The Periodic Table in Croatia

Directory of Open Access Journals (Sweden)

Raos, N.

2011-12-01

Full Text Available The Croatian (Yugoslav Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882, whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev. Such enthusiastic views, however, did not help in analyzing the contribution of Mendeleev and other scientists to the discovery and development of the periodic table of the elements.

38 CFR 3.17 - Disability and death pension; Mexican border period and later war periods.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Disability and death pension; Mexican border period and later war periods. 3.17 Section 3.17 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUDICATION Pension, Compensation, and Dependency and Indemnity...

Capital Finance Decisions for project managers - A reflection on current methods

Directory of Open Access Journals (Sweden)

C. Scheepers

2003-12-01

Full Text Available This paper evaluates some of current financial investment selection methodologies for capital projects. The proc ess (and criteria of capital investment decisions is reviewed. The capital budget for most organisations is prepared annually by a committee of senior managers who then present it for approval by the board of directors. Investment proposals are usually subjected to two financial tests, "payback" and "internal rate of return (IRR". The management committee usually decides on the tests and acceptance criteria vary according to the type of project. Some shortcomings of these most frequently used current tests (Payback & IRR are identified and it is recommended that the Net Present Value (NPV should be used as the primary method for analysing, comparing and selecting capital projects.

Periodic subsystem density-functional theory

International Nuclear Information System (INIS)

Genova, Alessandro; Pavanello, Michele; Ceresoli, Davide

2014-01-01

By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn–Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn–Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed

Periodic subsystem density-functional theory

Science.gov (United States)

Genova, Alessandro; Ceresoli, Davide; Pavanello, Michele

2014-11-01

By partitioning the electron density into subsystem contributions, the Frozen Density Embedding (FDE) formulation of subsystem Density Functional Theory (DFT) has recently emerged as a powerful tool for reducing the computational scaling of Kohn-Sham DFT. To date, however, FDE has been employed to molecular systems only. Periodic systems, such as metals, semiconductors, and other crystalline solids have been outside the applicability of FDE, mostly because of the lack of a periodic FDE implementation. To fill this gap, in this work we aim at extending FDE to treat subsystems of molecular and periodic character. This goal is achieved by a dual approach. On one side, the development of a theoretical framework for periodic subsystem DFT. On the other, the realization of the method into a parallel computer code. We find that periodic FDE is capable of reproducing total electron densities and (to a lesser extent) also interaction energies of molecular systems weakly interacting with metallic surfaces. In the pilot calculations considered, we find that FDE fails in those cases where there is appreciable density overlap between the subsystems. Conversely, we find FDE to be in semiquantitative agreement with Kohn-Sham DFT when the inter-subsystem density overlap is low. We also conclude that to make FDE a suitable method for describing molecular adsorption at surfaces, kinetic energy density functionals that go beyond the GGA level must be employed.

Potencial econômico da utilização de micro-terraceamento em lavouras de café: um estudo de caso = Economic potential of using micro-terracing in coffee farming: a case study

Directory of Open Access Journals (Sweden)

Ednaldo Lino Alves

2017-01-01

Full Text Available Dentre os principais problemas enfrentados pela cafeicultura de montanha atualmente está o alto custo de produção, decisivamente influenciado pela escassez e elevado custo de mão de obra. Este trabalho objetivou realizar uma análise de viabilidade econômica na utilização de micro-terraceamento em lavouras de café do interior paulista. O estudo comparou os custos de produção em dois sistemas: semi mecanizado (micro-terraceamento e manual, em um período de 10 anos. Os dados foram coletados em uma propriedade rural no município de São Sebastião da Grama, São Paulo, em uma área de 12 ha, já implantada e em produção. Para as receitas foi considerado o valor da saca de 60 kg de café arábica beneficiado a R$ 410,00. Os indicadores financeiros utilizados foram: Valor Presente Líquido [VPL], Taxa Interna de Retorno [TIR] e payback descontado. O micro-terraceamento se apresenta como alternativa economicamente viável; o fluxo de caixa do projeto demonstra valores de VPL positivos utilizando taxas mínimas de atratividade variando de 6% a 20%; TIR de 41% e Payback descontado de dois anos. A maior contribuição para a redução do custo de produção do terreno terraceado é do item orçamentário mão de obra, tanto nos tratos culturais quanto na colheita. O fluxo de caixa considerando a área micro-terraceada é positivo e superior ao da área comparada. = Among the main problems faced by mountain coffee is currently the high cost of the production, decisively influenced by the scarcity and high cost of manpower. This study aimed to conduct an economic feasibility study of the use of "micro-terracing" in coffee crop at São Paulo. The study compared the costs of production in two systems: semi-mechanized (micro-terracing and manual, in a period of 10 years. Data were collected on a farm in the city of São Sebastião da Grama, São Paulo, in an area of 12 ha, already deployed and in production. For the computation of the revenues

Physical explanation of the periodic table.

Science.gov (United States)

Ostrovsky, V N

2003-05-01

The Periodic Table of the elements, the most important generalization in chemistry, is often considered as a representative special case in the study of the relation between chemistry and physics. Its quantum interpretation was initiated, but not completed, by Niels Bohr. In this paper, post-Bohr conceptual developments are discussed from historical and epistemological points of view. The difference between high-precision numerical calculations for individual atoms and the theory of the periodic system as a whole is emphasized. Periodic laws met in Nature are not restricted to the chemical Periodic Table. A comparative study of these laws makes it possible to single out essential features that define the particular pattern of periodicity. It is shown that the periodic system of neutral ground state atoms now has a firm nonempirical quantum-theoretical basis. Alternative approaches, based on group theory and other mathematical schemes, are briefly discussed. It is argued that, while quantum theory is capable of fully accurate calculations for relatively simple atoms or molecular objects, the complexity of polyatomic molecules and chemical reactions guarantees the flourishing of chemistry as a separate scientific discipline.

34 CFR 75.251 - The budget period.

Science.gov (United States)

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false The budget period. 75.251 Section 75.251 Education... Multi-Year Projects § 75.251 The budget period. (a) The Secretary usually approves a budget period of... budget period; and (2) Indicates his or her intention to make contination awards to fund the remainder of...

77 FR 73993 - Agency Information Collection Activities; Comment Request; Indian Education Professional...

Science.gov (United States)

2012-12-12

...; Comment Request; Indian Education Professional Development Grants Program: GPRA and Service Payback Data... an existing information collection. DATES: Interested persons are invited to submit comments on or... understand the [[Page 73994

Wind Magnetic Clouds for the Period 2013 - 2015: Model Fitting, Types, Associated Shock Waves, and Comparisons to Other Periods

Science.gov (United States)

Lepping, R. P.; Wu, C.-C.; Berdichevsky, D. B.; Szabo, A.

2018-04-01

We give the results of parameter fitting of the magnetic clouds (MCs) observed by the Wind spacecraft for the three-year period 2013 to the end of 2015 (called the "Present" period) using the MC model of Lepping, Jones, and Burlaga ( J. Geophys. Res. 95, 11957, 1990). The Present period is almost coincident with the solar maximum of the sunspot number, which has a broad peak starting in about 2012 and extending to almost 2015. There were 49 MCs identified in the Present period. The modeling gives MC quantities such as size, axial attitude, field handedness, axial magnetic-field strength, center time, and closest-approach vector. Derived quantities are also estimated, such as axial magnetic flux, axial current density, and total axial current. Quality estimates are assigned representing excellent, fair/good, and poor. We provide error estimates on the specific fit parameters for the individual MCs, where the poor cases are excluded. Model-fitting results that are based on the Present period are compared to the results of the full Wind mission from 1995 to the end of 2015 (Long-term period), and compared to the results of two other recent studies that encompassed the periods 2007 - 2009 and 2010 - 2012, inclusive. We see that during the Present period, the MCs are, on average, slightly slower, slightly weaker in axial magnetic field (by 8.7%), and larger in diameter (by 6.5%) than those in the Long-term period. However, in most respects, the MCs in the Present period are significantly closer in characteristics to those of the Long-term period than to those of the two recent three-year periods. However, the rate of occurrence of MCs for the Long-term period is 10.3 year^{-1}, whereas this rate for the Present period is 16.3 year^{-1}, similar to that of the period 2010 - 2012. Hence, the MC occurrence rate has increased appreciably in the last six years. MC Type (N-S, S-N, All N, All S, etc.) is assigned to each MC; there is an inordinately large percentage of All S

Discovering Periodicity: Hands-On, Minds-On Organization of the Periodic Table by Visualizing the Unseen

Science.gov (United States)

Selco, Jodye; Bruno, Mary; Chan, Sue

2013-01-01

Understanding how the periodic table of elements is organized and how to read information from it is fundamental for understanding chemistry. Introductory chemistry courses usually include discussions detailing what elemental information can be determined by virtue of its position on the periodic table. Although many people have been exposed to…

Economic, environmental and social assessment of briquette fuel from agricultural residues in China – A study on flat die briquetting using corn stalk

International Nuclear Information System (INIS)

Hu, Jianjun; Lei, Tingzhou; Wang, Zhiwei; Yan, Xiaoyu; Shi, Xinguang; Li, Zaifeng; He, Xiaofeng; Zhang, Quanguo

2014-01-01

Biomass can be relatively easily stored and transported compared with other types of renewable energy sources. Crop straw can be converted into densified solid biofuel via briquette fuel technology to expand its possible applications and enhance its utilisation efficiency. However, the potential economic, environmental and social impacts of crop straw briquette fuel need to be assessed before its large-scale use. This paper provides a comprehensive evaluation of these impacts for a fully-operating 2 × 10 4 t/a corn stalk briquette fuel plant in China. The results show that with a life time of 15 years, a purchase price of 150 RMB/t for corn stalk and the current sales price of 400 RMB/t for briquette fuel, the plant has a net present value of 9.6 million RMB or 1.5 million USD, an internal rate of return of 36% and a short investment payback period of 4.4 years. The life cycle greenhouse gas emissions are found to be 323 t CO 2 ,e/year or 1 kg CO 2 ,e/GJ, much lower than that of coal. Additionally, the process reduces pollution by decreasing the amount of corn stalk that is discarded or burnt directly in the field. In terms of social impacts, the use of corn stalk briquetting fuel plant is expected to play an important role in increasing local residents' income, improving rural ecological environments, alleviating energy shortages, guaranteeing energy security, and promoting socialism new rural reconstruction. - Highlights: • A fully-operating 2 × 10 4 t/a corn stalk briquette fuel plant in China is analysed. • The plant has net present value of $1.5 million and payback period of 4.4 years. • Life cycle GHG emissions are 323 t CO 2 ,e/year or 1 kg CO 2 ,e/GJ, much lower than coal. • The plant will also have significant social benefits

Potential of Micro Hydroelectric Generator Embedded at 30,000 PE Effluent Discharge of Sewerage Treatment Plant

Science.gov (United States)

Che Munaaim, M. A.; Razali, N.; Ayob, A.; Hamidin, N.; Othuman Mydin, M. A.

2018-03-01

A micro hydroelectric generator is an energy conversion approach to generate electricity from potential (motion) energy to an electrical energy. In this research, it is desired to be implemented by using a micro hydroelectric generator which is desired to be embedded at the continuous flow of effluent discharge point of domestic sewerage treatment plant (STP). This research evaluates the potential of electricity generation from micro hydroelectric generator attached to 30,000 PE sewerage treatment plant. The power output obtained from calculation of electrical power conversion is used to identify the possibility of this system and its ability to provide electrical energy, which can minimize the cost of electric bill especially for the pumping system. The overview of this system on the practical application with the consideration of payback period is summarized. The ultimate aim of the whole application is to have a self-ecosystem electrical power generated for the internal use of STP by using its own flowing water in supporting the sustainable engineering towards renewable energy and energy efficient approach. The results shows that the output power obtained is lower than expected output power (12 kW) and fall beyond of the range of a micro hydro power (5kW - 100kW) since it is only generating 1.58 kW energy by calculation. It is also observed that the estimated payback period is longer which i.e 7 years to recoup the return of investment. A range of head from 4.5 m and above for the case where the flow shall at least have maintained at 0.05 m3/s in the selected plant in order to achieved a feasible power output. In conclusion, wastewater treatment process involves the flowing water (potential energy) especially at the effluent discharge point of STP is possibly harvested for electricity generation by embedding the micro hydroelectric generator. However, the selection of STP needs to have minimum 4.5 meter head with 0.05 m3/s of continuously flowing water to make

Determination of optimum insulation thickness in pipe for exergetic life cycle assessment

International Nuclear Information System (INIS)

Keçebaş, Ali

2015-01-01

Highlights: • It is aimed to determine optimum insulation thickness in pipe. • A new methodology is used as exergetic life cycle assessment for this purpose. • It is evaluated for various fuels, different pipe diameters and some combustion parameters. • This methodology is not suitable for determining optimum insulation thickness of a pipe. • There are benefits to our understanding of the need for insulation use in pipes. - Abstract: The energy saving and the environmental impacts’ reduction in the world building sector have gained great importance. Therefore, great efforts have been invested to create energy-saving green buildings. To do so, one of the many things to be done is the insulation of cylindrical pipes, canals and tanks. In the current study, the main focus is on the determination of the optimum insulation thickness of the pipes with varying diameters when different fuels are used. Therefore, through a new method combining exergy analysis and life cycle assessment, optimum insulation thickness of the pipes, total exergetic environmental impact, net saving and payback period were calculated. The effects of the insulation thickness on environmental and combustion parameters were analyzed in a detailed manner. The results revealed that optimum insulation thickness was affected by the temperature of the fuel when it enters into the combustion chamber, the temperature of the stack gas and the temperature of the combustion chamber. Under these optimum effects, the optimum insulation thickness of a 100 mm pipe was determined to be 55.7 cm, 57.2 cm and 59.3 cm for coal, natural gas and fuel–oil, respectively with the ratios of 76.32%, 81.84% and 84.04% net savings in the exergetic environmental impact. As the environmental impacts of the fuels and their products are bigger than those of the insulation material, the values of the optimum insulation thickness of the method used this study was found greater. Moreover, in the pipes with greater

Sizing a solar dish Stirling micro-CHP system for residential application in diverse climatic conditions based on 3E analysis

International Nuclear Information System (INIS)

Moghadam, Ramin Shabanpour; Sayyaadi, Hoseyn; Hosseinzade, Hadi

2013-01-01

Highlights: • 3E analysis was performed on solar CHP systems. • Significant primary energy saving and greenhouse gas reduction were obtained. • The engine was sized so that it had the best economic sound. • Various criteria at different weathers were used for sizing the engine. - Abstract: A solar dish Stirling cogeneration system is considered to provide energy demands of a residential building. As energy demands of the building and output power of the engine are functions of weather condition and solar irradiation flux, the benchmark building was considered to be located in five different cities in Iran with diverse climatic and solar irradiation conditions. The proposed solar dish Stirling micro-CHP system was analyzed based on 3E analysis. The 3E analysis evaluated primary energy saving analysis (energy analysis), carbon dioxide emission reduction (environmental analysis) and payback period for return of investment (economic analysis) and was compared to a reference building that utilized primary energy carriers for its demands. Three scenarios were considered for assessment and sizing the solar dish Stirling engine. In the first scenario, size of the solar dish Stirling engine was selected based on the lowest annual electric power demand while, in second, the highest annual electric power consumption was considered to specify size of the engine. In the third scenario, a solar dish Stirling engine with constant output capacity was considered for the five locations. It was shown that implementing the solar dish Stirling micro-CHP system had good potential in primary energy saving and carbon dioxide emission reduction in all scenarios and acceptable payback period for return of the investment in some scenarios. Finally, the best scenario for selecting size of the engine in each city was introduced using the TOPSIS decision making method. It was demonstrated that, for dry weather, the first scenario was the best while, for hot and humid cities and

Trigeneration scheme for a natural gas liquids extraction plant in the Middle East

International Nuclear Information System (INIS)

Eveloy, Valérie; Rodgers, Peter; Popli, Sahil

2014-01-01

Highlights: • Trigeneration scheme tailored to natural gas liquids extraction plant. • High ambient temperature and RH conditions in the Persian Gulf. • Absorption refrigeration powered by gas turbine (GT) exhaust gas waste heat. • GT compressor inlet air- and process gas cooling, process gas heating. • Significant OPEX and primary energy savings, favorable payback period and net present value. - Abstract: Natural gas processing plants in the Persian Gulf face extreme climatic conditions that constrain their gas turbine (GT) power generation and cooling capacities. However, due to a past history of low hydrocarbon prices, such plants have not fully exploited their waste heat recovery potential to date. The techno-economic performance of a combined cooling, heating and power (CCHP) scheme designed to enhance the energy efficiency of a major natural gas liquids extraction plant in the Persian Gulf is assessed. The trigeneration scheme utilizes double-effect water–lithium bromide absorption refrigeration powered by steam generated from GT exhaust gas waste heat to provide both GT compressor inlet air- and process gas cooling. Part of the generated steam is also used for process gas heating. Thermodynamic modeling reveals that recovery of 82 MW of GT waste heat would provide additional cooling and heating capacities of 75 MW and 24 MW to the plant, respectively, thereby permitting elimination of a 28 MW GT, and existing cooling and heating equipment. GT compressor inlet air cooling alone yields approximately 151 GW h of additional electric power annually, highlighting the effectiveness of absorption refrigeration in meeting compressor inlet air cooling loads throughout the year in the Gulf climate. The overall net annual operating expenditure savings contributed by the CCHP system would average approximately 14.6 million US$ over its lifespan, which corresponds to average yearly savings of 190 MMSCM of natural gas. The CCHP scheme economic payback period is

Potential of Micro Hydroelectric Generator Embedded at 30,000 PE Effluent Discharge of Sewerage Treatment Plant

Directory of Open Access Journals (Sweden)

Che Munaaim M.A.

2018-01-01

Full Text Available A micro hydroelectric generator is an energy conversion approach to generate electricity from potential (motion energy to an electrical energy. In this research, it is desired to be implemented by using a micro hydroelectric generator which is desired to be embedded at the continuous flow of effluent discharge point of domestic sewerage treatment plant (STP. This research evaluates the potential of electricity generation from micro hydroelectric generator attached to 30,000 PE sewerage treatment plant. The power output obtained from calculation of electrical power conversion is used to identify the possibility of this system and its ability to provide electrical energy, which can minimize the cost of electric bill especially for the pumping system. The overview of this system on the practical application with the consideration of payback period is summarized. The ultimate aim of the whole application is to have a self-ecosystem electrical power generated for the internal use of STP by using its own flowing water in supporting the sustainable engineering towards renewable energy and energy efficient approach. The results shows that the output power obtained is lower than expected output power (12 kW and fall beyond of the range of a micro hydro power (5kW - 100kW since it is only generating 1.58 kW energy by calculation. It is also observed that the estimated payback period is longer which i.e 7 years to recoup the return of investment. A range of head from 4.5 m and above for the case where the flow shall at least have maintained at 0.05 m3/s in the selected plant in order to achieved a feasible power output. In conclusion, wastewater treatment process involves the flowing water (potential energy especially at the effluent discharge point of STP is possibly harvested for electricity generation by embedding the micro hydroelectric generator. However, the selection of STP needs to have minimum 4.5 meter head with 0.05 m3/s of continuously flowing

Pilot Scale Production of Irradiated Natural Rubber Latex and its Dipping Products

Directory of Open Access Journals (Sweden)

M. Utama

2005-07-01

Full Text Available One hundred and fifty kg natural rubber latex (NRL before and after concentration were added with 3 phr (part hundred ratio of rubber normal butyl acrylate, then the mixture were irradiated at 25 kGy by gamma rays of 60Co in pilot scale. The irradiated natural rubber latex (INRL were then being to use for producing rubber products such as condom, surgical gloves, and spygmomanometer in factory scale. The quality of INRL and rubber products such as : total solid content (TSC, dry rubber content (DRC, KOH, VFA and MST number, tensile strength, modulus, elongation at break, extractable protein content, and response against Type I allergy etc. were evaluated. The economic aspect for producing INRL by means of Gamma Irradiator (GI and Electron Beam Machine (EBM such as payback period (PP, net present value (NPV and internal rate return (IRR were calculated. The results showed that the latex properties of INRL such as DRC, TSC, KOH, VFA, and MST number are not only found to the requirement of the ISO 2004 standard but also the latex has low protein, lipid, and carbohydrate content. The physical and mechanical properties (tensile strength, modulus, and elongation at break of rubber dipping products such as condom, gloves, and sphygmomanometer are not only found to the requirement of ISO 4074, ISO 10282, and ANSI/AAMI SP-1994 standards, but also the allergic response tested clinical latex-sensitive protein allergen by ELISA test on gloves, and by SPT test on condom are found to be negative. It indicates that production of INRL or PVNRL or RVNRL by EBM 250 keV/10 mA, was more cheap than by using gamma γ irradiator 200 kCi, or sulfur vulcanization. The value of PBP (payback period was 2,1 years, NPV (net present value was 4,250 US $, PI (profitability index 1,06 and IRR (internal rate of returns was 25,0%.

Thermal and economic analyses of a compact waste heat recovering system for the marine diesel engine using transcritical Rankine cycle

International Nuclear Information System (INIS)

Yang, Min-Hsiung

2015-01-01

Graphical abstract: Schematic diagram of the CWHRS for a marine diesel engine. - Highlights: • The economic optimization of a CWHRS of a marine engine is investigated. • The environmental protection refrigerant, R1234yf is used as the working fluid of the TRC system. • The optimal analysis and comparison of three models for waste heat recovering have been carried out. • The optimization of payback periods, CO_2 emission reducing and diesel oil saving are reported. - Abstract: The aim of this study is to investigate the economic performance of a novel compact waste heat recovering system for the marine diesel engine. The transcritical Rankine cycle is employed to convert the waste heat resources to useful work with R1234yf. To evaluate the utilizing efficiency and economic performance of waste heat resources, which are exhaust gas, cylinder cooling water and scavenge air cooling water, three operating models of the system are investigated and compared. The levelized energy cost, which represents the total cost per kilo-watt power, is employed to evaluate the economic performance of the system. The economic optimization and its corresponding optimal parameters of each operating model in the compact waste heat recovering system are obtained theoretically. The results show that the minimal levelized energy cost of the proposed system operated in Model I is the lowest of the three models, and then are Model II and Model III, which are 2.96% and 9.36% lower for, respectively. Similarly, the CO_2 emission reduction is the highest for Model I of the three models, and 21.6% and 30.1% lower are obtained for Model II and Model III, respectively. The compact waste heat recovering system operated in Model I has superiority on the payback periods and heavy diesel oil saving over the others. Finally, the correlations using specific work of working fluid and condensation temperature as parameters are proposed to assess the optimal conditions in economic performance

Thermoeconomic optimization of Solar Heating and Cooling systems

International Nuclear Information System (INIS)

Calise, F.; D'Accadia, M. Dentice; Vanoli, L.

2011-01-01

In the paper, the optimal thermoeconomic configuration of Solar Heating and Cooling systems (SHC) is investigated. In particular, a case study is presented, referred to an office building located in Naples (south Italy); for such building, three different SHC configurations were analyzed: the first one is based on the coupling of evacuated solar collectors with a single-stage LiBr-H 2 O absorption chiller equipped with a water-to-water electrical heat pump, to be used in case of insufficient solar radiation; in the second case, a similar layout is considered, but the capacities of the absorption chiller and the solar field are smaller, since they are requested to balance just a fraction of the total cooling load of the building selected for the case study; finally, in the third case, the electric heat pump is replaced by an auxiliary gas-fired heater. A zero-dimensional transient simulation model, developed in TRNSYS, was used to analyze each layout from both thermodynamic and economic points of view. In particular, a cost model was developed in order to assess the owning and operating costs for each plant layout. Furthermore, a mixed heuristic-deterministic optimization algorithm was implemented in order to determine the set of the synthesis/design variables able to maximize the overall thermo-economic performance of the systems under analysis. For this purpose, two different objective functions were selected: the Pay-Back Period and the overall annual cost. Possible public funding, in terms of Capital Cost Contributions and/or feed-in tariff, were also considered. The results are presented on monthly and weekly basis, paying special attention to the energy and monetary flows in the optimal configurations. In particular, the thermoeconomic analysis and optimization showed that a good funding policy for the promotion of such technologies should combine a feed-in tariff with a slight Capital Cost Contribution, allowing to achieve satisfactory Pay-Back Periods.

Environmental life cycle assessment and techno-economic analysis of triboelectric nanogenerators

KAUST Repository

Ahmed, Abdelsalam

2017-02-22

As the world economy grows and industrialization of the developing countries increases, the demand for energy continues to rise. Triboelectric nanogenerators (TENGs) have been touted as having great potential for low-carbon, non-fossil fuel energy generation. Mechanical energies from, amongst others, body motion, vibration, wind and waves are captured and converted by TENGs to harvest electricity, thereby minimizing global fossil fuel consumption. However, only by ascertaining performance efficiency along with low material and manufacturing costs as well as a favorable environmental profile in comparison with other energy harvesting technologies, can the true potential of TENGs be established. This paper presents a detailed techno-economic lifecycle assessment of two representative examples of TENG modules, one with a high performance efficiency (Module A) and the other with a lower efficiency (Module B) both fabricated using low-cost materials. The results are discussed across a number of sustainability metrics in the context of other energy harvesting technologies, notably photovoltaics. Module A possesses a better environmental profile, lower cost of production, lower CO2 emissions and shorter energy payback period (EPBP) compared to Module B. However, the environmental profile of Module B is slightly degraded due to the higher content of acrylic in its architecture and higher electrical energy consumption during fabrication. The end of life scenario of acrylic is environmentally viable given its recyclability and reuse potential and it does not generate toxic gases that are harmful to humans and the environment during combustion processes due to its stability during exposure to ultraviolet radiation. Despite the adoption of a less optimum laboratory manufacturing route, TENG modules generally have a better environmental profile than commercialized Si based and organic solar cells, but Module B has a slightly higher energy payback period than PV technology based

Organic Rankine cycle saves energy and reduces gas emissions for cement production

International Nuclear Information System (INIS)

Wang, Huarong; Xu, Jinliang; Yang, Xufei; Miao, Zheng; Yu, Chao

2015-01-01

We investigated ORCs (organic Rankine cycles) integrated with typical China cement production line. The dry air at the kiln cooler outlet with the temperature of 220 °C was the waste heat. The fluids of hexane, isohexane, R601, R123 and R245fa were selected for ORCs based on the critical temperature criterion. The developed ORC verified the thermodynamics analysis. The NPV (net present value) and PBP (payback period) methods were applied to evaluate the economic performance. The LCA (life cycle assessment) was applied to evaluate the environment impacts. ORCs could generate 67,85,540–81,21,650 kWh electricity per year, equivalent to save 2035–2436 tons standard coal and reduce 7743–9268 tons CO 2 emission, for a 4000 t/d cement production line. ORCs reduced gas emissions of CO 2 by 0.62–0.74%, SO 2 by 3.83–4.59% and NO x by 1.36–1.63%. The PBP (payback period) was 2.74–3.42 years. The ORCs had the reduction ratios of EIL (environment impact load) by 1.49–1.83%, GWP (global warming potential) by 0.74–0.92%, AP (acidification potential) by 2.34–2.84%, EP (eutrophication potential) by 0.96–1.22% and HTP (human toxicity potential) by 2.38–2.89%. The ORC with R601 as the fluid had the best economic performance and significant gas emission reductions. ORCs had good economic performance and reduce the gas emissions. - Highlights: • Organic Rankine Cycles were integrated with the cement production line. • Five organic fluids were used as the working fluids for ORCs. • Thermal, economic and gas emission performances were analyzed. • R601 was the best fluid for ORC with the heat source temperature of 220 °C. • ORCs had good economic and gas emission reduction performances

Thermoeconomic analysis of configuration methods for modular Organic Rankine Cycle units in low-temperature applications

International Nuclear Information System (INIS)

Preißinger, Markus; Schatz, Sabrina; Vogl, Anne; König-Haagen, Andreas; Brüggemann, Dieter

2016-01-01

Highlights: • Two configuration methods for modular ORC design are presented. • Thermodynamic analysis cover the low-temperature range up to 190 °C. • Four commonly knows working fluids from two chemical classes are investigated. • Economic analysis cover payback period and cash flow under realistic boundary conditions. • Suggestions for ORC manufacturer are given concerning configuration method. - Abstract: Organic Rankine Cycle (ORC) is a promising technology for the utilization of low-grade waste heat. However, due to tailor-made power plants for different heat source temperatures, specific investment costs are still too high to be profitable. This study compares two different methods to configure a modular ORC in the temperature range of 373–463 K. The first method assumes a simple adaption of the mass flow rate within the ORC (mass flow method). In the second method, simultaneous adaption of mass flow rate and working pressure (combined method) take place. The common purpose of both methods is the optimization of the net power output for heat source temperatures lower and higher than the reference plant. Analyses are carried out for common fluorinated refrigerants (R227ea and R236ea) as well as for iso-alkanes (isobutane and isopentane). It is shown that within a wide range of temperatures the deviation in net power output between the simpler mass flow method and the more sophisticated combined method is below 10%. However, the deviation strongly depends on the location of the pinch point and on the choice of the working fluid. In general, it is shown that the mass flow method in combination with a working fluid, for which the pinch point is located at the beginning of the preheating, is thermodynamically favorable for plant manufacturers. Economic analyses subsequently compare both methods with respect to payback period and cash flow. Additional investment costs for the combined method are allowed to be up to 10% in order to reach higher

Energy, exergy, environmental and economic analysis of industrial fired heaters based on heat recovery and preheating techniques

International Nuclear Information System (INIS)

Shekarchian, M.; Zarifi, F.; Moghavvemi, M.; Motasemi, F.; Mahlia, T.M.I.

2013-01-01

Highlights: • 4-E analysis of a typical industrial grade fired heater unit is studied. • This analysis is accomplished for the first time in this study. • Heat recovery and air preheating lead to substantial reduction in the fuel consumption. • The company’s current costs are tremendously reduced by these methods. • The methods lead to mitigation in GHG emission and to reduction in the associated taxes. - Abstract: Fired heaters are ubiquitous in both the petroleum and petrochemical industries, due to it being vital in their day to day operations. They form major components in petroleum refineries, petrochemical facilities, and processing units. This study was commissioned in order to analyze the economic benefits of incorporating both heat recovery and air preheating methods into the existing fired heater units. Four fired heater units were analyzed from the energy and environmental point of views. Moreover, the second law efficiency and the rate of irreversibility were also analyzed via the exergy analysis. Both analyses was indicative of the fact that the heat recovery process enhances both the first and second law efficiencies while simultaneously assisting in the production of high and low pressure water steam. The implementation and usage of the process improves the thermal and exergy efficiencies from 63.4% to 71.7% and 49.4%, to 54.8%, respectively. Additionally, the heat recovery and air preheating methods leads to a substantial reduction in fuel consumption, in the realm of up to 7.4%, while also simultaneously decreasing heat loss and the irreversibility of the unit. Nevertheless, the results of the economic analysis posits that although utilizing an air preheater unit enhances the thermal performance of the system, due to the air preheater’s capital and maintenance costs, incorporating an air preheater unit to an existing fired heater is not economically justifiable. Furthermore, the results of the sensitivity analysis and payback period

Analisis Kelayakan Finansial dan Non Finansial pada Usaha Kopra di Desa Siduwonge Kecamatan Randangan Kabupaten Pohuwato

Directory of Open Access Journals (Sweden)

Yuriko Boekoesoe

2015-04-01

Full Text Available The purpose of this study were: 1. To determine whether the copra business financially worth the effort in the Village District of Randangan Siduwonge Pohuwato. 2. To determine whether the effort is worth the effort copra nonfinancial Siduwonge Village District of Randangan Pohuwato. This study was conducted in May to July. This type of research is survey research. The data obtained in this study is that the data in the form of primary and secondary data. Sampling will be done against the 30 respondents using purposive sampling. The analysis used is the financial analysis of the Net Present Value (NPV, Internal Rate of Return (IRR, Gross B / C Ratio, Net B / C Ratio and Payback Period. The results showed 1. Financially copra business in the Village District of Randangan Pohuwato Siduwonge worth the effort with 9.2 Million NPV, IRR (20.11%, Gross B / C ratio (1.27, Net B / C ratio (3.38 and payback period of 7 years 6 months. 2. In non-financial businesses in the village copra Siduwonge District of Randangan Pohuwato divided on several aspects which are as follows: a. Aspects of the Market. In a marketing system for businesses in the Village Siduwonge copra, farmers sell directly to buyers who typically have long subscription. Where the buyer directly come to the farmers who sell the copra. b. Technical Aspects. In this technical aspect of the farmers in the village siduwonge almost all have their own land as many as 25 people, but there are also some who rent land that is 5 people. c. Management aspects. In the management aspect of the planning is done before the process of harvesting coconuts into copra to be produced, the farmers in the village siduwonge not incorporated in the organization and for the direction and supervision in accordance with the land held by the copra farmers and for supervision also aims to work performed by farm workers in accordance with a predetermined agreement.

Ice storage facilities may use excess contingents of electricity. Reduction of the payback period by smart grids; Eisspeicher koennen ueberschuessige Stromkontingente nutzen. Amortisationszeit durch Smart Grid verkuerzen

Energy Technology Data Exchange (ETDEWEB)

Schulz, Klaus [Fafco S.A., Biel (Switzerland); Schmid, Wolfgang

2013-03-11

In Germany, energy storage device attain a great importance in the energy supply. However, up to now economical technologies are missing in order to store fluctuating offers of electricity from renewable energy sources directly in a storage medium. Within the modern refrigeration and air conditioning, ice storage facilities proved over decades could take up this position and could be one component of the energy policy turnaround. New tariff offers as well as the construction of virtual power plants let expect that ice storage facilities may amortize within few years.

Water as a source of renewable energy. Recommendations and energy payback periods of eight techniques; Water als bron van duurzame energie. Aanbevelingen en energieterugverdientijden van acht technologieen

Energy Technology Data Exchange (ETDEWEB)

Van de Berg, M.; Geurts, F.; Stolk, N.

2010-02-15

This report describes the environmental impact of six energy technologies using water: thermal energy storage, tidal current, tidal energy with height of fall, wave energy, aquatic biomass and osmosis energy (blue energy) [Dutch] In dit rapport zijn de omgevingseffecten van zes energietechnologieen met water beschreven: warmte koude opslag, getijdenstroming, getijdenenergie op verval, golfenergie, aquatische biomassa en osmose-energie (blue energy)

Periodical test program in depth revision

International Nuclear Information System (INIS)

Feltin, C.; Zermizoglou, R.

1987-11-01

Inspection visits made to different sites during 1980 and 1981 evidenced the need to extend and define more precisely the periodical tests performed on safety related systems; thus Electricite de France was requested by the Safety Authorities to re-examine the periodical test program for all safety related systems. This paper presents the methodology adopted by Electricite de France in order to perform an exhaustive analysis of the periodical test program for the 900 and 1300 MWe plants, and the organization set up at the IPSN at one hand and Electricite de France on the other hand for the purpose of elaborating a periodical test program which would be ratified by the Safety Authorities

Optimal Design for Study-Abroad Scholarship: The Effect of Payback Policy

Science.gov (United States)

Lien, Donald; Wang, Yaqin

2010-01-01

This paper examines the optimal design for a study-abroad scholarship. A student is awarded a fixed-amount scholarship to participate in the program but will have to pay back the scholarship if his/her performance fails to meet a target level. When the program is highly productive, the scholarship is low and the target performance is high. The…

From the Mendeleev periodic table to particle physics and back to the periodic table

International Nuclear Information System (INIS)

Kibler, Maurice R.

2006-11-01

We briefly describe in this paper the passage from Mendeleev's chemistry (1869) to atomic physics (in the 1900's), nuclear physics (in the 1932's) and particle physics (from 1953 to 2006). We show how the consideration of symmetries, largely used in physics since the end of the 1920's, gave rise to a new format of the periodic table in the 1970's. More specifically, this paper is concerned with the application of the group SO(4,2)xSU(2) to the periodic table of chemical elements. It is shown how the Madelung rule of the atomic shell model can be used for setting up a periodic table that can be further rationalized via the group SO(4,2)xSU(2) and some of its subgroups. Qualitative results are obtained from this nonstandard table. (author)

Co-periodic stability of periodic waves in some Hamiltonian PDEs

Science.gov (United States)

Benzoni-Gavage, S.; Mietka, C.; Rodrigues, L. M.

2016-10-01

The stability of periodic traveling wave solutions to dispersive PDEs with respect to ‘arbitrary’ perturbations is still widely open. The focus is put here on stability with respect to perturbations of the same period as the wave, for KdV-like systems of one-dimensional Hamiltonian PDEs. Stability criteria are derived and investigated first in a general abstract framework, and then applied to three basic examples that are very closely related, and ubiquitous in mathematical physics, namely, a quasilinear version of the generalized Korteweg-de Vries equation (qKdV), and the Euler-Korteweg system in both Eulerian coordinates (EKE) and in mass Lagrangian coordinates (EKL). Those criteria consist of a necessary condition for spectral stability, and of a sufficient condition for orbital stability. Both are expressed in terms of a single function, the abbreviated action integral along the orbits of waves in the phase plane, which is the counterpart of the solitary waves moment of instability introduced by Boussinesq. Regarding solitary waves, the celebrated Grillakis-Shatah-Strauss stability criteria amount to looking for the sign of the second derivative of the moment of instability with respect to the wave speed. For periodic waves, the most striking results obtained here can be summarized as: an odd value for the difference between N—the size of the PDE system—and the negative signature of the Hessian of the action implies spectral instability, whereas a negative signature of the same Hessian being equal to N implies orbital stability. Since these stability criteria are merely encoded by the negative signature of matrices, they can at least be checked numerically. Various numerical experiments are presented, which clearly discriminate between stable cases and unstable cases for (qKdV), (EKE) and (EKL).

Periodic orbits near the particle resonance in galaxies

CERN Document Server

Contopoulos, George

1978-01-01

Near the particle resonance of a spiral galaxy the almost circular periodic orbits that exist inside the resonance (direct) or outside it (retrograde) are replaced by elongated trapped orbits around the maxima of the potential L/sub 4/ and L/sub 5/. These are the long- period trapped periodic orbits. The long-period orbits shrink to the points L/sub 4/, L/sub 5/ for a critical value of the Hamiltonian h. For still larger h, a family of short-period trapped orbits appears, with continuously growing size. The evolution of the periodic orbits with h is followed, theoretically and numerically, from the untrapped orbits to the long-periodic orbits and then to the short-periodic orbits, mainly in the case of a bar. In a tight spiral case an explanation of the asymmetric periodic and banana orbits is given, and an example of short-period orbits not surrounding L/sub 4/ or L/sub 5/ is provided. Another family of periodic orbits reaching corotation is trapped at the inner Lindblad resonance. (5 refs).

May flood-poor periods be more dangerous than flood-rich periods?

Science.gov (United States)

Salinas, Jose Luis; Di Baldassarre, Giuliano; Viglione, Alberto; Kuil, Linda; Bloeschl, Guenter

2014-05-01

River floods are among the most devastating natural hazards experienced by populations that, since the earliest recorded civilisations, have settled in floodplains because they offer favourable conditions for trade, agriculture, and economic development. The occurrence of a flood may cause loss of lives and tremendous economic damages and, therefore, is rightly seen as a very negative event by the communities involved. Occurrence of many floods in a row is, of course, even more frustrating and is rightly considered a unbearable calamity. Unfortunately, the occurrence of many floods in a limited number of consecutive years is not unusual. In many places in the world, it has been observed that extreme floods do not arrive randomly but cluster in time into flood-poor and flood-rich periods consistent with the Hurst effect. If this is the case, when are the people more in danger? When should people be more scared? In flood-poor or flood-rich periods? In this work, a Socio-Hydrology model (Di Baldassarre et al., 2013; Viglione et al., 2014) is used to show that, maybe counter-intuitively, flood-poor periods may be more dangerous than flood-rich periods. The model is a conceptualisation of a hypothetical setting of a city at a river where a community evolves, making choices between flood management options on the floodplain. The most important feedbacks between the economic, political, technological and hydrological processes of the evolution of that community are represented in the model. In particular, the model also accounts in a dynamic way for the evolution of the the community awareness to flood risk. Occurrence of floods tends to increase peoples' recognition that their property is in an area that is potentially at risk of flooding, both at the scales of individuals and communities, which is one of the main reasons why flood coping actions are taken. It is shown through examples that frequent flood events may result in moderate damages because they ensure that the

Engineering design and economic evaluation of a family-sized biogas project in Nigeria

International Nuclear Information System (INIS)

Adeoti, O.; Ilori, M.O.; Oyebisi, T.O.; Adekoya, L.O.

2000-01-01

To woo householders into harnessing the cooking energy potential of biogas in order to solve the perennial cooking energy problems at household level in Nigeria, this paper carried out the engineering design requirement, and used the discounted cash flow micro-economic assessments to evaluate the 6.0 m 3 family-sized biogas project in Nigeria. The project has an initial investment cost of 41,088 Naira, annual expenditure of 5909 Naira and an annual benefit of 13,347 Naira. The NPV, IRR, B/C and payback period of financial analysis are 0.050 million Naira, 17.52%, 2.26 and 6.6 years respectively. This shows that the 6.0 m 3 family-sized biogas project using cattle dung as substrate in Nigeria has a good economic potential. (author)

Application of phase-changing materials in future buildings. Improvement of energy efficiency and indoor climate; Anvendelse af faseskiftende materialer i fremtidens bygninger. Forbedring af energieffektivitet og indeklima

Energy Technology Data Exchange (ETDEWEB)

Rose, J. (Statens Byggeforskningsinstitut, Hoersholm (Denmark)); Lund Jensen, R.; Heiselberg, P. (Aalborg Univ. (Denmark)); Hansen, M.; Kjeldsen, A.M.; Dous, C. le (Teknologisk Institut, Taastrup (Denmark)); Uhre Christensen, N. (Ingenioerhoejskolen i AArhus (Denmark))

2011-07-01

The aim of the project was to establish the basis for using phase changing materials (PCM) to improve the temperature conditions during summer in future new buildings. With the implementation of the planned new building codes requiring very low energy consumption (passive houses), it will be necessary for buildings to be comfortable during summer without using extra power for ventilation and mechanical cooling. The project has developed a numerical method to calculate latent heat storage in constructions containing phase changing materials. The calculation method has been implemented in the BSim program. A functionality to include the effect PCMs has also been added to the Be10 calculation program. The project has shown that good energy savings can be achieved for cooling and heating, but the price of the materials means long pay-back periods. (LN)

Financial Analysis for Replacement of Construction Equipment in Saudi Arabia

Directory of Open Access Journals (Sweden)

Ali Shash

2012-11-01

Full Text Available This study report results of a survey conducted in the EasternProvince of Saudi Arabia to explore the procedures and financialtechniques that large-size contractors utilise in replacingequipment. The results indicated that contractors set severalreplacement alternatives that they evaluate by using a set ofvarious qualitative and quantitative factors. The contractors’business objectives, employee safety and morale, and, contractors’image in the industry were found to be the most influentialqualitative factors affecting the decision of equipment replacement.Inflation, downtime, obsolescence, salvage value, and depreciationare among the top quantitative factors that contractors considerwhile making a decision to replace equipment. Because of theirsimplicity and practicality, the net present value, payback period,and the economic life are the most popular techniques that areutilised for analysing the financial issues of proposed replacementalternatives.

Economic analysis of process steam and electricity generation by a 200 MW NHR

International Nuclear Information System (INIS)

Tian Li; Wang Yongqing

2000-01-01

New applications for low temperature nuclear heating reactors should be developed using economic analysis. This paper compares and analyzes the economics of the generation 1.5 MPa process steam and electricity by a 200 MW nuclear heating reactor (NHR-200) for industrial development. The project is very attractive economically with an internal rate of return of 19.61%, a net present worth (discount rate 10%) of 765 million yuan RMB and a capital recovery or payback period of about 5 years after construction is completed. Compared with only using the NHR-200 for in winter heating, the economic of process steam and electricity generation by NHR-200 are much better. In addition, the NHR-200 will significantly improve environmental pollution in cities and reduce the transport of coal from north to south in China

Performance and economic analysis of a plug and play regenerative brake for improving energy efficiency for traction elevators

Science.gov (United States)

Jeraputra, Chuttchaval; Tiptipakorn, Supun

2017-05-01

This paper presents performance and economic analysis of a plug and play regenerative brake for improving energy efficiency for traction elevators. The proposed regenerative brake recycles the energy loss of a dynamic brake and feeds into the grid while an elevator inverter is operating in the braking mode. According to field measurement of energy consumption, it reveals that the efficiency can be improved as much as 18%. The prototype of a regenerative brake 12 kW, 400V, 3ϕ is developed and tested on an elevator simulator. It is shown that it can transfer energy out of a DC capacitor before the dynamic brake kicks in. Further, an economic analysis is provided to carry out the payback period and the present worth equivalent to confirm economic feasibility.

Process integration in bioprocess indystry: waste heat recovery in yeast and ethyl alcohol plant

International Nuclear Information System (INIS)

Raskovic, P.; Anastasovski, A.; Markovska, Lj.; Mesko, V.

2010-01-01

The process integration of the bioprocess plant for production of yeast and alcohol was studied. Preliminary energy audit of the plant identified the huge amount of thermal losses, caused by waste heat in exhausted process streams, and reviled the great potential for energy efficiency improvement by heat recovery system. Research roadmap, based on process integration approach, is divided on six phases, and the primary tool used for the design of heat recovery network was Pinch Analysis. Performance of preliminary design are obtained by targeting procedure, for three process stream sets, and evaluated by the economic criteria. The results of process integration study are presented in the form of heat exchanger networks which fulfilled the utilization of waste heat and enable considerable savings of energy in short payback period.

Techno-Economic Analysis of Solar Water Heating Systems inTurkey.

Science.gov (United States)

Ertekin, Can; Kulcu, Recep; Evrendilek, Fatih

2008-02-25

In this study, solar water heater was investigated using meteorological and geographical data of 129 sites over Turkey. Three different collector types were compared in terms of absorber material (copper, galvanized sheet and selective absorber). Energy requirement for water heating, collector performances, and economical indicators were calculated with formulations using observed data. Results showed that selective absorbers were most appropriate in terms of coverage rate of energy requirement for water-heating all over Turkey. The prices of selective, copper and galvanized absorber type's heating systems in Turkey were 740.49, 615.69 and 490.89 USD, respectively. While payback periods (PBPs) of the galvanized absorber were lower, net present values (NPVs) of the selective absorber were higher than the rest. Copper absorber type collectors did not appear to be appropriate based on economical indicators.

The capital expenditure process for the health care supervisor.

Science.gov (United States)

Rogers, M M

1993-12-01

Competition for health care capital dollars has increased as third-party and government reimbursement decreases, patient volume decreases, and alternative services increase. Given this rationing situation, it is more important than ever that the health care supervisor carefully document and present a capital expenditure request. This request should outline skillfully the benefits and costs of undertaking a new service or replacing an old asset. A supervisor who can quantify the costs and benefits of a project and utilize one of the four common capital budgeting techniques: payback period, net present value, profitability index, or internal rate of return, will certainly be taking a step in the right direction for ensuring a serious evaluation of his or her proposal. This article attempts to explain this process using both narrative and quantitative examples.

The feasibility of using photovoltaic panels to illuminate the entryway to an apartment building

Directory of Open Access Journals (Sweden)

Sumarokova Liudmila

2017-01-01

Full Text Available The article considers the possibility of using an LED lighting system with a power source from solar modules in the climatic conditions of Siberia. The technical possibility of implementing an autonomous house lighting system is shown for example in the lighting of a residential five-story building located in Tomsk. The choice and justification of the neces-sary electrical equipment for solar panels was made. Calculations have been made for the energy consumption of the existing lighting system and a system with LED light sources from photovoltaic panels. The payback period of the project is determined. On the example of an autonomous sys-tem of interior lighting of an apartment building, conclusions were made about the feasibility and efficiency of using photovoltaic panels in the cli-matic conditions of Tomsk region.

ESCO Project for Buildings of Government Agencies in Thailand

Directory of Open Access Journals (Sweden)

Prukvilailert Monchai

2016-01-01

Full Text Available In Thailand, Department of Alternative Energy Development and Efficiency (DEDE have organized the ESCO project to promote and encourage the use of machinery, materials and equipment having high efficiency for government buildings. ESCO company provides the invest and management for changing equipments in the buildings. In this paper, the evaluation of the project has been presented. The potential of electricity savings is about 77 million kwhr/year. It can reduce imports of crude oil about 6.58 thousand tons of crude oil (Ktoe/year. The budget to invest is BHT 1,504 million, with an average payback period of 4.85. However, we found that the establishment of the budget is the barriers. The recommendations and solutions using legal process have been presented to proceed the project in the future.

ECONOMIC AND FINANCIAL ANALYSIS OF THE BUILDINGS REHABILITATION SOLUTIONS

Directory of Open Access Journals (Sweden)

STAN IVAN F.E.

2016-07-01

Full Text Available The paper includes a simplified economical and financial analysis of the buildings rehabilitation solutions, for heating and lighting. The most important economic and financial indicators analyzed and determined are: economic return on investment and payback period of investment in dynamic form, net present value, and internal rate of return economic residual value of the investment on thermal insulation, building maintenance costs, energy costs. In order to reduce the electricity consumption: the methods consisted in replacing inefficient lighting with some efficient energy and for heat consumption: the proposed solution was building rehabilitation (exterior wall insulation, floor insulation board. The analysis consists in determining the economical and financial indicators before and after the building rehabilitation. The 3 rooms apartment is located in Craiova town, (wind zone IV, 2nd floor, orientation is S.

Analisa Kelayakan Finansial Pengembangan Cold Storage Plant di Pelabuhan Perikanan Lampulo Baru Banda Aceh

Directory of Open Access Journals (Sweden)

Juanda Juanda

2014-02-01

Full Text Available The research aims to analyze financial feasibility of cold storage development in Lampulo Baru Fish Port Banda Aceh in accordance with discounted investment ctiteria; Net Present Value (NPV, Net Benefit Cost Ratio (NBCR, Gross Benefit Cost Ratio (GBCR and payback period (PBP. The research was conducted in Lampulo Baru Fish Port on November 2013 – January 2014. Data was mainly collected by using survei and interview/ focus group discussion techniques. Data were analyzed by using financial analysis with investment criteria. The result of research showed that the development of cold storage plant in Lampulo Baru Fish Port with capacity of 80 ton fishes is financially feasible, indicated by discounted investment criteria values; NPV = IDR. 1,463,819,997,-. NBCR = 2.33, GBCR = 1.03,  and PBP = 2.33 years.

Development of an innovative solar absorber

Science.gov (United States)

Goodchild, Gavin

Solar thermal systems have great potential to replace or reduce the dependence of conventional fossil fuel based heating technologies required for space and water heating. Specifically solar domestic hot water systems can contribute 50-75% of the annual thermal load. To date residential users have been slow to purchase and install systems, primarily due to the large monetary investment required to purchase and install a system. Recent innovations in materials design and manufacturing techniques, offer opportunities for the development of absorber plate designs that have the potential to reduce cost, increase efficiency and reduce payback periods. Consequently, this design study was conducted in conjunction with industrial partners to develop an improved absorber based on roll bond manufacturing that can be produced at reduced cost with comparable or greater thermal efficiency.

Field Demonstration of Ground-Source Integrated Heat Pump Part I. Technology and Field Demo System/Site Descriptions, and Preliminary Summer/Fall Performance Analysis for One Site

Energy Technology Data Exchange (ETDEWEB)

Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gehl, Anthony C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-02-01

The field study is planned to continue through the 2016 cooling season with the draft final project report due by September 30, 2016. This report provides a description of both installations and preliminary 2015 cooling and fall season performance results for the Knoxville site. For the August 18 through December 14 period, the Knoxville site GS-IHP provided 53.6% total source energy savings compared to a baseline electric RTU/heat pump and electric WH. Peak demand savings ranged from 33% to 59% per month. Energy cost savings of 53.1% have been achieved to date with more than half of that coming from reduced demand charges. Data on installation and maintenance costs are being collected and will be combined with total test period energy savings data for a payback analysis to be included in the project final report. The GS-IHP also saved a significant amount of carbon emissions. The total emission savings for the Knoxville site for the August-December 2015 period were ~0.8 metric tons. If trading for carbon credits ever becomes a reality, additional cost savings would be realized.

A technique to detect periodic and non-periodic ultra-rapid flux time variations with standard radio-astronomical data

Science.gov (United States)

Borra, Ermanno F.; Romney, Jonathan D.; Trottier, Eric

2018-06-01

We demonstrate that extremely rapid and weak periodic and non-periodic signals can easily be detected by using the autocorrelation of intensity as a function of time. We use standard radio-astronomical observations that have artificial periodic and non-periodic signals generated by the electronics of terrestrial origin. The autocorrelation detects weak signals that have small amplitudes because it averages over long integration times. Another advantage is that it allows a direct visualization of the shape of the signals, while it is difficult to see the shape with a Fourier transform. Although Fourier transforms can also detect periodic signals, a novelty of this work is that we demonstrate another major advantage of the autocorrelation, that it can detect non-periodic signals while the Fourier transform cannot. Another major novelty of our work is that we use electric fields taken in a standard format with standard instrumentation at a radio observatory and therefore no specialized instrumentation is needed. Because the electric fields are sampled every 15.625 ns, they therefore allow detection of very rapid time variations. Notwithstanding the long integration times, the autocorrelation detects very rapid intensity variations as a function of time. The autocorrelation could also detect messages from Extraterrestrial Intelligence as non-periodic signals.

From the Mendeleev periodic table to particle physics and back to the periodic table

Energy Technology Data Exchange (ETDEWEB)

Kibler, Maurice R. [Universite de Lyon, Institut de Physique Nucleaire, Universite Lyon 1 and CNRS/IN2P3, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne Cedex (France)

2006-11-15

We briefly describe in this paper the passage from Mendeleev's chemistry (1869) to atomic physics (in the 1900's), nuclear physics (in the 1932's) and particle physics (from 1953 to 2006). We show how the consideration of symmetries, largely used in physics since the end of the 1920's, gave rise to a new format of the periodic table in the 1970's. More specifically, this paper is concerned with the application of the group SO(4,2)xSU(2) to the periodic table of chemical elements. It is shown how the Madelung rule of the atomic shell model can be used for setting up a periodic table that can be further rationalized via the group SO(4,2)xSU(2) and some of its subgroups. Qualitative results are obtained from this nonstandard table. (author)

Autoinflammatory Diseases with Periodic Fevers.

Science.gov (United States)

Sag, Erdal; Bilginer, Yelda; Ozen, Seza

2017-07-01

One purpose of this review was to raise awareness for the new autoinflammatory syndromes. These diseases are increasingly recognized and are in the differential diagnosis of many disease states. We also aimed to review the latest recommendations for the diagnosis, management, and treatment of these patients. Familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS), and hyperimmunoglobulinemia D and periodic fever syndrome/mevalonate kinase deficiency (HIDS/MVKD) are the more common autoinflammatory diseases that are characterized by periodic fevers and attacks of inflammation. Recently much collaborative work has been done to understand the characteristics of these patients and to develop recommendations to guide the physicians in the care of these patients. These recent recommendations will be summarized for all four diseases. FMF is the most common periodic fever disease. We need to further understand the pathogenesis and the role of single mutations in the disease. Recently, the management and treatment of the disease have been nicely reviewed. CAPS is another interesting disease associated with severe complications. Anti-interleukin-1 (anti-IL-1) treatment provides cure for these patients. TRAPS is characterized by the longest delay in diagnosis; thus, both pediatricians and internists should be aware of the characteristic features and the follow-up of these patients. HIDS/MVKD is another autoinflammatory diseases characterized with fever attacks. The spectrum of disease manifestation is rather large in this disease, and we need further research on biomarkers for the optimal management of these patients.

PERIODIC SIGNALS IN BINARY MICROLENSING EVENTS

International Nuclear Information System (INIS)

Guo, Xinyi; Stefano, Rosanne Di; Esin, Ann; Taylor, Jeffrey

2015-01-01

Gravitational microlensing events are powerful tools for the study of stellar populations. In particular, they can be used to discover and study a variety of binary systems. A large number of binary lenses have already been found through microlensing surveys and a few of these systems show strong evidence of orbital motion on the timescale of the lensing event. We expect that more binary lenses of this kind will be detected in the future. For binaries whose orbital period is comparable to the event duration, the orbital motion can cause the lensing signal to deviate drastically from that of a static binary lens. The most striking property of such light curves is the presence of quasi-periodic features, which are produced as the source traverses the same regions in the rotating lens plane. These repeating features contain information about the orbital period of the lens. If this period can be extracted, then much can be learned about the lensing system even without performing time-consuming, detailed light-curve modeling. However, the relative transverse motion between the source and the lens significantly complicates the problem of period extraction. To resolve this difficulty, we present a modification of the standard Lomb–Scargle periodogram analysis. We test our method for four representative binary lens systems and demonstrate its efficiency in correctly extracting binary orbital periods

Periodicity and repeatability in data

Science.gov (United States)

Southwood, D.

Using magnetic data from the first two years in Saturn orbit, the basic periodicity of apparent is examined with the aim of elucidating the `cam' shaft model of Espinosa et al. (2003) identifying the nature of the `cam' and giving a definitive period for its rotation. An initial hypothesis, supported by the spectral analysis of analysis of the first 8 months in orbit Gianpieri et al. (2006), is made that the source of the period is linked to something inside the planet and therefore that the source inertia means that the period effectively does not change over the 2 years. Moreover one expects that the source phase is fixed. Using this approach, not only can the period identified by spectral analysis (647.1 + 0.6 min.) be verified but also by phase analysis between successive passes over the 2 years the period can be refined to 647.6 + 0.1 min. The signal itself is remarkably reproducible from pass to pass. It appears in all three components of the field and its polarisation is unambiguously not attributable to direct detection of an internal field. Not only does the signal not decay rapidly with distance from the planet, but although it has the m=1 symmetry of a tilted dipole, the field lines diverge from the planet indicating an exterior source. This feature led to the `cam' model. The polarisation and comparisons of passes with different latitude profiles show a surprising north-south symmetry in the azimuthal field. The absence of asymmetry with respect to the magnetic equator rules out a direct magnetospheric-ionospheric interaction source. Accordingly, it is proposed that the basic `cam' effect is generated by a single hemisphere anomaly which creates hemisphere to hemisphere field aligned currents. The existence of Saturn phase related anomaly appears to produce a basic asymmetry in the inner magnetosphere that sets the phase of both an inflowing and outflowing sector in a rotating circulation system.

The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

International Nuclear Information System (INIS)

Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen

2013-01-01

Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage

The transition mechanism from a symmetric single period discharge to a period-doubling discharge in atmospheric helium dielectric-barrier discharge

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dingzong; Wang, Yanhui; Wang, Dezhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China)

2013-06-15

Period-doubling and chaos phenomenon have been frequently observed in atmospheric-pressure dielectric-barrier discharges. However, how a normal single period discharge bifurcates into period-doubling state is still unclear. In this paper, by changing the driving frequency, we study numerically the transition mechanisms from a normal single period discharge to a period-doubling state using a one-dimensional self-consistent fluid model. The results show that before a discharge bifurcates into a period-doubling state, it first deviates from its normal operation and transforms into an asymmetric single period discharge mode. Then the weaker discharge in this asymmetric discharge will be enhanced gradually with increasing of the frequency until it makes the subsequent discharge weaken and results in the discharge entering a period-doubling state. In the whole transition process, the spatial distribution of the charged particle density and the electric field plays a definitive role. The conclusions are further confirmed by changing the gap width and the amplitude of the applied voltage.

Time-Varying Periodicity in Intraday Volatility

DEFF Research Database (Denmark)

Andersen, Torben Gustav; Thyrsgaard, Martin; Todorov, Viktor

We develop a nonparametric test for deciding whether return volatility exhibits time-varying intraday periodicity using a long time-series of high-frequency data. Our null hypothesis, commonly adopted in work on volatility modeling, is that volatility follows a stationary process combined...... with a constant time-of-day periodic component. We first construct time-of-day volatility estimates and studentize the high-frequency returns with these periodic components. If the intraday volatility periodicity is invariant over time, then the distribution of the studentized returns should be identical across...... with estimating volatility moments through their sample counterparts. Critical values are computed via easy-to-implement simulation. In an empirical application to S&P 500 index returns, we find strong evidence for variation in the intraday volatility pattern driven in part by the current level of volatility...

Economic comparison of a sixty day dry period with no dry period on Dutch dairy farms

NARCIS (Netherlands)

Heeren, J.A.H.; Steeneveld, W.; Berentsen, P.B.M.

2014-01-01

In the Netherlands it is general practice that dairy cows have a dry period of six to eight weeks. Research, however, shows that omission of the dry period avoids the negative energy balance after calving with its potential negative effects on metabolic disorders, infectious diseases, and fertility.

Three dimensional periodic foundations for base seismic isolation

International Nuclear Information System (INIS)

Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

2015-01-01

Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

The School Advanced Ventilation Engineering Software (SAVES)

Science.gov (United States)

The School Advanced Ventilation Engineering Software (SAVES) package is a tool to help school designers assess the potential financial payback and indoor humidity control benefits of Energy Recovery Ventilation (ERV) systems for school applications.

Periodic solutions of dissipative systems revisited

Directory of Open Access Journals (Sweden)

Górniewicz Lech

2006-01-01

Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

Periodic solutions of dissipative systems revisited

Directory of Open Access Journals (Sweden)

Lech Górniewicz

2006-05-01

Full Text Available We reprove in an extremely simple way the classical theorem that time periodic dissipative systems imply the existence of harmonic periodic solutions, in the case of uniqueness. We will also show that, in the lack of uniqueness, the existence of harmonics is implied by uniform dissipativity. The localization of starting points and multiplicity of periodic solutions will be established, under suitable additional assumptions, as well. The arguments are based on the application of various asymptotic fixed point theorems of the Lefschetz and Nielsen type.

Multi-periodic nanostructures for photon control

DEFF Research Database (Denmark)

Kluge, Christian; Adam, Jost; Barié, Nicole

2014-01-01

We propose multi-periodic nanostructures yielded by superposition of multiple binary gratings for wide control over photon emission in thin-film devices. We present wavelength- and angle-resolved photoluminescence measurements of multi-periodically nanostructured organic light-emitting layers...

Multiphase averaging of periodic soliton equations

International Nuclear Information System (INIS)

Forest, M.G.

1979-01-01

The multiphase averaging of periodic soliton equations is considered. Particular attention is given to the periodic sine-Gordon and Korteweg-deVries (KdV) equations. The periodic sine-Gordon equation and its associated inverse spectral theory are analyzed, including a discussion of the spectral representations of exact, N-phase sine-Gordon solutions. The emphasis is on physical characteristics of the periodic waves, with a motivation from the well-known whole-line solitons. A canonical Hamiltonian approach for the modulational theory of N-phase waves is prescribed. A concrete illustration of this averaging method is provided with the periodic sine-Gordon equation; explicit averaging results are given only for the N = 1 case, laying a foundation for a more thorough treatment of the general N-phase problem. For the KdV equation, very general results are given for multiphase averaging of the N-phase waves. The single-phase results of Whitham are extended to general N phases, and more importantly, an invariant representation in terms of Abelian differentials on a Riemann surface is provided. Several consequences of this invariant representation are deduced, including strong evidence for the Hamiltonian structure of N-phase modulational equations

Periods found in heat measurements obtained by calorimetry

International Nuclear Information System (INIS)

Jordan, K.C.

1984-01-01

During a span of 640 days, a periodicity of 1.5158 +- 0.0008 days was discovered in successive heater equilibria on Calorimeter No. 127. Measurements were taken at 12-h intervals, with occasional changes of exactly 3 or 6 h in the schedule of measurements. This schedule eliminated all other possible periods except a period of 0.150156 days. Periods of 1.519125 and 1.511283 days were discovered in data on the excess length of day as obtained by the US Naval Observatory over a period of 24 y. These two periods could equally well represent periods of 0.150189 and 0.150112 days, since measurements were obtained only once every 24 h. It is suggested that periods observed in sensitive calorimeters and in length of day data may be related. 1 reference, 6 figures, 5 tables

Approaches and Methods of Periodization in Literary History

Directory of Open Access Journals (Sweden)

Naser Gholi Sarli

2013-10-01

Full Text Available Abstract One of the most fundamental acts of historiography is to classify historical information in diachronic axis. The method of this classification or periodization shows the theoretical approach of the historian and determines the structure and the form of his history. Because of multiple criteria of analysis and various literary genres, periodization in literary history is more complicated than that of general history. We can distinguish two approaches in periodization of literary history, although these can be used together: extrinsic or social-cultural approach (based on criteria extrinsic to literature and intrinsic or formalist approach (based on criteria intrinsic to literature. Then periodization in literary history can be formulated in different methods and may be based upon various criteria: chronological such as century, decade and year organic patterns of evolution great poets and writers literary emblems and evaluations of every period events, concepts and periods of general or political history analogy of literary history and history of ideas or history of arts approaches and styles of language dominant literary norms. These methods actually are used together and everyone has adequacy in special kind of literary history. In periodization of Persian contemporary literature, some methods and models current in periodization of poetry have been applied identically to periodization of prose. Periodization based upon century, decade and year is the simplest and most mechanical method but sometimes certain centuries in some countries have symbolic and stylistic meaning, and decades were used often for subdivisions of literary history, especially nowadays with fast rhythm of literary change. Periodization according to organic patterns of evolution equates the changes of literary history with the life phases of an organism, and offers an account of birth, mature and death (and sometimes re-birth of literary genres, but this method have

Approaches and Methods of Periodization in Literary History

Directory of Open Access Journals (Sweden)

Dr. N. Gh. Sarli

Full Text Available One of the most fundamental acts of historiography is to classify historical information in diachronic axis. The method of this classification or periodization shows the theoretical approach of the historian and determines the structure and the form of his history. Because of multiple criteria of analysis and various literary genres, periodization in literary history is more complicated than that of general history. We can distinguish two approaches in periodization of literary history, although these can be used together: extrinsic or social-cultural approach (based on criteria extrinsic to literature and intrinsic or formalist approach (based on criteria intrinsic to literature. Then periodization in literary history can be formulated in different methods and may be based upon various criteria: chronological such as century, decade and year; organic patterns of evolution; great poets and writers; literary emblems and evaluations of every period; events, concepts and periods of general or political history; analogy of literary history and history of ideas or history of arts; approaches and styles of language; dominant literary norms. These methods actually are used together and everyone has adequacy in special kind of literary history. In periodization of Persian contemporary literature, some methods and models current in periodization of poetry have been applied identically to periodization of prose. Periodization based upon century, decade and year is the simplest and most mechanical method but sometimes certain centuries in some countries have symbolic and stylistic meaning, and decades were used often for subdivisions of literary history, especially nowadays with fast rhythm of literary change.Periodization according to organic patterns of evolution equates the changes of literary history with the life phases of an organism, and offers an account of birth, mature and death (and sometimes re-birth of literary genres, but this method have

Approaches and Methods of Periodization in Literary History

Directory of Open Access Journals (Sweden)

Naser Gholi Sarli

2013-11-01

Full Text Available Abstract One of the most fundamental acts of historiography is to classify historical information in diachronic axis. The method of this classification or periodization shows the theoretical approach of the historian and determines the structure and the form of his history. Because of multiple criteria of analysis and various literary genres, periodization in literary history is more complicated than that of general history. We can distinguish two approaches in periodization of literary history, although these can be used together: extrinsic or social-cultural approach (based on criteria extrinsic to literature and intrinsic or formalist approach (based on criteria intrinsic to literature. Then periodization in literary history can be formulated in different methods and may be based upon various criteria: chronological such as century, decade and year organic patterns of evolution great poets and writers literary emblems and evaluations of every period events, concepts and periods of general or political history analogy of literary history and history of ideas or history of arts approaches and styles of language dominant literary norms. These methods actually are used together and everyone has adequacy in special kind of literary history. In periodization of Persian contemporary literature, some methods and models current in periodization of poetry have been applied identically to periodization of prose. Periodization based upon century, decade and year is the simplest and most mechanical method but sometimes certain centuries in some countries have symbolic and stylistic meaning, and decades were used often for subdivisions of literary history, especially nowadays with fast rhythm of literary change. Periodization according to organic patterns of evolution equates the changes of literary history with the life phases of an organism, and offers an account of birth, mature and death (and sometimes re-birth of literary genres, but this method have

The period-luminosity relation for Cepheids

International Nuclear Information System (INIS)

Brodie, J.P.

1980-01-01

Numerical simulations of the empirical determination of the period-luminosity-colour relation for classical Cepheids are presented. In this study the quantitative effects of random errors, reddening, sample size and the presence of both colour and period cut-offs (imposed by the finite extent of the instability strip) on the observational redetermination of the original relation are evaluated. Both random errors in the photometry and correlated errors in the reddening corrections are shown to have systematic effects. Especially sensitive to these errors is the colour coefficient in the period-luminosity-colour relation, where the ratio of the error to the width of the instability strip is the determining factor. With present observations only broad confidence limits can be placed on present knowledge of the intrinsic period-luminosity-colour relation and/or its variations from galaxy to galaxy. (author)

Broiler adaptation to post-hatching period

Directory of Open Access Journals (Sweden)

Maiorka Alex

2006-01-01

Full Text Available In the latest years more attention has been given to mechanisms for bird adaptation at post-hatching period by management of environmental conditions and formulations of diets offered during this period when digestive, immune, and thermo-regulating systems suffer slight changes. In post-hatching period, digestive system is anatomically complete, but its functionality is still immature in relation to adult birds. The chick immunity depends on maternal antibodies transferred to egg just before laying. In addition, variations within thermal comfort zone might affect initial development of chick. For example, high temperatures may induce hyperthermia with dehydration, while low temperatures may lead to hypothermia responsible by pulmonary hypertension syndrome. In conclusion, productivity might be enhanced when good conditions are offered to chicks during the period from last embryo development to first days after hatching.

The physiological period length of the human circadian clock in vivo is directly proportional to period in human fibroblasts.

Directory of Open Access Journals (Sweden)

Lucia Pagani

Full Text Available BACKGROUND: Diurnal behavior in humans is governed by the period length of a circadian clock in the suprachiasmatic nuclei of the brain hypothalamus. Nevertheless, the cell-intrinsic mechanism of this clock is present in most cells of the body. We have shown previously that for individuals of extreme chronotype ("larks" and "owls", clock properties measured in human fibroblasts correlated with extreme diurnal behavior. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we have measured circadian period in human primary fibroblasts taken from normal individuals and, for the first time, compared it directly with physiological period measured in vivo in the same subjects. Human physiological period length was estimated via the secretion pattern of the hormone melatonin in two different groups of sighted subjects and one group of totally blind subjects, each using different methods. Fibroblast period length was measured via cyclical expression of a lentivirally delivered circadian reporter. Within each group, a positive linear correlation was observed between circadian period length in physiology and in fibroblast gene expression. Interestingly, although blind individuals showed on average the same fibroblast clock properties as sighted ones, their physiological periods were significantly longer. CONCLUSIONS/SIGNIFICANCE: We conclude that the period of human circadian behaviour is mostly driven by cellular clock properties in normal individuals and can be approximated by measurement in peripheral cells such as fibroblasts. Based upon differences among sighted and blind subjects, we also speculate that period can be modified by prolonged unusual conditions such as the total light deprivation of blindness.

Inflation from periodic extra dimensions

Energy Technology Data Exchange (ETDEWEB)

Higaki, Tetsutaro [Department of Physics, Keio University, Kanagawa 223-8522 (Japan); Tatsuta, Yoshiyuki, E-mail: thigaki@rk.phys.keio.ac.jp, E-mail: y_tatsuta@akane.waseda.jp [Department of Physics, Waseda University, Tokyo 169-8555 (Japan)

2017-07-01

We discuss a realization of a small field inflation based on string inspired supergravities. In theories accompanying extra dimensions, compactification of them with small radii is required for realistic situations. Since the extra dimension can have a periodicity, there will appear (quasi-)periodic functions under transformations of moduli of the extra dimensions in low energy scales. Such a periodic property can lead to a UV completion of so-called multi-natural inflation model where inflaton potential consists of a sum of multiple sinusoidal functions with a decay constant smaller than the Planck scale. As an illustration, we construct a SUSY breaking model, and then show that such an inflaton potential can be generated by a sum of world sheet instantons in intersecting brane models on extra dimensions containing orbifold. We show also predictions of cosmic observables by numerical analyzes.

Project 2nd Periodic Report - Section 2

DEFF Research Database (Denmark)

Healy, Mark; Knowles, Emma; Johnstone, Cameron

The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive.......The work described in this publication has received support from the European Community - Research Infrastructure Action under the FP7 “Capacities” Specific Programme through grant agreement number 262552, MaRINET. Project Periodic Report. 2nd Period: October 2012 – March 2014 inclusive....

Shock dynamics in layered periodic media

KAUST Repository

Ketcheson, David I.; Leveque, Randall J.

2012-01-01

of shock waves in a one-dimensional periodic layered medium by a computational study of time-reversibility and entropy evolution. We find that periodic layered media tend to inhibit shock formation. For small initial conditions and large impedance variation

Periodic vehicle inspection (MOT). [previously: Periodic Vehicle Inspection of cars (MOT).

NARCIS (Netherlands)

2010-01-01

In the 1980s the periodic vehicle inspection (MOT) of various categories of vehicles was introduced in the Netherlands. This fact sheet will discuss the legal framework of this measure and the research carried out into its effects on road safety, also in an international context. For instance, the

Topological imprint for periodic orbits

International Nuclear Information System (INIS)

Martín, Jesús San; Moscoso, Ma José; Gómez, A González

2012-01-01

The more self-crossing points an orbit has the more complex it is. We introduce the topological imprint to characterize crossing points and focus on the period-doubling cascade. The period-doubling cascade topological imprint determines the topological imprint for orbits in chaotic bands. In addition, there is a closer link between this concept and the braids studied by Lettelier et al (2000 J. Phys. A: Math. Gen. 33 1809–25). (paper)

5 CFR 9901.512 - Probationary periods.

Science.gov (United States)

2010-01-01

... 9901.512 Administrative Personnel DEPARTMENT OF DEFENSE HUMAN RESOURCES MANAGEMENT AND LABOR RELATIONS SYSTEMS (DEPARTMENT OF DEFENSE-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF DEFENSE NATIONAL SECURITY... Probationary periods. (a) Initial probationary period. (1) An employee who is given a career, career...

Period Variations for the Cepheid VZ Cyg

Science.gov (United States)

Sirorattanakul, Krittanon; Engle, Scott; Pepper, Joshua; Wells, Mark; Laney, Clifton D.; Rodriguez, Joseph E.; Stassun, Keivan G.

2017-12-01

The Cepheid Period-Luminosity law is a key rung on the extragalactic distance ladder. However, numerous Cepheids are known to undergo period variations. Monitoring, refining, and understanding these period variations allows us to better determine the parameters of the Cepheids themselves and of the instability strip in which they reside, and to test models of stellar evolution. VZ Cyg, a classical Cepheid pulsating at ˜4.864 days, has been observed for over 100 years. Combining data from literature observations, the Kilodegree Extremely Little Telescope (KELT) transit survey, and new targeted observations with the Robotically Controlled Telescope (RCT) at Kitt Peak, we find a period change rate of dP/dt = -0.0642 ± 0.0018 s yr-1. However, when only the recent observations are examined, we find a much higher period change rate of dP/dt = -0.0923 ± 0.0110 s yr-1. This higher rate could be due to an apparent long-term (P ≈ 26.5 years) cyclic period variation. The possible interpretations of this single Cepheid’s complex period variations underscore both the need to regularly monitor pulsating variables and the important benefits that photometric surveys such as KELT can have on the field. Further monitoring of this interesting example of Cepheid variability is recommended to confirm and better understand the possible cyclic period variations. Further, Cepheid timing analyses are necessary to fully understand their current behaviors and parameters, as well as their evolutionary histories.

Viral infection model with periodic lytic immune response

International Nuclear Information System (INIS)

Wang Kaifa; Wang Wendi; Liu Xianning

2006-01-01

Dynamical behavior and bifurcation structure of a viral infection model are studied under the assumption that the lytic immune response is periodic in time. The infection-free equilibrium is globally asymptotically stable when the basic reproductive ratio of virus is less than or equal to one. There is a non-constant periodic solution if the basic reproductive ratio of the virus is greater than one. It is found that period doubling bifurcations occur as the amplitude of lytic component is increased. For intermediate birth rates, the period triplication occurs and then period doubling cascades proceed gradually toward chaotic cycles. For large birth rate, the period doubling cascade proceeds gradually toward chaotic cycles without the period triplication, and the inverse period doubling can be observed. These results can be used to explain the oscillation behaviors of virus population, which was observed in chronic HBV or HCV carriers

Dispersion Differences and Consistency of Artificial Periodic Structures.

Science.gov (United States)

Cheng, Zhi-Bao; Lin, Wen-Kai; Shi, Zhi-Fei

2017-10-01

Dispersion differences and consistency of artificial periodic structures, including phononic crystals, elastic metamaterials, as well as periodic structures composited of phononic crystals and elastic metamaterials, are investigated in this paper. By developing a K(ω) method, complex dispersion relations and group/phase velocity curves of both the single-mechanism periodic structures and the mixing-mechanism periodic structures are calculated at first, from which dispersion differences of artificial periodic structures are discussed. Then, based on a unified formulation, dispersion consistency of artificial periodic structures is investigated. Through a comprehensive comparison study, the correctness for the unified formulation is verified. Mathematical derivations of the unified formulation for different artificial periodic structures are presented. Furthermore, physical meanings of the unified formulation are discussed in the energy-state space.

Existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems with several deviating arguments.

Science.gov (United States)

Fan, M; Wang, K; Jiang, D

1999-08-01

In this paper, we study the existence and global attractivity of positive periodic solutions of periodic n-species Lotka-Volterra competition systems. By using the method of coincidence degree and Lyapunov functional, a set of easily verifiable sufficient conditions are derived for the existence of at least one strictly positive (componentwise) periodic solution of periodic n-species Lotka-Volterra competition systems with several deviating arguments and the existence of a unique globally asymptotically stable periodic solution with strictly positive components of periodic n-species Lotka-Volterra competition system with several delays. Some new results are obtained. As an application, we also examine some special cases of the system we considered, which have been studied extensively in the literature. Some known results are improved and generalized.

Periodic and secular changes in SS 433

International Nuclear Information System (INIS)

Collins, G.W.; Newsom, G.H.

1983-01-01

The recent history of SS 433 is reviewed with particular attention being given to the discovery of the periodic phenomena displayed by this object. Several periods ranging from days to months are established as being present in the spectrum of the ''moving'' lines as well as in other aspects of the emission from the object. In addition evidence for secular change in some of the defining parameters of the system is presented. Although these secular changes may eventually prove to be periodic on a rather long time scale, some interpretation of both the periodic and secular phenomena is possible. It is shown that it is possible to interpret all the known periodic phenomena in terms of a processing object responding to the time-varying torques that one would expect in a binary system

38 CFR 3.2 - Periods of war.

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Periods of war. 3.2..., Compensation, and Dependency and Indemnity Compensation General § 3.2 Periods of war. This section sets forth the beginning and ending dates of each war period beginning with the Indian wars. Note that the term...

Periodicity, the Canon and Sport

Directory of Open Access Journals (Sweden)

Thomas F. Scanlon

2015-10-01

Full Text Available The topic according to this title is admittedly a broad one, embracing two very general concepts of time and of the cultural valuation of artistic products. Both phenomena are, in the present view, largely constructed by their contemporary cultures, and given authority to a great extent from the prestige of the past. The antiquity of tradition brings with it a certain cachet. Even though there may be peripheral debates in any given society which question the specifics of periodization or canonicity, individuals generally accept the consensus designation of a sequence of historical periods and they accept a list of highly valued artistic works as canonical or authoritative. We will first examine some of the processes of periodization and of canon-formation, after which we will discuss some specific examples of how these processes have worked in the sport of two ancient cultures, namely Greece and Mesoamerica.

The Dynamic Multi-Period Vehicle Routing Problem

DEFF Research Database (Denmark)

Wen, Min; Cordeau, Jean-Francois; Laporte, Gilbert

This paper considers the Dynamic Multi-Period Vehicle Routing Problem which deals with the distribution of orders from a depot to a set of customers over a multi-period time horizon. Customer orders and their feasible service periods are dynamically revealed over time. The objectives are to minim......This paper considers the Dynamic Multi-Period Vehicle Routing Problem which deals with the distribution of orders from a depot to a set of customers over a multi-period time horizon. Customer orders and their feasible service periods are dynamically revealed over time. The objectives...... are to minimize total travel costs and customer waiting, and to balance the daily workload over the planning horizon. This problem originates from a large distributor operating in Sweden. It is modeled as a mixed integer linear program, and solved by means of a three-phase heuristic that works over a rolling...... planning horizon. The multi-objective aspect of the problem is handled through a scalar technique approach. Computational results show that our solutions improve upon those of the Swedish distributor....

Painful periods (dysmenorrhea) (image)

Science.gov (United States)

Primary dysmenorrhea is a normal cramping of the lower abdomen caused by hormone-induced uterine contractions before the period. Secondary dysmenorrhea may be caused by abnormal conditions such as ...

Discontinuous Spirals of Stable Periodic Oscillations

DEFF Research Database (Denmark)

Sack, Achim; Freire, Joana G.; Lindberg, Erik

2013-01-01

We report the experimental discovery of a remarkable organization of the set of self-generated periodic oscillations in the parameter space of a nonlinear electronic circuit. When control parameters are suitably tuned, the wave pattern complexity of the periodic oscillations is found to increase...

Selecting Full-Text Undergraduate Periodicals Databases.

Science.gov (United States)

Still, Julie M.; Kassabian, Vibiana

1999-01-01

Examines how libraries and librarians can compare full-text general periodical indices, using ProQuest Direct, Periodical Abstracts (via Ovid), and EBSCOhost as examples. Explores breadth and depth of coverage; manipulation of results (email/download/print); ease of use (searching); and indexing quirks. (AEF)

Almost periodic Hamiltonians: an algebraic approach

International Nuclear Information System (INIS)

Bellissard, J.

1981-07-01

We develop, by analogy with the study of periodic potential, an algebraic theory for almost periodic hamiltonians, leading to a generalized Bloch theorem. This gives rise to results concerning the spectral measures of these operators in terms of those of the corresponding Bloch hamiltonians

Direct application of geothermal energy at the L'eggs Product Plant, Las Cruces, New Mexico. Final report

Energy Technology Data Exchange (ETDEWEB)

1981-02-01

The study program to determine the feasibility of interfacing a potential geothermal resource of Dona Ana County, New Mexico L'eggs Product industrial process is discussed in this final report. Five separate sites were evaluated initially as to geothermal potential and technical feasibility. Preliminary analysis revealed that three sites were considered normal, but that two sites (about three miles from the L'eggs Plant) had very high shallow subsurface temperature gradients (up to 14.85/sup 0/F/100 ft). An initial engineering analysis showed that to meet the L'eggs plant temperature and energy requirements a geothermal fluid temperature of about 250/sup 0/F and 200 gpm flow rate would be necessary. A brief economic comparison indicated that the L'eggs plant site and a geothermal site approximately four miles from the plant did merit further investigation. Detailed engineering and economic design and analysis of these two sites (including the drilling of an 1873 feet deep temperature gradient test hole at the L'eggs Plant) showed that development of the four mile distant site was technically feasible and was the more economic option. It was determined that a single-stage flash system interface design would be most appropriate for the L'eggs Plant. Approximately 39 billion Btu/yr of fossil fuel could be replaced with geothermal energy at the L'eggs facility for a total installed system cost of slightly over $2 million. The projected economic payback period was calculated to be 9.2 years before taxes. This payback was not considered acceptable by L'eggs Products, Inc., to merit additional design or construction work at this time.

Jersey City energy conservation demonstration program. Final report

Energy Technology Data Exchange (ETDEWEB)

Newbold, R.F.

1978-08-01

The Aerospace Corporation, the City Government, and the Board of Education of Jersey City have conducted a group of energy-conservation experiments to explore a number of conservation techniques believed to offer quick payback and to be of wide applicability. Experiments include the updating and/or rehabilitation of the energy-consuming features of old buildings and installation of devices designed to minimize energy losses caused by human error or laxity. Specific examples include: upgrading of the deteriorated and inefficient steam-distribution system of the city hall (originally constructed in 1894); an extensive program of reducing infiltration in an old school building; use of several timing devices in connection with heating, ventilation, and lighting systems to encourage energy-conservation practices; retrofit of school classrooms with high-pressure sodium lamps; and demonstration of practical and cost-effective ways of increasing the efficiency of conventional steam boilers. The report presents: the nature of the selected experiments; technical, human, and organizational factors that proved significant in performing and evaluating the experiments; discussions of observations and lessons learned; and general recommendations for an extended program of energy conservation in local governments. It is emphasized that, in retrofit of existing buildings, the unexpected is commonplace; and the habits and attitudes of building occupants are elements of the system that must always be taken into account. This report shows the benefits of energy saving, cost saving, and added comfort that may be attained by retrofitting old buildings, noting typical complications that arise. The effectiveness of the conservation methods is presented in terms of costs relative to effective payback periods calculated from results of their application in Jersey City.

Economic performance of photovoltaic water pumping systems with business model innovation in China

International Nuclear Information System (INIS)

Zhang, Chi; Campana, Pietro Elia; Yang, Jin; Yan, Jinyue

2017-01-01

Highlights: • A new business model of PV systems is proposed for PV water pumping systems (PVWP). • Three PVWP and one PV-roof scenarios are analysed to estimate economic performance. • The impacts of market incentives in four PV scenarios are insubstantial for its economic payback. • The PVWP system with added-value products will improve economy potential. - Abstract: Expansion by photovoltaic (PV) technologies in the renewable energy market requires exploring added value integrated with business model innovation. In recent years, a pilot trial of PV water pumping (PVWP) technologies for the conservation of grassland and farmland has been conducted in China. In this paper, we studied the added value of the PVWP technologies with an emphasis on the integration of the value proposition with the operation system and customer segmentation. Using the widely used existing PV business models (PV-roof) as a reference, we evaluated discounted cash flow (DCF) and net present value (NPV) under the scenarios of traditional PV roof, PVWP pilot, PVWP scale-up, and PVWP social network, where further added value via social network was included in the business model. The results show that the integrated PVWP system with social network products significantly improves the performance in areas such as the discounted payback period, internal rate of return (IRR), and return on investment (ROI). We conclude that scenario PVWP social network with business model innovation, can result in value add-ins, new sources of revenue, and market incentives. The paper also suggests that current policy incentives for PV industry are not efficient due to a limited source of revenue, and complex procedures of feed-in tariff verification.

Variable-Period Undulators For Synchrotron Radiation

Science.gov (United States)

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22

A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high-energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Variable-Period Undulators for Synchrotron Radiation

Energy Technology Data Exchange (ETDEWEB)

Shenoy, Gopal; Lewellen, John; Shu, Deming; Vinokurov, Nikolai

2005-02-22

A new and improved undulator design is provided that enables a variable period length for the production of synchrotron radiation from both medium-energy and high energy storage rings. The variable period length is achieved using a staggered array of pole pieces made up of high permeability material, permanent magnet material, or an electromagnetic structure. The pole pieces are separated by a variable width space. The sum of the variable width space and the pole width would therefore define the period of the undulator. Features and advantages of the invention include broad photon energy tunability, constant power operation and constant brilliance operation.

Convectons in periodic and bounded domains

International Nuclear Information System (INIS)

Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa; Knobloch, Edgar

2010-01-01

Numerical continuation is used to compute spatially localized convection in a binary fluid with no-slip laterally insulating boundary conditions and the results are compared with the corresponding ones for periodic boundary conditions (PBC). The change in the boundary conditions produces a dramatic change in the snaking bifurcation diagram that describes the organization of localized states with PBC: the snaking branches turn continuously into a large amplitude state that resembles periodic convection with defects at the sidewalls. Odd parity convectons are more affected by the boundary conditions since the sidewalls suppress the horizontal pumping action that accompanies these states in spatially periodic domains.

Convectons in periodic and bounded domains

Energy Technology Data Exchange (ETDEWEB)

Mercader, Isabel; Batiste, Oriol; Alonso, Arantxa [Departament de Fisica Aplicada, Universitat Politecnica de Catalunya, Barcelona (Spain); Knobloch, Edgar [Department of Physics, University of California, Berkeley, CA 94720 (United States)

2010-04-15

Numerical continuation is used to compute spatially localized convection in a binary fluid with no-slip laterally insulating boundary conditions and the results are compared with the corresponding ones for periodic boundary conditions (PBC). The change in the boundary conditions produces a dramatic change in the snaking bifurcation diagram that describes the organization of localized states with PBC: the snaking branches turn continuously into a large amplitude state that resembles periodic convection with defects at the sidewalls. Odd parity convectons are more affected by the boundary conditions since the sidewalls suppress the horizontal pumping action that accompanies these states in spatially periodic domains.

The period-age relation for cepheids

International Nuclear Information System (INIS)

Efremov, Yu.N.

1978-01-01

The list of 119 cepheid-members of 55 clusters and associations of the Magellanic Clouds, the Galaxy, and M31 is given. The period-age relation is found from the data on 64 cepheids in 29 clusters for which the age determinations are available, the ages of extragalactic clusters were determined mainly from their integral colours. The U-B colours are found to be of much better age parameters than the B-V ones. The composite period-age relation agrees well with the theoretical one. The observed dispersion of the period-age relation leads to an estimate of the age dispersion about 1x10 7 years in the associations. Some peculiarities of the cepheids with the shortest periods amongst others in the same clusters are probably explained if they are overtone pulsators. The period-age relation may be used for an investigation of the recent history of star formation in the galaxies. This relation allows to determine the age gradient across the spiral arm in M31 which is in agreement with the density wave theory predictions. The distribution of cepheids in our Galaxy and neighbouring galaxies is consistent with the conception of star formation lasting for some dozen million years in cells with a dimension of some hundreds of parsecs

Period Changes of 23 Field RR Lyrae Stars

Directory of Open Access Journals (Sweden)

Soo-Chang Rey

1994-12-01

Full Text Available The secular period behavior of 23 field RR Lyrae stars is studied in order to determine if the observed period changes could be attributed, at least in the mean, to stellar evolution. The sample of stars is subdivided into two Oosterhoff groups based on the metallicity and period-shift. Despite the small sample size, we found a distinct bias toward positive period changes in the group variables. The period changes of the group variables in globular clusters. This provides yet another support for the Lee, Demarque, and Zinn(1990 evolutionary models of RR Lyrae stars and their explanation of the Sandage period-shift effect.

The Periodic Table CD.

Science.gov (United States)

Banks, Alton J.; Holmes, Jon L.

1995-01-01

Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

The effects of regeneration temperature of the desiccant wheel on the performance of desiccant cooling cycles for greenhouse thermally insulated

Science.gov (United States)

Rjibi, Amel; Kooli, Sami; Guizani, Amenaallah

2018-05-01

The use of solar energy for cooling greenhouses in the hot period in Mediterranean climate is an important issue. Desiccant evaporative cooling (DEC) system is advantageous because it uses a low grade thermal energy and preserves the merits to be friendly environmentally technology. In this paper, a numerical investigation was carried out on a desiccant cooling system powered by air solar collectors coupled to an insulated greenhouse. The influence of the regeneration temperature on the air stream properties at every system component state point was studied. The performance of the desiccant cooling system was evaluated in terms of thermal and electric coefficient of performance. Results show that the best performance of the system (COPel = 14 and COPth = 0.94) was obtained for a 60 °C regeneration temperature and a supply flow rate ratio of 0.2. An economic analysis shows that the use of the DEC system for greenhouse cooling is attractive and profitable since the payback period is 1 years. The use of the proposed system allows saving 9396 kWh/year of electric energy compared to conventional system.

46 CFR 403.115 - Accounting period.

Science.gov (United States)

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Accounting period. 403.115 Section 403.115 Shipping COAST GUARD (GREAT LAKES PILOTAGE), DEPARTMENT OF HOMELAND SECURITY GREAT LAKES PILOTAGE UNIFORM ACCOUNTING SYSTEM General § 403.115 Accounting period. Each Association subject to this part shall maintain...

David's Understanding of Functions and Periodicity

Science.gov (United States)

Gerson, Hope

2008-01-01

This is a study of David, a senior enrolled in a high school precalculus course. David's understandings of functions and periodicity was explored, through clinical interviews and contextualized through classroom observations. Although David's precalculus class was traditional his understanding of periodic functions was unconventional David engaged…

Multi-Period Trading via Convex Optimization

DEFF Research Database (Denmark)

Boyd, Stephen; Busseti, Enzo; Diamond, Steve

2017-01-01

We consider a basic model of multi-period trading, which can be used to evaluate the performance of a trading strategy. We describe a framework for single-period optimization, where the trades in each period are found by solving a convex optimization problem that trades off expected return, risk......, transaction cost and holding cost such as the borrowing cost for shorting assets. We then describe a multi-period version of the trading method, where optimization is used to plan a sequence of trades, with only the first one executed, using estimates of future quantities that are unknown when the trades....... In this paper, we do not address a critical component in a trading algorithm, the predictions or forecasts of future quantities. The methods we describe in this paper can be thought of as good ways to exploit predictions, no matter how they are made. We have also developed a companion open-source software...

Periodic and in-service inspection programs

International Nuclear Information System (INIS)

Dinu, M.

2000-01-01

Periodic and in-service inspection programs for Cernavoda NPP consists of periodic inspections of CANDU NPP components CSAN N-285.4 and CSAN N-285.4, in-service inspections and repair and modifications general inspection. Periodic inspection program document (PIPD) determines the systems and components subject to inspection, the category of the inspection, techniques, areas and other details.The current status of the inspection programs is presented, including containment , erosion/corrosion, pressure vessel support and snubbers, main steam lines inspection programs. Qualification program in Cernavoda NPP involves equipment qualification in the on-site laboratory, yearly certification, special equipment qualification in the National Institute of Metrology. All procedures are approved by the ISCIR (regulatory body for pressure vessel and lifting equipment) and CNCAN (National Commission on Nuclear Activities Control). Qualification of the personnel is performed according to the ISCIR Technical prescription CR 11/82 for up to 3 year period. Final qualification and licensing is performed by CNCAN