WorldWideScience

Sample records for efficient source reduction

  1. Hydrogenated graphenes by birch reduction: influence of electron and proton sources on hydrogenation efficiency, magnetism, and electrochemistry

    Czech Academy of Sciences Publication Activity Database

    Eng, A.Y.S.; Sofer, Z.; Huber, Š.; Bouša, D.; Maryško, Miroslav; Pumera, M.

    2015-01-01

    Roč. 21, č. 7 (2015), 16828-16838 ISSN 0947-6539 Institutional support: RVO:68378271 Keywords : hydrogenated graphenes * birch reduction * magnetism * electrochemistry * hydrogenation efficiency Subject RIV: CA - Inorganic Chemistry Impact factor: 5.771, year: 2015

  2. Renewable Energy Sources, Energy Efficiency and Reduction of Greenhouse Gas Emissions as Main Sources Development of 'Green Economy' in Croatia until 2050

    International Nuclear Information System (INIS)

    Cosic, B.; Duic, N.; Krajacic, G.; Novosel, T.; Puksec, T.; Ridjan, I.

    2012-01-01

    Most countries will need a shift in their energy strategies in order to limit the increase in global warming and to reduce the emissions of greenhouse gases. It is worrying that while technologies with little or no greenhouse gas emissions exist, and are used for a couple of decades now, the increase of their market share is extremely low and the investments and subsidies in fossil fuels are substantially larger on a world wide scale. For changes to accrue it is necessary to carefully plan both the energy consumption and supply. A correct and rational prediction of future energy consumption is the basic assumption for the advanced analysis and modelling of energy systems and it will, as an input, have a profound influence on them. In this paper a bottom up approach was selected because it is the most suitable methodology to describe the legal, economic or purely technical mechanisms. Scenarios for the energy supply in 100% renewable systems in 2050 and the possibility to create a low-carbon society were simulated using the EnergyPLAN model for energy system analysis. Comparison of the necessary useful energy for space heating in 2050 shows a difference greater than 16% for different rates of renovation of the existing buildings in the residential sector of 1% and 3% annually. The electrification of road transport for passenger cars in combination with increased requirements for energy efficiency of internal combustion engines can reduce the energy consumption in the transport sector by 30% in comparison to the reference scenario for 2050. It is possible to reduce the emission of greenhouse gases by 82% in the period 2030-2050 and the use of renewable energy sources and the production of synthetic fuels can enable a transition to a 100% renewable energy system in Croatia in 2050. Doing so would create 192000 jobs in plant maintenance and fuel production alone, increase the security of energy supply and reduce the expenditure for the purchase of fossil fuels by 4

  3. Reduction of Climate Gases by Energy Efficiency

    International Nuclear Information System (INIS)

    Moe, N.

    1998-01-01

    Carbon dioxide cannot be depolluted in practice. However, there are two areas where measures can be taken to avoid CO 2 emissions: 1. Energy-efficiency. 2. Use of sustainable energy sources in energy production. It is characteristic that many measures which are good for the environment are also good from the point of view of cost efficiency, preparedness and employment. This is tru, for instance, of the greater use of biofuels instead of fossil fuels, collective heating systems as opposed to individual ones and economy measures - especially more efficient use of electricity. It is a question of thinking of the system as a whole. Methane is another factor which contributes to the greenhouse effect. Methane emissions can also be avoided, or reduced, by system-thinking. System-thinking is, for instance, not ro deposit combustible waste but to use it as an energy source. And why not produce electricity by using methane from existing landfill sites. Electrical energy is the most useful form of energy. Therefore, electricity should not, as a principal rule, be used for heating, or as process energy. The fact that energy-efficiency and emission of greenhouse gases are interrelated is shown in the following two examples. 1. Only about 25% of the energy content in extracted coal will reach the consumers as electricity when the production takes place in an ordinary, coal-fires condensing power station. 2. When district heating (room-heating and hot water) is produced in a modern heat-production plant by flue-gas condensation, about 90% of the energy is utilised for heating purposes. To obtain an overall picture of the amount of energy used for a purpose, e.g. heating or electricity, you must view the entire process from extraction to final use. Such a picture can show the energy efficiency and what losses arise. Efficiency measures can reduce the energy bill. They can also reduce pollution, greenhouse gases among other things. Examples will be given in this paper of energy

  4. High efficiency atomic hydrogen source

    International Nuclear Information System (INIS)

    Lagomarsino, V.; Bassi, D.; Bertok, E.; De Paz, M.; Tommasini, F.

    1974-01-01

    This work presents preliminary results of research intended to produce a M.W. discharge atomic hydrogen source with good dissociation at pressures larger than 10 torr. Analysis of the recombination process at these pressures shows that the volume recombination by three body collisions may be more important than wall recombination or loss of atoms by diffusion and flow outside the discharge region

  5. High efficiency optoelectronic terahertz sources

    Science.gov (United States)

    Lampin, Jean-François; Peytavit, Emilien; Akalin, Tahsin; Ducournau, G.; Hindle, Francis; Mouret, Gael

    2010-08-01

    We have developed a new generation of optoelectronic large bandwidth terahertz sources based on TEM horn antennas monolithically integrated with several types of photodetectors: low-temperature grown GaAs (LTG-GaAs) planar photoconductors, vertically integrated LTG-GaAs photoconductors on silicon substrate and uni-travelling-carrier photodiodes. Results of pulsed (time-domain) and photomixing (CW, frequency domain) experiments are presented.

  6. EDF source term reduction project main outcomes and further developments

    International Nuclear Information System (INIS)

    Ranchoux, Gilles; Bonnefon, Julien; Benfarah, Moez; Wintergerst Matthieu; Gressier, Frederic; Leclercq, Stephanie

    2012-09-01

    The dose reduction is a strategic purpose for EDF in link with the stakes of, nuclear acceptability, respect of regulation and productivity gains. This consists not only in improving the reactor shutdown organization (time spent in control area, biological shielding,...) but also in improving the radiological state of the unit and the efficiency of the source term reduction operations. Since 2003, EDF has been running an innovative project called 'Source Term Reduction' federating the different EDF research and engineering centers in order to: - participate to the long term view about Radiological Protection issues (international feedback analyses), - develop contamination prediction tools (OSCAR software) suitable for the industrial needs (operating units and EPR design), - develop scientific models useful for the understanding of contamination mechanisms to support the strategic decision processes, - carry on with updating and analyzing of contamination measurements feedback in corrosion products (EMECC and CZT campaigns), - carry on with the operational support at short or middle term by optimizing startup and shutdown processes, pre-oxidation or and by improving purification efficiency or material characteristics. This paper will show in a first part the main 2011 results in occupational exposure (collective and individual dose, RCS index...). In a second part, an overview of the main EDF outcomes of the last 3 years in the field of source term reduction will be presented. Future developments extended to contamination issues in EDF NPPs will be also pointed out in this paper. (authors)

  7. Sustaining with efficiency the renewable energy sources

    International Nuclear Information System (INIS)

    Bano, L.; Lorenzoni, A.

    2008-01-01

    European energy policy requires actions, in favour of a more widespread diffusion of renewable energy sources. Is essential to have an efficient financial support to reduce costs. Are presented an estimated of electric power from renewable energy sources and some criticism. Is proposed a modification of green certificates market based on bilateral tradable agreements [it

  8. Efficiency of radon reduction techniques and strategies

    International Nuclear Information System (INIS)

    Hubert, Ph.; Monchecourt, D.

    2000-01-01

    Radon is a lung carcinogen recognized by the World Health Organisation and it is present in dwellings. In France, the first actions to measure the exposition of the population were made in 1982, and the first national recommendation was published in 1999. In parallel, information booklets on radon and possible actions to lower its concentration in house were made available to the public. The aim of this study was to test the economic feasibility of different methods to reduce radon level in housing. The first step was to identify the cost and the radon reduction rate of different methods, all based on insulation or ventilation of the buildings. Using the data of the Environmental Protection Agency (EPA), we selected six measures and combined them to obtain a total of twenty potential solutions. We also used the 'duration' model of the Biological Effects of Ionising Radiation committee (BEIR VI) to determine the probability of dying from a cancer associated to a fixed exposure to radon. Knowing this information, it was possible to make cost-efficiency analysis on our data and thus keep six interesting methods. Combining these results with the value of human life of the human capital approach we could find what was the most interesting method to apply for a known level of radon and a specific duration of exposure in a house. In given house, for each level of initial exposure, a cost benefit approach allowed to determine if one, or several techniques, or none, is worthwhile to apply. In favorable cases (i.e : easily remediable houses), and with a figure for the price of human life of about 0,9 MEuro, actions should be undertaken at levels as low as 80 Bq.m -3 . As we know the radon distribution in France, the second step was to see what would be the effects on this distribution if all inhabitants used the optimal approach against their radon exposure defined by our function. Thus, overall costs and overall risks could be computed. However, in public health issues, the

  9. Virtual Generation (Energy Efficiency) The Cheapest Source For Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Hasnie, Sohail

    2010-09-15

    Energy efficiency is the cheapest source of energy that has escaped the minds of the politicians in the developing countries. This paper argues for large scale utility led end use efficiency programs in a new paradigm, where 1 million efficient light bulbs is synonymous to a 50 MW power station that costs only 2% of the traditional fossil fuel power station and zero maintenance. Bulk procurement, setting up new standards and generation of certified emissions reduction is part of this strategy. It discusses implementation of a $20 million pilot in the Philippines supported by the Asian Development Bank.

  10. Efficient Rank Reduction of Correlation Matrices

    NARCIS (Netherlands)

    I. Grubisic (Igor); R. Pietersz (Raoul)

    2005-01-01

    textabstractGeometric optimisation algorithms are developed that efficiently find the nearest low-rank correlation matrix. We show, in numerical tests, that our methods compare favourably to the existing methods in the literature. The connection with the Lagrange multiplier method is established,

  11. The Efficient Utilization of Open Source Information

    Energy Technology Data Exchange (ETDEWEB)

    Baty, Samuel R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Intelligence and Systems Analysis

    2016-08-11

    These are a set of slides on the efficient utilization of open source information. Open source information consists of a vast set of information from a variety of sources. Not only does the quantity of open source information pose a problem, the quality of such information can hinder efforts. To show this, two case studies are mentioned: Iran and North Korea, in order to see how open source information can be utilized. The huge breadth and depth of open source information can complicate an analysis, especially because open information has no guarantee of accuracy. Open source information can provide key insights either directly or indirectly: looking at supporting factors (flow of scientists, products and waste from mines, government budgets, etc.); direct factors (statements, tests, deployments). Fundamentally, it is the independent verification of information that allows for a more complete picture to be formed. Overlapping sources allow for more precise bounds on times, weights, temperatures, yields or other issues of interest in order to determine capability. Ultimately, a "good" answer almost never comes from an individual, but rather requires the utilization of a wide range of skill sets held by a team of people.

  12. Economic efficiency of CO2 reduction programs

    International Nuclear Information System (INIS)

    Tahvonen, O.; Storch, H. von; Storch, J. von

    1993-01-01

    A highly simplified time-dependent low-dimensional system has been designed to describe conceptually the interaction of climate and economy. Enhanced emission of carbon dioxide (CO 2 ) is understood as the agent that not only favors instantaneous consumption but also causes unfavorable climate changes at a later time. The problem of balancing these two counterproductive effects of CO 2 emissions on a finite time horizon is considered. The climate system is represented by just two parameters, namely a globally averaged near-surface air-temperature and a globally averaged troposheric CO 2 concentration. The costs of abating CO 2 emissions are monitored by a function which depends quadratically on the percentage reduction of emission compared to an 'uncontrolled emission' scenario. Parameters are fitted to historical climate data and to estimates from studies of CO 2 abatement costs. Two optimization approaches, which differ from earlier attempts to describe the interaction of economy and climate, are discussed. In the 'cost oriented' strategy an optimal emission path is identified which balances the abatement costs and explicitly formulated damage costs. These damage costs, whose estimates are very uncertain, are hypothesized to be a linear function of the time-derivative of temperature. In the 'target oriented' strategy an emission path is chosen so that the abatement costs are minimal while certain restrictions on the terminal temperature and concentration change are met. (orig.)

  13. Efficient semiconductor multicycle terahertz pulse source

    Science.gov (United States)

    Nugraha, P. S.; Krizsán, G.; Polónyi, Gy; Mechler, M. I.; Hebling, J.; Tóth, Gy; Fülöp, J. A.

    2018-05-01

    Multicycle THz pulse generation by optical rectification in GaP semiconductor nonlinear material is investigated by numerical simulations. It is shown that GaP can be an efficient and versatile source with up to about 8% conversion efficiency and a tuning range from 0.1 THz to about 7 THz. Contact-grating technology for pulse-front tilt can ensure an excellent focusability and scaling the THz pulse energy beyond 1 mJ. Shapeable infrared pump pulses with a constant intensity-modulation period can be delivered for example by a flexible and efficient dual-chirped optical parametric amplifier. Potential applications include linear and nonlinear THz spectroscopy and THz-driven acceleration of electrons.

  14. Modeling of detective quantum efficiency considering scatter-reduction devices

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Woong; Kim, Dong Woon; Kim, Ho Kyung [Pusan National University, Busan (Korea, Republic of)

    2016-05-15

    The reduction of signal-to-noise ratio (SNR) cannot be restored and thus has become a severe issue in digital mammography.1 Therefore, antiscatter grids are typically used in mammography. Scatter-cleanup performance of various scatter-reduction devices, such as air gaps,2 linear (1D) or cellular (2D) grids,3, 4 and slot-scanning devices,5 has been extensively investigated by many research groups. In the present time, a digital mammography system with the slotscanning geometry is also commercially available.6 In this study, we theoretically investigate the effect of scattered photons on the detective quantum efficiency (DQE) performance of digital mammography detectors by using the cascaded-systems analysis (CSA) approach. We show a simple DQE formalism describing digital mammography detector systems equipped with scatter reduction devices by regarding the scattered photons as additive noise sources. The LFD increased with increasing PMMA thickness, and the amounts of LFD indicated the corresponding SF. The estimated SFs were 0.13, 0.21, and 0.29 for PMMA thicknesses of 10, 20, and 30 mm, respectively. While the solid line describing the measured MTF for PMMA with 0 mm was the result of least-squares of regression fit using Eq. (14), the other lines were simply resulted from the multiplication of the fit result (for PMMA with 0 mm) with the (1-SF) estimated from the LFDs in the measured MTFs. Spectral noise-power densities over the entire frequency range were not much changed with increasing scatter. On the other hand, the calculation results showed that the spectral noise-power densities increased with increasing scatter. This discrepancy may be explained by that the model developed in this study does not account for the changes in x-ray interaction parameters for varying spectral shapes due to beam hardening with increasing PMMA thicknesses.

  15. Source Reduction Effectiveness at Fuel Contaminated Sites, Technical Summary Report

    National Research Council Canada - National Science Library

    2000-01-01

    This report assesses the degree to which various types or engineered source-reduction efforts at selected fuel-contaminated sites have resulted in decreasing concentrations of fuel constituents dissolved in groundwater...

  16. Designing building energy efficiency programs for greenhouse gas reductions

    International Nuclear Information System (INIS)

    Blackhurst, Michael; Lima Azevedo, Ines; Scott Matthews, H.; Hendrickson, Chris T.

    2011-01-01

    Costs and benefits of building energy efficiency are estimated as a means of reducing greenhouse gas emissions in Pittsburgh, PA and Austin, TX. The analysis includes electricity and natural gas consumption, covering 75% of building energy consumption in Pittsburgh and 85% in Austin. Two policy objectives were evaluated: maximize GHG reductions given initial budget constraints or maximize social savings given target GHG reductions. This approach evaluates the trade-offs between three primary and often conflicting program design parameters: initial capital constraints, social savings, and GHG reductions. Results suggest uncertainty in local stocks, demands, and efficiency significantly impacts anticipated outcomes. Annual GHG reductions of 1 ton CO 2 eq/capita/yr in Pittsburgh could cost near nothing or over $20 per capita annually. Capital-constrained policies generate slightly less social savings (a present value of a few hundred dollars per capita) than policies that maximize social savings. However, sectors and end uses targeted for intervention vary depending on policy objectives and constraints. Optimal efficiency investment strategies for some end uses vary significantly (in excess of 100%) between Pittsburgh and Austin, suggesting that resources and guidance conducted at the national scale may mislead state and local decision-makers. Results are used to provide recommendations for efficiency program administrators. - Highlights: → We use public data to estimate local building energy costs, benefits and greenhouse gas reductions. → We use optimization to evaluate trade-offs between program objectives and capital constraints. → Local energy market conditions significantly influence efficiency expectations. → Different program objectives can lead to different effective investment strategies. → We reflect on the implications of our results for efficiency program design.

  17. Designing building energy efficiency programs for greenhouse gas reductions

    Energy Technology Data Exchange (ETDEWEB)

    Blackhurst, Michael, E-mail: mfb@andrew.cmu.edu [Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, 1 University Station C1752, Austin, TX 78712 (United States); Lima Azevedo, Ines, E-mail: iazevedo@cmu.edu [Department of Engineering and Public Policy, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States); Scott Matthews, H., E-mail: hsm@cmu.edu [Department of Engineering and Public Policy, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States); Department of Civil and Environmental Engineering, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States); Hendrickson, Chris T., E-mail: cth@andrew.cmu.edu [Department of Civil and Environmental Engineering, Carnegie Mellon University, 119 Porter Hall, Pittsburgh, PA 15213 (United States)

    2011-09-15

    Costs and benefits of building energy efficiency are estimated as a means of reducing greenhouse gas emissions in Pittsburgh, PA and Austin, TX. The analysis includes electricity and natural gas consumption, covering 75% of building energy consumption in Pittsburgh and 85% in Austin. Two policy objectives were evaluated: maximize GHG reductions given initial budget constraints or maximize social savings given target GHG reductions. This approach evaluates the trade-offs between three primary and often conflicting program design parameters: initial capital constraints, social savings, and GHG reductions. Results suggest uncertainty in local stocks, demands, and efficiency significantly impacts anticipated outcomes. Annual GHG reductions of 1 ton CO{sub 2} eq/capita/yr in Pittsburgh could cost near nothing or over $20 per capita annually. Capital-constrained policies generate slightly less social savings (a present value of a few hundred dollars per capita) than policies that maximize social savings. However, sectors and end uses targeted for intervention vary depending on policy objectives and constraints. Optimal efficiency investment strategies for some end uses vary significantly (in excess of 100%) between Pittsburgh and Austin, suggesting that resources and guidance conducted at the national scale may mislead state and local decision-makers. Results are used to provide recommendations for efficiency program administrators. - Highlights: > We use public data to estimate local building energy costs, benefits and greenhouse gas reductions. > We use optimization to evaluate trade-offs between program objectives and capital constraints. > Local energy market conditions significantly influence efficiency expectations. > Different program objectives can lead to different effective investment strategies. > We reflect on the implications of our results for efficiency program design.

  18. California Air Resources board's mobil source emission reduction credit guidelines

    International Nuclear Information System (INIS)

    Dunwoody Lentz, C.; Werner, B.

    1993-01-01

    The California Air Resources Board has developed guidance for the generation and use of mobil source emission reduction credits. Mobil source credits can be used to improve air quality, or to mitigate increases in emissions associated with industrial and non-industrial sources. They are created by programs which reduce mobile source emission beyond the reductions required by federal, state, and local laws or air quality attainment plans. Significant amounts of credit can be generated by some types of programs which reduce mobile source emissions of oxides of nitrogen (NO x ) and reactive organic gases (ROG). Mobile source credit programs must be carefully structured to ensure that emission reductions are real, accurately quantified, enforceable, and have a defined life. Three potentially feasible programs for the creation of mobile source credits include accelerated retirement of older vehicles, purchase of low-emission buses, and purchase of zero-emission vehicles. These programs are evaluated for their ability to generate credit and to assess their cost effectiveness. Based on the examples presented, two methods of generating mobile source credits, the accelerated retirement of older vehicles and the purchase of low-emission buses, appear to be cost-effective when compared to other emission control measures

  19. BP Canada Energy Company energy efficiency and GHG reduction opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, B. [BP Canada Energy Company, Calgary, AB (Canada)

    2004-07-01

    This paper presented an outline of the BP Canada Energy Company's energy efficiency program, which uses an innovative approach that relies on front line operations staff to generate, evaluate and implement ideas for energy reduction projects. An outline of the organization team was presented, with details of the small central Calgary group responsible for coordination, technical support and tracking of data. Key objectives of the team were identified as: the promotion of energy efficiency; sharing of best practices; and coordination of efforts at operations at both the development and corporate level. An outline of BP upstream operations and emissions reduction strategies was provided along with a timeline of BP Canada greenhouse gas (GHG) emissions and sustainable reductions projects. A chart representing energy savings through conversion to natural gas was also presented, sorted by project type. Results included over 400 GHG or energy reduction projects completed, with an average pay out of 30 months as well as 300,000 tonnes equivalent of GHGs reduced at an estimated value of of $13,000,000. Areas of focus for future projects include: compression; fired equipment; flaring; venting; and fugitive emissions. Strategies to reduce emissions in all areas of future research were also provided. tabs, figs.

  20. Highly efficient sources of single indistinguishable photons

    DEFF Research Database (Denmark)

    Gregersen, Niels

    2013-01-01

    be electrically driven. Several design strategies addressing these requirements have been proposed. In the cavity-based source, light emission is controlled using resonant cavity quantum electrodynamics effects, whereas in the waveguide-based source, broadband electric field screening effects are employed......Solid-state sources capable of emitting single photons on demand are of great interest in quantum information applications. Ideally, such a source should emit exactly one photon into the collection optics per trigger, the emitted photons should be indistinguishable and the source should...

  1. Renewable energy sources: Energy Efficiency Agency

    International Nuclear Information System (INIS)

    Bulgarensky, Mihael

    2004-01-01

    The paper presents the activities of the Energy Efficiency Agency, its main functions, as well as the new legislation stimulating the use of RES, stipulated in the new Energy Law of Bulgaria. The second part of the paper describes the potential of renewable energy in i.e. wind energy; solar energy; biomass energy; hydro energy; geothermal energy; draft of a National Program on RES 2005-2015. The third part describes the main issues of the new ENERGY EFFICIENCY LAW and the established Energy efficiency fund. (Author)

  2. An efficient architecture for LVQ-SLM for PAPR reduction

    International Nuclear Information System (INIS)

    Khalid, S.; Yasin, M.

    2010-01-01

    In this paper we propose an efficient architecture for the implementation of a LVQ (Learning Vector Quantization)NN (Neural Network), used as a classifier, for PAPR (Peak to Average Power Ratio) reduction. A special feature of the implementation is a combinatorial module for nearest neighbor search that allows online execution of this important operation during classification. The LVQ classifier is programmed in Verilog and the entire circuit is synthesized on FPGAs (Field Programmable Gate Arrays) using Xilinx at the rate ISE (Integrated Software Environment) 8.1i. The model is implemented with 64 sub carriers, considering the parametric values of WLANs standard IEEE 802.11a. Using the architecture, efficient on-line classification is achieved. (author)

  3. Identifying Efficient Nitrate Reduction Strategies in the Upper Danube

    Directory of Open Access Journals (Sweden)

    Angel Udias

    2016-08-01

    Full Text Available Nitrogen losses in the form of Nitrate (N-NO3 from point and diffuse sources of pollution are recognized to be the leading cause of water body impairment throughout Europe. Implementation of conservation programs is perceived as being crucial for restoring and protecting the good ecological status of freshwater bodies. The success of conservation programs depends on the efficient identification of management solutions with respect to the envisaged environmental and economic objectives. This is a complex task, especially considering that costs and effectiveness of conservation strategies depend on their locations. We applied a multi-objective, spatially explicit analysis tool, the R-SWAT-DM framework, to search for efficient, spatially-targeted solution of Nitrate abatement in the Upper Danube Basin. The Soil Water Assessment Tool (SWAT model served as the nonpoint source pollution estimator for current conditions as well as for scenarios with modified agricultural practices and waste water treatment upgrading. A spatially explicit optimization analysis that considered point and diffuse sources of Nitrate was performed to search for strategies that could achieve largest pollution abatement at minimum cost. The set of optimal spatial conservation strategies identified in the Basin indicated that it could be possible to reduce Nitrate loads by more than 50% while simultaneously provide a higher income.

  4. Ionization efficiency calculations for cavity thermoionization ion source

    International Nuclear Information System (INIS)

    Turek, M.; Pyszniak, K.; Drozdziel, A.; Sielanko, J.; Maczka, D.; Yuskevich, Yu.V.; Vaganov, Yu.A.

    2009-01-01

    The numerical model of ionization in a thermoionization ion source is presented. The review of ion source ionization efficiency calculation results for various kinds of extraction field is given. The dependence of ionization efficiency on working parameters like ionizer length and extraction voltage is discussed. Numerical simulations results are compared to theoretical predictions obtained from a simplified ionization model

  5. Improving computational efficiency of Monte Carlo simulations with variance reduction

    International Nuclear Information System (INIS)

    Turner, A.; Davis, A.

    2013-01-01

    CCFE perform Monte-Carlo transport simulations on large and complex tokamak models such as ITER. Such simulations are challenging since streaming and deep penetration effects are equally important. In order to make such simulations tractable, both variance reduction (VR) techniques and parallel computing are used. It has been found that the application of VR techniques in such models significantly reduces the efficiency of parallel computation due to 'long histories'. VR in MCNP can be accomplished using energy-dependent weight windows. The weight window represents an 'average behaviour' of particles, and large deviations in the arriving weight of a particle give rise to extreme amounts of splitting being performed and a long history. When running on parallel clusters, a long history can have a detrimental effect on the parallel efficiency - if one process is computing the long history, the other CPUs complete their batch of histories and wait idle. Furthermore some long histories have been found to be effectively intractable. To combat this effect, CCFE has developed an adaptation of MCNP which dynamically adjusts the WW where a large weight deviation is encountered. The method effectively 'de-optimises' the WW, reducing the VR performance but this is offset by a significant increase in parallel efficiency. Testing with a simple geometry has shown the method does not bias the result. This 'long history method' has enabled CCFE to significantly improve the performance of MCNP calculations for ITER on parallel clusters, and will be beneficial for any geometry combining streaming and deep penetration effects. (authors)

  6. Reduction Assessment of Agricultural Non-Point Source Pollutant Loading

    OpenAIRE

    Fu, YiCheng; Zang, Wenbin; Zhang, Jian; Wang, Hongtao; Zhang, Chunling; Shi, Wanli

    2018-01-01

    NPS (Non-point source) pollution has become a key impact element to watershed environment at present. With the development of technology, application of models to control NPS pollution has become a very common practice for resource management and Pollutant reduction control in the watershed scale of China. The SWAT (Soil and Water Assessment Tool) model is a semi-conceptual model, which was put forward to estimate pollutant production & the influences on water quantity-quality under different...

  7. Reduction of characteristic RL time for fast, efficient magnetic levitation

    Directory of Open Access Journals (Sweden)

    Yuqing Li

    2017-09-01

    Full Text Available We demonstrate the reduction of characteristic time in resistor-inductor (RL circuit for fast, efficient magnetic levitation according to Kirchhoff’s circuit laws. The loading time is reduced by a factor of ∼4 when a high-power resistor is added in series with the coils. By using the controllable output voltage of power supply and voltage of feedback circuit, the loading time is further reduced by ∼ 3 times. The overshoot loading in advance of the scheduled magnetic field gradient is equivalent to continuously adding a resistor without heating. The magnetic field gradient with the reduced loading time is used to form the upward magnetic force against to the gravity of the cooled Cs atoms, and we obtain an effectively levitated loading of the Cs atoms to a crossed optical dipole trap.

  8. Economic Analysis of Nitrate Source Reductions in California Agriculture

    Science.gov (United States)

    Medellin-Azuara, J.; Howitt, R.; Rosenstock, T.; Harter, T.; Pettygrove, S. G.; Dzurella, K.; Lund, J. R.

    2011-12-01

    We present an analytical approach to assess the economic impact of improving nitrogen management practices in California agriculture. We employ positive mathematical programming to calibrate crop production to base input information. The production function representation is a nested constant elasticity of substitution with two nests: one for applied water and one for applied nitrogen. The first nest accounts for the tradeoffs between irrigation efficiency and capital investments in irrigation technology. The second nest represents the tradeoffs between nitrogen application efficiency and the marginal costs of improving nitrogen efficiency. In the production function nest, low elasticities of substitution and water and nitrogen stress constraints keep agricultural crop yields constant despite changes in nitrogen management practices. We use the Tulare Basin, and the Salinas Valley in California's Central Valley and Central Coast respectively as our case studies. Preliminary results show that initial reductions of 25% in nitrogen loads to groundwater may not impose large costs to agricultural crop production as substitution of management inputs results in only small declines in net revenue from farming and total land use. Larger reductions in the nitrogen load to groundwater of 50% imposes larger marginal costs for better nitrogen management inputs and reductions in the area of lower valued crops grown in the study areas. Despite the shortage of data on quantitative effects of improved nitrogen efficiency; our results demonstrate the potential of combining economic and agronomic data into a model that can reflect differences in cost and substitutabilty in nitrogen application methods, that can be used to reduce the quantity of nitrogen leaching into groundwater.

  9. Landscape planning for agricultural nonpoint source pollution reduction III: Assessing phosphorus and sediment reduction potential

    Science.gov (United States)

    Diebel, M.W.; Maxted, J.T.; Robertson, Dale M.; Han, S.; Vander Zanden, M. J.

    2009-01-01

    Riparian buffers have the potential to improve stream water quality in agricultural landscapes. This potential may vary in response to landscape characteristics such as soils, topography, land use, and human activities, including legacies of historical land management. We built a predictive model to estimate the sediment and phosphorus load reduction that should be achievable following the implementation of riparian buffers; then we estimated load reduction potential for a set of 1598 watersheds (average 54 km2) in Wisconsin. Our results indicate that land cover is generally the most important driver of constituent loads in Wisconsin streams, but its influence varies among pollutants and according to the scale at which it is measured. Physiographic (drainage density) variation also influenced sediment and phosphorus loads. The effect of historical land use on present-day channel erosion and variation in soil texture are the most important sources of phosphorus and sediment that riparian buffers cannot attenuate. However, in most watersheds, a large proportion (approximately 70%) of these pollutants can be eliminated from streams with buffers. Cumulative frequency distributions of load reduction potential indicate that targeting pollution reduction in the highest 10% of Wisconsin watersheds would reduce total phosphorus and sediment loads in the entire state by approximately 20%. These results support our approach of geographically targeting nonpoint source pollution reduction at multiple scales, including the watershed scale. ?? 2008 Springer Science+Business Media, LLC.

  10. Load Reduction, Demand Response and Energy Efficient Technologies and Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Boyd, Paul A.; Parker, Graham B.; Hatley, Darrel D.

    2008-11-19

    The Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) was tasked by the DOE Office of Electricity (OE) to recommend load reduction and grid integration strategies, and identify additional demand response (energy efficiency/conservation opportunities) and strategies at the Forest City Housing (FCH) redevelopment at Pearl Harbor and the Marine Corps Base Hawaii (MCBH) at Kaneohe Bay. The goal was to provide FCH staff a path forward to manage their electricity load and thus reduce costs at these FCH family housing developments. The initial focus of the work was at the MCBH given the MCBH has a demand-ratchet tariff, relatively high demand (~18 MW) and a commensurate high blended electricity rate (26 cents/kWh). The peak demand for MCBH occurs in July-August. And, on average, family housing at MCBH contributes ~36% to the MCBH total energy consumption. Thus, a significant load reduction in family housing can have a considerable impact on the overall site load. Based on a site visit to the MCBH and meetings with MCBH installation, FCH, and Hawaiian Electric Company (HECO) staff, recommended actions (including a "smart grid" recommendation) that can be undertaken by FCH to manage and reduce peak-demand in family housing are made. Recommendations are also made to reduce overall energy consumption, and thus reduce demand in FCH family housing.

  11. Spectral Efficiency of OCDMA Systems With Coherent Pulsed Sources

    Science.gov (United States)

    Rochette, Martin; Rusch, Leslie A.

    2005-03-01

    We present a model to evaluate the upper limit of the spectral efficiency of optical code-division multiple-access (OCDMA) systems with coherent sources. Phase-encoded and direct-sequence OCDMA systems are evaluated using this model. The results show that a spectral efficiency of 2.24x10^-2 b/s.Hz can be achieved with a maximum bit error rate of 10^-10 in these systems of the number of users. This result demonstrates that the maximum spectral efficiency of OCDMA systems with coherent sources is at least a factor of 5 higher than OCDMA systems with incoherent sources.

  12. Research on point source simulating the γ-ray detection efficiencies of stander source

    International Nuclear Information System (INIS)

    Tian Zining; Jia Mingyan; Shen Maoquan; Yang Xiaoyan; Cheng Zhiwei

    2010-01-01

    For φ 75 mm x 25 mm sample, the full energy peak efficiencies on different heights of sample radius were obtained using the point sources, and the function parameters about the full energy peak efficiencies of point sources based on radius was fixed. The 59.54 keV γ-ray, 661.66 keV γ-ray, 1173.2 keV γ-ray, 1332.5 keV γ-ray detection efficiencies on different height of samples were obtained, based on the full energy peak efficiencies of point sources and its height, and the function parameters about the full energy peak efficiencies of surface sources based on sample height was fixed. The detection efficiency of (75 mm x 25 mm calibration source can be obtained by integrality, the detection efficiencies simulated by point sources are consistent with the results of stander source in 10%. Therefore, the calibration method of stander source can be substituted by the point source simulation method, and it tis feasible when there is no stander source.) (authors)

  13. Improving the efficiency of deconvolution algorithms for sound source localization

    DEFF Research Database (Denmark)

    Lylloff, Oliver Ackermann; Fernandez Grande, Efren; Agerkvist, Finn T.

    2015-01-01

    of the unknown acoustic source distribution and the beamformer's response to a point source, i.e., point-spread function. A significant limitation of deconvolution is, however, an additional computational effort compared to beamforming. In this paper, computationally efficient deconvolution algorithms...

  14. Reductive dechlorination of trichloroethene DNAPL source zones: source zone architecture versus electron donor availability

    Science.gov (United States)

    Krol, M.; Kokkinaki, A.; Sleep, B.

    2014-12-01

    The persistence of dense-non-aqueous-phase liquids (DNAPLs) in the subsurface has led practitioners and regulatory agencies to turn towards low-maintenance, low-cost remediation methods. Biological degradation has been suggested as a possible solution, based on the well-proven ability of certain microbial species to break down dissolved chlorinated ethenes under favorable conditions. However, the biodegradation of pure phase chlorinated ethenes is subject to additional constraints: the continuous release of electron acceptor at a rate governed by mass transfer kinetics, and the temporal and spatial heterogeneity of DNAPL source zones which leads to spatially and temporally variable availability of the reactants for reductive dechlorination. In this work, we investigate the relationship between various DNAPL source zone characteristics and reaction kinetics using COMPSIM, a multiphase groundwater model that considers non-equilibrium mass transfer and Monod-type kinetics for reductive dechlorination. Numerical simulations are performed for simple, homogeneous trichloroethene DNAPL source zones to demonstrate the effect of single source zone characteristics, as well as for larger, more realistic heterogeneous source zones. It is shown that source zone size, and mass transfer kinetics may have a decisive effect on the predicted bio-enhancement. Finally, we evaluate the performance of DNAPL bioremediation for realistic, thermodynamically constrained, concentrations of electron donor. Our results indicate that the latter may be the most important limitation for the success of DNAPL bioremediation, leading to reduced bio-enhancement and, in many cases, comparable performance with water flooding.

  15. High-efficiency target-ion sources for RIB generation

    International Nuclear Information System (INIS)

    Alton, G.D.

    1993-01-01

    A brief review is given of high-efficiency ion sources which have been developed or are under development at ISOL facilities which show particular promise for use at existing, future, or radioactive ion beam (RIB) facilities now under construction. Emphasis will be placed on those sources which have demonstrated high ionization efficiency, species versatility, and operational reliability and which have been carefully designed for safe handling in the high level radioactivity radiation fields incumbent at such facilities. Brief discussions will also be made of the fundamental processes which affect the realizable beam intensities in target-ion sources. Among the sources which will be reviewed will be selected examples of state-of-the-art electron-beam plasma-type ion sources, thermal-ionization, surface-ionization, ECR, and selectively chosen ion source concepts which show promise for radioactive ion beam generation. A few advanced, chemically selective target-ion sources will be described, such as sources based on the use of laser-resonance ionization, which, in principle, offer a more satisfactory solution to isobaric contamination problems than conventional electromagnetic techniques. Particular attention will be given to the sources which have been selected for initial or future use at the Holifield Radioactive Ion Beam Facility now under construction at the Oak Ridge National Laboratory

  16. Analytical calculations of the efficiency of gamma scintillators total efficiency for coaxial disk sources

    Energy Technology Data Exchange (ETDEWEB)

    Selim, Y S; Abbas, M I; Fawzy, M A [Physics Department, Faculty of Science, Alexandria University, Aleaxndria (Egypt)

    1997-12-31

    Total efficiency of clad right circular cylindrical Nal(TI) scintillation detector from a coaxial isotropic radiating circular disk source has been calculated by the of rigid mathematical expressions. Results were tabulated for various gamma energies. 2 figs., 5 tabs.

  17. Mathematical efficiency calibration with uncertain source geometries using smart optimization

    International Nuclear Information System (INIS)

    Menaa, N.; Bosko, A.; Bronson, F.; Venkataraman, R.; Russ, W. R.; Mueller, W.; Nizhnik, V.; Mirolo, L.

    2011-01-01

    The In Situ Object Counting Software (ISOCS), a mathematical method developed by CANBERRA, is a well established technique for computing High Purity Germanium (HPGe) detector efficiencies for a wide variety of source shapes and sizes. In the ISOCS method, the user needs to input the geometry related parameters such as: the source dimensions, matrix composition and density, along with the source-to-detector distance. In many applications, the source dimensions, the matrix material and density may not be well known. Under such circumstances, the efficiencies may not be very accurate since the modeled source geometry may not be very representative of the measured geometry. CANBERRA developed an efficiency optimization software known as 'Advanced ISOCS' that varies the not well known parameters within user specified intervals and determines the optimal efficiency shape and magnitude based on available benchmarks in the measured spectra. The benchmarks could be results from isotopic codes such as MGAU, MGA, IGA, or FRAM, activities from multi-line nuclides, and multiple counts of the same item taken in different geometries (from the side, bottom, top etc). The efficiency optimization is carried out using either a random search based on standard probability distributions, or using numerical techniques that carry out a more directed (referred to as 'smart' in this paper) search. Measurements were carried out using representative source geometries and radionuclide distributions. The radionuclide activities were determined using the optimum efficiency and compared against the true activities. The 'Advanced ISOCS' method has many applications among which are: Safeguards, Decommissioning and Decontamination, Non-Destructive Assay systems and Nuclear reactor outages maintenance. (authors)

  18. An efficient chemoselective reduction of furan series unsaturated dinitriles

    Czech Academy of Sciences Publication Activity Database

    Bobáľ, P.; Bobálová, Janette

    2013-01-01

    Roč. 18, č. 2 (2013), s. 2212-2221 ISSN 1420-3049 Institutional support: RVO:68081715 Keywords : chemoselective reduction * regioselective reduction * conjugated olefins Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.095, year: 2013 http://www.mdpi.com/1420-3049/18/2/2212

  19. Calculation of the counting efficiency for extended sources

    International Nuclear Information System (INIS)

    Korun, M.; Vidmar, T.

    2002-01-01

    A computer program for calculation of efficiency calibration curves for extended samples counted on gamma- and X ray spectrometers is described. The program calculates efficiency calibration curves for homogeneous cylindrical samples placed coaxially with the symmetry axis of the detector. The method of calculation is based on integration over the sample volume of the efficiencies for point sources measured in free space on an equidistant grid of points. The attenuation of photons within the sample is taken into account using the self-attenuation function calculated with a two-dimensional detector model. (author)

  20. Experimental study on source efficiencies for estimating surface contamination level

    International Nuclear Information System (INIS)

    Ichiji, Takeshi; Ogino, Haruyuki

    2008-01-01

    Source efficiency was measured experimentally for various materials, such as metals, nonmetals, flooring materials, sheet materials and other materials, contaminated by alpha and beta emitter radioactive nuclides. Five nuclides, 147 Pm, 60 Co, 137 Cs, 204 Tl and 90 Sr- 90 Y, were used as the beta emitters, and one nuclide 241 Am was used as the alpha emitter. The test samples were prepared by placing drops of the radioactive standardized solutions uniformly on the various materials using an automatic quantitative dispenser system from Musashi Engineering, Inc. After placing drops of the radioactive standardized solutions, the test materials were allowed to dry for more than 12 hours in a draft chamber with a hood. The radioactivity of each test material was about 30 Bq. Beta rays or alpha rays from the test materials were measured with a 2-pi gas flow proportional counter from Aloka Co., Ltd. The source efficiencies of the metals, nonmetals and sheet materials were higher than 0.5 in the case of contamination by the 137 Cs, 204 Tl and 90 Sr- 90 Y radioactive standardized solutions, higher than 0.4 in the case of contamination by the 60 Co radioactive standardized solution, and higher than 0.25 in the case of contamination by the alpha emitter the 241 Am radioactive standardized solution. These values were higher than those given in Japanese Industrial Standards (JIS) documents. In contrast, the source efficiencies of some permeable materials were lower than those given in JIS documents, because source efficiency varies depending on whether the materials or radioactive sources are wet or dry. This study provides basic data on source efficiency, which is useful for estimating the surface contamination level of materials. (author)

  1. Pengaruh Brand Credibility Terhadap Information Efficiency Dan Risk Reduction, Serta Dampaknya Atas Repurchase Intention

    OpenAIRE

    Faisal, Aekram

    2015-01-01

    This research conducted to know the influence of Brand Credibility to Information efficiency and Risk reduction, also the influence of Information efficiency and Risk reduction to Repurchase intention. This research aimed to know the influence of Brand Credibility to Repurchase intention that mediated by Information efficiency and Risk reduction. The methodology of this research is testing hypothesis research. The sample collecting by questionnaire of 150 respondents from Starb...

  2. Sources of Developmental Change in the Efficiency of Information Search

    Science.gov (United States)

    Ruggeri, Azzurra; Lombrozo, Tania; Griffiths, Thomas L.; Xu, Fei

    2016-01-01

    Children are active learners: they learn not only from the information people offer and the evidence they happen to observe, but by actively seeking information. However, children's information search strategies are typically less efficient than those of adults. In two studies, we isolate potential sources of developmental change in how children…

  3. The peak efficiency calibration of volume source using 152Eu point source in computer

    International Nuclear Information System (INIS)

    Shen Tingyun; Qian Jianfu; Nan Qinliang; Zhou Yanguo

    1997-01-01

    The author describes the method of the peak efficiency calibration of volume source by means of 152 Eu point source for HPGe γ spectrometer. The peak efficiency can be computed by Monte Carlo simulation, after inputting parameter of detector. The computation results are in agreement with the experimental results with an error of +-3.8%, with an exception one is about +-7.4%

  4. Fully probabilistic seismic source inversion – Part 1: Efficient parameterisation

    Directory of Open Access Journals (Sweden)

    S. C. Stähler

    2014-11-01

    Full Text Available Seismic source inversion is a non-linear problem in seismology where not just the earthquake parameters themselves but also estimates of their uncertainties are of great practical importance. Probabilistic source inversion (Bayesian inference is very adapted to this challenge, provided that the parameter space can be chosen small enough to make Bayesian sampling computationally feasible. We propose a framework for PRobabilistic Inference of Seismic source Mechanisms (PRISM that parameterises and samples earthquake depth, moment tensor, and source time function efficiently by using information from previous non-Bayesian inversions. The source time function is expressed as a weighted sum of a small number of empirical orthogonal functions, which were derived from a catalogue of >1000 source time functions (STFs by a principal component analysis. We use a likelihood model based on the cross-correlation misfit between observed and predicted waveforms. The resulting ensemble of solutions provides full uncertainty and covariance information for the source parameters, and permits propagating these source uncertainties into travel time estimates used for seismic tomography. The computational effort is such that routine, global estimation of earthquake mechanisms and source time functions from teleseismic broadband waveforms is feasible.

  5. Do energy efficiency measures promote the use of renewable sources?

    International Nuclear Information System (INIS)

    Marques, Antonio C.; Fuinhas, Jose A.

    2011-01-01

    This paper analyses the factors behind the deployment of renewable energy, focusing particularly on the effect of energy efficiency policies and measures. The impact of these factors is appraised within the context of several phases of the use of renewable sources. We therefore apply the quantile regression technique to a set of 21 European Countries in two time spans: from 1990 to 1998, and from 1999 to 2006. We control variables of policy, environment, socioeconomic characteristics, and electricity generation. For the second period, energy efficiency policies and measures concerning renewable sources effectively promote renewables, namely in the take-off phase. We shed light on the lobbying effect of traditional energy industries, showing that it depends both on the period under analysis, and on the kind of traditional energy source.

  6. Highly efficient catalytic reductive degradation of various organic ...

    Indian Academy of Sciences (India)

    aDepartment of Applied Sciences (Chemical Science Division), GUIST, Gauhati University, ... Highly improved catalytic reductive degradation of different organic dyes, in the ... was prepared by a facile co-precipitation method using ultra-high dilute aqueous solutions. ...... face chemical-modification for engineering the intrin-.

  7. Molasses as an efficient low-cost carbon source for biological Cr(VI) removal

    Energy Technology Data Exchange (ETDEWEB)

    Michailides, Michail K. [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Tekerlekopoulou, Athanasia G., E-mail: atekerle@upatras.gr [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Akratos, Christos S.; Coles, Sandra [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Pavlou, Stavros [Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-26504 Patras (Greece); Department of Chemical Engineering, University of Patras, GR-26504 Patras (Greece); Vayenas, Dimitrios V. [Department of Environmental and Natural Resources Management, University of Patras, 2 G. Seferi Str., GR-30100 Agrinio (Greece); Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Stadiou Str., Platani, P.O. Box 1414, GR-26504 Patras (Greece)

    2015-01-08

    Highlights: • Suspended and attached growth reactors were examined for Cr(VI) bio-reduction. • Molasses was proved an efficient and very low cost carbon source. • Molasses was more efficient than sugar in enhancing Cr(VI) reduction. • SBR with recirculation was the most proper operating mode. - Abstract: In the present study, indigenous microorganisms from industrial sludge were used to reduce the activity of Cr(VI). Molasses, a by-product of sugar processing, was selected as the carbon source (instead of sugar used in a previous work) as it is a low-cost energy source for bioprocesses. Initially, experiments were carried out in suspended growth batch reactors for Cr(VI) concentrations of 1.5–110 mg/L. The time required for complete Cr(VI) reduction increased with initial Cr(VI) concentration. Initial molasses concentration was also found to influence the Cr(VI) reduction rate. The optimal concentration for all initial Cr(VI) concentrations tested was 0.8 gC/L. Experiments were also carried out in packed-bed reactors. Three different operating modes were used to investigate the optimal performance and efficiency of the filter, i.e. batch, continuous and SBR with recirculation. The latter mode with a recirculation rate of 0.5 L/min lead to significantly high Cr(VI) reduction rates (up to 135 g/m{sup 2} d). The results of this work were compared with those of a similar work using sugar as the carbon source and indicate that molasses could prove a feasible technological solution to a serious environmental problem.

  8. Energy efficiency: a source of savings; a priority objective

    International Nuclear Information System (INIS)

    Bethencourt, Anne de; Chorin, Jacky

    2013-01-01

    Energy efficiency is defined as consumption of less energy whilst delivering the same service. Significant progress has been made through the impact of technology, price increases and awareness of waste. Too often viewed as a constraint, energy efficiency nonetheless constitutes the leading potential source of domestic energy for the 2020 goal. Energy efficiency is or will be (depending on the will of the stakeholders, public authorities and society as a whole) a key market for the future and a pathway to creative innovation. Everything is pointing in that direction: the obligation to reduce greenhouse gas emissions fourfold, the new European Directive on Energy Efficiency to be incorporated, the expected increase in energy prices, the presence in France of industry leaders and of a small-scale but important industry in this sector. The goals in energy efficiency entail: - at Community level, that the objective of 20% energy savings for the 2020 goal becomes binding; - at national level, that public policies for energy efficiency are part of a long-term vision, based on the achievements of the Grenelle Environment Forum and avoid sending out any wrong signals which might adversely affect progress. The ESEC proposals are built around the following four themes: - (residential and service sector) buildings: Make energy efficiency into a real sector and a new opportunity 'work together', Optimise tools and regulations, Be innovative in terms of financial support; - fuel poverty; - industry and agriculture; - the particular situation of the overseas departments

  9. Plasma control for efficient extreme ultra-violet source

    International Nuclear Information System (INIS)

    Takahashi, Kensaku; Nakajima, Mitsuo; Kawamura, Tohru; Shiho, Makoto; Hotta, Eiki; Horioka, Kazuhiko

    2008-01-01

    To generate a high efficiency extreme-ultraviolet (EUV) source, effects of plasma shape for controlling radiative plasmas based on xenon capillary discharge are experimentally investigated. The radiation characteristics observed via tapered capillary discharge are compared with those of straight one. From the comparison, the long emission period and different plasma behaviors of tapered capillary discharge are confirmed. This means that control of the plasma geometry is effective for prolonging the EUV emission period. This result also indicates that the plasma shape control seems to have a potential for enhancing the conversion efficiency. (author)

  10. Efficiency of deodorant materials for ammonia reduction in indoor air

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Mizutani, Chiyomi; Melikov, Arsen Krikor

    2014-01-01

    A comparative study about the removability of ammonia gas in the air by activated carbon fiber (ACF) felt chemically treated with acid and a cotton fabric processed with iron phthalocyanine with copper (Cu) was performed in small-scale experiments. The test rig consisted of a heated plate and its...... proved activated carbon fiber felt with acid to be highly efficient in removing ammonia gas. Air temperature did not have profound effect on ACF performance. However, efficiency of the carbon fiber felt decreased when relative humidity was raised from 20 to 80%....

  11. Energy efficiency of the CTX magnetized coaxial plasma source

    International Nuclear Information System (INIS)

    Fernandez, J.C.; Barnes, C.W.; Jarboe, T.R.; Knox, S.O.; Platts, D.A.; McKenna, K.F.

    1985-01-01

    The energy efficiency of the CTX coaxial plasma source in creating spheromaks is determined experimentally to be in agreement with the theoretical prediction of lambda/sub sp//lambda/sub g/, where del x B = lambda/sub sp/ B in the spheromak, and lambda/sub g/ identical with μ 0 I/sub g//phi/sub g/ with I/sub g/ the source current and phi/sub g/ the magnetic flux through either source electrode. This is shown to be equivalent to magnetic helicity conservation. The spheromak impurity radiation was measured using an absolutely calibrated single chord bolometer system. The theoretical efficiency is within the experimental uncertainty of the ratio of spheromak radiated energy to source input energy in a group of ''dirty'' discharges. But the radiation measurement uncertainty is too large to determine whether a substantial part of the excess source energy not used in the production of spheromak magnetic energy is radiated from the spheromak volume

  12. Agroforestry buffers for nonpoint source pollution reductions from agricultural watersheds.

    Science.gov (United States)

    Udawatta, Ranjith P; Garrett, Harold E; Kallenbach, Robert

    2011-01-01

    Despite increased attention and demand for the adoption of agroforestry practices throughout the world, rigorous long-term scientific studies confirming environmental benefits from the use of agroforestry practices are limited. The objective was to examine nonpoint-source pollution (NPSP) reduction as influenced by agroforestry buffers in watersheds under grazing and row crop management. The grazing study consists of six watersheds in the Central Mississippi Valley wooded slopes and the row crop study site consists of three watersheds in a paired watershed design in Central Claypan areas. Runoff water samples were analyzed for sediment, total nitrogen (TN), and total phosphorus (TP) for the 2004 to 2008 period. Results indicate that agroforestry and grass buffers on grazed and row crop management sites significantly reduce runoff, sediment, TN, and TP losses to streams. Buffers in association with grazing and row crop management reduced runoff by 49 and 19%, respectively, during the study period as compared with respective control treatments. Average sediment loss for grazing and row crop management systems was 13.8 and 17.9 kg ha yr, respectively. On average, grass and agroforestry buffers reduced sediment, TN, and TP losses by 32, 42, and 46% compared with the control treatments. Buffers were more effective in the grazing management practice than row crop management practice. These differences could in part be attributed to the differences in soils, management, and landscape features. Results from this study strongly indicate that agroforestry and grass buffers can be designed to improve water quality while minimizing the amount of land taken out of production. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

  13. Source term reduction at DAEC (including stellite ball recycling)

    International Nuclear Information System (INIS)

    Smith, R.; Schebler, D.

    1995-01-01

    The Duane Arnold Energy Center was seeking methods to reduce dose rates from the drywell due to Co-60. Duane Arnold is known in the industry to have one of the highest drywell dose rates from the industry standardized 'BRAC' point survey. A prime method to reduce dose rates due to Co-60 is the accelerated replacement of stellite pins and rollers in control rod blades due to their high stellite (cobalt) content. Usually the cobalt content in alloys of stellite is greater than 60% cobalt by weight. During the RFO-12 refueling outage at Duane Arnold, all of the remaining cobalt bearing control rod blades were replaced and new stellite free control rod blades were installed in the core. This left Duane Arnold with the disposal of highly radioactive stellite pins and rollers. The processing of control rod blades for disposal is a very difficult evolution. First, the velocity limiter (a bottom portion of the component) and the highly radioactive upper stellite control rod blade ins and rollers are separated from the control rod blade. Next, the remainder of the control rod blade is processed (chopped and/or crushed) to aid packaging the waste for disposal. The stellite bearings are then often carefully placed in with the rest of the waste in a burial liner to provide shielding for disposal or more often are left as 'orphans' in the spent fuel pool because their high specific activity create shipping and packaging problems. Further investigation by the utility showed that the stellite balls and pins could be recycled to a source manufacturer rather than disposed of in a low-level burial site. The cost savings to the utility was on the order of $200,000 with a gross savings of $400,000 in savings in burial site charges. A second advantage of the recycling of the stellite pins and rollers was a reduction in control in radioactive waste shipments

  14. Improving the Efficiency of Solid State Light Sources

    International Nuclear Information System (INIS)

    Joanna McKittrick

    2003-01-01

    This proposal addresses the national need to develop a high efficiency light source for general illumination applications. The goal is to perform research that would lead to the fabrication of a unique solid state, white-emitting light source. This source is based on an InGaN/GaN UV-emitting chip that activates a luminescent material (phosphor) to produce white light. White-light LEDs are commercially available which use UV from a GaN chip to excite a phosphor suspended in epoxy around the chip. Currently, these devices are relatively inefficient. This research will target one technical barrier that presently limits the efficiency of GaN based devices. Improvements in efficiencies will be achieved by improving the internal conversion efficiency of the LED die, by improving the coupling between the die and phosphor(s) to reduce losses at the surfaces, and by selecting phosphors to maximize the emissions from the LEDs in conversion to white light. The UCSD research team proposes for this project to develop new phosphors that have high quantum efficiencies that can be activated by the UV-blue (360-410 nm) light emitted by the GaN device. The main goal for the UCSD team was to develop new phosphor materials with a very specific property: phosphors that could be excited at long UV-wavelengths (λ=350-410 nm). The photoluminescence of these new phosphors must be activated with photons emitted from GaN based dies. The GaN diodes can be designed to emit UV-light in the same range (λ=350-410 nm). A second objective, which is also very important, is to search for alternate methods to fabricate these phosphors with special emphasis in saving energy and time and reduce pollution

  15. Energy Efficiency of Biogas Produced from Different Biomass Sources

    International Nuclear Information System (INIS)

    Begum, Shahida; Nazri, A H

    2013-01-01

    Malaysia has different sources of biomass like palm oil waste, agricultural waste, cow dung, sewage waste and landfill sites, which can be used to produce biogas and as a source of energy. Depending on the type of biomass, the biogas produced can have different calorific value. At the same time the energy, being used to produce biogas is dependent on transportation distance, means of transportation, conversion techniques and for handling of raw materials and digested residues. An energy systems analysis approach based on literature is applied to calculate the energy efficiency of biogas produced from biomass. Basically, the methodology is comprised of collecting data, proposing locations and estimating the energy input needed to produce biogas and output obtained from the generated biogas. The study showed that palm oil and municipal solid waste is two potential sources of biomass. The energy efficiency of biogas produced from palm oil residues and municipal solid wastes is 1.70 and 3.33 respectively. Municipal solid wastes have the higher energy efficiency due to less transportation distance and electricity consumption. Despite the inherent uncertainties in the calculations, it can be concluded that the energy potential to use biomass for biogas production is a promising alternative.

  16. Power Electronics as Efficient Interface of Renewable Energy Sources

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Chen, Zhe; Kjær, Søren Bækhøj

    2004-01-01

    The global electrical energy consumption is steadily rising and consequently there is a demand to increase the power generation capacity. A significant percentage of the required capacity increase can be based on renewable energy sources. Wind turbine technology, as the most cost effective...... renewable energy conversion system, will play an important part in our future energy supply. But other sources like microturbines, photovoltaics and fuel cell systems may also be serious contributor to the power supply. Characteristically, power electronics will be an efficient and important interface...... to the grid and this paper will first briefly discuss three different alternative/ renewable energy sources. Next, various configurations of the wind turbine technology are presented, as this technology seems to be most developed and cost-effective. Finally, the developments and requirements from the grid...

  17. Pure sources and efficient detectors for optical quantum information processing

    Science.gov (United States)

    Zielnicki, Kevin

    Over the last sixty years, classical information theory has revolutionized the understanding of the nature of information, and how it can be quantified and manipulated. Quantum information processing extends these lessons to quantum systems, where the properties of intrinsic uncertainty and entanglement fundamentally defy classical explanation. This growing field has many potential applications, including computing, cryptography, communication, and metrology. As inherently mobile quantum particles, photons are likely to play an important role in any mature large-scale quantum information processing system. However, the available methods for producing and detecting complex multi-photon states place practical limits on the feasibility of sophisticated optical quantum information processing experiments. In a typical quantum information protocol, a source first produces an interesting or useful quantum state (or set of states), perhaps involving superposition or entanglement. Then, some manipulations are performed on this state, perhaps involving quantum logic gates which further manipulate or entangle the intial state. Finally, the state must be detected, obtaining some desired measurement result, e.g., for secure communication or computationally efficient factoring. The work presented here concerns the first and last stages of this process as they relate to photons: sources and detectors. Our work on sources is based on the need for optimized non-classical states of light delivered at high rates, particularly of single photons in a pure quantum state. We seek to better understand the properties of spontaneous parameteric downconversion (SPDC) sources of photon pairs, and in doing so, produce such an optimized source. We report an SPDC source which produces pure heralded single photons with little or no spectral filtering, allowing a significant rate enhancement. Our work on detectors is based on the need to reliably measure single-photon states. We have focused on

  18. Effect of heterogeneity on enhanced reductive dechlorination: Analysis of remediation efficiency and groundwater acidification

    Science.gov (United States)

    Brovelli, A.; Lacroix, E.; Robinson, C. E.; Gerhard, J.; Holliger, C.; Barry, D. A.

    2011-12-01

    Enhanced reductive dehalogenation is an attractive in situ treatment technology for chlorinated contaminants. The process includes two acid-forming microbial reactions: fermentation of an organic substrate resulting in short-chain fatty acids, and dehalogenation resulting in hydrochloric acid. The accumulation of acids and the resulting drop of groundwater pH are controlled by the mass and distribution of chlorinated solvents in the source zone, type of electron donor, alternative terminal electron acceptors available and presence of soil mineral phases able to buffer the pH (such as carbonates). Groundwater acidification may reduce or halt microbial activity, and thus dehalogenation, significantly increasing the time and costs required to remediate the aquifer. In previous work a detailed geochemical and groundwater flow simulator able to model the fermentation-dechlorination reactions and associated pH change was developed. The model accounts for the main processes influencing microbial activity and groundwater pH, including the groundwater composition, the electron donor used and soil mineral phase interactions. In this study, the model was applied to investigate how spatial variability occurring at the field scale affects dechlorination rates, groundwater pH and ultimately the remediation efficiency. Numerical simulations were conducted to examine the influence of heterogeneous hydraulic conductivity on the distribution of the injected, fermentable substrate and on the accumulation/dilution of the acidic products of reductive dehalogenation. The influence of the geometry of the DNAPL source zone was studied, as well as the spatial distribution of soil minerals. The results of this study showed that the heterogeneous distribution of the soil properties have a potentially large effect on the remediation efficiency. For examples, zones of high hydraulic conductivity can prevent the accumulation of acids and alleviate the problem of groundwater acidification. The

  19. Efficient 1.6 Micron Laser Source for Methane DIAL

    Science.gov (United States)

    Shuman, Timothy; Burnham, Ralph; Nehrir, Amin R.; Ismail, Syed; Hair, Johnathan W.

    2013-01-01

    Methane is a potent greenhouse gas and on a per molecule basis has a warming influence 72 times that of carbon dioxide over a 20 year horizon. Therefore, it is important to look at near term radiative effects due to methane to develop mitigation strategies to counteract global warming trends via ground and airborne based measurements systems. These systems require the development of a time-resolved DIAL capability using a narrow-line laser source allowing observation of atmospheric methane on local, regional and global scales. In this work, a demonstrated and efficient nonlinear conversion scheme meeting the performance requirements of a deployable methane DIAL system is presented. By combining a single frequency 1064 nm pump source and a seeded KTP OPO more than 5 mJ of 1.6 µm pulse energy is generated with conversion efficiencies in excess of 20%. Even without active cavity control instrument limited linewidths (50 pm) were achieved with an estimated spectral purity of 95%. Tunable operation over 400 pm (limited by the tuning range of the seed laser) was also demonstrated. This source demonstrated the critical needs for a methane DIAL system motivating additional development of the technology.

  20. Fast space-varying convolution using matrix source coding with applications to camera stray light reduction.

    Science.gov (United States)

    Wei, Jianing; Bouman, Charles A; Allebach, Jan P

    2014-05-01

    Many imaging applications require the implementation of space-varying convolution for accurate restoration and reconstruction of images. Here, we use the term space-varying convolution to refer to linear operators whose impulse response has slow spatial variation. In addition, these space-varying convolution operators are often dense, so direct implementation of the convolution operator is typically computationally impractical. One such example is the problem of stray light reduction in digital cameras, which requires the implementation of a dense space-varying deconvolution operator. However, other inverse problems, such as iterative tomographic reconstruction, can also depend on the implementation of dense space-varying convolution. While space-invariant convolution can be efficiently implemented with the fast Fourier transform, this approach does not work for space-varying operators. So direct convolution is often the only option for implementing space-varying convolution. In this paper, we develop a general approach to the efficient implementation of space-varying convolution, and demonstrate its use in the application of stray light reduction. Our approach, which we call matrix source coding, is based on lossy source coding of the dense space-varying convolution matrix. Importantly, by coding the transformation matrix, we not only reduce the memory required to store it; we also dramatically reduce the computation required to implement matrix-vector products. Our algorithm is able to reduce computation by approximately factoring the dense space-varying convolution operator into a product of sparse transforms. Experimental results show that our method can dramatically reduce the computation required for stray light reduction while maintaining high accuracy.

  1. Ringing Artefact Reduction By An Efficient Likelihood Improvement Method

    Science.gov (United States)

    Fuderer, Miha

    1989-10-01

    In MR imaging, the extent of the acquired spatial frequencies of the object is necessarily finite. The resulting image shows artefacts caused by "truncation" of its Fourier components. These are known as Gibbs artefacts or ringing artefacts. These artefacts are particularly. visible when the time-saving reduced acquisition method is used, say, when scanning only the lowest 70% of the 256 data lines. Filtering the data results in loss of resolution. A method is described that estimates the high frequency data from the low-frequency data lines, with the likelihood of the image as criterion. It is a computationally very efficient method, since it requires practically only two extra Fourier transforms, in addition to the normal. reconstruction. The results of this method on MR images of human subjects are promising. Evaluations on a 70% acquisition image show about 20% decrease of the error energy after processing. "Error energy" is defined as the total power of the difference to a 256-data-lines reference image. The elimination of ringing artefacts then appears almost complete..

  2. Field-scale modeling of acidity production and remediation efficiency during in situ reductive dechlorination

    Science.gov (United States)

    Brovelli, A.; Robinson, C. E.; Barry, D. A.; Gerhard, J.

    2009-12-01

    Enhanced reductive dechlorination is a viable technology for in situ remediation of chlorinated solvent DNAPL source areas. Although in recent years increased understanding of this technology has led to more rapid dechlorination rates, complete dechlorination can be hindered by unfavorable conditions. Hydrochloric acid produced from dechlorination and organic acids generated from electron donor fermentation can lead to significant groundwater acidification. Adverse pH conditions can inhibit the activity of dehalogenating microorganisms and thus slow or stall the remediation process. The extent of acidification likely to occur at a contaminated site depends on a number of factors including (1) the extent of dechlorination, (2) the pH-sensitivity of dechlorinating bacteria, and (3) the geochemical composition of the soil and water, in particular the soil’s natural buffering capacity. The substantial mass of solvents available for dechlorination when treating DNAPL source zones means that these applications are particularly susceptible to acidification. In this study a reactive transport biogeochemical model was developed to investigate the chemical and physical parameters that control the build-up of acidity and subsequent remediation efficiency. The model accounts for the site water chemistry, mineral precipitation and dissolution kinetics, electron donor fermentation, gas phase formation, competing electron-accepting processes (e.g., sulfate and iron reduction) and the sensitivity of microbial processes to pH. Confidence in the model was achieved by simulating a well-documented field study, for which the 2-D field scale model was able to reproduce long-term variations of pH, and the concurrent build up of reaction products. Sensitivity analyses indicated the groundwater flow velocity is able to reduce acidity build-up when the rate of advection is comparable or larger than the rate of dechlorination. The extent of pH change is highly dependent on the presence of

  3. Technical Note: On the efficiency of variance reduction techniques for Monte Carlo estimates of imaging noise.

    Science.gov (United States)

    Sharma, Diksha; Sempau, Josep; Badano, Aldo

    2018-02-01

    Monte Carlo simulations require large number of histories to obtain reliable estimates of the quantity of interest and its associated statistical uncertainty. Numerous variance reduction techniques (VRTs) have been employed to increase computational efficiency by reducing the statistical uncertainty. We investigate the effect of two VRTs for optical transport methods on accuracy and computing time for the estimation of variance (noise) in x-ray imaging detectors. We describe two VRTs. In the first, we preferentially alter the direction of the optical photons to increase detection probability. In the second, we follow only a fraction of the total optical photons generated. In both techniques, the statistical weight of photons is altered to maintain the signal mean. We use fastdetect2, an open-source, freely available optical transport routine from the hybridmantis package. We simulate VRTs for a variety of detector models and energy sources. The imaging data from the VRT simulations are then compared to the analog case (no VRT) using pulse height spectra, Swank factor, and the variance of the Swank estimate. We analyze the effect of VRTs on the statistical uncertainty associated with Swank factors. VRTs increased the relative efficiency by as much as a factor of 9. We demonstrate that we can achieve the same variance of the Swank factor with less computing time. With this approach, the simulations can be stopped when the variance of the variance estimates reaches the desired level of uncertainty. We implemented analytic estimates of the variance of Swank factor and demonstrated the effect of VRTs on image quality calculations. Our findings indicate that the Swank factor is dominated by the x-ray interaction profile as compared to the additional uncertainty introduced in the optical transport by the use of VRTs. For simulation experiments that aim at reducing the uncertainty in the Swank factor estimate, any of the proposed VRT can be used for increasing the relative

  4. Sources and acceleration efficiencies for energetic particles in the heliosphere

    International Nuclear Information System (INIS)

    Kucharek, H; Moebius, E

    2006-01-01

    Shocks at solar wind stream interaction regions, coronal mass ejections and magnetospheric obstacles have long been known for their intimate link with particle acceleration. Much enhanced capabilities to determine mass and charge composition at interplanetary shocks with ACE and SOHO have enabled us to identify sources and acceleration processes for the energetic particles. Both solar wind and interstellar pickup ions are substantial sources for particle acceleration in corotating interaction regions and at coronal mass ejections driven shocks and that flare particles are re-accelerated. Suprathermal distributions, such as pickup ions and pre-existing flare populations are accelerated much more efficiently than particles out of the solar wind. Recent results of the termination shock crossing by Voyager I and the scientific goals of the upcoming IBEX mission will be discussed

  5. Efficient Bayesian experimental design for contaminant source identification

    Science.gov (United States)

    Zhang, Jiangjiang; Zeng, Lingzao; Chen, Cheng; Chen, Dingjiang; Wu, Laosheng

    2015-01-01

    In this study, an efficient full Bayesian approach is developed for the optimal sampling well location design and source parameters identification of groundwater contaminants. An information measure, i.e., the relative entropy, is employed to quantify the information gain from concentration measurements in identifying unknown parameters. In this approach, the sampling locations that give the maximum expected relative entropy are selected as the optimal design. After the sampling locations are determined, a Bayesian approach based on Markov Chain Monte Carlo (MCMC) is used to estimate unknown parameters. In both the design and estimation, the contaminant transport equation is required to be solved many times to evaluate the likelihood. To reduce the computational burden, an interpolation method based on the adaptive sparse grid is utilized to construct a surrogate for the contaminant transport equation. The approximated likelihood can be evaluated directly from the surrogate, which greatly accelerates the design and estimation process. The accuracy and efficiency of our approach are demonstrated through numerical case studies. It is shown that the methods can be used to assist in both single sampling location and monitoring network design for contaminant source identifications in groundwater.

  6. Efficiency factor of a chemical nuclear reactor with gamma sources

    International Nuclear Information System (INIS)

    Anguis T, C.

    1975-01-01

    A chemonuclear reactor is simulated in order to calculate the efficiency factor of molecular species in chemical reactions induced by gamma radiation, with the purpose to obtain information for its design and consider the electromagnetic energy as a possible solution to the present problem of energy. The research is based on a mathematical model of succesive Compton processes applied to spherical and cylindrical geometry and corroborated through the absorbed dose and the experimental date of the increase factor, for the radioisotopic sources Co-60 and Cs-137 relating the quantity of energy deposited into various cylinders with the G value, the relation radius/height of the reactor is optimized according to the molecular production. This is illustrated with the radiolysis of a solution of CH 3 OH/H 2 O which forms H 2 and with the obtainment of C 2 H 5 Br that represents and industrial process induced radioactively. The results show a greater energy deposition with Cs-137 but a larger production of H 2 /hr with Co-60, and besides we can find high production values of C 2 H 5 Br. The cylinder with more advantages is that whose relation R/H is of 0.5. It can be concluded that the final selection of the reactor should be made after a more intense study of the used isotope and the source activity. The efficiency factor of H 2 can be increased selecting the appropriate type and concentration of solute of the irradiated aqueous solutions

  7. High Efficient Reduction of Graphene Oxide via Nascent Hydrogen at Room Temperature

    Directory of Open Access Journals (Sweden)

    Qiqi Zhuo

    2018-02-01

    Full Text Available To develop a green and efficient method to synthesize graphene in relative milder conditions is prerequisite for graphene applications. A chemical reducing method has been developed to high efficiently reduce graphene oxide (GO using Fe2O3 and NH3BH3 as catalyst and reductants, respectively. During the process, environmental and strong reductive nascent hydrogen were generated surrounding the surface of GO sheets by catalyst hydrolysis reaction of NH3BH3 and were used for reduction of GO. The reduction process was studied by ultraviolet absorption spectroscopy, Raman spectroscopy, and Fourier transform infrared spectrum. The structure and morphology of the reduced GO were characterized with scanning electron microscopy and transmission electron microscopy. Compared to metal (Mg/Fe/Zn/Al particles and acid system which also use nascent hydrogen to reduce GO, this method exhibited higher reduction efficiency (43.6%. Also the reduction was carried out at room temperature condition, which is environmentally friendly. As a supercapacitor electrode, the reversible capacity of reduced graphene oxide was 113.8 F g−1 at 1 A g−1 and the capacitance retention still remained at 90% after 200 cycles. This approach provides a new method to reduce GO with high reduction efficiency by green reductant.

  8. Thermal Performance and Efficiency Investigation of Conventional Boost, Z-source and Y-source Converters

    DEFF Research Database (Denmark)

    Gadalla, Brwene Salah Abdelkarim; Schaltz, Erik; Siwakoti, Yam Prasad

    2016-01-01

    Boost converters are needed in many applications that require the output voltage to be higher than the input voltage. Recently, boost type converters have been attracted by the industrial applications, and hence it has become an extremely hot topic of research. Recently, many researchers proposed...... the impedance source converters with their unique advantages as having a high voltage gain in a small range of duty cycle ratio. However, the thermal behaviour of the semiconductor devices and passive elements in the impedance source converter is an important issue from a reliability point of view and has...... not been investigated yet. Therefore this paper presents a comparison between the conventional boost, the Z-source, and the Y-source converters based on the thermal evaluation of semiconductors. In addition, the three topologies are also compared with respect to their efficiency. The operational principle...

  9. Potential Sources for Financing Environmental Protection Projects – Focusing on Energy Efficiency

    Directory of Open Access Journals (Sweden)

    Milan Počuča

    2015-05-01

    Full Text Available This paper elaborates financial mechanisms for financing energy efficiency with particular emphasis on the resources from financial institutions and equity funds and capital from the companies themselves. By conducting relevant academic research of literature and data from print and electronic sources (statistical reports, laws and regulations, statements of companies and financial institutions, as well as from the practical experience of some countries, it has been observed that the poor representation of adapted financial mechanisms is a major constraint to the emergence of a culture of energy efficiency in most countries, including Serbia. Even where they exist they are not necessarily known to make use of successful experiences. By conducting an analysis of the relevant academic literature and an analysis of practical experiences in the domain of energy efficiency and renewable energy sources it was concluded that energy efficiency is a significant potential for growth of the economic strength of Serbia, and therefore incentives should nfluence a greater use of renewable energy and a reduction in use of the fossil fuels as an energy source.

  10. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  11. Strategic GHG reduction through the use of ground source heat pump technology

    International Nuclear Information System (INIS)

    Hanova, J; Dowlatabadi, H

    2007-01-01

    Higher energy prices and concern about climate change is drawing increasing attention to ground source heat pump (GSHP) systems. Their clear advantage lies in being able to provide heating using 25 to 30% of the energy consumed by even the most efficient conventional alternatives. Their drawback has been high capital costs and uncertainty about whether the emissions associated with the electric power used to energise the system has higher system-wide emissions than the highest-efficiency furnaces. This study delineates circumstances under which GSHP systems achieve net emission reductions, for different electricity generation methods, heat pump efficiencies, and heating loads. We illustrate the effect of relative fuel prices on annual operating savings using fuel prices in multiple countries. Annual operating savings determine how rapidly the technology achieves payback and then generates return on the initial capital investment. Finally, we highlight the least cost supply curve for using GSHP to reduce greenhouse gas emissions. Using the United States as a base reference case, this study explores the potential of GSHP in cold-climate countries worldwide

  12. Reduction of NOx emission from stationary combustion sources

    International Nuclear Information System (INIS)

    Nelson, P.F.

    1992-01-01

    The environmental impacts of NO x emission from stationary combustion sources are briefly described. These include the formation of both acid rain and photochemical smog, major environmental problems. The three mechanisms which have been identified for the formation of NO x in combustion (thermal, prompt and fuel) are also briefly outlined. Recently stringent standards have been introduced to control emissions of NO x and the review describes the major primary and secondary measures. 10 refs. 2 tabs., 5 figs

  13. Effect of process parameters and injector position on the efficiency of NOx reduction by selective non catalytic reduction technique

    International Nuclear Information System (INIS)

    Hamid, A.; Mehmood, M.A.; Irfan, N.; Javed, M.T.; Waheed, K.

    2009-01-01

    An experimental investigation has been performed to study the effect of atomizer pressure dilution of the reducing reagent and the injector position on the efficiency or the NOx reduction by a selective non-catalytic reduction technique using urea as a reducing agent. Experiments were performed with a flow reactor in which flue gas was generated by the combustion of methane in air at stoichiometric amount of oxygen and the desired levels of initial NOx (400-450 ppm) were achieved by doping the flame with ammonia. The work was directed to investigate the effect of atomizer pressure, dilution of urea reagent and the injector position. The atomizer pressure was varied from 1 to 3bar and 20-25% increase in efficiency was observed by decreasing the pressure. Effect of dilution of urea solution was investigated by varying the strength of the solution from the 8 to 32% and 40-45% increase in the efficiency was observed. Effects of injector position was investigated by injecting the urea solution both in co current and counter current direction of the flue gases and 20-25% increase in the efficiency was observed in counter current direction. (author)

  14. Disaster Risk Reduction through Innovative Uses of Crowd Sourcing (Invited)

    Science.gov (United States)

    Berger, J.; Greene, M.

    2010-12-01

    Crowd sourcing can be described as a method of distributed problem-solving. It takes advantage of the power of the crowd, which can in some cases be a community of experts and in other cases the collective insight of a broader range of contributors with varying degrees of domain knowledge. The term crowd sourcing was first used by Jeff Howe in a June 2006 Wired magazine article “The Rise of Crowdsourcing,” and is a combination of the terms “crowd” and “outsourcing.” Some commonly known examples of crowd sourcing, in its broadest sense, include Wikepedia, distributed participatory design projects, and consumer websites such as Yelp and Angie’s List. The popularity and success of early large-scale crowd sourcing activities is made possible through leveraging Web 2.0 technologies that allow for mass participation from distributed individuals. The Earthquake Engineering Research Institute (EERI) in Oakland, California recently participated in two crowd sourcing projects. One was initiated and coordinated by EERI, while in the second case EERI was invited to contribute once the crowd sourcing activity was underway. In both projects there was: 1) the determination of a problem or set of tasks that could benefit immediately from the engagement of an informed volunteer group of professionals; 2) a segmenting of the problem into discrete pieces that could be completed in a short period of time (from ten minutes to four hours); 3) a call to action, where an interested community was made aware of the project; and 4) the collection, aggregation, vetting and ultimately distribution of the results in a relatively short period of time. The first EERI crowd sourcing example was the use of practicing engineers and engineering students in California to help estimate the number of pre-1980 concrete buildings in the high seismic risk counties in the state. This building type is known to perform poorly in earthquakes, and state officials were interested in understanding

  15. Energy efficiency and renewable energy sources in Nordic homes

    Energy Technology Data Exchange (ETDEWEB)

    Hyysalo, S; Rinkinen, J [Aalto Univ. School of Economics, Helsinki (Finland). Dept. of Management and International Business; Heiskanen, E [National Consumer Research Centre, Helsinki (Finland)

    2011-07-01

    The role of citizens as innovators, adaptors of existing technologies and diffusers of new climate-relevant innovations has been studied extensively in recent years. Since the late 1970s, sociological and demographic research on residential energy use has consistently found great variations in energy use among similar households. It has been suggested that these variations constitute a source of innovative low-carbon practices. Yet, while there are many generic technologies available for end-use efficiency and renewables, their slow rate of diffusion suggests that they are not as such applicable to local conditions. Citizens have a key role in their adoption and adaptation to local conditions, as well in their diffusion to other users. Against this backdrop, the track 4 of NCF called for poster presentations of innovative new products, modifications of existing products, news ways of make use of existing technologies as well as such living practices that reduce energy use or enable the utilization of renewable energy sources in domestic settings in the Nordic countries. (orig.)

  16. Reduction efficiency prediction of CENIBRA's recovery boiler by direct minimization of gibbs free energy

    Directory of Open Access Journals (Sweden)

    W. L. Silva

    2008-09-01

    Full Text Available The reduction efficiency is an important variable during the black liquor burning process in the Kraft recovery boiler. This variable value is obtained by slow experimental routines and the delay of this measure disturbs the pulp and paper industry customary control. This paper describes an optimization approach for the reduction efficiency determination in the furnace bottom of the recovery boiler based on the minimization of the Gibbs free energy. The industrial data used in this study were directly obtained from CENIBRA's data acquisition system. The resulting approach is able to predict the steady state behavior of the chemical composition of the furnace recovery boiler, - especially the reduction efficiency when different operational conditions are used. This result confirms the potential of this approach in the analysis of the daily operation of the recovery boiler.

  17. Energy efficiency and reduction of CO2 emissions from campsites management in a protected area.

    Science.gov (United States)

    Del Moretto, Deny; Branca, Teresa Annunziata; Colla, Valentina

    2018-06-02

    Campsites can be a pollution source, mainly due to the energy consumption. In addition, the green areas, thanks to the direct CO 2 sequestration and the shading, indirectly prevent the CO 2 emissions related to energy consumption. The methodology presented in this paper allowed assessing the annual CO 2 emissions directly related to the campsite management and the consequent environmental impact in campsite clusters in Tuscany. The software i-Tree Canopy was exploited, enabling to evaluate in terms of "canopy" the tonnes of CO 2 sequestered by the vegetation within each campsite. Energy and water consumptions from 2012 to 2015 were assessed for each campsite. As far as the distribution of sequestered CO 2 is concerned, the campsites ranking was in accordance to their size. According to the indicator "T-Tree" or canopy cover, a larger area of the canopy cover allows using less outdoor areas covered by trees for the sequestration of the remaining amount of pollutants. The analysis shows that the considered campsites, that are located in a highly naturalistic Park, present significant positive aspects both in terms of CO 2 emission reductions and of energy efficiency. However, significant margins of improvement are also possible and they were analysed in the paper. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Estimating the Value of Price Risk Reduction in Energy Efficiency Investments in Buildings

    Directory of Open Access Journals (Sweden)

    Pekka Tuominen

    2017-10-01

    Full Text Available This paper presents a method for calculating the value of price risk reduction to a consumer that can be achieved with investments in energy efficiency. The value of price risk reduction is discussed to some length in general terms in the literature reviewed but, so far, no methodology for calculating the value has been presented. Here we suggest such a method. The problem of valuating price risk reduction is approached using a variation of the Black–Scholes model by considering a hypothetical financial instrument that a consumer would purchase to insure herself against unexpected price hikes. This hypothetical instrument is then compared with an actual energy efficiency investment that reaches the same level of price risk reduction. To demonstrate the usability of the method, case examples are calculated for typical single-family houses in Finland. The results show that the price risk entailed in household energy consumption can be reduced by a meaningful amount with energy efficiency investments, and that the monetary value of this reduction can be calculated. It is argued that this often-overlooked benefit of energy efficiency investments merits more consideration in future studies.

  19. Greenhouse Gas reduction for scenarios of power sources development of the Republic of Moldova

    Directory of Open Access Journals (Sweden)

    Comendant I.

    2010-04-01

    Full Text Available For the new power market conditions, Moldova power sources development options up to 2033 are evaluated, and for the six scenarios selected the greenhouse gas reduction impact is determined.

  20. Efficient Symmetry Reduction and the Use of State Symmetries for Symbolic Model Checking

    Directory of Open Access Journals (Sweden)

    Christian Appold

    2010-06-01

    Full Text Available One technique to reduce the state-space explosion problem in temporal logic model checking is symmetry reduction. The combination of symmetry reduction and symbolic model checking by using BDDs suffered a long time from the prohibitively large BDD for the orbit relation. Dynamic symmetry reduction calculates representatives of equivalence classes of states dynamically and thus avoids the construction of the orbit relation. In this paper, we present a new efficient model checking algorithm based on dynamic symmetry reduction. Our experiments show that the algorithm is very fast and allows the verification of larger systems. We additionally implemented the use of state symmetries for symbolic symmetry reduction. To our knowledge we are the first who investigated state symmetries in combination with BDD based symbolic model checking.

  1. Effect of 30-Gy irradiation in conjunction with leukocyte reduction filter on platelet and transfusion efficiency

    International Nuclear Information System (INIS)

    Shimojima, Hiromi; Sawada, Umihiko; Horie, Takashi; Itoh, Takeyoshi

    2001-01-01

    To evaluate the effect of 30-Gy irradiation in conjunction with leukocyte reduction filter on platelet and transfusion efficiency, we studied platelet recovery, leukocyte reduction rate, content of platelet factor 4 and β-thromboglobulin in platelet products, platelet functions, and positive rates of platelet surface membranes CD42 and CD62, prior to and after treatment. We also evaluated the efficiency of platelet transfusion by estimating post- transfusion (1 and 24 hour) corrected count increment (CCI), and transfusion side effects. Recovery of platelets was 91.8±6.5% and depletion rate of leukocytes was 1.7±1.1 log. There was no significant difference in platelet activation markers or function tests prior to and after the procedure. The mean post-transfusion CCI and 1 and 24 hours were 16,550 (n=114) and 13,310 (n=93), respectively, with 30-Gy irradiation and leukocyte reduction filter. Those treated solely with leukocyte reduction filter were 14,970 (n=114) and 10,880 (n=118), respectively. There was no increase in transfusion side effects after the treatment of platelet concentrate with 30-Gy irradiation combined with leukocyte reduction filter compared with treatment by leukocyte reduction filter alone. These results indicate that treatment with 30 Gy irradiation in conjunction with leukocyte reduction filter is safe and effective in platelet transfusion. (author)

  2. Solar fuel processing efficiency for ceria redox cycling using alternative oxygen partial pressure reduction methods

    International Nuclear Information System (INIS)

    Lin, Meng; Haussener, Sophia

    2015-01-01

    Solar-driven non-stoichiometric thermochemical redox cycling of ceria for the conversion of solar energy into fuels shows promise in achieving high solar-to-fuel efficiency. This efficiency is significantly affected by the operating conditions, e.g. redox temperatures, reduction and oxidation pressures, solar irradiation concentration, or heat recovery effectiveness. We present a thermodynamic analysis of five redox cycle designs to investigate the effects of working conditions on the fuel production. We focused on the influence of approaches to reduce the partial pressure of oxygen in the reduction step, namely by mechanical approaches (sweep gassing or vacuum pumping), chemical approaches (chemical scavenger), and combinations thereof. The results indicated that the sweep gas schemes work more efficient at non-isothermal than isothermal conditions, and efficient gas phase heat recovery and sweep gas recycling was important to ensure efficient fuel processing. The vacuum pump scheme achieved best efficiencies at isothermal conditions, and at non-isothermal conditions heat recovery was less essential. The use of oxygen scavengers combined with sweep gas and vacuum pump schemes further increased the system efficiency. The present work can be used to predict the performance of solar-driven non-stoichiometric redox cycles and further offers quantifiable guidelines for system design and operation. - Highlights: • A thermodynamic analysis was conducted for ceria-based thermochemical cycles. • Five novel cycle designs and various operating conditions were proposed and investigated. • Pressure reduction method affects optimal operating conditions for maximized efficiency. • Chemical oxygen scavenger proves to be promising in further increasing efficiency. • Formulation of quantifiable design guidelines for economical competitive solar fuel processing

  3. Sources of Technical Efficiency Among Smallholders Maize Farmers ...

    African Journals Online (AJOL)

    The results show that the mean technical efficiency score for famers in the study area is 62.3%. This implies that there is a significant room for increasing maize yield in the study area if farmers use the resources at their disposal efficiently. Moreover, the results show that the efficiency of maize farmers in the study area is ...

  4. An efficient catalytic reductive amination: A facile one-pot access to ...

    Indian Academy of Sciences (India)

    An efficient catalytic reductive amination: A facile one-pot access to ... itors and in the manufacture of detergents and plastics.1 ... ammoniaborane/Ti(OiPr)4,5e ... demonstrated the first method for synthesis of 1,2- ... and column chromatography (Silica gel, n-hexane/ethyl .... supporting information at www.ias.ac.in/chemsci.

  5. Efficient oxygen reduction reaction using ruthenium tetrakis(diaquaplatinum)octacarboxyphthalocyanine catalyst supported on MWCNT platform

    CSIR Research Space (South Africa)

    Maxakato, NW

    2011-02-01

    Full Text Available -1 Electroanalysis 2011, 23, No. 2, 325 ? 329 Efficient Oxygen Reduction Reaction Using Ruthenium Tetrakis(diaquaplatinum)Octacarboxyphthalocyanine Catalyst Supported on MWCNT Platform Nobanathi W. Maxakato,a Solomon A. Mamuru,a Kenneth I. Ozoemena*a, b a...

  6. High-efficiency thermal ionization sources for mass spectrometry

    International Nuclear Information System (INIS)

    Olivares, Jose A.

    1996-01-01

    A version of the thermal ionization cavity (TIC) source developed specifically for use in mass spectrometry is presented. The performance of this ion source has been characterized extensively both with the use of an isotope separator and a quadrupole mass spectrometer. A detailed description of the TIC source for mass spectrometry is given along with the performance characteristics observed

  7. Reduction of Radioactive Waste Through the Reuse and Recycle Policy of the Sealed Radioactive Sources Management

    OpenAIRE

    Marpaung, T

    2012-01-01

    In the past few years, the utilization of sealed source for medical, industrial and research purposes has shown an accelerating increase. This situation will lead to increases in the amount of sealed radioactive. During its use, a sealed radioactive waste will eventually become either a spent sealed source or disused sealed radioactive source (DSRS), due to certain factors. The reduction of the amount of radioactive waste can be executed through the application of reuse and recycle of sealed ...

  8. Abatement vs. treatment for efficient diffuse source water pollution management in terrestrial-marine systems.

    Science.gov (United States)

    Roebeling, P C; Cunha, M C; Arroja, L; van Grieken, M E

    2015-01-01

    Marine ecosystems are affected by water pollution originating from coastal catchments. The delivery of water pollutants can be reduced through water pollution abatement as well as water pollution treatment. Hence, sustainable economic development of coastal regions requires balancing of the marginal costs from water pollution abatement and/or treatment and the associated marginal benefits from marine resource appreciation. Water pollution delivery reduction costs are, however, not equal across abatement and treatment options. In this paper, an optimal control approach is developed and applied to explore welfare maximizing rates of water pollution abatement and/or treatment for efficient diffuse source water pollution management in terrestrial-marine systems. For the case of diffuse source dissolved inorganic nitrogen water pollution in the Tully-Murray region, Queensland, Australia, (agricultural) water pollution abatement cost, (wetland) water pollution treatment cost and marine benefit functions are determined to explore welfare maximizing rates of water pollution abatement and/or treatment. Considering partial (wetland) treatment costs and positive water quality improvement benefits, results show that welfare gains can be obtained, primarily, through diffuse source water pollution abatement (improved agricultural management practices) and, to a minor extent, through diffuse source water pollution treatment (wetland restoration).

  9. The critical role of the industrial sector in reaching long-term emission reduction, energy efficiency and renewable targets

    International Nuclear Information System (INIS)

    Fais, Birgit; Sabio, Nagore; Strachan, Neil

    2016-01-01

    Highlights: • A new industrial modelling approach in a whole energy systems model is developed. • The contribution of UK industry to long-term energy policy targets is analysed. • Emission reductions of up to 77% can be achieved in the UK industry until 2050. • The UK industry sector is essential for achieving the overall efficiency commitments. • UK industry can make a moderate contribution to the expansion of renewable energies. - Abstract: This paper evaluates the critical contribution of the industry sector to long-term decarbonisation, efficiency and renewable energy policy targets. Its methodological novelty is the incorporation of a process-oriented modelling approach based on a comprehensive technology database for the industry sector in a national energy system model for the UK (UKTM), allowing quantification of the role of both decarbonisation of upstream energy vectors and of mitigation options in the industrial sub-categories. This enhanced model is then applied in a comparative policy scenario analysis that explores various target dimensions on emission mitigation, renewable energy and energy efficiency at both a national and European level. The results show that ambitious emission cuts in the industry sector of up to 77% until 2050 compared to 2010 can be achieved. Moreover, with a reduction in industrial energy demand of up to 31% between 2010 and 2050, the sector is essential for achieving the overall efficiency commitments. The industry sector also makes a moderate contribution to the expansion of renewable energies mostly through the use of biomass for low-temperature heating services. However, additional sub-targets on renewable sources and energy efficiency need to be assessed critically, as they can significantly distort the cost-efficiency of the long-term mitigation pathway.

  10. Reduction of firewood consumption by households in south-central Chile associated with energy efficiency programs

    International Nuclear Information System (INIS)

    Schueftan, Alejandra; González, Alejandro D.

    2013-01-01

    Cities in the central-southern area of Chile face serious environmental pollution due to extensive use of firewood for heating. Low energy efficiency of constructions and cold climate increase the problem, which also affects native forests. The aims of this study are to characterize energy consumption in dwellings of this region, investigate the reduction potential, and study social and environmental consequences of high consumption of firewood. Actual energy consumption is studied with information from surveys, potential for reduction is modeled with software and other consequences are analyzed from previous studies. Results for the city of Valdivia show high firewood consumption per household, with a media bulk volume near 12 m 3 /year. Thermal regulations are softer compared with other countries. Moreover, around 85% of buildings were built before enforcing codes in 2007, and has almost no thermal protection. The reduction potential due to thermal improvements is found to be very high (62%) if buildings are refurbished to comply with the present Chilean Norm of 2007, but it reaches a 77% reduction if refurbished according to stricter foreign regulations. Therefore, an energy efficiency program strongly addressing existing buildings has the largest potential for reducing firewood use, and therefore mitigate environmental and health impacts. - Highlights: • High firewood consumption and environmental pollution in cities of south-central Chile. • High use of firewood due to inefficient constructions and soft thermal regulations. • Potential reduction of energy consumption up to 77% with more demanding regulations. • Policies should address building stock before thermal regulation, corresponding to 85%

  11. An efficient CDMA decoder for correlated information sources

    International Nuclear Information System (INIS)

    Efraim, Hadar; Yacov, Nadav; Kanter, Ido; Shental, Ori

    2009-01-01

    We consider the detection of correlated information sources in the ubiquitous code-division multiple-access (CDMA) scheme. We propose a message-passing based scheme for detecting correlated sources directly, with no need for source coding. The detection is done simultaneously over a block of transmitted binary symbols (word). Simulation results are provided, demonstrating a substantial improvement in bit error rate in comparison with the unmodified detector and the alternative of source compression. The robustness of the error-performance improvement is shown under practical model settings, including wrong estimation of the generating Markov transition matrix and finite-length spreading codes

  12. Amorphizing of Cu Nanoparticles toward Highly Efficient and Robust Electrocatalyst for CO2 Reduction to Liquid Fuels with High Faradaic Efficiencies.

    Science.gov (United States)

    Duan, Yan-Xin; Meng, Fan-Lu; Liu, Kai-Hua; Yi, Sha-Sha; Li, Si-Jia; Yan, Jun-Min; Jiang, Qing

    2018-04-01

    Conversion of carbon dioxide (CO 2 ) into valuable chemicals, especially liquid fuels, through electrochemical reduction driven by sustainable energy sources, is a promising way to get rid of dependence on fossil fuels, wherein developing of highly efficient catalyst is still of paramount importance. In this study, as a proof-of-concept experiment, first a facile while very effective protocol is proposed to synthesize amorphous Cu NPs. Unexpectedly, superior electrochemical performances, including high catalytic activity and selectivity of CO 2 reduction to liquid fuels are achieved, that is, a total Faradaic efficiency of liquid fuels can sum up to the maximum value of 59% at -1.4 V, with formic acid (HCOOH) and ethanol (C 2 H 6 O) account for 37% and 22%, respectively, as well as a desirable long-term stability even up to 12 h. More importantly, this work opens a new avenue for improved electroreduction of CO 2 based on amorphous metal catalysts. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Power Efficiency Improvements through Peak-to-Average Power Ratio Reduction and Power Amplifier Linearization

    Directory of Open Access Journals (Sweden)

    Zhou G Tong

    2007-01-01

    Full Text Available Many modern communication signal formats, such as orthogonal frequency-division multiplexing (OFDM and code-division multiple access (CDMA, have high peak-to-average power ratios (PARs. A signal with a high PAR not only is vulnerable in the presence of nonlinear components such as power amplifiers (PAs, but also leads to low transmission power efficiency. Selected mapping (SLM and clipping are well-known PAR reduction techniques. We propose to combine SLM with threshold clipping and digital baseband predistortion to improve the overall efficiency of the transmission system. Testbed experiments demonstrate the effectiveness of the proposed approach.

  14. The photonic nanowire: A highly efficient single-photon source

    DEFF Research Database (Denmark)

    Gregersen, Niels

    2014-01-01

    The photonic nanowire represents an attractive platform for a quantum light emitter. However, careful optical engineering using the modal method, which elegantly allows access to all relevant physical parameters, is crucial to ensure high efficiency.......The photonic nanowire represents an attractive platform for a quantum light emitter. However, careful optical engineering using the modal method, which elegantly allows access to all relevant physical parameters, is crucial to ensure high efficiency....

  15. A credit line appropriated for energy efficiency and renewable energy sources in Bulgaria

    International Nuclear Information System (INIS)

    Iliev, I.

    2008-01-01

    The credit line was developed by the European Bank for Reconstruction and Development (EBRD) in co-operation with the Bulgarian government. In this financial project several bulgarian banks are involved. The purpose of this project is to support mainly the private enterprises in the sector of energy efficiency and renewable energy sources. The main steps of the applying process are discussed and useful practical information is given. In Bulgaria till now 125 projects are successful financed with total amount about 72 million Euro. The projects will generate annually more than 457 000 MWh electric power and 615 285 MWh thermal power, as well as an annual reduction of about 494 200 t CO 2 emissions is expected

  16. Source reduction for prevention of methylene chloride hazards: cases from four industrial sectors

    Directory of Open Access Journals (Sweden)

    Ellenbecker Michael J

    2003-07-01

    Full Text Available Abstract Background Source reduction, defined as chemical, equipment and process changes that intervene in an industrial process to eliminate or reduce hazards, has not figured as a front-line strategy for the protection of workers' health. Such initiatives are popular for environmental protection, but their feasibility and effectiveness as an industrial hygiene approach have not been well described. Methods We investigated four cases of source reduction as a hazard prevention strategy in Massachusetts companies that had used methylene chloride, an occupational carcinogen, for cleaning and adhesive thinning. Three cases were retrospective and one was prospective, where the researchers assisted with the source reduction process change. Data were collected using qualitative research methods, including in-depth interviews and site visits. Results Motivated by environmental restrictions, a new worker health standard, and opportunity for productivity improvements, three companies eliminated their use of methylene chloride by utilizing available technologies and drop-in substitutes. Aided by technical assistance from the investigators, a fourth case dramatically reduced its use of methylene chloride via process and chemistry changes. While the companies' evaluations of potential work environment impacts of substitutes were not extensive, and in two cases new potential hazards were introduced, the overall impact of the source reduction strategy was deemed beneficial, both from a worker health and a production standpoint. Conclusion The findings from these four cases suggest that source reduction should be considered potentially feasible and effective for reducing or eliminating the potential hazards of methylene chloride exposure. Especially when faced with a hazard that is both an environmental and worker health concern, companies may chose to change their processes rather than rely on local exhaust ventilation equipment or personal protective

  17. Using mobile source emission reductions to offset stationary surce rule requirements

    International Nuclear Information System (INIS)

    Nazemi, M.A.; Beruldsen, K.J.

    1993-01-01

    A number of mobile source strategies have been evaluated that could potentially be used as an alternative means of compliance with existing stationary source regulations, at a lower cost. The evaluation was spurred by both public and private sector interest in identifying the lowest cost air pollution reduction strategies, and the realization that mobile sources are the predominate contributor to the air pollution problem in the South Coast Air Quality Basin. Strategies evaluated included removing older vehicles from the in-use population, use of alternative fuels, inspection and maintenance measures, application of remote sensing technology, exceeding AVR requirements, as well as a number of other strategies. Key implementation issues have been identified, so that the viability of each mobile source strategies could be assessed. These issues include: (1) quantification of emissions benefits, (2) determining whether the mobile source strategy would generate emission reductions surplus to existing and planned mobile source regulations, and (3) assessing the potential for enforceability. The results of evaluation indicate that there are a number of promising mobile source emission strategies that could provide quantifiable, surplus, and enforceable emission reductions

  18. Water splitting-biosynthetic system with CO₂ reduction efficiencies exceeding photosynthesis.

    Science.gov (United States)

    Liu, Chong; Colón, Brendan C; Ziesack, Marika; Silver, Pamela A; Nocera, Daniel G

    2016-06-03

    Artificial photosynthetic systems can store solar energy and chemically reduce CO2 We developed a hybrid water splitting-biosynthetic system based on a biocompatible Earth-abundant inorganic catalyst system to split water into molecular hydrogen and oxygen (H2 and O2) at low driving voltages. When grown in contact with these catalysts, Ralstonia eutropha consumed the produced H2 to synthesize biomass and fuels or chemical products from low CO2 concentration in the presence of O2 This scalable system has a CO2 reduction energy efficiency of ~50% when producing bacterial biomass and liquid fusel alcohols, scrubbing 180 grams of CO2 per kilowatt-hour of electricity. Coupling this hybrid device to existing photovoltaic systems would yield a CO2 reduction energy efficiency of ~10%, exceeding that of natural photosynthetic systems. Copyright © 2016, American Association for the Advancement of Science.

  19. A high efficiency thermal ionization source adapted to mass spectrometers

    International Nuclear Information System (INIS)

    Chamberlin, E.P.; Olivares, J.A.

    1996-01-01

    A tungsten crucible thermal ionization source mounted on a quadrupole mass spectrometer is described. The crucible is a disposable rod with a fine hole bored in one end; it is heated by electron bombardment. The schematic design of the assembly, including water cooling, is described and depicted. Historically, the design is derived from that of ion sources used on ion separators at Los Alamos and Dubna, but the crucible is made smaller and simplified. 10 refs., 4 figs

  20. Efficient Model Order Reduction for the Dynamics of Nonlinear Multilayer Sheet Structures with Trial Vector Derivatives

    Directory of Open Access Journals (Sweden)

    Wolfgang Witteveen

    2014-01-01

    Full Text Available The mechanical response of multilayer sheet structures, such as leaf springs or car bodies, is largely determined by the nonlinear contact and friction forces between the sheets involved. Conventional computational approaches based on classical reduction techniques or the direct finite element approach have an inefficient balance between computational time and accuracy. In the present contribution, the method of trial vector derivatives is applied and extended in order to obtain a-priori trial vectors for the model reduction which are suitable for determining the nonlinearities in the joints of the reduced system. Findings show that the result quality in terms of displacements and contact forces is comparable to the direct finite element method but the computational effort is extremely low due to the model order reduction. Two numerical studies are presented to underline the method’s accuracy and efficiency. In conclusion, this approach is discussed with respect to the existing body of literature.

  1. Size and morphology controlled NiSe nanoparticles as efficient catalyst for the reduction reactions

    Energy Technology Data Exchange (ETDEWEB)

    Subbarao, Udumula; Marakatti, Vijaykumar S. [New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064 (India); Amshumali, Mungalimane K. [New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064 (India); Department of Chemistry and Industrial Chemistry, Vijayanagara Sri Krishnadevaraya University, Jnanasagara Campus, Cantonment, Bellary 583105 (India); Loukya, B. [International Center for Materials Science, Jakkur P.O., Bangalore 560064 (India); Singh, Dheeraj Kumar [Chemistry & Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064 (India); Datta, Ranjan [International Center for Materials Science, Jakkur P.O., Bangalore 560064 (India); Peter, Sebastian C., E-mail: sebastiancp@jncasr.ac.in [New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur P.O., Bangalore 560064 (India)

    2016-12-15

    Facile and efficient ball milling and polyol methods were employed for the synthesis of nickel selenide (NiSe) nanoparticle. The particle size of the NiSe nanoparticle has been controlled mechanically by varying the ball size in the milling process. The role of the surfactants in the formation of various morphologies was studied. The compounds were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray energy dispersive spectroscopy (EDS). The efficiency of the NiSe nanoparticle as a catalyst was tested for the reduction of para-nitroaniline (PNA) to para-phenyldiamine (PPD) and para-nitrophenol (PNP) to para-aminophenol (PAP) using NaBH{sub 4} as the reducing agent. Particle size, morphology and the presence of surfactant played a crucial role in the reduction process. - Graphical abstract: NiSe nanoparticles in different size and morphology were synthesized using facile ball milling and polyol methods. Particle size, morphology and the presence of surfactant in these materials played a crucial role in the hydrogenation of PNA and PNP. - Highlights: • NiSe nanoparticles synthesized using ball milling and solution phase methods. • NiSe nanoparticle is an efficient catalyst for the reduction of PNA and PNP. • NiSe is found to be better than the best reported noble metal catalysts.

  2. Size and morphology controlled NiSe nanoparticles as efficient catalyst for the reduction reactions

    International Nuclear Information System (INIS)

    Subbarao, Udumula; Marakatti, Vijaykumar S.; Amshumali, Mungalimane K.; Loukya, B.; Singh, Dheeraj Kumar; Datta, Ranjan; Peter, Sebastian C.

    2016-01-01

    Facile and efficient ball milling and polyol methods were employed for the synthesis of nickel selenide (NiSe) nanoparticle. The particle size of the NiSe nanoparticle has been controlled mechanically by varying the ball size in the milling process. The role of the surfactants in the formation of various morphologies was studied. The compounds were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray energy dispersive spectroscopy (EDS). The efficiency of the NiSe nanoparticle as a catalyst was tested for the reduction of para-nitroaniline (PNA) to para-phenyldiamine (PPD) and para-nitrophenol (PNP) to para-aminophenol (PAP) using NaBH 4 as the reducing agent. Particle size, morphology and the presence of surfactant played a crucial role in the reduction process. - Graphical abstract: NiSe nanoparticles in different size and morphology were synthesized using facile ball milling and polyol methods. Particle size, morphology and the presence of surfactant in these materials played a crucial role in the hydrogenation of PNA and PNP. - Highlights: • NiSe nanoparticles synthesized using ball milling and solution phase methods. • NiSe nanoparticle is an efficient catalyst for the reduction of PNA and PNP. • NiSe is found to be better than the best reported noble metal catalysts.

  3. Slow-wave metamaterial open panels for efficient reduction of low-frequency sound transmission

    Science.gov (United States)

    Yang, Jieun; Lee, Joong Seok; Lee, Hyeong Rae; Kang, Yeon June; Kim, Yoon Young

    2018-02-01

    Sound transmission reduction is typically governed by the mass law, requiring thicker panels to handle lower frequencies. When open holes must be inserted in panels for heat transfer, ventilation, or other purposes, the efficient reduction of sound transmission through holey panels becomes difficult, especially in the low-frequency ranges. Here, we propose slow-wave metamaterial open panels that can dramatically lower the working frequencies of sound transmission loss. Global resonances originating from slow waves realized by multiply inserted, elaborately designed subwavelength rigid partitions between two thin holey plates contribute to sound transmission reductions at lower frequencies. Owing to the dispersive characteristics of the present metamaterial panels, local resonances that trap sound in the partitions also occur at higher frequencies, exhibiting negative effective bulk moduli and zero effective velocities. As a result, low-frequency broadened sound transmission reduction is realized efficiently in the present metamaterial panels. The theoretical model of the proposed metamaterial open panels is derived using an effective medium approach and verified by numerical and experimental investigations.

  4. Implementation of variance-reduction techniques for Monte Carlo nuclear logging calculations with neutron sources

    NARCIS (Netherlands)

    Maucec, M

    2005-01-01

    Monte Carlo simulations for nuclear logging applications are considered to be highly demanding transport problems. In this paper, the implementation of weight-window variance reduction schemes in a 'manual' fashion to improve the efficiency of calculations for a neutron logging tool is presented.

  5. Efficient cesiation in RF driven surface plasma negative ion source

    Energy Technology Data Exchange (ETDEWEB)

    Belchenko, Yu.; Ivanov, A.; Konstantinov, S.; Sanin, A., E-mail: sanin@inp.nsk.su; Sotnikov, O. [Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2016-02-15

    Experiments on hydrogen negative ions production in the large radio-frequency negative ion source with cesium seed are described. The system of directed cesium deposition to the plasma grid periphery was used. The small cesium seed (∼0.5 G) provides an enhanced H{sup −} production during a 2 month long experimental cycle. The gradual increase of negative ion yield during the long-term source runs was observed after cesium addition to the source. The degraded H{sup −} production was recorded after air filling to the source or after the cesium washing away from the driver and plasma chamber walls. The following source conditioning by beam shots produces the gradual recovery of H{sup −} yield to the high value. The effect of H{sup −} yield recovery after cesium coverage passivation by air fill was studied. The concept of cesium coverage replenishment and of H{sup −} yield recovery due to sputtering of cesium from the deteriorated layers is discussed.

  6. Analysis of inconsistent source sampling in monte carlo weight-window variance reduction methods

    Directory of Open Access Journals (Sweden)

    David P. Griesheimer

    2017-09-01

    Full Text Available The application of Monte Carlo (MC to large-scale fixed-source problems has recently become possible with new hybrid methods that automate generation of parameters for variance reduction techniques. Two common variance reduction techniques, weight windows and source biasing, have been automated and popularized by the consistent adjoint-driven importance sampling (CADIS method. This method uses the adjoint solution from an inexpensive deterministic calculation to define a consistent set of weight windows and source particles for a subsequent MC calculation. One of the motivations for source consistency is to avoid the splitting or rouletting of particles at birth, which requires computational resources. However, it is not always possible or desirable to implement such consistency, which results in inconsistent source biasing. This paper develops an original framework that mathematically expresses the coupling of the weight window and source biasing techniques, allowing the authors to explore the impact of inconsistent source sampling on the variance of MC results. A numerical experiment supports this new framework and suggests that certain classes of problems may be relatively insensitive to inconsistent source sampling schemes with moderate levels of splitting and rouletting.

  7. Energy Efficiency and Importance of Renewable Energy Sources in Latvia

    Science.gov (United States)

    Skapare, I.; Kreslins, A.

    2007-10-01

    The main goal of Latvian energy policy is to ensure safe and environmentally friendly long-term energy supply at cost-effective prices, contributing to enhance competitiveness, and to ensure safe energy transit. The Latvian Parliament approved an Energy Efficiency Strategy in 2000. Its objective is to decrease energy consumption per unit of GDP by 25% by 2010. Awareness raising, implementation of standards and economic incentives for self financing are the main instruments to increase energy efficiency, mentioned in the strategy. Latvia, as many other European Union member states, is dependent on the import of primary energy resources. The Latvian Renewable Energy strategy is still under development. The only recent study on RES was developed in the framework of a PHARE program in year 2000: "Renewable energy resource program", where three main objectives for a future RES strategy were proposed: 1. To increase the use of wood waste and low value wood and forest residues. 2. To improve efficiency of combustion technologies and to replace outdated plants. 3. To increase the use of renewables in Combined Heat and Power plants (CHP). Through the Renewable Energy and Energy Efficiency Partnership, partners will develop a set of new shared activities, and coordinate and strengthen existing efforts in this area.

  8. Energy sources consumption: end uses, efficiency and productivity

    International Nuclear Information System (INIS)

    Martin, J.M.

    2005-01-01

    This document analyzes the impact of the choices made by all actors, from the energy producers to the process and infrastructure designers and the end users, in the evolution of energy consumptions. Some very little improvements made in the energy efficiency of appliances can become equivalent to the production of several oil fields or power plants at the world scale. More efficient energy uses will not replace the additional productions but they must be considered together to be compared. The energy files are first analyzed as a whole in order to show the hidden field of energy choices. In this framework, users, designers and fitters have to face very different choices because they consider efficiency improvements under different aspects: scientifical, technical, economical and social (public information and habits). These differences in efficiency uses have a time and spatial impact on the growth of energy consumption. The economical and social factors influence the collective way to consume energy and are expressed by the energy intensity of the economic activity. The last part of this document analyzes the influence of this notion on the world energy consumption scenarios at the 2050 prospects. (J.S.)

  9. Feasibility study of broadband efficient ''water window'' source

    International Nuclear Information System (INIS)

    Higashiguchi, Takeshi; Yugami, Noboru; Otsuka, Takamitsu; Jiang Weihua; Endo, Akira; Li Bowen; Dunne, Padraig; O'Sullivan, Gerry

    2012-01-01

    We demonstrate a table-top broadband emission water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs) in the 2-4 nm region, extending below the carbon K edge (4.37 nm). Arrays resulting from n=4-n=4 transitions are overlaid with n=4-n=5 emission and shift to shorter wavelength with increasing atomic number. An outline of a microscope design for single-shot live cell imaging is proposed based on a bismuth plasma UTA source, coupled to multilayer mirror optics.

  10. Management Methods of Energy Efficiency and reduction of Greenhouse Gas Emissions

    International Nuclear Information System (INIS)

    Actina, G.; Grackova, L.; Zebergs, V.; Zeltins, N.

    2007-01-01

    The management methods of energy efficiency and reduction of GHG emissions and their introduction depend on the financing possibilities and the management structures. Analysis is made of the following methods for the management of the process of raising energy efficiency: an energy audit and certification; the third-party financing; networks for energy efficiency and services of raising energy efficiency. In Latvia more than a half of all the energy resources are consumed for heating and the supply of hot water. The thermal parameters of buildings are poor therefore wide introduction of buildings certification, based on energy audit is of particular importance. The third-party financing would allow resolving the justified problems of audit and certification in order to hasten the heating process of buildings, particularly, owing to the appearance of respective foreign third-party financing companies, although the privatisation of dwelling houses and reorganisation of their management is not yet completed. The networks for energy efficiency have not found supporters in Latvia, however, great importance is attached to the thermal parameters of industrial premises, which are as poor as in the other buildings of the country, and here is a considerable potential of energy economy. Concerning the services of raising energy efficiency, the management method of this process is supposed to reach maximum energy economy after thermo and technical renovation of buildings at their various stages. It is connected with general organisational and financial adjustment of the management of buildings, as well as with the development of the energy service company.(author)

  11. Conservation – a new and efficient source of energy

    CSIR Research Space (South Africa)

    National Building Research Institute

    1981-09-01

    Full Text Available Energy is becoming increasingly expensive. Conservation can offset the increase in energy cost and can therefore be considered a new and can fairly inexpensive source of energy. The following article looks at the ways in which energy savings in both...

  12. Flux and Mass Reduction Resulting from ZVIClay Remediation of a PCE DNAPL Source Zone

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Kjeldsen, Peter; Riis, C.

    2010-01-01

    of bentonite clay. The degradation of PCE in the treated source area and the development in the downstream flux of chlorinated compounds have been monitored in six sampling campaigns. A PCE half-life of 50 days and a reduction of the average concentration of PCE of more than 99% were found during the first...

  13. Modeling the effects of integrating larval habitat source reduction and insecticide treated nets for malaria control.

    Directory of Open Access Journals (Sweden)

    Laith Yakob

    Full Text Available Integrated vector management for malaria control has received a lot of recent interest. Attacking multiple points in the transmission cycle is hoped to act synergistically and improve upon current single-tool interventions based on the use of insecticide-treated bed nets (ITNs. In the present study, we theoretically examined the application of larval habitat source reduction with ITNs in reducing malaria transmission. We selected this type of environmental management to complement ITNs because of a potential secondary mode of action that both control strategies share. In addition to increasing vector mortality, ITNs reduce the rate at which female mosquitoes locate human hosts for blood feeding, thereby extending their gonotrophic cycle. Similarly, while reducing adult vector emergence and abundance, source reduction of larval habitats may prolong the cycle duration by extending delays in locating oviposition sites. We found, however, that source reduction of larval habitats only operates through this secondary mode of action when habitat density is below a critical threshold. Hence, we illustrate how this strategy becomes increasingly effective when larval habitats are limited. We also demonstrate that habitat source reduction is better suited to human populations of higher density and in the presence of insecticide resistance or when the insecticidal properties of ITNs are depleted.

  14. Implementation of VOC source reduction practices in a manufactured house and in school classrooms

    International Nuclear Information System (INIS)

    Hodgson, A.T.; Apte, M.G.; Shendell, D.G.; Beal, D.; McIlvaine, J.E.R.

    2002-01-01

    Detailed studies of a new manufactured house and four new industrialized relocatable school classrooms were conducted to determine the emission sources of formaldehyde and other VOCs and to identify and implement source reduction practices. Procedures were developed to generate VOC emission factors that allowed reasonably accurate predictions of indoor air VOC concentrations. Based on the identified sources of formaldehyde and other aldehydes, practices were developed to reduce the concentrations of these compounds in new house construction. An alternate ceiling panel reduced formaldehyde concentrations in the classrooms. Overall, the classrooms had relatively low VOC concentrations

  15. Reduction of Radioactive Waste Through the Reuse and Recycle Policy of the Sealed Radioactive Sources Management

    Directory of Open Access Journals (Sweden)

    T. Marpaung

    2012-08-01

    Full Text Available In the past few years, the utilization of sealed source for medical, industrial and research purposes has shown an accelerating increase. This situation will lead to increases in the amount of sealed radioactive. During its use, a sealed radioactive waste will eventually become either a spent sealed source or disused sealed radioactive source (DSRS, due to certain factors. The reduction of the amount of radioactive waste can be executed through the application of reuse and recycle of sealed source. The reuse and recycle policy for spent and disused sealed sources are not already specified yet. The reuse of spent sealed sources can be applied only for the sources which had been used in the medical field for radiotherapy, namely the reuse of a teletherapy Co-60 source in a calibration facility. The recycle of a spent sealed source can be performed for radioactive sources with relatively high activities and long half-lives; however, the recycling activity may only be performed by the manufacturer. To avoid legal conflicts, in the amendment to the Government Regulation No.27 Year 2002 on Management of Radioactive Waste, there will be a recommendation for a new scheme in the management of radioactive waste to facilitate the application of the principles of reduce, reuse, and recycle

  16. Reduction of Radioactive Waste Through the Reuse and Recycle Policy of the Sealed Radioactive Sources Management

    International Nuclear Information System (INIS)

    Marpaung, T.

    2012-01-01

    In the past few years, the utilization of sealed source for medical, industrial and research purposes has shown an accelerating increase. This situation will lead to increases in the amount of sealed radioactive. During its use, a sealed radioactive waste will eventually become either a spent sealed source or disused sealed radioactive source (DSRS), due to certain factors. The reduction of the amount of radioactive waste can be executed through the application of reuse and recycle of sealed source. The reuse and recycle policy for spent and disused sealed sources are not already specified yet. The reuse of spent sealed sources can be applied only for the sources which had been used in the medical field for radiotherapy, namely the reuse of a teletherapy Co-60 source in a calibration facility. The recycle of a spent sealed source can be performed for radioactive sources with relatively high activities and long half-lives; however, the recycling activity may only be performed by the manufacturer. To avoid legal conflicts, in the amendment to the Government Regulation No.27 Year 2002 on Management of Radioactive Waste, there will be a recommendation for a new scheme in the management of radioactive waste to facilitate the application of the principles of reduce, reuse, and recycle (author)

  17. Verification of high efficient broad beam cold cathode ion source

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Reheem, A. M., E-mail: amreheem2009@yahoo.com [Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, P.N.13759, Cairo (Egypt); Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), Cairo (Egypt); Ahmed, M. M. [Physics Department, Faculty of Science, Helwan University, Cairo (Egypt); Abdelhamid, M. M.; Ashour, A. H. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), Cairo (Egypt)

    2016-08-15

    An improved form of cold cathode ion source has been designed and constructed. It consists of stainless steel hollow cylinder anode and stainless steel cathode disc, which are separated by a Teflon flange. The electrical discharge and output characteristics have been measured at different pressures using argon, nitrogen, and oxygen gases. The ion exit aperture shape and optimum distance between ion collector plate and cathode disc are studied. The stable discharge current and maximum output ion beam current have been obtained using grid exit aperture. It was found that the optimum distance between ion collector plate and ion exit aperture is equal to 6.25 cm. The cold cathode ion source is used to deposit aluminum coating layer on AZ31 magnesium alloy using argon ion beam current which equals 600 μA. Scanning electron microscope and X-ray diffraction techniques used for characterizing samples before and after aluminum deposition.

  18. Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels

    Science.gov (United States)

    Singh, Meenesh R.; Clark, Ezra L.; Bell, Alexis T.

    2015-11-01

    Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32-42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0-0.9 V, 0.9-1.95 V, and 1.95-3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices.

  19. Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels.

    Science.gov (United States)

    Singh, Meenesh R; Clark, Ezra L; Bell, Alexis T

    2015-11-10

    Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32-42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0-0.9 V, 0.9-1.95 V, and 1.95-3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices.

  20. Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels

    Science.gov (United States)

    Singh, Meenesh R.; Clark, Ezra L.; Bell, Alexis T.

    2015-01-01

    Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32–42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0–0.9 V, 0.9–1.95 V, and 1.95–3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. We show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices. PMID:26504215

  1. Co- and defect-rich carbon nanofiber films as a highly efficient electrocatalyst for oxygen reduction

    Science.gov (United States)

    Kim, Il To; Song, Myeong Jun; Shin, Seoyoon; Shin, Moo Whan

    2018-03-01

    Many efforts are continuously devoted to developing high-efficiency, low-cost, and highly scalable oxygen reduction reaction (ORR) electrocatalysts to replace precious metal catalysts. Herein, we successfully synthesize Co- and defect-rich carbon nanofibers (CNFs) using an efficient heat treatment approach involving the pyrolysis of electrospun fibers at 370 °C under air. The heat treatment process produces Co-decorated CNFs with a high Co mass ratio, enriched pyridinic N, Co-pyridinic Nx clusters, and defect-rich carbon structures. The synergistic effects from composition and structural changes in the designed material increase the number of catalytically active sites for the ORR in an alkaline solution. The prepared Co- and defect-rich CNFs exhibit excellent ORR activities with a high ORR onset potential (0.954 V vs. RHE), a large reduction current density (4.426 mA cm-2 at 0.40 V), and a nearly four-electron pathway. The catalyst also exhibits a better long-term durability than commercial Pt/C catalysts. This study provides a novel hybrid material as an efficient ORR catalyst and important insight into the design strategy for CNF-based hybrid materials as electrochemical electrodes.

  2. Isotope studies on the comparative efficiency of nitrogenous sources

    Energy Technology Data Exchange (ETDEWEB)

    Dev, G; Rennie, D A [Saskatchewan Univ., Saskatoon (Canada). Dept. of Soil Science

    1979-03-01

    In a growth chamber experiment with /sup 15/N-labelled potassium nitrate, ammonium sulphate and urea at 75 and 150kg nitrogen/ha and ammonium nitrate at 150kg nitrogen/ha, nitrogen application produced significant responses of dry matter yield and total nitrogen uptake by shoot and root of barley in chernozemic dark brown Elstow silt loam and deep black Hoey clay soil. Total nitrogen removal per pot and isotope-derived criteria, viz. percentage nitrogen derived from fertilizer, 'A' value and percentage fertilizer nitrogen utilization, indicated that potassium nitrate was the most efficient and urea the least.

  3. Application of sorption heat pumps for increasing of new power sources efficiency

    Science.gov (United States)

    Vasiliev, L.; Filatova, O.; Tsitovich, A.

    2010-07-01

    In the 21st century the way to increase the efficiency of new sources of energy is directly related with extended exploration of renewable energy. This modern tendency ensures the fuel economy needs to be realized with nature protection. The increasing of new power sources efficiency (cogeneration, trigeneration systems, fuel cells, photovoltaic systems) can be performed by application of solid sorption heat pumps, regrigerators, heat and cold accumulators, heat transformers, natural gas and hydrogen storage systems and efficient heat exchangers.

  4. Impact of a simultaneous reduction in fishing subsidies and introduction of efficient management of rents

    DEFF Research Database (Denmark)

    Merayo, Eugenia; Waldo, Staffan; Nielsen, Max

    2018-01-01

    of the largest fishing nations within the EU. A static bio-economic model is used to analyze the effect of simultaneous elimination of subsidies and introduction of an economically efficient management system for the Northwest Spanish fleet. It is concluded that improvements in management would bring substantial......Subsidies to the fishing sector have long been criticized for fueling over-fishing, and a reduction in subsidies is currently on the agenda in the negotiations within the World Trade Organization (WTO). This article analyzes the role of subsidies and other management measures for Spain, one...... rents to the industry, up to €164 million, irrespective of subsidy level, but also a reduction in fishing effort of almost 60%. Under a management scheme that maximizes economic rents, elimination of subsidies in the fishery would increase social welfare, induced by a decrease in the equilibrium fishing...

  5. Slat templated formation of efficient oxygen reduction electrocatalyst with a fluidic precursor

    Science.gov (United States)

    Tan, Yao

    2018-05-01

    Development of cost-effective and efficient oxygen reduction catalyst is critical for the commercialization of proton exchange membrane fuel cell. Metal and nitrogen co-doped carbon is recognized as a promising alternative to traditional platinum-based oxygen reduction catalyst. Herein, we report a novel metal and nitrogen co-doped carbon catalyst with an ionic liquid precursor. Salt template, which can be easily removed with mild treatment after the synthesis, is used to generate abundant mesopores in the resulting catalyst. We show that the novel catalyst shows a superior activity comparable to commercial Pt/C catalyst. Furthermore, the important role of the mesopore for the activity of the catalyst is demonstrated.

  6. Efficient control of ultrafast optical nonlinearity of reduced graphene oxide by infrared reduction

    Energy Technology Data Exchange (ETDEWEB)

    Bhattachraya, S.; Maiti, R.; Das, A. C.; Saha, S.; Mondal, S.; Ray, S. K.; Bhaktha, S. N. B.; Datta, P. K., E-mail: pkdatta.iitkgp@gmail.com [Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2016-07-07

    Simultaneous occurrence of saturable absorption nonlinearity and two-photon absorption nonlinearity in the same medium is well sought for the devices like optical limiter and laser mode-locker. Pristine graphene sheet consisting entirely of sp{sup 2}-hybridized carbon atoms has already been identified having large optical nonlinearity. However, graphene oxide (GO), a precursor of graphene having both sp{sup 2} and sp{sup 3}-hybridized carbon atom, is increasingly attracting cross-discipline researchers for its controllable properties by reduction of oxygen containing groups. In this work, GO has been prepared by modified Hummers method, and it has been further reduced by infrared (IR) radiation. Characterization of reduced graphene oxide (RGO) by means of Raman spectroscopy, X-ray photoelectron spectroscopy, and UV-Visible absorption measurements confirms an efficient reduction with infrared radiation. Here, we report precise control of non-linear optical properties of RGO in femtosecond regime with increased degrees of IR reduction measured by open aperture z-scan technique. Depending on the intensity, both saturable absorption and two-photon absorption effects are found to contribute to the non-linearity of all the samples. Saturation dominates at low intensity (∼127 GW/cm{sup 2}) while two-photon absorption becomes prominent at higher intensities (from 217 GW/cm{sup 2} to 302 GW/cm{sup 2}). The values of two-photon absorption co-efficient (∼0.0022–0.0037 cm/GW for GO, and ∼0.0128–0.0143 cm/GW for RGO) and the saturation intensity (∼57 GW/cm{sup 2} for GO, and ∼194 GW/cm{sup 2} for RGO) increase with increasing reduction, indicating GO and RGO as novel tunable photonic devices. We have also explained the reason of tunable nonlinear optical properties by using amorphous carbon model.

  7. Efficient control of ultrafast optical nonlinearity of reduced graphene oxide by infrared reduction

    International Nuclear Information System (INIS)

    Bhattachraya, S.; Maiti, R.; Das, A. C.; Saha, S.; Mondal, S.; Ray, S. K.; Bhaktha, S. N. B.; Datta, P. K.

    2016-01-01

    Simultaneous occurrence of saturable absorption nonlinearity and two-photon absorption nonlinearity in the same medium is well sought for the devices like optical limiter and laser mode-locker. Pristine graphene sheet consisting entirely of sp"2-hybridized carbon atoms has already been identified having large optical nonlinearity. However, graphene oxide (GO), a precursor of graphene having both sp"2 and sp"3-hybridized carbon atom, is increasingly attracting cross-discipline researchers for its controllable properties by reduction of oxygen containing groups. In this work, GO has been prepared by modified Hummers method, and it has been further reduced by infrared (IR) radiation. Characterization of reduced graphene oxide (RGO) by means of Raman spectroscopy, X-ray photoelectron spectroscopy, and UV-Visible absorption measurements confirms an efficient reduction with infrared radiation. Here, we report precise control of non-linear optical properties of RGO in femtosecond regime with increased degrees of IR reduction measured by open aperture z-scan technique. Depending on the intensity, both saturable absorption and two-photon absorption effects are found to contribute to the non-linearity of all the samples. Saturation dominates at low intensity (∼127 GW/cm"2) while two-photon absorption becomes prominent at higher intensities (from 217 GW/cm"2 to 302 GW/cm"2). The values of two-photon absorption co-efficient (∼0.0022–0.0037 cm/GW for GO, and ∼0.0128–0.0143 cm/GW for RGO) and the saturation intensity (∼57 GW/cm"2 for GO, and ∼194 GW/cm"2 for RGO) increase with increasing reduction, indicating GO and RGO as novel tunable photonic devices. We have also explained the reason of tunable nonlinear optical properties by using amorphous carbon model.

  8. Delivering energy efficiency and carbon reduction schemes in England: Lessons from Green Deal Pioneer Places

    International Nuclear Information System (INIS)

    Marchand, Robert D.; Koh, S.C. Lenny; Morris, Jonathan C.

    2015-01-01

    Against a background of growing international and national carbon reduction legislation, the UK government introduced the “Green Deal” to deliver a significant increase in housing energy efficiency and reduction in carbon emissions. This paper reflects on one English local authority's experience delivering a programme intended to foster local interest in the Green Deal. Drawing on social surveys and pre and post Green Deal intervention interviews with five demonstrator homes (households that applied to receive a Green Deal package fully funded by the scheme, providing a test bed for the Green Deal recruitment and installation process), this paper shows that awareness and understanding of the Green Deal scheme is low. There is opposition to the cost of finance offered but a strong interest in improving household warmth and for funding improvements through payments added to the electricity bill. Demonstrator home residents perceived Green Deals had improved the warmth and quality of their home, but saving money was the primary motivator for their involvement, not increasing warmth. Whilst Green Deal has not delivered the level of success that was hoped, much can be learned from the scheme to improve future energy efficiency schemes that will be necessary to deliver emission reduction commitments. -- Highlights: •Resident awareness and understanding of the Green Deal is low. •Green Deal assessment costs and loan interest rates are biggest barriers to uptake. •Funding energy improvements via a charge on electricity bill welcomed by residents. •Saving money rather than increasing warmth main motivator for scheme involvement. •Insights from this work should be used to inform future emission reduction schemes

  9. Environmental friendly high efficient light source plasma lamp - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Courret, G.; Calame, L. [Haute Ecole d' ingenierie et de gestion du canton de Vaud, Institut de micro et nano techniques, Yverdon-les-Bains (Switzerland); Meyer, A. [Solaronix SA, Aubonne (Switzerland)

    2007-07-01

    This illustrated final report for the Swiss Federal Office of Energy (SFOE) takes a look at work done on the development of a sulphur-based plasma lamp. In 2007, the capability of a new modulator has been explored. The most important results are discussed. With the production of a 1.2 cm{sup 3} bulb, the way towards the production of a 100 W lamp has been opened. The authors comment that modulation by impulses increases the luminous efficiency in comparison to modulation using a continuous sinusoidal wave. The report deals with the history of the project, the development of the new modulator, the use of rotational effects and the optimisation of the amount of active substances - tellurium and selenium - in the bulb. The electromagnetic coupling system used is described and discussed.

  10. An efficient source of continuous variable polarization entanglement

    DEFF Research Database (Denmark)

    Dong, R.; Heersink, J.; Yoshikawa, J.-I.

    2007-01-01

    classical excitation in Ŝ3. Polarization entanglement was generated by interfering two independent polarization squeezed fields on a symmetric beam splitter. The resultant beams exhibit strong quantum noise correlations in the dark Ŝ1-Ŝ2 polarization plane. To verify entanglement generation, we......We have experimentally demonstrated the efficient creation of highly entangled bipartite continuous variable polarization states. Exploiting an optimized scheme for the production of squeezing using the Kerr non-linearity of a glass fibre we generated polarization squeezed pulses with a mean...... was found to depend critically on the beam-splitting ratio of the entangling beam splitter. Carrying out measurements on a different set of conjugate Stokes parameters, correlations of -3.6 ±0.3 and -3.4 ±0.3 dB have been observed. This result is more robust against asymmetries in the entangling beam...

  11. Research of noise emission sources in railway transport and effective ways of their reduction

    Directory of Open Access Journals (Sweden)

    Zvolenský Peter

    2017-01-01

    Full Text Available In the EU conditions attention is systematically paid to noise reduction on the railways. Because TSI rules systematically tighten limits for noise emissions from railway vehicles, noise research must be addressed by all Member States, as the main technical solutions for railway vehicles and construction technological aspects of railway operations can result in lower noise exposure of affected areas or objects. The paper focuses on theoretical investigation of sources and paths of sound propagation, possibilities of noise reduction both on vehicles and by infrastructure and experimental measurements of the situation in transport practice. Methodology for reducing railway noise around tracks has been presented, too.

  12. Exploring Efficiencies in Data Reduction, Analysis, and Distribution in the Exascale Era

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    DataDirect Networks (DDN) is world leader in massively scalable storage. Fellinger will discuss how the growth of data sets beyond the petabyte boundary presents new challenges to researchers in delivering and extracting usable information. He will also explore a Big Data processing architecture that overcomes constraints in network bandwidth and service layers in large-scale data distribution to enable researchers to request raw data through a filter or an analysis library. This technology, operating directly within the storage device, enables the reduction of service latency and process cycles to provide a more efficient feedback loop in iterative scientific experiments to increase data-intensive processing efficiency by up to 400%. About the speaker Dave Fellinger has over three decades of engineering experience, including film systems, ASIC design and development, GaAs semiconductor manufacture, RAID and storage systems, and video processing devices, and has architected high-performance storage syst...

  13. Reduction at the source of household wastes: why not trying the inciting tariffing?; La reduction a la source des dechets menagers: pourquoi ne pas essayer la tarification incitative?

    Energy Technology Data Exchange (ETDEWEB)

    Glachant, M.

    2002-11-01

    This article discusses how the existing financing tools of the household wastes management implemented in France can be changed to become inciting tools for the reduction of the volume of wastes at the source. It comprises 5 parts: the first part presents the present day way of financing of the public utility of household wastes in France and discusses its (very modest) inciting effect. In the next two parts the possible modalities to make it more inciting are discussed. These parts stresses on two questions: is it better to charge the upstream producers via contributions to chartered companies or to charge the downstream households via volume- or weight-proportional fees? How much should they pay? Then some experiences of inciting tariffing are briefly reviewed: the Duales German system of upstream charging and the US and Dutch downstream charging systems. (J.S.)

  14. Renewables vs. energy efficiency: The cost of carbon emissions reduction in Spain

    International Nuclear Information System (INIS)

    López-Peña, Álvaro; Pérez-Arriaga, Ignacio; Linares, Pedro

    2012-01-01

    While support instruments have succeeded to largely deploy renewables during the 1996–2008 period, little attention has been paid to energy efficiency measures, resulting in a high energy intensity and large growth of energy demand. Energy-related CO 2 emissions have increased significantly. At the same time, important investments in combined cycle gas turbines have taken place. This paper analyses whether, from a cost minimization viewpoint, renewable support has been the best policy for reducing emissions, when compared to the promotion of energy efficiency in sectors such as transportation or buildings. We use a model of the Spanish energy sector to examine its evolution in the time period considered under different policies. It is a bottom-up, static, partial equilibrium, linear programming model of the complete Spanish energy system. We conclude that demand side management (DSM) clearly dominates renewable energy (RE) support if the reduction of emissions at minimum cost is the only concern. We also quantify the savings that could have been achieved: a total of €5 billion per year, mainly in RE subsidies and in smaller costs of meeting the reduced demand (net of DSM implementation cost). - Highlights: ► Energy efficiency is cheaper than renewables for reducing carbon emissions. ► Energy efficiency measures could have saved more than €5 billion per year in Spain. ► Savings could have been bigger without overcapacity in gas combined cycles.

  15. Reduction of the environmental concentration of air pollutants by proper geometrical orientation of industrial line sources

    International Nuclear Information System (INIS)

    Tadmor, J.

    1980-01-01

    An account is given of an Israeli study of two line sources, one composed of 10 and the other of 20 individual sources. The height of release ranged from 15.7 to 39.6 m, with a uniform rate of release of a gaseous pollutant of 1 Ci/s for each source. Average pollutant concentration was plotted as a function of the rotation angle of the line sources. Reduction of pollutant concentration by a particular rotation of the line sources attained values of up to 50%. At certain rotation angles of the line sources, the environmental concentration was lower even as compared with a single high source. Results also depended on atmospheric conditions. It is suggested that considering the increase in cost of augmenting the height of release as a means of reducing the air pollutant concentration, determination of the optimum geometric orientation of the line sources should be considered as an economical means of improving environmental air quality. (U.K.)

  16. Drosophila learn efficient paths to a food source.

    Science.gov (United States)

    Navawongse, Rapeechai; Choudhury, Deepak; Raczkowska, Marlena; Stewart, James Charles; Lim, Terrence; Rahman, Mashiur; Toh, Alicia Guek Geok; Wang, Zhiping; Claridge-Chang, Adam

    2016-05-01

    Elucidating the genetic, and neuronal bases for learned behavior is a central problem in neuroscience. A leading system for neurogenetic discovery is the vinegar fly Drosophila melanogaster; fly memory research has identified genes and circuits that mediate aversive and appetitive learning. However, methods to study adaptive food-seeking behavior in this animal have lagged decades behind rodent feeding analysis, largely due to the challenges presented by their small scale. There is currently no method to dynamically control flies' access to food. In rodents, protocols that use dynamic food delivery are a central element of experimental paradigms that date back to the influential work of Skinner. This method is still commonly used in the analysis of learning, memory, addiction, feeding, and many other subjects in experimental psychology. The difficulty of microscale food delivery means this is not a technique used in fly behavior. In the present manuscript we describe a microfluidic chip integrated with machine vision and automation to dynamically control defined liquid food presentations and sensory stimuli. Strikingly, repeated presentations of food at a fixed location produced improvements in path efficiency during food approach. This shows that improved path choice is a learned behavior. Active control of food availability using this microfluidic system is a valuable addition to the methods currently available for the analysis of learned feeding behavior in flies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. An efficient source of continuous variable polarization entanglement

    International Nuclear Information System (INIS)

    Dong Ruifang; Heersink, Joel; Yoshikawa, Jun-Ichi; Gloeckl, Oliver; Andersen, Ulrik L; Leuchs, Gerd

    2007-01-01

    We have experimentally demonstrated the efficient creation of highly entangled bipartite continuous variable polarization states. Exploiting an optimized scheme for the production of squeezing using the Kerr non-linearity of a glass fibre we generated polarization squeezed pulses with a mean classical excitation in S-hat 3 . Polarization entanglement was generated by interfering two independent polarization squeezed fields on a symmetric beam splitter. The resultant beams exhibit strong quantum noise correlations in the dark S-hat 1 - S-hat 2 polarization plane. To verify entanglement generation, we characterized the quantum correlations of the system for two different sets of conjugate Stokes parameters. The quantum correlations along the squeezed and the anti-squeezed Stokes parameters were observed to be -4.1±0.3 and -2.6±0.3 dB below the shot noise level, respectively. The degree of correlations was found to depend critically on the beam-splitting ratio of the entangling beam splitter. Carrying out measurements on a different set of conjugate Stokes parameters, correlations of -3.6±0.3 and -3.4±0.3 dB have been observed. This result is more robust against asymmetries in the entangling beam splitter, even in the presence of excess noise

  18. Semi-empirical Calculation of Detection Efficiency for Voluminous Source Based on Effective Solid Angle Concept

    Energy Technology Data Exchange (ETDEWEB)

    Kang, M. Y.; Kim, J. H.; Choi, H. D.; Sun, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    To calculate the full energy (FE) absorption peak efficiency for arbitrary volume sample, we developed and verified the Effective Solid Angle (ESA) Code. The procedure for semi-empirical determination of the FE efficiency for the arbitrary volume sources and the calculation principles and processes about ESA code is referred to, and the code was validated with a HPGe detector (relative efficiency 32%, n-type) in previous studies. In this study, we use different type and efficiency of HPGe detectors, in order to verify the performance of the ESA code for the various detectors. We calculated the efficiency curve of voluminous source and compared with experimental data. We will carry out additional validation by measurement of various medium, volume and shape of CRM volume sources with detector of different efficiency and type. And we will reflect the effect of the dead layer of p-type HPGe detector and coincidence summing correction technique in near future.

  19. A comprehensive analysis of China's regional energy saving and emission reduction efficiency: From production and treatment perspectives

    International Nuclear Information System (INIS)

    Wu, Jie; Lv, Lin; Sun, Jiasen; Ji, Xiang

    2015-01-01

    Energy and environmental issues have recently aroused increasing interest in China and many approaches are used to evaluate energy and environmental performance. In this paper, a two-stage network DEA framework is applied to evaluate the efficiency of energy saving and emission reduction in China during the period of the eleventh five-year plan, from 2006 to 2010. In this study, economic activities are divided into production and treatment processes. This is different from previous research which generally focused on either environmental efficiency or energy efficiency, omitting the integration of energy and environmental measures. Today, energy saving and emission reduction are both parts of the basic state policy of China and are equally important. The empirical results in this study show that: (i) eastern China has the best energy saving and emission reduction efficiency, performing is better than western and central China. (ii) The efficiency of the production process in central China is better than that in western China while the western area performs better than the central area in term of treatment efficiency. (iii) Integrated efficiency of energy saving and emission reduction of China was relatively stable in the five years and the pollution treatment efficiency maintained a rising trend. -- Highlights: •We measured China's regional energy saving and emission reduction efficiency using two-stage DEA approach. •The production and treatment processes are incorporated in evaluation. •Eastern China performs best in terms of energy saving and emission reduction efficiency. •Integrated efficiency of energy saving and emission reduction of China kept a stable trend during 2006–2010

  20. Short and long term efficiencies of debris risk reduction measures: Application to a European LEO mission

    Science.gov (United States)

    Lang, T.; Kervarc, R.; Bertrand, S.; Carle, P.; Donath, T.; Destefanis, R.; Grassi, L.; Tiboldo, F.; Schäfer, F.; Kempf, S.; Gelhaus, J.

    2015-01-01

    Recent numerical studies indicate that the low Earth orbit (LEO) debris environment has reached a point such that even if no further space launches were conducted, the Earth satellite population would remain relatively constant for only the next 50 years or so. Beyond that, the debris population would begin to increase noticeably, due to the production of collisional debris (Liou and Johnson, 2008). Measures to be enforced play thus a major role to preserve an acceptable space mission risk and ensure sustainable space activities. The identification of such measures and the quantification of their efficiency over time for LEO missions is of prime concern in the decision-making process, as it has been investigated for the last few decades by the Inter-Agency Space Debris Coordination Committee (IADC). This paper addresses the final results of a generic methodology and the characteristics of a tool developed to assess the efficiency of the risk reduction measures identified for the Sentinel-1 (S1) mission. This work is performed as part of the 34-month P2-ROTECT project (Prediction, Protection & Reduction of OrbiTal Exposure to Collision Threats), funded by the European Union within the Seventh Framework Programme. Three ways of risk reduction have been investigated, both in short and long-term, namely: better satellite protection, better conjunction prediction, and cleaner environment. According to our assumptions, the S1 mission vulnerability evaluations in the long term (from 2093 to 2100) show that full compliance to the mitigation measures leads to a situation twice safer than that induced by an active debris removal of 5 objects per year in a MASTER2009 Business-As-Usual context. Because these measures have visible risk reduction effects in the long term, complementary measures with short response time are also studied. In the short term (from 2013 to 2020), a better prediction of the conjunctions is more efficient than protecting the satellite S1 itself. By

  1. Reduction of sources of error and simplification of the Carbon-14 urea breath test

    International Nuclear Information System (INIS)

    Bellon, M.S.

    1997-01-01

    Full text: Carbon-14 urea breath testing is established in the diagnosis of H. pylori infection. The aim of this study was to investigate possible further simplification and identification of error sources in the 14 C urea kit extensively used at the Royal Adelaide Hospital. Thirty six patients with validated H. pylon status were tested with breath samples taken at 10,15, and 20 min. Using the single sample value at 15 min, there was no change in the diagnostic category. Reduction or errors in analysis depends on attention to the following details: Stability of absorption solution, (now > 2 months), compatibility of scintillation cocktail/absorption solution. (with particular regard to photoluminescence and chemiluminescence), reduction in chemical quenching (moisture reduction), understanding counting hardware and relevance, and appropriate response to deviation in quality assurance. With this experience, we are confident of the performance and reliability of the RAPID-14 urea breath test kit now available commercially

  2. An efficient iterative model reduction method for aeroviscoelastic panel flutter analysis in the supersonic regime

    Science.gov (United States)

    Cunha-Filho, A. G.; Briend, Y. P. J.; de Lima, A. M. G.; Donadon, M. V.

    2018-05-01

    The flutter boundary prediction of complex aeroelastic systems is not an easy task. In some cases, these analyses may become prohibitive due to the high computational cost and time associated with the large number of degrees of freedom of the aeroelastic models, particularly when the aeroelastic model incorporates a control strategy with the aim of suppressing the flutter phenomenon, such as the use of viscoelastic treatments. In this situation, the use of a model reduction method is essential. However, the construction of a modal reduction basis for aeroviscoelastic systems is still a challenge, owing to the inherent frequency- and temperature-dependent behavior of the viscoelastic materials. Thus, the main contribution intended for the present study is to propose an efficient and accurate iterative enriched Ritz basis to deal with aeroviscoelastic systems. The main features and capabilities of the proposed model reduction method are illustrated in the prediction of flutter boundary for a thin three-layer sandwich flat panel and a typical aeronautical stiffened panel, both under supersonic flow.

  3. Thermodynamic and achievable efficiencies for solar-driven electrochemical reduction of carbon dioxide to transportation fuels

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Meenesh R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint Center for Artificial Photosynthesis, Material Science Division; Clark, Ezra L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint Center for Artificial Photosynthesis, Material Science Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemical & Biomolecular Engineering; Bell, Alexis T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint Center for Artificial Photosynthesis, Material Science Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemical & Biomolecular Engineering

    2015-10-26

    Thermodynamic, achievable, and realistic efficiency limits of solar-driven electrochemical conversion of water and carbon dioxide to fuels are investigated as functions of light-absorber composition and configuration, and catalyst composition. The maximum thermodynamic efficiency at 1-sun illumination for adiabatic electrochemical synthesis of various solar fuels is in the range of 32–42%. Single-, double-, and triple-junction light absorbers are found to be optimal for electrochemical load ranges of 0–0.9 V, 0.9–1.95 V, and 1.95–3.5 V, respectively. Achievable solar-to-fuel (STF) efficiencies are determined using ideal double- and triple-junction light absorbers and the electrochemical load curves for CO2 reduction on silver and copper cathodes, and water oxidation kinetics over iridium oxide. The maximum achievable STF efficiencies for synthesis gas (H2 and CO) and Hythane (H2 and CH4) are 18.4% and 20.3%, respectively. Whereas the realistic STF efficiency of photoelectrochemical cells (PECs) can be as low as 0.8%, tandem PECs and photovoltaic (PV)-electrolyzers can operate at 7.2% under identical operating conditions. Finally, we show that the composition and energy content of solar fuels can also be adjusted by tuning the band-gaps of triple-junction light absorbers and/or the ratio of catalyst-to-PV area, and that the synthesis of liquid products and C2H4 have high profitability indices.

  4. Pollution prevention through energy efficiency: methodology for evaluating greenhouse gas reductions

    International Nuclear Information System (INIS)

    Widge, V.; Arnold, F.; Karmali, A.

    1992-01-01

    This paper outlines an analytical framework for evaluating the potential for greenhouse gas emission reductions through investments in energy efficiency. In particular, it will describe a model called the Energy and Technology Switching (ETS) model which has been developed at ICF Incorporated. The ETS model has several useful capabilities - it can assess the implications of changing the energy efficiency of new shipments and existing stock of equipment and appliances, or even changes in patterns of fuel use. The ETS model predicts energy use, emissions of related carbon dioxide and other greenhouse gases, and private and social costs (such as energy costs, avoided capital and fuel costs). It also tracks changes in fuel and technology use over time for a user specified end-use application. The paper is organized into three parts: - The first part of the paper describes the methodology used in estimating the reduction in greenhouse gas emissions and the associated net costs of policies that could affect energy use. - In order to demonstrate the model's capabilities, in the second part of the paper, a sample analysis is presented. ICF incorporated has used the ETS model to estimate for the Global Change Division of the U.S. Environmental Protection Agency the costs of reducing greenhouse gas emissions in the residential and commercial sectors of the U.S. economy, encompassing a wide range of technologies and fuel-types. The assumptions and results of this analysis are presented. - Finally, the paper outlines some of the potential uses of this model in assessing pollution prevention opportunities through energy efficient measures. 11 figs

  5. The potentional of renewable energy sources for greenhouse gases emissions reduction in Macedonia

    Directory of Open Access Journals (Sweden)

    Dedinec Aleksandar

    2012-01-01

    Full Text Available As European Union (EU candidate country, Macedonia is in the process of adoption of the EU strategic energy policies, harmonization of the national legislation with the EU legislation and defining the respective national goals. In this regard, the government has recently adopted a National Strategy for Utilization of Renewable Energy Sources (RES, prepared by ICEIM-MANU. The main goal of this paper is to assess the potential for greenhouse gases (GHG emissions reduction by implementation of 21%-RES-scenarios from the Strategy. The corresponding emissions reduction is calculated against the baseline (reference scenario developed within the Second National Communication on Climate Change. Furthermore, all potential RES technologies are analyzed from economic aspect and combined in a form of emissions reduction cost curve, displaying the total marginal cost of the GHG emissions reduction by RES. Finally, on the bases of the environmental and economic effectiveness of the considered RES technologies, as well as taking into account the country specific barriers, the priority actions for GHG emissions reduction are identified.

  6. International Standards to Develop and Promote Energy Efficiency and Renewable Energy Sources

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    International Standards are a powerful tool for disseminating new technologies and good practices, developing global markets and supporting the harmonization of government policies on energy efficiency and renewable sources on a global scale.

  7. Assessment of the Efficiency of Sediment Deposition Reduction in the Zengwen River Watershed in Taiwan

    Science.gov (United States)

    Wu, M.; Tan, H. N.; Lo, W. C.; Tsai, C. T.

    2015-12-01

    The river upstream of watersheds in Taiwan is very steep, where soil and rock are often unstable so that the river watershed typically has the attribute of high sand yield and turbid runoff due to the excessive erosion in the heavy rainfall seasons. If flood water overflows the river bank, it would lead to a disaster in low-altitude plains. When flood retards or recesses, fine sediment would deposit. Over recent decades, many landslides arise in the Zengwen river watershed due to climate changes, earthquakes, and typhoons. The rocks and sands triggered by these landslides would move to the river channel through surface runoff, which may induce sediment disasters and also render an impact on the stability and sediment transport of the river channel. The risk of the sediment disaster could be reduced by implementing dredging works. However, because of the nature of the channel, the dredged river sections may have sediment depositions back; thus, causing an impact on flood safety. Therefore, it is necessary to evaluate the effectiveness of dredged works from the perspectives of hydraulic, sediment transport, and flood protection to achieve the objective of both disaster prevention and river bed stability. We applied the physiographic soil erosion-deposition (PSED) model to simulate the sediment yield, the runoff, and sediment transport rate of the Zengwen river watershed corresponding to one-day rainstorms of the return periods of 25, 50, and 100 year. The potential of sediment deposition and erosion in the river sections of the Zengwen river could be simulated by utilizing the alluvial river-movable bed two dimensional (ARMB-2D) model. The results reveal that the tendency for the potential of river sediment deposition and erosion obtained from these two models is agreeable. Furthermore, in order to evaluate the efficiency of sediment deposition reduction, two quantized values, the rate of sediment deposition reduction and the ratio of sediment deposition reduction

  8. Speckle noise reduction on a laser projection display via a broadband green light source.

    Science.gov (United States)

    Yu, Nan Ei; Choi, Ju Won; Kang, Heejong; Ko, Do-Kyeong; Fu, Shih-Hao; Liou, Jiun-Wei; Kung, Andy H; Choi, Hee Joo; Kim, Byoung Joo; Cha, Myoungsik; Peng, Lung-Han

    2014-02-10

    A broadband green light source was demonstrated using a tandem-poled lithium niobate (TPLN) crystal. The measured wavelength and temperature bandwidth were 6.5 nm and 100 °C, respectively, spectral bandwidth was 36 times broader than the periodically poled case. Although the conversion efficiency was smaller than in the periodic case, the TPLN device had a good figure of merit owing to the extremely large bandwidth for wavelength and temperature. The developed broadband green light source exhibited speckle noise approximately one-seventh of that in the conventional approach for a laser projection display.

  9. Efficiency Improvement through Reduction in Friction and Wear in Powertrain Systems

    Energy Technology Data Exchange (ETDEWEB)

    Michael Killian

    2009-09-30

    The objective of this project is to improve the efficiency of truck drivelines through reduction of friction and parasitic losses in transmission and drive axles. Known efficiencies for these products exceeded 97 percent, so the task was not trivial. The project relied on a working relationship between modeling and hardware testing. Modeling was to shorten the development cycle by guiding the selection of materials, processes and strategies. Bench top and fixture tests were to validate the models. Modeling was performed at a world class, high academic level, but in the end, modeling did not impact the hardware development as much as intended. Insights leading to the most significant accomplishments came from bench top and fixture tests and full scale dynamometer tests. A key development in the project was the formulation of the implementation strategy. Five technical elements with potential to minimize friction and parasitic losses were identified. These elements included churning, lubrication, surface roughness, coatings and textures. An interesting fact is that both Caterpillar and Eaton independently converged on the same set of technical elements in formulating their implementation strategies. Exploiting technical elements of the implementation strategy had a positive impact on transmission and drive axle efficiencies. During one dynamometer test of an Eaton Best Tech 1 transmission, all three gear ranges tested: Under drive, direct drive and over drive, showed efficiencies greater than 99 percent. Technology boosts to efficiency for transmissions reached 1 percent, while efficiency improvements to drive axle pushed 2 percent. These advancements seem small, but the accomplishment is large considering that these products normally run at greater than 97 percent efficiency. Barriers and risks to implementing these technology elements are clear. Schemes using a low fill sump and spray tubes endanger the gears and bearings by lubricant starvation. Gear coatings have

  10. Validation of the intrinsic spatial efficiency method for non cylindrical homogeneous sources using MC simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Ramírez, Pablo, E-mail: rapeitor@ug.uchile.cl; Ruiz, Andrés [Departamento de Física, Facultad de Ciencias, Universidad de Chile (Chile)

    2016-07-07

    The Monte Carlo simulation of the gamma spectroscopy systems is a common practice in these days. The most popular softwares to do this are MCNP and Geant4 codes. The intrinsic spatial efficiency method is a general and absolute method to determine the absolute efficiency of a spectroscopy system for any extended sources, but this was only demonstrated experimentally for cylindrical sources. Due to the difficulty that the preparation of sources with any shape represents, the simplest way to do this is by the simulation of the spectroscopy system and the source. In this work we present the validation of the intrinsic spatial efficiency method for sources with different geometries and for photons with an energy of 661.65 keV. In the simulation the matrix effects (the auto-attenuation effect) are not considered, therefore these results are only preliminaries. The MC simulation is carried out using the FLUKA code and the absolute efficiency of the detector is determined using two methods: the statistical count of Full Energy Peak (FEP) area (traditional method) and the intrinsic spatial efficiency method. The obtained results show total agreement between the absolute efficiencies determined by the traditional method and the intrinsic spatial efficiency method. The relative bias is lesser than 1% in all cases.

  11. Semi-empirical Determination of Detection Efficiency for Voluminous Source by Effective Solid Angle Method

    Energy Technology Data Exchange (ETDEWEB)

    Kang, M. Y.; Kim, J. H.; Choi, H. D. [Seoul National Univ., Seoul (Korea, Republic of); Sun, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In the field of γ-ray measurements, the determination of full energy (FE) absorption peak efficiency for a voluminous sample is difficult, because the preparation of the certified radiation source with the same chemical composition and geometry for the original voluminous sample is not easy. In order to solve this inconvenience, simulation or semi-empirical methods are preferred in many cases. Effective Solid Angle (ESA) Code which includes semi-empirical approach has been developed by the Applied Nuclear Physics Group in Seoul National University. In this study, we validated ESA code by using Marinelli type voluminous KRISS (Korea Research Institute of Standards and Science) CRM (Certified Reference Materials) sources and IAEA standard γ-ray point sources. And semi-empirically determined efficiency curve for voluminous source by using the ESA code is compared with the experimental value. We calculated the efficiency curve of voluminous source from the measured efficiency of standard point source by using the ESA code. We will carry out the ESA code validation by measurement of various CRM volume sources with detector of different efficiency.

  12. Proton conductive Pt-Co nanoparticles anchoring on citric acid functionalized graphene for efficient oxygen reduction reaction

    Science.gov (United States)

    Zhao, Yige; Liu, Jingjun; Wu, Yijun; Wang, Feng

    2017-08-01

    Designing highly efficient electro-catalysts for the oxygen reduction reaction (ORR) has been regarded as a demanding task in the development of renewable energy sources. However, little attention has been paid on improving Pt-based catalysts by promoting proton transfer from the electrolyte solutions to the catalyst layer at the cathode. Herein, we design proton conductive Pt-Co alloy nanoparticles anchoring on citric acid functionalized graphene (Pt-Co/CA-G) catalysts for efficient ORR. The facile modification approach for graphene can introduce oxygenated functional groups on the graphene surface to promote proton transfer as well as keeping the high electron conductivity without destroying the graphene original structure. The electrochemical results show that the Pt-Co/CA-G catalyst exhibits more excellent ORR activity and stability than the commercial Pt/C catalyst, which can be attributed to its improved proton transfer ability. The fast proton transfer comes from the hydrogen-bonding networks formed by the interaction between the oxygenated functional groups and water molecules. This work provides not only a novel and simple approach to modify graphene but also an effective strategy to improve Pt-based catalysts for the ORR.

  13. High-efficiency single-photon source: The photonic wire geometry

    DEFF Research Database (Denmark)

    Claudon, J.; Bazin, Maela; Malik, Nitin S.

    2009-01-01

    We present a single-photon-source design based on the emission of a quantum dot embedded in a semiconductor (GaAs) nanowire. The nanowire ends are engineered (efficient metallic mirror and tip taper) to reach a predicted record-high collection efficiency of 90% with a realistic design. Preliminar...

  14. Plasmonics for solid-state lighting : enhanced excitation and directional emission of highly efficient light sources

    NARCIS (Netherlands)

    Lozano, G.; Louwers, Davy J.; Rodriguez, S.R.K.; Murai, S.; Jansen, O.T.A.; Verschuuren, M.A.; Gomez Rivas, J.

    2013-01-01

    Light sources based on reliable and energy-efficient light-emitting diodes (LEDs) are instrumental in the development of solid-state lighting (SSL). Most research efforts in SSL have focused on improving both the intrinsic quantum efficiency (QE) and the stability of light emitters. For this reason,

  15. Efficient response spectrum analysis of a reactor using Model Order Reduction

    International Nuclear Information System (INIS)

    Oh, Jin Ho; Choi, Jin Bok; Ryu, Jeong Soo

    2012-01-01

    A response spectrum analysis (RSA) has been widely used to evaluate the structural integrity of various structural components in the nuclear industry. However, solving the large and complex structural systems numerically using the RSA requires a considerable amount of computational resources and time. To overcome this problem, this paper proposes the RSA based on the model order reduction (MOR) technique achieved by applying a projection from a higher order to a lower order space using Krylov subspaces generated by the Arnoldi algorithm. The dynamic characteristics of the final reduced system are almost identical with those of the full system by matching the moments of the reduced system with those of the full system up to the required nth order. It is remarkably efficient in terms of computation time and does not require a global system. Numerical examples demonstrate that the proposed method saves computational costs effectively, and provides a reduced system framework that predicts the accurate responses of a global system

  16. Efficient Analysis of Structures with Rotatable Elements Using Model Order Reduction

    Directory of Open Access Journals (Sweden)

    G. Fotyga

    2016-04-01

    Full Text Available This paper presents a novel full-wave technique which allows for a fast 3D finite element analysis of waveguide structures containing rotatable tuning elements of arbitrary shapes. Rotation of these elements changes the resonant frequencies of the structure, which can be used in the tuning process to obtain the S-characteristics desired for the device. For fast commutations of the response as the tuning elements are rotated, the 3D finite element method is supported by multilevel model-order reduction, orthogonal projection at the boundaries of macromodels and the operation called macromodels cloning. All the time-consuming steps are performed only once in the preparatory stage. In the tuning stage, only small parts of the domain are updated, by means of a special meshing technique. In effect, the tuning process is performed extremely rapidly. The results of the numerical experiments confirm the efficiency and validity of the proposed method.

  17. Metal-organic framework superhydrophobic coating on Kevlar fabric with efficient drag reduction and wear resistance

    Science.gov (United States)

    Li, Deke; Guo, Zhiguang

    2018-06-01

    Superhydrophobic layers are extremely essential for protecting material surface in various applications. In this study, a stable superhydrophobic mixed matrix surface with a 152.2° contact angle can be fabricated through the technology of layer-by-layer hot-pressing (HoP), and then modified by 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) on the ZIF-8@Kevlar fabric surface. The morphology and chemical composition were analyzed by the means of SEM, XRD and FTIR. The obtained superhydrophobic coatings showed excellent antiwear performance and drag reduction under desired working conditions. Moreover, we successfully applied superhydrophobic F-ZIF-8@Kevlar fabric in the alcohol adsorbent with high removal capacity, and it can be reused for several times without serious efficiency loss.

  18. Prediction With Dimension Reduction of Multiple Molecular Data Sources for Patient Survival

    Directory of Open Access Journals (Sweden)

    Adam Kaplan

    2017-07-01

    Full Text Available Predictive modeling from high-dimensional genomic data is often preceded by a dimension reduction step, such as principal component analysis (PCA. However, the application of PCA is not straightforward for multisource data, wherein multiple sources of ‘omics data measure different but related biological components. In this article, we use recent advances in the dimension reduction of multisource data for predictive modeling. In particular, we apply exploratory results from Joint and Individual Variation Explained (JIVE, an extension of PCA for multisource data, for prediction of differing response types. We conduct illustrative simulations to illustrate the practical advantages and interpretability of our approach. As an application example, we consider predicting survival for patients with glioblastoma multiforme from 3 data sources measuring messenger RNA expression, microRNA expression, and DNA methylation. We also introduce a method to estimate JIVE scores for new samples that were not used in the initial dimension reduction and study its theoretical properties; this method is implemented in the R package R.JIVE on CRAN, in the function jive.predict.

  19. A Universal Method to Engineer Metal Oxide-Metal-Carbon Interface for Highly Efficient Oxygen Reduction.

    Science.gov (United States)

    Lv, Lin; Zha, Dace; Ruan, Yunjun; Li, Zhishan; Ao, Xiang; Zheng, Jie; Jiang, Jianjun; Chen, Hao Ming; Chiang, Wei-Hung; Chen, Jun; Wang, Chundong

    2018-03-27

    Oxygen is the most abundant element in the Earth's crust. The oxygen reduction reaction (ORR) is also the most important reaction in life processes and energy converting/storage systems. Developing techniques toward high-efficiency ORR remains highly desired and a challenge. Here, we report a N-doped carbon (NC) encapsulated CeO 2 /Co interfacial hollow structure (CeO 2 -Co-NC) via a generalized strategy for largely increased oxygen species adsorption and improved ORR activities. First, the metallic Co nanoparticles not only provide high conductivity but also serve as electron donors to largely create oxygen vacancies in CeO 2 . Second, the outer carbon layer can effectively protect cobalt from oxidation and dissociation in alkaline media and as well imparts its higher ORR activity. In the meanwhile, the electronic interactions between CeO 2 and Co in the CeO 2 /Co interface are unveiled theoretically by density functional theory calculations to justify the increased oxygen absorption for ORR activity improvement. The reported CeO 2 -Co-NC hollow nanospheres not only exhibit decent ORR performance with a high onset potential (922 mV vs RHE), half-wave potential (797 mV vs RHE), and small Tafel slope (60 mV dec -1 ) comparable to those of the state-of-the-art Pt/C catalysts but also possess long-term stability with a negative shift of only 7 mV of the half-wave potential after 2000 cycles and strong tolerance against methanol. This work represents a solid step toward high-efficient oxygen reduction.

  20. Recovery Act: Tennessee Energy Efficient Schools Initiative Ground Source Heat Pump Program

    Energy Technology Data Exchange (ETDEWEB)

    Townsend, Terry [Townsend Engineering, Inc., Davenport, IA (United States); Slusher, Scott [Townsend Engineering, Inc., Davenport, IA (United States)

    2017-04-24

    The Tennessee Energy Efficient Schools Initiative (EESI) Hybrid-Water Source Heat Pump (HY-GSHP) Program sought to provide installation costs and operation costs for different Hybrid water source heat pump systems’ configurations so that other State of Tennessee School Districts will have a resource for comparison purposes if considering a geothermal system.

  1. Efficiency correction for disk sources using coaxial High-Purity Ge detectors

    International Nuclear Information System (INIS)

    Chatani, Hiroshi.

    1993-03-01

    Efficiency correction factors for disk sources were determined by making use of closed-ended coaxial High-Purity Ge (HPGe) detectors, their relative efficiencies for a 3' 'x3' ' NaI(Tl) with the 1.3 MeV γ-rays were 30 % and 10 %, respectively. Parameters for the correction by mapping method were obtained systematically, using several monoenergetic (i.e. no coincidence summing loses) γ-ray sources produced by irradiation in the Kyoto University Reactor (KUR) core. These were found out that (1) the systematics of the Gaussian fitting parameters, which were calculated using the relative efficiency distributions of HPGe, to the γ-ray energies are recognized, (2) the efficiency distributions deviate from the Gaussian distributions outside of the radii of HPGe. (3) mapping method is a practical use in satisfactory accuracy, as the results in comparison with the disk source measurements. (author)

  2. Energy efficiency improvement and CO2 emission reduction opportunities in the cement industry in China

    International Nuclear Information System (INIS)

    Hasanbeigi, Ali; Morrow, William; Masanet, Eric; Sathaye, Jayant; Xu, Tengfang

    2013-01-01

    China's annual cement production (i.e., 1868 Mt) in 2010 accounted for nearly half of the world's annual cement production in the same year. We identified and analyzed 23 energy efficiency technologies and measures applicable to the processes in China's cement industry. The Conservation Supply Curve (CSC) used in this study is an analytical tool that captures both the engineering and the economic perspectives of energy conservation. Using bottom–up CSC models, the cumulative cost-effective and technical electricity and fuel savings, as well as the CO 2 emission reduction potentials for the Chinese cement industry for 2010–2030 are estimated. By comparison, the total final energy saving achieved by the implementation of these 23 efficiency measures in the Chinese cement industry over 20 years (2010–2030) is equal to 30% of the total primary energy supply of Latin America or Middle East or around 71% of primary energy supply of Brazil in 2007. In addition, a sensitivity analysis with respect to the discount rate is conducted to assess its effect on the results. The result of this study gives a comprehensive and easy to understand perspective to the Chinese cement industry and policy makers about the energy efficiency potential and its associated cost. - Highlights: ► Estimation of energy saving potential in the entire Chinese cement industry. ► Development of the bottom–up technology-rich Conservation Supply Curve models. ► Discussion of different approaches for developing conservation supply curves. ► Primary energy saving over 20 years equal to 33% of primary energy of Latin America

  3. Multiple imputation using linked proxy outcome data resulted in important bias reduction and efficiency gains: a simulation study.

    Science.gov (United States)

    Cornish, R P; Macleod, J; Carpenter, J R; Tilling, K

    2017-01-01

    When an outcome variable is missing not at random (MNAR: probability of missingness depends on outcome values), estimates of the effect of an exposure on this outcome are often biased. We investigated the extent of this bias and examined whether the bias can be reduced through incorporating proxy outcomes obtained through linkage to administrative data as auxiliary variables in multiple imputation (MI). Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) we estimated the association between breastfeeding and IQ (continuous outcome), incorporating linked attainment data (proxies for IQ) as auxiliary variables in MI models. Simulation studies explored the impact of varying the proportion of missing data (from 20 to 80%), the correlation between the outcome and its proxy (0.1-0.9), the strength of the missing data mechanism, and having a proxy variable that was incomplete. Incorporating a linked proxy for the missing outcome as an auxiliary variable reduced bias and increased efficiency in all scenarios, even when 80% of the outcome was missing. Using an incomplete proxy was similarly beneficial. High correlations (> 0.5) between the outcome and its proxy substantially reduced the missing information. Consistent with this, ALSPAC analysis showed inclusion of a proxy reduced bias and improved efficiency. Gains with additional proxies were modest. In longitudinal studies with loss to follow-up, incorporating proxies for this study outcome obtained via linkage to external sources of data as auxiliary variables in MI models can give practically important bias reduction and efficiency gains when the study outcome is MNAR.

  4. Analysis of the Spectral Efficiency of Frequency-Encoded OCDMA Systems With Incoherent Sources

    Science.gov (United States)

    Rochette, Martin; Ayotte, Simon; Rusch, Leslie A.

    2005-04-01

    This paper presents the spectral efficiency of frequency-encoded (FE) optical code-division multiple-access (OCDMA) systems with incoherent sources. The spectral efficiency of five code families compatible with FE-OCDMA is calculated as a function of the number of users. Analytical equations valid in the limiting case of Gaussian noise are also developed for the bit-error rate and the spectral efficiency. Among the code families considered, the modified quadratic congruence code leads to the maximum achievable spectral efficiency.

  5. pH control for enhanced reductive bioremediation of chlorinated solvent source zones

    International Nuclear Information System (INIS)

    Robinson, Clare; Barry, D.A.; McCarty, Perry L.; Gerhard, Jason I.; Kouznetsova, Irina

    2009-01-01

    Enhanced reductive dehalogenation is an attractive treatment technology for in situ remediation of chlorinated solvent DNAPL source areas. Reductive dehalogenation is an acid-forming process with hydrochloric acid and also organic acids from fermentation of the electron donors typically building up in the source zone during remediation. This can lead to groundwater acidification thereby inhibiting the activity of dehalogenating microorganisms. Where the soils' natural buffering capacity is likely to be exceeded, the addition of an external source of alkalinity is needed to ensure sustained dehalogenation. To assist in the design of bioremediation systems, an abiotic geochemical model was developed to provide insight into the processes influencing the groundwater acidity as dehalogenation proceeds, and to predict the amount of bicarbonate required to maintain the pH at a suitable level for dehalogenating bacteria (i.e., > 6.5). The model accounts for the amount of chlorinated solvent degraded, site water chemistry, electron donor, alternative terminal electron-accepting processes, gas release and soil mineralogy. While calcite and iron oxides were shown to be the key minerals influencing the soil's buffering capacity, for the extensive dehalogenation likely to occur in a DNAPL source zone, significant bicarbonate addition may be necessary even in soils that are naturally well buffered. Results indicated that the bicarbonate requirement strongly depends on the electron donor used and availability of competing electron acceptors (e.g., sulfate, iron (III)). Based on understanding gained from this model, a simplified model was developed for calculating a preliminary design estimate of the bicarbonate addition required to control the pH for user-specified operating conditions.

  6. pH control for enhanced reductive bioremediation of chlorinated solvent source zones

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Clare, E-mail: clare.robinson@epfl.ch [Laboratoire de technologie ecologique, Institut d' ingenierie de l' environnement, Station No. 2, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Now at: Department of Civil and Environmental Engineering, University of Western Ontario, London, Canada N6A 5B9 (Canada); Barry, D.A., E-mail: andrew.barry@epfl.ch [Laboratoire de technologie ecologique, Institut d' ingenierie de l' environnement, Station No. 2, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); McCarty, Perry L., E-mail: pmccarty@stanford.edu [Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020 (United States); Gerhard, Jason I., E-mail: j.gerhard@ed.ac.uk [Now at: Department of Civil and Environmental Engineering, University of Western Ontario, London, Canada N6A 5B9 (Canada); Institute for Infrastructure and Environment, University of Edinburgh, Edinburgh, EH9 3JL (United Kingdom); Kouznetsova, Irina, E-mail: irina.kouznetsova@ed.ac.uk [Institute for Infrastructure and Environment, University of Edinburgh, Edinburgh, EH9 3JL (United Kingdom)

    2009-08-01

    Enhanced reductive dehalogenation is an attractive treatment technology for in situ remediation of chlorinated solvent DNAPL source areas. Reductive dehalogenation is an acid-forming process with hydrochloric acid and also organic acids from fermentation of the electron donors typically building up in the source zone during remediation. This can lead to groundwater acidification thereby inhibiting the activity of dehalogenating microorganisms. Where the soils' natural buffering capacity is likely to be exceeded, the addition of an external source of alkalinity is needed to ensure sustained dehalogenation. To assist in the design of bioremediation systems, an abiotic geochemical model was developed to provide insight into the processes influencing the groundwater acidity as dehalogenation proceeds, and to predict the amount of bicarbonate required to maintain the pH at a suitable level for dehalogenating bacteria (i.e., > 6.5). The model accounts for the amount of chlorinated solvent degraded, site water chemistry, electron donor, alternative terminal electron-accepting processes, gas release and soil mineralogy. While calcite and iron oxides were shown to be the key minerals influencing the soil's buffering capacity, for the extensive dehalogenation likely to occur in a DNAPL source zone, significant bicarbonate addition may be necessary even in soils that are naturally well buffered. Results indicated that the bicarbonate requirement strongly depends on the electron donor used and availability of competing electron acceptors (e.g., sulfate, iron (III)). Based on understanding gained from this model, a simplified model was developed for calculating a preliminary design estimate of the bicarbonate addition required to control the pH for user-specified operating conditions.

  7. Solion ion source for high-efficiency, high-throughput solar cell manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Koo, John, E-mail: john-koo@amat.com; Binns, Brant; Miller, Timothy; Krause, Stephen; Skinner, Wesley; Mullin, James [Applied Materials, Inc., Varian Semiconductor Equipment Business Unit, 35 Dory Road, Gloucester, Massachusetts 01930 (United States)

    2014-02-15

    In this paper, we introduce the Solion ion source for high-throughput solar cell doping. As the source power is increased to enable higher throughput, negative effects degrade the lifetime of the plasma chamber and the extraction electrodes. In order to improve efficiency, we have explored a wide range of electron energies and determined the conditions which best suit production. To extend the lifetime of the source we have developed an in situ cleaning method using only existing hardware. With these combinations, source life-times of >200 h for phosphorous and >100 h for boron ion beams have been achieved while maintaining 1100 cell-per-hour production.

  8. Highly efficient photonic nanowire single-photon sources for quantum information applications

    DEFF Research Database (Denmark)

    Gregersen, Niels; Claudon, J.; Munsch, M.

    2013-01-01

    to a collection efficiency of only 1-2 %, and efficient light extraction thus poses a major challenge in SPS engineering. Initial efforts to improve the efficiency have exploited cavity quantum electrodynamics (cQED) to efficiently couple the emitted photons to the optical cavity mode. An alternative approach......Within the emerging field of optical quantum information processing, the current challenge is to construct the basic building blocks for the quantum computing and communication systems. A key component is the singlephoton source (SPS) capable of emitting single photons on demand. Ideally, the SPS...... must feature near-unity efficiency, where the efficiency is defined as the number of detected photons per trigger, the probability g(2)(τ=0) of multi-photon emission events should be 0 and the emitted photons are required to be indistinguishable. An optically or electrically triggered quantum light...

  9. Copper increases reductive dehalogenation of haloacetamides by zero-valent iron in drinking water: Reduction efficiency and integrated toxicity risk.

    Science.gov (United States)

    Chu, Wenhai; Li, Xin; Bond, Tom; Gao, Naiyun; Bin, Xu; Wang, Qiongfang; Ding, Shunke

    2016-12-15

    The haloacetamides (HAcAms), an emerging class of nitrogen-containing disinfection byproducts (N-DBPs), are highly cytotoxic and genotoxic, and typically occur in treated drinking waters at low μg/L concentrations. Since many drinking distribution and storage systems contain unlined cast iron and copper pipes, reactions of HAcAms with zero-valent iron (ZVI) and metallic copper (Cu) may play a role in determining their fate. Moreover, ZVI and/or Cu are potentially effective HAcAm treatment technologies in drinking water supply and storage systems. This study reports that ZVI alone reduces trichloroacetamide (TCAcAm) to sequentially form dichloroacetamide (DCAcAm) and then monochloroacetamide (MCAcAm), whereas Cu alone does not impact HAcAm concentrations. The addition of Cu to ZVI significantly improved the removal of HAcAms, relative to ZVI alone. TCAcAm and their reduction products (DCAcAm and MCAcAm) were all decreased to below detection limits at a molar ratio of ZVI/Cu of 1:1 after 24 h reaction (ZVI/TCAcAm = 0.18 M/5.30 μM). TCAcAm reduction increased with the decreasing pH from 8.0 to 5.0, but values from an integrated toxic risk assessment were minimised at pH 7.0, due to limited removal MCAcAm under weak acid conditions (pH = 5.0 and 6.0). Higher temperatures (40 °C) promoted the reductive dehalogenation of HAcAms. Bromine was preferentially removed over chlorine, thus brominated HAcAms were more easily reduced than chlorinated HAcAms by ZVI/Cu. Although tribromoacetamide was more easily reduced than TCAcAm during ZVI/Cu reduction, treatment of tribromoacetamide resulted in a higher integrated toxicity risk than TCAcAm, due to the formation of monobromoacetamide (MBAcAm). Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Endogenous NO3- in the root as a source of substrate for reduction in the light

    International Nuclear Information System (INIS)

    Rufty, T.W. Jr.; Volk, R.J.; MacKown, C.T.

    1987-01-01

    An experiment was conducted to investigate the reduction of endogenous NO 3 - , which had been taken up by plants in darkness, during the course of the subsequent light period. Vegetative, nonnodulated soybean plant (Glycine max [L.]. Merrill, Ransom) were exposed to 1.0 millimolar 15 NO 3 - for 12 hours in darkness and then returned to a solution containing 1.0 millimolar 14 NO 3 - for the 12 hours chase period in the light. Another set of plants was exposed to 15 NO 3 - during the light period to allow a direct comparison of contributions of substrate from the endogenous and exogenous sources. At the end of the 15 NO 3 - exposure in the dark, 70% of the absorbed 15 NO 3 - remained unreduced, and 83% of this unreduced NO 3 - was retained in roots. The pool of endogenous 15 NO 3 - in roots was depleted at a steady rate during the initial 9 hours of light and was utilized almost exclusively in the formation of insoluble reduced-N in leaves. Unlabeled endogenous NO 3 - , which had accumulated in the root prior to the previous dark period, also was depleted in the light. When exogenous 15 NO 3 - was supplied during the light period, the rate of assimilation progressively increased, reflecting an increased rate of uptake and decreased accumulation of NO 3 - in the root tissue. The dark-absorbed endogenous NO 3 - in the root was the primary source of substrate for whole-plant NO 3 - reduction in the first 6 hours of the light period, and exogenous NO 3 - was the primary source of substrate thereafter

  11. New Source Review (NSR) Air Permitting and Energy Efficiency for Industrial Projects, IECA Manufacturers for Energy Efficiency Coalition Meeting (Presentation) – April 18, 2012

    Science.gov (United States)

    This presentation provides information about major new source review (NSR), including recent improvement changes and court rulings, flexible air permits rule, significant deterioration rules, and energy efficiency considerations.

  12. Pollution from the electric power sector in Japan and efficient pollution reduction

    International Nuclear Information System (INIS)

    Matsushita, Kyohei; Yamane, Fumihiro

    2012-01-01

    Under the scheme of the Kyoto Protocol, there are plans for the efficient reduction of carbon dioxide emissions. In the electric power sector, nuclear power generation, which emits no carbon dioxide in the process of generating electricity, has come under scrutiny. However, this energy produces a new environmental issue: the disposal of radioactive waste. First, we derive shadow prices of carbon dioxide and low-level waste as marginal abatement costs in the case of the electric power sector in Japan, employing a directional output distance function. It is found that the shadow prices are US$39 per tonne for carbon dioxide and US$1531 per liter for low-level waste. Secondly, we calculate the indirect Morishima elasticity between carbon dioxide and low-level waste in order to identify their substitutability, and it is found that the substitution of low-level waste for carbon dioxide is easier than the reverse. This result suggests that, with the amount of generated electricity fixed, carbon dioxide can be substituted more easily by low-level waste when the relative price of carbon dioxide increases, for example, as a result of implementation of a carbon dioxide tax or an emissions trading system.

  13. A highly efficient single-photon source based on a quantum dot in a photonic nanowire

    DEFF Research Database (Denmark)

    Claudon, Julien; Bleuse, Joel; Malik, Nitin Singh

    2010-01-01

    –4 or a semiconductor quantum dot5–7. Achieving a high extraction efficiency has long been recognized as a major issue, and both classical solutions8 and cavity quantum electrodynamics effects have been applied1,9–12. We adopt a different approach, based on an InAs quantum dot embedded in a GaAs photonic nanowire......The development of efficient solid-state sources of single photons is a major challenge in the context of quantum communication,optical quantum information processing and metrology1. Such a source must enable the implementation of a stable, single-photon emitter, like a colour centre in diamond2...

  14. Counter-facing plasma guns for efficient extreme ultra-violet plasma light source

    Science.gov (United States)

    Kuroda, Yusuke; Yamamoto, Akiko; Kuwabara, Hajime; Nakajima, Mitsuo; Kawamura, Tohru; Horioka, Kazuhiko

    2013-11-01

    A plasma focus system composed of a pair of counter-facing coaxial guns was proposed as a long-pulse and/or repetitive high energy density plasma source. We applied Li as the source of plasma for improvement of the conversion efficiency, the spectral purity, and the repetition capability. For operation of the system with ideal counter-facing plasma focus mode, we changed the system from simple coaxial geometry to a multi-channel configuration. We applied a laser trigger to make synchronous multi-channel discharges with low jitter. The results indicated that the configuration is promising to make a high energy density plasma with high spectral efficiency.

  15. Efficiency of the heat pump cooperating with various heat sources in monovalent and bivalent systems

    Energy Technology Data Exchange (ETDEWEB)

    Kurpaska, S.; Latala, H. [Krakow Univ. of Agriculture, Krakow (Poland). Inst. of Agricultural Engineering and Computer Science

    2010-07-01

    This paper reported on a study that tested the efficiency of compressor heat pumps cooperating with various types of lower heat sources such as horizontal ground heat exchangers, vertical exchangers and sources operating in the bivalent system. The system for receiving energy consisted of a traditional heating system and liquid-air exchangers. The study identified a strong relationship between the heating efficiency of the analysed systems and temperature inside the structure. The study showed that the bivalent system was fully capable of meeting a heat requirement of about 1 MJ -2.

  16. Reduction of gas flow into a hollow cathode ion source for a neutral beam injector

    International Nuclear Information System (INIS)

    Tanaka, S.; Akiba, M.; Arakawa, Y.; Horiike, H.; Sakuraba, J.

    1982-01-01

    Experimental studies have been made on the reduction of the gas flow rate into ion sources which utilize a hollow cathode. The electron emitter of the hollow cathode was a barium oxide impregnated porous tungsten tube. The hollow cathode was mounted to a circular or a rectangular bucket source and the following results were obtained. There was a tendency for the minimum gas flow rate for the stable source operation to decrease with increasing orifice diameter of the hollow cathode up to 10 mm. A molybdenum button with an appropriate diameter set in front of the orifice reduced the minimum gas flow rate to one half of that without button. An external magnetic field applied antiparallel to the field generated by the heater current stabilized the discharges and reduced the minimum gas flow rate to one half of that without field. Combination of the button and the antiparallel field reduced the minimum gas flow rate from the initial value (9.5 Torr 1/s) to 2.4 Torr 1/s. The reason for these effects was discussed on the basis of the theory for arc starvation

  17. Catalysts for cleaner combustion of coal, wood and briquettes sulfur dioxide reduction options for low emission sources

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.V. [Global Environmental Solutions, Inc., Morton Grove, IL (United States)

    1995-12-31

    Coal fired, low emission sources are a major factor in the air quality problems facing eastern European cities. These sources include: stoker-fired boilers which feed district heating systems and also meet local industrial steam demand, hand-fired boilers which provide heat for one building or a small group of buildings, and masonary tile stoves which heat individual rooms. Global Environmental Systems is marketing through Global Environmental Systems of Polane, Inc. catalysts to improve the combustion of coal, wood or fuel oils in these combustion systems. PCCL-II Combustion Catalysts promotes more complete combustion, reduces or eliminates slag formations, soot, corrosion and some air pollution emissions and is especially effective on high sulfur-high vanadium residual oils. Glo-Klen is a semi-dry powder continuous acting catalyst that is injected directly into the furnace of boilers by operating personnel. It is a multi-purpose catalyst that is a furnace combustion catalyst that saves fuel by increasing combustion efficiency, a cleaner of heat transfer surfaces that saves additional fuel by increasing the absorption of heat, a corrosion-inhibiting catalyst that reduces costly corrosion damage and an air pollution reducing catalyst that reduces air pollution type stack emissions. The reduction of sulfur dioxides from coal or oil-fired boilers of the hand fired stoker design and larger, can be controlled by the induction of the Glo-Klen combustion catalyst and either hydrated lime or pulverized limestone.

  18. Polyaniline-Derived Ordered Mesoporous Carbon as an Efficient Electrocatalyst for Oxygen Reduction Reaction

    Directory of Open Access Journals (Sweden)

    Kai Wan

    2015-06-01

    Full Text Available Nitrogen-doped ordered mesoporous carbon was synthesized by using polyaniline as the carbon source and SBA-15 as the template. The microstructure, composition and electrochemical behavior were extensively investigated by the nitrogen sorption isotherm, X-ray photoelectron spectroscopy, cyclic voltammetry and rotating ring-disk electrode. It is found that the pyrolysis temperature yielded a considerable effect on the pore structure, elemental composition and chemical configuration. The pyrolysis temperature from 800 to 1100 °C yielded a volcano-shape relationship with both the specific surface area and the content of the nitrogen-activated carbon. Electrochemical tests showed that the electrocatalytic activity followed a similar volcano-shape relationship, and the carbon catalyst synthesized at 1000 °C yielded the best performance. The post-treatment in NH3 was found to further increase the specific surface area and to enhance the nitrogen doping, especially the edge-type nitrogen, which favored the oxygen reduction reaction in both acid and alkaline media. The above findings shed light on electrocatalysis and offer more strategies for the controllable synthesis of the doped carbon catalyst.

  19. An Analysis of Sources of Technological Change in Efficiency Improvement of Fluorescent Lamp Systems

    Science.gov (United States)

    Imanaka, Takeo

    In Japan, energy efficient fluorescent lamp systems which use “rare-earth phosphors” and “electronic ballasts” have shown rapid diffusion since 1990s. This report investigated sources of technological change in the efficiency improvement of fluorescent lamp systems: (i) Fluorescent lamp and luminaires have been under steady technological development for getting more energy efficient lighting and the concepts to achieve high efficiency had been found in such activities; however, it took long time until they realized and become widely used; (ii) Electronic ballasts and rare-earth phosphors add fluorescent lamp systems not only energy efficiency but also various values such as compactness, lightweight, higher output, and better color rendering properties, which have also been expected and have induced research and development (R&D) (iii) Affordable electronic ballasts are realized by the new technology “power MOSFET” which is based on IC technologies and has been developed for large markets of information and communication technologies and mobile devices; and (iv) Rare-earth phosphors became available after rare-earth industries developed for the purpose of supplying rare-earth phosphors for color television. In terms of sources of technological change, (i) corresponds to “R&D” aiming at the particular purpose i.e. energy efficiency in this case, on the other hand, (ii), (iii), and (iv) correspond to “spillovers” from activities aiming at other purposes. This case exhibits an actual example in which “spillovers” were the critical sources of technological change in energy technology.

  20. Innovative Basis of Research of Energy-Efficient Potential and Effectiveness of Renewable Energy Sources

    OpenAIRE

    Hasanov Seymur Latif oglu; Hasanov Elnur Latif oglu

    2018-01-01

    In recent years, countries of the world have been trying to attract new energy sources (wind, sun, biogas, waves, drainage, non-conventional energy sources such as hydroelectric power of small rivers) in their fuel-energy balance. Azerbaijan has renewable natural resources, favorable for its energy-efficient potential, according to the amount of sunny and windy days. In this article was given total information about renewable energy potential of Azerbaijan Republic. In this article we use inf...

  1. Preliminary Ionization Efficiencies of 11C and 14O with the LBNL ECR Ion Sources

    International Nuclear Information System (INIS)

    Xie, Z.Q.; Cerny, J.; Guo, F.Q.; Joosten, R.; Larimer, R.M.; Lyneis, C.M.; McMahan, P.; Norman, E.B.; O'Neil, J.P.; Powell, J.; Rowe, M.W.; VanBrocklin, H.F.; Wutte, D.; Xu, X.J.; Haustein, P.

    1998-01-01

    High charge states, up to fully stripped 11 C and 14 O ion, beams have been produced with the electron cyclotron resonance ion sources (LBNL, ECR and AECR-U) at Lawrence Berkeley National Laboratory. The radioactive atoms of 11 C and 14 O were collected in batch mode with an LN 2 trap and then bled into the ECR ion sources. Ionization efficiency as high as 11% for 11 C 4+ was achieved

  2. Analysis of Energy Efficiency in Dynamic Optical Networks Employing Solar Energy Sources

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    The paper presents energy efficient routing in dynamic optical networks, where solar energy sources are employed for the network nodes. Different parameters are evaluated, including the number of nodes that have access to solar energy sources, the different maximum solar output power, traffic type...... and the locations of solar powered nodes. Results show a maximum 39% savings in energy consumption with different increases in connection blocking probability....

  3. Test of Effective Solid Angle code for the efficiency calculation of volume source

    Energy Technology Data Exchange (ETDEWEB)

    Kang, M. Y.; Kim, J. H.; Choi, H. D. [Seoul National Univ., Seoul (Korea, Republic of); Sun, G. M. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    It is hard to determine a full energy (FE) absorption peak efficiency curve for an arbitrary volume source by experiment. That's why the simulation and semi-empirical methods have been preferred so far, and many works have progressed in various ways. Moens et al. determined the concept of effective solid angle by considering an attenuation effect of γ-rays in source, media and detector. This concept is based on a semi-empirical method. An Effective Solid Angle code (ESA code) has been developed for years by the Applied Nuclear Physics Group in Seoul National University. ESA code converts an experimental FE efficiency curve determined by using a standard point source to that for a volume source. To test the performance of ESA Code, we measured the point standard sources and voluminous certified reference material (CRM) sources of γ-ray, and compared with efficiency curves obtained in this study. 200∼1500 KeV energy region is fitted well. NIST X-ray mass attenuation coefficient data is used currently to check for the effect of linear attenuation only. We will use the interaction cross-section data obtained from XCOM code to check the each contributing factor like photoelectric effect, incoherent scattering and coherent scattering in the future. In order to minimize the calculation time and code simplification, optimization of algorithm is needed.

  4. Phonon scattering inhibits simultaneous near-unity efficiency and indistinguishability in semiconductor single-photon sources

    DEFF Research Database (Denmark)

    Iles-Smith, Jake; McCutcheon, Dara P. S.; Nazir, Ahsan

    2017-01-01

    in these systems in giving rise to trade-offs between indistinguishability and efficiency. We analyse the two source architectures most commonly employed: a QD embedded in a waveguide and a QD coupled to an optical cavity. For waveguides, we demonstrate that the broadband Purcell effect results in a simple inverse...... relationship, in which indistinguishability and efficiency cannot be simultaneously increased. For cavities, the frequency selectivity of the Purcell enhancement results in a more subtle trade-off, in which indistinguishability and efficiency can be increased simultaneously, although not arbitrarily, which...

  5. Calculated Absolute Detection Efficiencies of Cylindrical Nal (Tl) Scintillation Crystals for Aqueous Spherical Sources

    Energy Technology Data Exchange (ETDEWEB)

    Strindehag, O; Tollander, B

    1968-08-15

    Calculated values of the absolute total detection efficiencies of cylindrical scintillation crystals viewing spherical sources of various sizes are presented. The calculation is carried out for 2 x 2 inch and 3 x 3 inch Nal(Tl) crystals and for sources which have the radii 1/4, 1/2, 3/4 and 1 times the crystal radius. Source-detector distances of 5-20 cm and gamma energies in the range 0.1 - 5 MeV are considered. The correction factor for absorption in the sample container wall and in the detector housing is derived and calculated for a practical case.

  6. Stator Current Harmonic Reduction in a Novel Half Quasi-Z-Source Wind Power Generation System

    Directory of Open Access Journals (Sweden)

    Shoudao Huang

    2016-09-01

    Full Text Available The generator stator current gets distorted with unacceptable levels of total harmonic distortion (THD because impedance-source wind power generation systems use three-phase diode rectifiers. The stator current harmonics will cause increasing losses and torque ripple, which reduce the efficiency and stability of the system. This paper proposes a novel half quasi-Z-source inverter (H-qZSI for grid-connected wind power generation systems, which can reduce the generator stator current harmonics a great deal. When H-qZSI operates in the shoot-through zero state, the derivative of the generator stator current is only determined by the instantaneous value of the generator stator voltage, so the nonlinear relationship between generator stator current and stator voltage is improved compared with the traditional impedance-source inverter. Theoretically, it is indicated that the stator current harmonics can be reduced effectively by means of the proposed H-qZSI. Finally, simulation and experimental results are given to verify the theoretical analysis.

  7. NO{sub 2} and CO nonattainment areas: a pragmatic approach to source reduction assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cernuschi, S; Giugliano, M; Marzolo, F [D.I.I.A.R. - Politecnico di Milano, Milan (Italy). Environmental Section

    1996-12-31

    Many Italian large conurbations have CO and NO{sub 2} air quality standards exceeded and, consequently, require control enforcement plans to attain and maintain regulations not respected. In planning the interventions to be undertaken a fundamental issue is represented by the relationships between active emission sources and air quality, commonly described through mathematical models for evaluating the expected effects of the different reduction scenarios. This approach, relatively feasible for slightly or non reactive pollutants like CO, becomes not as easy to be applied for secondary pollutants, like NO{sub 2}, mainly for the complex photo chemical reaction systems involved in their atmospheric presence and the consequent modeling difficulties related either to the description of the system itself than to the detail in input data required. A practicable alternative in this framework relies in the utilization of statistical models for deriving, through the empirical description of the relationships between the parameters of interest, the reduction levels required for complying with the standards. Following an approach already applied with useful results to the same area, present work reports on the development and application to Milan urban area of statistical models for describing the relationships between CO and NO{sub x} annual concentration averages and the corresponding air quality standard parameters (number of standard exceedances for CO and 98th percentile of hourly concentrations for NO{sub 2}). The models are utilised upstream to simple roll-back models for the assessment of the reduction in emissions strength required for attaining air quality standards for the area. (author)

  8. NO{sub 2} and CO nonattainment areas: a pragmatic approach to source reduction assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cernuschi, S.; Giugliano, M.; Marzolo, F. [D.I.I.A.R. - Politecnico di Milano, Milan (Italy). Environmental Section

    1995-12-31

    Many Italian large conurbations have CO and NO{sub 2} air quality standards exceeded and, consequently, require control enforcement plans to attain and maintain regulations not respected. In planning the interventions to be undertaken a fundamental issue is represented by the relationships between active emission sources and air quality, commonly described through mathematical models for evaluating the expected effects of the different reduction scenarios. This approach, relatively feasible for slightly or non reactive pollutants like CO, becomes not as easy to be applied for secondary pollutants, like NO{sub 2}, mainly for the complex photo chemical reaction systems involved in their atmospheric presence and the consequent modeling difficulties related either to the description of the system itself than to the detail in input data required. A practicable alternative in this framework relies in the utilization of statistical models for deriving, through the empirical description of the relationships between the parameters of interest, the reduction levels required for complying with the standards. Following an approach already applied with useful results to the same area, present work reports on the development and application to Milan urban area of statistical models for describing the relationships between CO and NO{sub x} annual concentration averages and the corresponding air quality standard parameters (number of standard exceedances for CO and 98th percentile of hourly concentrations for NO{sub 2}). The models are utilised upstream to simple roll-back models for the assessment of the reduction in emissions strength required for attaining air quality standards for the area. (author)

  9. PROSPECTS OF ENERGY EFFICIENCY IMPROVEMENT AND DEVELOPMENT OF THE RENEWABLE ENERGY SOURCES IN PROVINCE OF VOJVODINA

    Energy Technology Data Exchange (ETDEWEB)

    Gvozdenac, D.; Ciric, R.; Tesic, M.

    2007-07-01

    The paper presents the outcome of the research in the field of energy efficiency improvement and development of the renewable energy sources in province of Vojvodina (Serbia). The summarized results of the paper are: - Potentials for energy efficiency improvement in Vojvodina, - Potentials for development of renewable energy sources in Vojvodina, - Proposal of measures of the energy policy for the promotion of research and development (R and D) which will use local scientific and technical potentials in the field of renewable energy sources and energy efficiency and improve the sustainability on the long run. - Proposal of measures for the energy policy in the domain of renewable energy sources development and energy efficiency and estimation of potentials for improvements by applying proposed measures in order to accomplish established tasks. - Synthesizing findings and proposals in the Action Plan of the Executive Council of the Autonomous Province of Vojvodina for the realization of the medium term program as well as the establishment of the monitoring plan for the assessment of program objectives progress. (auth)

  10. Recent Advances for High-Efficiency Sources of Single Photons Based on Photonic Nanowires

    DEFF Research Database (Denmark)

    Gerard, J. M.; Claudon, J.; Munsch, M.

    2012-01-01

    Photonic nanowires have recently been used to tailor the spontaneous emission of embedded quantum dots, and to develop record efficiency single-photon sources. We will present recent developments in this field mainly 1) the observation of a strong inhibition of the spontaneous emission of quantum...

  11. Efficient all solid-state continuous-wave yellow-orange light source

    DEFF Research Database (Denmark)

    Janousek, Jiri; Johansson, Sandra; Tidemand-Lichtenberg, Peter

    2005-01-01

    We present highly efficient sum-frequency generation between two CW IR lasers using periodically poled KTP. The system is based on the 1064 and 1342 nm laser-lines of two Nd:YVO4 lasers. This is an all solid-state light source in the yellow-orange spectral range. The system is optimized in terms ...

  12. A high-efficiency electrically-pumped single-photon source based on a photonics nanowire

    DEFF Research Database (Denmark)

    Gregersen, Niels; Nielsen, Torben Roland; Mørk, Jesper

    An electrically-pumped single-photon source design with a predicted efficiency of 89% is proposed. The design is based on a quantum dot embedded in a photonic nanowire with tailored ends and optimized contact electrodes. Unlike cavity-based approaches, the photonic nanowire features broadband...

  13. Further comments on the geometrical efficiency of a parallel-disk source and detector system

    International Nuclear Information System (INIS)

    Ruby, L.

    1994-01-01

    A derivation is presented for a previously published formula, which determines the geometrical efficiency of a parallel-disk source and detector system. The formula involves an integral over a product of two Bessel functions. An algebraic approximation to the integral is also discussed. (orig.)

  14. Increase of plasma ion source efficiency utilizing collisions of the second kind

    International Nuclear Information System (INIS)

    Winkler, H.

    1979-01-01

    It is experimentally found that the efficiency of a plasma ion source for use in an electromagnetic separator can be increased under appropriate operating conditions utilizing collisions of the second kind, of a proper gas is additionally introduced into the arc chamber containing atoms with metastable excited levels. (author)

  15. A Nearest Neighbor Classifier Employing Critical Boundary Vectors for Efficient On-Chip Template Reduction.

    Science.gov (United States)

    Xia, Wenjun; Mita, Yoshio; Shibata, Tadashi

    2016-05-01

    Aiming at efficient data condensation and improving accuracy, this paper presents a hardware-friendly template reduction (TR) method for the nearest neighbor (NN) classifiers by introducing the concept of critical boundary vectors. A hardware system is also implemented to demonstrate the feasibility of using an field-programmable gate array (FPGA) to accelerate the proposed method. Initially, k -means centers are used as substitutes for the entire template set. Then, to enhance the classification performance, critical boundary vectors are selected by a novel learning algorithm, which is completed within a single iteration. Moreover, to remove noisy boundary vectors that can mislead the classification in a generalized manner, a global categorization scheme has been explored and applied to the algorithm. The global characterization automatically categorizes each classification problem and rapidly selects the boundary vectors according to the nature of the problem. Finally, only critical boundary vectors and k -means centers are used as the new template set for classification. Experimental results for 24 data sets show that the proposed algorithm can effectively reduce the number of template vectors for classification with a high learning speed. At the same time, it improves the accuracy by an average of 2.17% compared with the traditional NN classifiers and also shows greater accuracy than seven other TR methods. We have shown the feasibility of using a proof-of-concept FPGA system of 256 64-D vectors to accelerate the proposed method on hardware. At a 50-MHz clock frequency, the proposed system achieves a 3.86 times higher learning speed than on a 3.4-GHz PC, while consuming only 1% of the power of that used by the PC.

  16. An efficient chaotic source coding scheme with variable-length blocks

    International Nuclear Information System (INIS)

    Lin Qiu-Zhen; Wong Kwok-Wo; Chen Jian-Yong

    2011-01-01

    An efficient chaotic source coding scheme operating on variable-length blocks is proposed. With the source message represented by a trajectory in the state space of a chaotic system, data compression is achieved when the dynamical system is adapted to the probability distribution of the source symbols. For infinite-precision computation, the theoretical compression performance of this chaotic coding approach attains that of optimal entropy coding. In finite-precision implementation, it can be realized by encoding variable-length blocks using a piecewise linear chaotic map within the precision of register length. In the decoding process, the bit shift in the register can track the synchronization of the initial value and the corresponding block. Therefore, all the variable-length blocks are decoded correctly. Simulation results show that the proposed scheme performs well with high efficiency and minor compression loss when compared with traditional entropy coding. (general)

  17. Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency

    International Nuclear Information System (INIS)

    Kim, T. S.; Jeong, S. H.; Chang, D. H.; In, S. R.; Park, M.; Jung, B. K.; Lee, K. W.; Wang, S. J.; Bae, Y. S.; Park, H. T.; Kim, J. S.; Cho, W.; Choi, D. J.

    2016-01-01

    Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP

  18. Three-dimensional porous hollow fibre copper electrodes for efficient and high-rate electrochemical carbon dioxide reduction

    NARCIS (Netherlands)

    Kas, Recep; Hummadi, Khalid Khazzal; Kortlever, Ruud; de Wit, Patrick; Milbrat, Alexander; Luiten-Olieman, Maria W.J.; Benes, Nieck Edwin; Koper, Marc T.M.; Mul, Guido

    2016-01-01

    Aqueous-phase electrochemical reduction of carbon dioxide requires an active, earth-abundant electrocatalyst, as well as highly efficient mass transport. Here we report the design of a porous hollow fibre copper electrode with a compact three-dimensional geometry, which provides a large area,

  19. Selective and efficient reduction of carbon dioxide to carbon monoxide on oxide-derived nanostructured silver electrocatalysts

    NARCIS (Netherlands)

    Ma, Ming; Trześniewski, Bartek J.; Xie, Jie; Smith, Wilson A.

    2016-01-01

    In this work, the selective electrocatalytic reduction of carbon dioxide to carbon monoxide on oxide-derived silver electrocatalysts is presented. By a simple synthesis technique, the overall high faradaic efficiency for CO production on the oxide-derived Ag was shifted by more than 400 mV towards a

  20. Reduction of PM emissions from specific sources reflected on key components concentrations of ambient PM10

    Science.gov (United States)

    Minguillon, M. C.; Querol, X.; Monfort, E.; Alastuey, A.; Escrig, A.; Celades, I.; Miro, J. V.

    2009-04-01

    The relationship between specific particulate emission control and ambient levels of some PM10 components (Zn, As, Pb, Cs, Tl) was evaluated. To this end, the industrial area of Castellón (Eastern Spain) was selected, where around 40% of the EU glazed ceramic tiles and a high proportion of EU ceramic frits (middle product for the manufacture of ceramic glaze) are produced. The PM10 emissions from the ceramic processes were calculated over the period 2000 to 2007 taking into account the degree of implementation of corrective measures throughout the study period. Abatement systems (mainly bag filters) were implemented in the majority of the fusion kilns for frit manufacture in the area as a result of the application of the Directive 1996/61/CE, leading to a marked decrease in PM10 emissions. On the other hand, ambient PM10 sampling was carried out from April 2002 to July 2008 at three urban sites and one suburban site of the area and a complete chemical analysis was made for about 35 % of the collected samples, by means of different techniques (ICP-AES, ICP-MS, Ion Chromatography, selective electrode and elemental analyser). The series of chemical composition of PM10 allowed us to apply a source contribution model (Principal Component Analysis), followed by a multilinear regression analysis, so that PM10 sources were identified and their contribution to bulk ambient PM10 was quantified on a daily basis, as well as the contribution to bulk ambient concentrations of the identified key components (Zn, As, Pb, Cs, Tl). The contribution of the sources identified as the manufacture and use of ceramic glaze components, including the manufacture of ceramic frits, accounted for more than 65, 75, 58, 53, and 53% of ambient Zn, As, Pb, Cs and Tl levels, respectively (with the exception of Tl contribution at one of the sites). The important emission reductions of these sources during the study period had an impact on ambient key components levels, such that there was a high

  1. Efficiency potentials of heat pumps with combined heat and power. For maximum reduction of CO2 emissions and for electricity generation from fossil fuels with CO2 reduction in Switzerland

    International Nuclear Information System (INIS)

    Rognon, F.

    2005-06-01

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) takes a look at how the efficiency potential of heat pumps together with combined heat and power systems can help provide a maximum reduction of CO 2 emissions and provide electricity generation from fossil fuel in Switzerland together with reductions in CO 2 emissions. In Switzerland, approximately 80% of the low-temperature heat required for space-heating and for the heating-up of hot water is produced by burning combustibles. Around a million gas and oil boilers were in use in Switzerland in 2000, and these accounted for approximately half the country's 41.1 million tonnes of CO 2 emissions. The authors state that there is a more efficient solution with lower CO 2 emissions: the heat pump. With the enormous potential of our environment it would be possible to replace half the total number of boilers in use today with heat pumps. This would be equivalent to 90 PJ p.a. of useful heat, or 500,000 systems. The power source for heat pumps should come from the substitution of electric heating systems (electric resistor-based systems) and from the replacement of boilers. This should be done by using combined heat and power systems with full heat utilisation. This means, according to the authors, that the entire required power source can be provided without the need to construct new electricity production plants. The paper examines and discusses the theoretical, technical, market and realisable potentials

  2. An inexact fuzzy two-stage stochastic model for quantifying the efficiency of nonpoint source effluent trading under uncertainty

    International Nuclear Information System (INIS)

    Luo, B.; Maqsood, I.; Huang, G.H.; Yin, Y.Y.; Han, D.J.

    2005-01-01

    Reduction of nonpoint source (NPS) pollution from agricultural lands is a major concern in most countries. One method to reduce NPS pollution is through land retirement programs. This method, however, may result in enormous economic costs especially when large sums of croplands need to be retired. To reduce the cost, effluent trading can be employed to couple with land retirement programs. However, the trading efforts can also become inefficient due to various uncertainties existing in stochastic, interval, and fuzzy formats in agricultural systems. Thus, it is desired to develop improved methods to effectively quantify the efficiency of potential trading efforts by considering those uncertainties. In this respect, this paper presents an inexact fuzzy two-stage stochastic programming model to tackle such problems. The proposed model can facilitate decision-making to implement trading efforts for agricultural NPS pollution reduction through land retirement programs. The applicability of the model is demonstrated through a hypothetical effluent trading program within a subcatchment of the Lake Tai Basin in China. The study results indicate that the efficiency of the trading program is significantly influenced by precipitation amount, agricultural activities, and level of discharge limits of pollutants. The results also show that the trading program will be more effective for low precipitation years and with stricter discharge limits

  3. Reducing plant radiation fields by source term reduction - tracking cobalt and antimony to their sources at Gentilly-2

    International Nuclear Information System (INIS)

    Gauthier, P.; Guzonas, D.A.

    2006-01-01

    the same specifications at Gentilly-2 as at other CANDU 6 plants. Consequently, the task group revisited operating and maintenance practices, going back through station operating history to identify operational practices that could have lead to increased 59 Co release and/or 60 Co production. The focus rapidly moved to the fuel handling system, as it had long been suspected, but never proven, that the Stellite ram balls were a major source of 59 Co; the fuelling machines provide a direct route for the introduction of corrosion or wear products into the reactor core. Data on the gamma fields measured in the fuelling machine D 2 O supply room from 1995 to the present were reviewed. Water samples were taken and chemically analysed. The results confirmed the presence of 59 Co, probably generated by the wear and corrosion of the Stellite ram balls, and also confirmed the presence of antimony in the system. As part of the task group program, γ-spectrometry was performed in the course of a refuelling cycle. The results showed that variations in the general radiation fields observed in the fuelling machine D 2 O supply room resulted from variations of the 122 Sb and 124 Sb concentrations in the process water. The presence of 122 Sb (t 1/2 3.2 d) suggested that the antimony was recently released from the reactor core. 60 Co was also detected but the level was constant; 59 Co from the ram balls is invisible to γ-spectrometry before it is activated to 60 Co. Remedial actions were implemented in mid-July, 2004. Shortly after, a significant reduction in the radiation fields in the Gentilly-2 fuelling machine D2 O supply room was confirmed. During an unplanned outage in December 2004, a decrease in fields, in particular those due to 60 Co and radioantimony, was found at the reactor face. Activity monitoring scheduled for the 2005 annual outage should confirm if the source of the abnormally high fields has finally been identified. This presentation will describe the task force

  4. A nano-graphite cold cathode for an energy-efficient cathodoluminescent light source

    Directory of Open Access Journals (Sweden)

    Alexander N. Obraztsov

    2013-08-01

    Full Text Available The development of new types of light sources is necessary in order to meet the growing demands of consumers and to ensure an efficient use of energy. The cathodoluminescence process is still under-exploited for light generation because of the lack of cathodes suitable for the energy-efficient production of electron beams and appropriate phosphor materials. In this paper we propose a nano-graphite film material as a highly efficient cold cathode, which is able to produce high intensity electron beams without energy consumption. The nano-graphite film material was produced by using chemical vapor deposition techniques. Prototypes of cathodoluminescent lamp devices with a construction optimized for the usage of nano-graphite cold cathodes were developed, manufactured and tested. The results indicate prospective advantages of this type of lamp and the possibility to provide advanced power efficiency as well as enhanced spectral and other characteristics.

  5. Defect-meditated efficient catalytic activity toward p-nitrophenol reduction: A case study of nitrogen doped calcium niobate system

    International Nuclear Information System (INIS)

    Su, Yiguo; Huang, Shushu; Wang, Tingting; Peng, Liman; Wang, Xiaojing

    2015-01-01

    Graphical abstract: A series of nitrogen doped Ca 2 Nb 2 O 7 was successfully prepared via ion-exchange method, which was found to be an efficient and green noble-metal-free catalyst toward catalytic reduction of p-nitrophenol. - Highlights: • Nitrogen doped Ca 2 Nb 2 O 7 was found to be an efficient and green noble-metal-free catalyst toward catalytic reduction of p-nitrophenol. • Defective nitrogen and oxygen species were found to play synergetic roles in the reduction of p-nitrophenol. • Nitrogen doped Ca 2 Nb 2 O 7 showed photo-synergistic promotion effects toward p-nitrophenol reduction under UV light irradiation. - Abstract: This work reported on the synthesis of a series of nitrogen doped Ca 2 Nb 2 O 7 with tunable nitrogen content that were found to be efficient and green noble-metal-free catalysts toward catalytic reduction of p-nitrophenol. XPS and ESR results indicated that the introduction of nitrogen in Ca 2 Nb 2 O 7 gave rise to a large number of defective nitrogen and oxygen species. Defective nitrogen and oxygen species were found to play synergetic roles in the reduction of p-nitrophenol. The underlying mechanism is completely different from those reported for metallic nanoparticles. Moreover, the more negative conduction band edge potential enabled nitrogen doped Ca 2 Nb 2 O 7 to show photo-synergistic effects that could accelerate the reduction rate toward p-nitrophenol under UV light irradiation. This work may provide a strategy for tuning the catalytic performance by modulating the chemical composition, electronic structure as well as surface defect chemistry

  6. Development of high efficiency Versatile Arc Discharge Ion Source at CERN ISOLDE.

    Science.gov (United States)

    Penescu, L; Catherall, R; Lettry, J; Stora, T

    2010-02-01

    We report here recent developments of Forced Electron Beam Induced Arc Discharge (FEBIAD) ion sources at the ISOLDE radioactive ion beam facility, hosted at the European Organization for Nuclear Research (CERN). As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5-20 times larger than with the standard ISOLDE FEBIAD ion sources and reach 60% for radon, which allowed the identification at ISOLDE of (229)Rn, an isotope that had never previously been observed in the laboratory. A factor of 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model, which gives precise insights on the processes affecting the ionization, is used to design optimal sources (grouped under the name of VADIS--Versatile Arc Discharge Ion Source) for the different chemical classes of the produced isotopes, as already demonstrated for the noble gases.

  7. Laser-produced multi-charged heavy ions as efficient soft x-ray sources

    International Nuclear Information System (INIS)

    Higashiguchi, Takeshi; Suzuki, Yuhei; Kawasaki, Masato

    2016-01-01

    We demonstrate EUV and soft x-ray sources in the 2 to 7 nm spectral region related to the beyond EUV (BEUV) question at 6x nm and a water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs), extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on a high-Z plasma UTA source, coupled to x-ray optics. We will discuss the progress and Z-scaling of UTA emission spectra to achieve lab-scale table-top, efficient, high-brightness high-Z plasma EUV-soft x-ray sources for in vivo bio-imaging applications. (author)

  8. Reduction of non-point source contaminants associated with road-deposited sediments by sweeping.

    Science.gov (United States)

    Kim, Do-Gun; Kang, Hee-Man; Ko, Seok-Oh

    2017-09-19

    Road-deposited sediments (RDS) on an expressway, residual RDS collected after sweeping, and RDS removed by means of sweeping were analyzed to evaluate the degree to which sweeping removed various non-point source contaminants. The total RDS load was 393.1 ± 80.3 kg/km and the RDS, residual RDS, and swept RDS were all highly polluted with organics, nutrients, and metals. Among the metals studied, Cu, Zn, Pb, Ni, Ca, and Fe were significantly enriched, and most of the contaminants were associated with particles within the size range from 63 μm to 2 mm. Sweeping reduced RDS and its associated contaminants by 33.3-49.1% on average. We also measured the biological oxygen demand (BOD) of RDS in the present work, representing to our knowledge the first time that this has been done; we found that RDS contains a significant amount of biodegradable organics and that the reduction of BOD by sweeping was higher than that of other contaminants. Significant correlations were found between the contaminants measured, indicating that the organics and the metals originated from both exhaust and non-exhaust particles. Meanwhile, the concentrations of Cu and Ni were higher in 63 μm-2 mm particles than in smaller particles, suggesting that some metals in RDS likely exist intrinsically in particles, rather than only as adsorbates on particle surfaces. Overall, the results in this study showed that sweeping to collect RDS can be a good alternative for reduction of contaminants in runoff.

  9. The effect of multimicrophone noise reduction systems on sound source localization by users of binaural hearing aids.

    Science.gov (United States)

    Van den Bogaert, Tim; Doclo, Simon; Wouters, Jan; Moonen, Marc

    2008-07-01

    This paper evaluates the influence of three multimicrophone noise reduction algorithms on the ability to localize sound sources. Two recently developed noise reduction techniques for binaural hearing aids were evaluated, namely, the binaural multichannel Wiener filter (MWF) and the binaural multichannel Wiener filter with partial noise estimate (MWF-N), together with a dual-monaural adaptive directional microphone (ADM), which is a widely used noise reduction approach in commercial hearing aids. The influence of the different algorithms on perceived sound source localization and their noise reduction performance was evaluated. It is shown that noise reduction algorithms can have a large influence on localization and that (a) the ADM only preserves localization in the forward direction over azimuths where limited or no noise reduction is obtained; (b) the MWF preserves localization of the target speech component but may distort localization of the noise component. The latter is dependent on signal-to-noise ratio and masking effects; (c) the MWF-N enables correct localization of both the speech and the noise components; (d) the statistical Wiener filter approach introduces a better combination of sound source localization and noise reduction performance than the ADM approach.

  10. Market Analysis and Consumer Impacts Source Document. Part III. Consumer Behavior and Attitudes Toward Fuel Efficient Vehicles

    Science.gov (United States)

    1980-12-01

    This source document on motor vehicle market analysis and consumer impacts consists of three parts. Part III consists of studies and reviews on: consumer awareness of fuel efficiency issues; consumer acceptance of fuel efficient vehicles; car size ch...

  11. A novel high-efficiency single-mode quantum dot single photon source

    DEFF Research Database (Denmark)

    Gerard, J.M.; Gregersen, Niels; Nielsen, Torben Roland

    2008-01-01

    We present a novel single-mode single photon source exploiting the emission of a semiconductor quantum dot (QD) located inside a photonic wire. Besides an excellent coupling (>95%) of QD spontaneous emission to the fundamental guided mode [1], we show that a single photon collection efficiency...... above 80% within a 0.5 numerical aperture can be achieved using a bottom Bragg mirror and a tapering of the nanowire tip. Because this photon collection strategy does not exploit the Purcell effect, it could also be efficiently applied to broadband single photon emitters such as F-centers in diamond....

  12. Tow efficiency correction functions of source self-absorption of an HPGe detector

    International Nuclear Information System (INIS)

    Gao Zheng; Ma Yusheng; Luo Jianghua; Chen Luning

    2007-01-01

    The efficiency correction function of source absorption of an HPGe γ detector is determined by experiment in energy range from 59.5 keV to 1408 keV and density range from 0.3 g/cm 3 to 2.0 g/cm 3 . Fit Polynomial and fit Sigmoidal are compared. The results show that fit Sigmoidal is better than fit polynomial, and the detection efficiency at any points of energy and density could be conveniently calculated with it in calibrated range. (authors)

  13. An efficient closed-form solution for acoustic emission source location in three-dimensional structures

    Directory of Open Access Journals (Sweden)

    Xibing Li

    2014-02-01

    Full Text Available This paper presents an efficient closed-form solution (ECS for acoustic emission(AE source location in three-dimensional structures using time difference of arrival (TDOA measurements from N receivers, N ≥ 6. The nonlinear location equations of TDOA are simplified to linear equations. The unique analytical solution of AE sources for unknown velocity system is obtained by solving the linear equations. The proposed ECS method successfully solved the problems of location errors resulting from measured deviations of velocity as well as the existence and multiplicity of solutions induced by calculations of square roots in existed close-form methods.

  14. A novel power source for high-precision, highly efficient micro w-EDM

    International Nuclear Information System (INIS)

    Chen, Shun-Tong; Chen, Chi-Hung

    2015-01-01

    The study presents the development of a novel power source for high-precision, highly efficient machining of micropart microstructures using micro wire electrical discharge machining (w-EDM). A novel power source based on a pluri resistance–capacitance (pRC) circuit that can generate a high-frequency, high-peak current with a short pulse train is proposed and designed to enhance the performance of micro w-EDM processes. Switching between transistors is precisely controlled in the designed power source to create a high-frequency short-pulse train current. Various microslot cutting tests in both aluminum and copper alloys are conducted. Experimental results demonstrate that the pRC power source creates instant spark erosion resulting in markedly less material for removal, diminishing discharge crater size, and consequently an improved surface finish. A new evaluation approach for spark erosion ability (SEA) to assess the merits of micro EDM power sources is also proposed. In addition to increasing the speed of micro w-EDM by increasing wire feed rates by 1.6 times the original feed rate, the power source is more appropriate for machining micropart microstructures since there is less thermal breaking. Satisfactory cutting of an elaborate miniature hook-shaped structure and a high-aspect ratio microstructure with a squared-pillar array also reveal that the developed pRC power source is effective, and should be very useful in the manufacture of intricate microparts. (paper)

  15. New Source Review and coal plant efficiency gains: How new and forthcoming air regulations affect outcomes

    International Nuclear Information System (INIS)

    Adair, Sarah K.; Hoppock, David C.; Monast, Jonas J.

    2014-01-01

    Forthcoming carbon dioxide (CO 2 ) regulations for existing power plants in the United States have heightened interest in thermal efficiency gains for coal-fired power plants. Plant modifications to improve thermal efficiency can trigger New Source Review (NSR), a Clean Air Act requirement to adopt of state-of-the-art pollution controls. This article explores whether existing coal plants would likely face additional pollution control requirements if they undertake modifications that trigger NSR. Despite emissions controls that are or will be installed under the Mercury and Air Toxics Standards (MATS) and Clean Air Interstate Rule (CAIR) or its replacement, 80% of coal units (76% of capacity) that are expected to remain in operation are not projected to meet the minimum NSR requirements for at least one pollutant: nitrogen oxides or sulfur dioxide. This is an important consideration for the U.S. Environmental Protection Agency and state policymakers as they determine the extent to which CO 2 regulation will rely on unit-by-unit thermal efficiency gains versus potential flexible compliance strategies such as averaging, trading, energy efficiency, and renewable energy. NSR would likely delay and add cost to thermal efficiency projects at a majority of coal units, including projects undertaken to comply with forthcoming CO 2 regulation. - Highlights: • We explore the status of the U.S. coal-fired fleet relative to New Source Review (NSR) requirements. • Modifications to improve thermal efficiency can trigger NSR. • Thermal efficiency gains may also be an important strategy for forthcoming CO 2 regulation. • 80% Of non-retiring coal-fired units are projected not to meet minimum NSR requirements. • NSR is an important consideration for the design of CO 2 regulations for existing plants

  16. Stable and Efficient Advanced Oxygen Reduction Alloy Catalysts for PEM Fuel Cells, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Human exploration of space demands highly efficient, light-weight, long lifetime and maintenance-free power generation systems. Energy storage applications,...

  17. Effects of various organic carbon sources on simultaneous V(V) reduction and bioelectricity generation in single chamber microbial fuel cells.

    Science.gov (United States)

    Hao, Liting; Zhang, Baogang; Cheng, Ming; Feng, Chuanping

    2016-02-01

    Four ordinary carbon sources affecting V(V) reduction and bioelectricity generation in single chamber microbial fuel cells (MFCs) were investigated. Acetate supported highest maximum power density of 589.1mW/m(2), with highest V(V) removal efficiency of 77.6% during 12h operation, compared with glucose, citrate and soluble starch. Exorbitant initial V(V) concentration led to lower V(V) removal efficiencies and power outputs. Extra addition of organics had little effect on the improvement of MFCs performance. V(V) reduction and bioelectricity generation were enhanced and then suppressed by the increase of conductivity. The larger the external resistance, the higher the V(V) removal efficiencies and voltage outputs. High-throughput 16S rRNA gene pyrosequencing analysis implied the accumulation of Enterobacter which had the capabilities of V(V) reduction, electrochemical activity and fermentation, accompanied with other functional species as Pseudomonas, Spirochaeta, Sedimentibacter and Dysgonomonas. This study steps forward to remediate V(V) contaminated environment based on MFC technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Counter-facing plasma guns for efficient extreme ultra-violet plasma light source

    Directory of Open Access Journals (Sweden)

    Kuroda Yusuke

    2013-11-01

    Full Text Available A plasma focus system composed of a pair of counter-facing coaxial guns was proposed as a long-pulse and/or repetitive high energy density plasma source. We applied Li as the source of plasma for improvement of the conversion efficiency, the spectral purity, and the repetition capability. For operation of the system with ideal counter-facing plasma focus mode, we changed the system from simple coaxial geometry to a multi-channel configuration. We applied a laser trigger to make synchronous multi-channel discharges with low jitter. The results indicated that the configuration is promising to make a high energy density plasma with high spectral efficiency.

  19. Novel design of high voltage pulse source for efficient dielectric barrier discharge generation by using silicon diodes for alternating current

    Science.gov (United States)

    Truong, Hoa Thi; Hayashi, Misaki; Uesugi, Yoshihiko; Tanaka, Yasunori; Ishijima, Tatsuo

    2017-06-01

    This work focuses on design, construction, and optimization of configuration of a novel high voltage pulse power source for large-scale dielectric barrier discharge (DBD) generation. The pulses were generated by using the high-speed switching characteristic of an inexpensive device called silicon diodes for alternating current and the self-terminated characteristic of DBD. The operation started to be powered by a primary DC low voltage power supply flexibly equipped with a commercial DC power supply, or a battery, or DC output of an independent photovoltaic system without transformer employment. This flexible connection to different types of primary power supply could provide a promising solution for the application of DBD, especially in the area without power grid connection. The simple modular structure, non-control requirement, transformer elimination, and a minimum number of levels in voltage conversion could lead to a reduction in size, weight, simple maintenance, low cost of installation, and high scalability of a DBD generator. The performance of this pulse source has been validated by a load of resistor. A good agreement between theoretically estimated and experimentally measured responses has been achieved. The pulse source has also been successfully applied for an efficient DBD plasma generation.

  20. ZVI-Clay remediation of a chlorinated solvent source zone, Skuldelev, Denmark: 2. Groundwater contaminant mass discharge reduction

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Lange, Ida Vedel; Bjerg, Poul Løgstrup

    2012-01-01

    The impact of source mass depletion on the down-gradient contaminant mass discharge was monitored for a 19-month period as a part of a field demonstration of the ZVI-Clay soil mixing remediation technology. Groundwater samples were collected from conventional monitoring wells (120 samples) and a ...... down-gradient contaminant mass discharge reduction (76%) for the parent compound (PCE), while the overall reduction of chlorinated ethenes was smaller (21%)....

  1. Methods of formation of efficiency indexes of electric power sources integration in regional electric power systems

    International Nuclear Information System (INIS)

    Marder, L.I.; Myzin, A.I.

    1993-01-01

    A methodic approach to the grounding of the integration process efficiency within the Unified electric power system is given together with the selection of a rational areal structure and concentration of power-generating source capacities. Formation of an economic functional according to alternative scenavies including the cost components taking account of the regional interests is considered. A method for estimation and distribution of the effect from electric power production integration in the power systems under new economic conditions is proposed

  2. European Union's renewable energy sources and energy efficiency policy review. The Spanish perspective

    Energy Technology Data Exchange (ETDEWEB)

    De Alegria Mancisidor, Itziar Martinez; Diaz de Basurto Uraga, Pablo; Ruiz de Arbulo Lopez, Patxi [Departamento de Organizacion de Empresas, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (Spain); Martinez de Alegria Mancisidor, Inigo [Departamento de Electronica y Telecomunicaciones, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (Spain)

    2009-01-15

    The European Union's (EU) energy objectives, legislation and programmes are determinant for the current strategy for the promotion of renewable energy sources (RES) and energy efficiency (EE) in Spain, which is becoming a key element for its international competitiveness. Firstly, this article explores the evolution of the EU's energy strategy, focusing on the adopted legislations and programmes to promote RES and EE. It concludes with an analysis of the impact of those measures in Spain. (author)

  3. European Union's renewable energy sources and energy efficiency policy review. The Spanish perspective

    International Nuclear Information System (INIS)

    De Alegria Mancisidor, Itziar Martinez; Diaz de Basurto Uraga, Pablo; Ruiz de Arbulo Lopez, Patxi; Martinez de Alegria Mancisidor, Inigo

    2009-01-01

    The European Union's (EU) energy objectives, legislation and programmes are determinant for the current strategy for the promotion of renewable energy sources (RES) and energy efficiency (EE) in Spain, which is becoming a key element for its international competitiveness. Firstly, this article explores the evolution of the EU's energy strategy, focusing on the adopted legislations and programmes to promote RES and EE. It concludes with an analysis of the impact of those measures in Spain. (author)

  4. Energy Efficient Routing Algorithms in Dynamic Optical Core Networks with Dual Energy Sources

    DEFF Research Database (Denmark)

    Wang, Jiayuan; Fagertun, Anna Manolova; Ruepp, Sarah Renée

    2013-01-01

    This paper proposes new energy efficient routing algorithms in optical core networks, with the application of solar energy sources and bundled links. A comprehensive solar energy model is described in the proposed network scenarios. Network performance in energy savings, connection blocking...... probability, resource utilization and bundled link usage are evaluated with dynamic network simulations. Results show that algorithms proposed aiming for reducing the dynamic part of the energy consumption of the network may raise the fixed part of the energy consumption meanwhile....

  5. Potential CO{sub 2} reduction by implementing energy efficiency standard for room air conditioner in Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mahlia, T.M.I.; Masjuki, H.H.; Choudhury, I.A.; Saidur, R. [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2001-09-01

    This study attempts to predict the environmental impact of implementing an energy efficiency standard for room air conditioners in Malaysia. The ownership of room air conditioners has increased tremendously in this country. At present, there are about 528,792 room air conditioners in Malaysian households. In the year 2020, it will be about 1,511,276. The potential carbon dioxide reduction is based on the predicted electricity savings from implementing a minimum energy efficiency standard for room air conditioners. The electricity savings are calculated based on the predicted electricity consumption by a single air conditioner in the Malaysian household. The replacement of less efficient units of this appliance is reflected in reduced electricity consumption and emissions from power plants. The energy efficiency provisions of this regulation and agreement provide targets to save money, energy and, most importantly, to protect the environment. (Author)

  6. Target-ion source unit ionization efficiency measurement by method of stable ion beam implantation

    CERN Document Server

    Panteleev, V.N; Fedorov, D.V; Moroz, F.V; Orlov, S.Yu; Volkov, Yu.M

    The ionization efficiency is one of the most important parameters of an on-line used target-ion source system exploited for production of exotic radioactive beams. The ionization efficiency value determination as a characteristic of a target-ion source unit in the stage of its normalizing before on-line use is a very important step in the course of the preparation for an on-line experiment. At the IRIS facility (Petersburg Nuclear Physics Institute, Gatchina) a reliable and rather precise method of the target-ion source unit ionization efficiency measurement by the method of stable beam implantation has been developed. The method worked out exploits an off-line mass-separator for the implantation of the ion beams of selected stable isotopes of different elements into a tantalum foil placed inside the Faraday cup in the focal plane of the mass-separator. The amount of implanted ions has been measured with a high accuracy by the current integrator connected to the Faraday cup. After the implantation of needed a...

  7. High efficiency 4H-SiC betavoltaic power sources using tritium radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Christopher; Portnoff, Samuel [Widetronix Corp., Ithaca, New York 14850 (United States); Spencer, M. G. [Department of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14850 (United States)

    2016-01-04

    Realization of an 18.6% efficient 4H-silicon carbide (4H-SiC) large area betavoltaic power source using the radioisotope tritium is reported. A 200 nm 4H-SiC P{sup +}N junction is used to collect high-energy electrons. The electron source is a titanium tritide (TiH{sup 3}{sub x}) foil, or an integrated titanium tritide region formed by the diffusion of tritium into titanium. The specific activity of the source is directly measured. Dark current measured under short circuit conditions was less than 6.1 pA/cm{sup 2}. Samples measured with an external tritium foil produced an open circuit voltage of 2.09 V, short circuit current of 75.47 nA/cm{sup 2}, fill factor of 0.86, and power efficiency of 18.6%. Samples measured with an integrated source produced power efficiencies of 12%. Simulations were done to determine the beta spectrum (modified by self absorption) exiting the source and the electron hole pair generation function in the 4H-SiC. The electron-hole pair generation function in 4H-SiC was modeled as a Gaussian distribution, and a closed form solution of the continuity equation was used to analyze the cell performance. The effective surface recombination velocity in our samples was found to be 10{sup 5}–10{sup 6 }cm/s. Our analysis demonstrated that the surface recombination dominates the performance of a tritium betavoltaic device but that using a thin P{sup +}N junction structure can mitigate some of the negative effects.

  8. Evaluation of Efficiency Activities in the Industrial Sector Undertaken in Response to Greenhouse Gas Emission Reduction Targets

    Energy Technology Data Exchange (ETDEWEB)

    Price, Lynn; de la Rue du Can, Stephane; Lu, Hongyou; Horvath, Arpad

    2010-05-21

    The 2006 California Global Warming Solutions Act calls for reducing greenhouse gas (GHG) emissions to 1990 levels by 2020. Meeting this target will require action from all sectors of the California economy, including industry. The industrial sector consumes 25% of the energy used and emits 28% of the carbon dioxide (CO{sub 2}) produced in the state. Many countries around the world have national-level GHG reduction or energy-efficiency targets, and comprehensive programs focused on implementation of energy efficiency and GHG emissions mitigation measures in the industrial sector are essential for achieving their goals. A combination of targets and industry-focused supporting programs has led to significant investments in energy efficiency as well as reductions in GHG emissions within the industrial sectors in these countries. This project has identified program and policies that have effectively targeted the industrial sector in other countries to achieve real energy and CO{sub 2} savings. Programs in Ireland, France, The Netherlands, Denmark, and the UK were chosen for detailed review. Based on the international experience documented in this report, it is recommended that companies in California's industrial sector be engaged in a program to provide them with support to meet the requirements of AB32, The Global Warming Solution Act. As shown in this review, structured programs that engage industry, require members to evaluate their potential efficiency measures, plan how to meet efficiency or emissions reduction goals, and provide support in achieving the goals, can be quite effective at assisting companies to achieve energy efficiency levels beyond those that can be expected to be achieved autonomously.

  9. Systematization of efficiency correction for gamma-ray disk sources with semiconductor detectors

    International Nuclear Information System (INIS)

    Chatani, Hiroshi

    1999-01-01

    Full energy peak efficiency correction for disk sources has been systematically studied using the mapping method with two high-purity germanium detectors and two low-energy photon spectrometers. The following are found using only single-line (i.e., no coincidence summing loses) γ-rays: (1) The efficiency distributions on a plane parallel to the entrance window of semiconductor detectors is in perfect accord with Gaussian curves inside the circumference of the cylindrical Ge crystal, however, they deviate from the curves outside the circumference. (2) The width parameters of the Gaussian function fitted to the efficiency distributions have a systematic relationship with γ-ray energy. (3) The mapping method is of practical use and has satisfactory accuracy

  10. Compact high efficiency, light weight 200-800 MHz high power RF source

    International Nuclear Information System (INIS)

    Shrader, M.B.; Preist, D.H.

    1985-01-01

    There has long been a need for a new more efficient less bulky high power RF power source to drive accelerators in the 200 to 800 MHz region. Results on a recent 5-year EIMAC sponsored R and D program which have lead to the introduction of the Klystrode for UHF television and troposcatter applications indicate that at power levels of 1MW or more efficiencies in excess of 75% can be obtained at 450 MHz. Efficiencies of this order coupled with potential size and weight parameters which are a fraction of those of existing high power UHF generators open up new applications which heretofore would have been impractical if not impossible. Measurements at 470 MHz on existing Klystrodes are given. Projected operating conditions for a 1MW 450 MHz Klystrode having an overall length of 60 inches and a total tube, circuit, and magnet weight of 250 pounds is presented

  11. [Efficiencies of contamination source for flooring and some materials used in unencapsulated radioactivity handling facilities].

    Science.gov (United States)

    Yoshida, M; Yoshizawa, M; Minami, K

    1990-09-01

    The efficiencies of contamination source, defined in ISO Report 7506-1, were experimentally determined for such materials as flooring, polyethylene, smear-tested filter paper and stainless steel plate. 5 nuclides of 147Pm, 60Co, 137Cs, 204Tl and 90Sr-Y were used to study beta-ray energy dependence of the efficiency, and 241Am as alpha-ray emitter. The charge-up effect in the measurement by a window-less 2 pi-proportional counter was evaluated to obtain reliable surface emission rate. The measured efficiencies for non-permeable materials, except for two cases, are more than 0.5 even for 147Pm. The ISO recommendations were shown to be conservative enough on the basis of present results.

  12. Efficiencies of contamination source for flooring and some materials used in unencapsulated radioactivity handling facilities

    International Nuclear Information System (INIS)

    Yoshida, Makoto; Yoshizawa, Michio; Minami, Kentaro

    1990-01-01

    The efficiencies of contamination source, defined in ISO Report 7506-1, were experimentally determined for such materials as flooring, polyethylene, smear-tested filter paper and stainless steel plate. 5 nuclides of 147 Pm, 60 Co, 137 Cs, 204 Tl and 90 Sr-Y were used to study β-ray energy dependence of the efficiency, and 241 Am as α-ray emitter. The charge-up effect in the measurement by a window-less 2π-proportional counter was evaluated to obtain reliable surface emission rate. The measured efficiencies for non-permeable materials, except for two cases, are more than 0.5 even for 147 Pm. The ISO recommendations were shown to be conservative enough on the basis of present results. (author)

  13. Environmental friendly high efficient light source. Plasma lamp. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Courret, G.

    2006-07-01

    This annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of a high-efficiency source of light based on the light emission of a plasma. The report presents a review of work done in 2006, including thermodynamics and assessment of the efficiency of the magnetron, tests with small bulbs, study of the standing wave ratio (microwave fluxes) and the development of a new coupling system to allow ignition in very small bulbs. Also, knowledge on the fillings of the bulb and induced effects of the modulator were gained. The development of a second generation of modulator to obtain higher efficiency at lower power is noted.

  14. The Sources of Efficiency of the Nigerian Banking Industry: A Two- Stage Approach

    Directory of Open Access Journals (Sweden)

    Frances Obafemi

    2013-11-01

    Full Text Available The paper employed a two-stage Data Envelopment Analysis (DEA approach to examine the sources oftechnical efficiency in the Nigerian banking sub-sector. Using a cross sectionof commercial and merchant banks, the study showed that the Nigerian bankingindustry was not efficient both in the pre-and-post-liberalization era. Thestudy further revealed that market share was the strongest determinant oftechnical efficiency in the Nigerian banking Industry. Thus, appropriatemacroeconomic policy, institutional development and structural reforms mustaccompany financial liberalization to create the stable environment requiredfor it to succeed. Hence, the present bank consolidation and reforms by theCentral Bank of Nigeria, which started with Soludo and continued with Sanusi,are considered necessary, especially in the areas of e banking and reorganizingthe management of banks.

  15. Ionization efficiency of a COMIC ion source equipped with a quartz plasma chamber

    International Nuclear Information System (INIS)

    Suominen, P.; Stora, T.; Sortais, P.; Medard, J.

    2012-01-01

    Increased ionization efficiencies of light noble gases and molecules are required for new physics experiments in present and future radioactive ion beam facilities. In order to improve these beams, a new COMIC-type ion source with fully quartz made plasma chamber was tested. The beam current stability is typically better than 1 % and beams are easily reproducible. The highest efficiency for xenon is about 15 %. However, the main goal is to produce molecular beam including radioactive carbon (in CO or CO 2 ), in which case the efficiency was measured to be only about 0.2%. This paper describes the experimental prototype and its performance and provides ideas for future development. This paper is followed by the associated poster. (authors)

  16. Strategies for carbon dioxide emissions reductions: Residential natural gas efficiency, economic, and ancillary health impacts in Maryland

    International Nuclear Information System (INIS)

    Ruth, Matthias; Blohm, Andrew; Mauer, Joanna; Gabriel, Steven A.; Kesana, Vijay G.; Chen Yihsu; Hobbs, Benjamin F.; Irani, Daraius

    2010-01-01

    As part of its commitments to the Regional Greenhouse Gas Initiative (RGGI), the State of Maryland, USA, auctions emission permits to electric utilities, creating revenue that can be used to benefit consumers and the environment. This paper explores the CO 2 emissions reductions that may be possible by allocating some of that revenue to foster efficiency improvements in the residential sector's use of natural gas. Since these improvements will require changes to the capital stock of houses and end use equipment, efficiency improvements may be accompanied by economic and ancillary health impacts, both of which are quantified in this paper.

  17. A high-efficiency positive (negative) surface ionization source for radioactive ion beam (abstract)a

    International Nuclear Information System (INIS)

    Alton, G.D.; Mills, G.D.

    1996-01-01

    A versatile, new concept, spherical-geometry, positive (negative) surface-ionization source has been designed and fabricated which will have the capability of generating both positive- and negative-ion beams without mechanical changes to the source. The source utilizes a highly permeable, high-work-function Ir ionizer (φ≡5.29 eV) for ionizing highly electropositive atoms/molecules; while for negative-surface ionization, the work function is lowered to φ≡1.43 eV by continually feeding cesium vapor through the ionizer matrix. The use of this technique for negative ion beam generation has the potential of overcoming the chronic poisoning effects experienced with LaB 6 while enhancing considerably the efficiency for negative surface ionization of atoms and molecules with intermediate electron affinities. The flexibility of operation in either mode makes it especially attractive for radioactive ion beam applications and, therefore, the source will be used as a complementary replacement for the high-temperature electron impact ionization sources presently in use at the Holifield radioactive beam facility. The design features and operational principles of the source will be described in this report. copyright 1996 American Institute of Physics

  18. Moab, Utah: Using Energy Data to Target Carbon Reductions from Building Energy Efficiency (City Energy: From Data to Decisions)

    Energy Technology Data Exchange (ETDEWEB)

    Strategic Priorities and Impact Analysis Team, Office of Strategic Programs

    2017-11-01

    This fact sheet "Moab, Utah: Using Energy Data to Target Carbon Reductions from Building Energy Efficiency" explains how the City of Moab used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

  19. Evaporative Air Coolers Optimization for Energy Consumption Reduction and Energy Efficiency Ratio Increment

    OpenAIRE

    Leila Torkaman; Nasser Ghassembaglou

    2015-01-01

    Significant quota of Municipal Electrical Energy consumption is related to Decentralized Air Conditioning which is mostly provided by evaporative coolers. So the aim is to optimize design of air conditioners to increase their efficiencies. To achieve this goal, results of practical standardized tests for 40 evaporative coolers in different types collected and simultaneously results for same coolers based on one of EER (Energy Efficiency Ratio) modeling styles are figured ...

  20. Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam

    2012-12-15

    This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment may be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.

  1. Radiological Threat Reduction (RTR) program: implementing physical security to protect large radioactive sources worldwide

    International Nuclear Information System (INIS)

    Lowe, Daniel L.

    2004-01-01

    The U.S. Department of Energy's Radiological Threat Reduction (RTR) Program strives to reduce the threat of a Radiological Dispersion Device (RDD) incident that could affect U.S. interests worldwide. Sandia National Laboratories supports the RTR program on many different levels. Sandia works directly with DOE to develop strategies, including the selection of countries to receive support and the identification of radioactive materials to be protected. Sandia also works with DOE in the development of guidelines and in training DOE project managers in physical protection principles. Other support to DOE includes performing rapid assessments and providing guidance for establishing foreign regulatory and knowledge infrastructure. Sandia works directly with foreign governments to establish cooperative agreements necessary to implement the RTR Program efforts to protect radioactive sources. Once necessary agreements are in place, Sandia works with in-country organizations to implement various security related initiatives, such as installing security systems and searching for (and securing) orphaned radioactive sources. The radioactive materials of interest to the RTR program include Cobalt 60, Cesium 137, Strontium 90, Iridium 192, Radium 226, Plutonium 238, Americium 241, Californium 252, and Others. Security systems are implemented using a standardized approach that provides consistency through out the RTR program efforts at Sandia. The approach incorporates a series of major tasks that overlap in order to provide continuity. The major task sequence is to: Establish in-country contacts - integrators, Obtain material characterizations, Perform site assessments and vulnerability assessments, Develop upgrade plans, Procure and install equipment, Conduct acceptance testing and performance testing, Develop procedures, and Conduct training. Other tasks are incorporated as appropriate and commonly include such as support of reconfiguring infrastructure, and developing security

  2. Efficient and stable model reduction scheme for the numerical simulation of broadband acoustic metamaterials

    DEFF Research Database (Denmark)

    Hyun, Jaeyub; Kook, Junghwan; Wang, Semyung

    2015-01-01

    ) as a basis vector. The proposed AQSRV-based model reduction scheme has the following two representative features: (1) Multiple frequency subintervals and (2) Adaptive selection of the subinterval information (i.e., the proper number and location of the center frequencies) and basis vector at each subinterval...

  3. Uranium- and Thorium-Doped Graphene for Efficient Oxygen and Hydrogen Peroxide Reduction

    Czech Academy of Sciences Publication Activity Database

    Sofer, Z.; Jankovský, O.; Šimek, P.; Klimová, K.; Macková, Anna; Pumera, M.

    2014-01-01

    Roč. 8, č. 7 (2014), s. 7106-7114 ISSN 1936-0851 R&D Projects: GA ČR(CZ) GBP108/12/G108 Institutional support: RVO:61389005 Keywords : graphene * actinides * electrochemistry * oxygen reduction * uranium Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 12.881, year: 2014

  4. Cuprous oxide nanoparticles dispersed on reduced graphene oxide as an efficient electrocatalyst for oxygen reduction reaction.

    Science.gov (United States)

    Yan, Xiao-Yan; Tong, Xi-Li; Zhang, Yue-Fei; Han, Xiao-Dong; Wang, Ying-Yong; Jin, Guo-Qiang; Qin, Yong; Guo, Xiang-Yun

    2012-02-11

    Cuprous oxide (Cu(2)O) nanoparticles dispersed on reduced graphene oxide (RGO) were prepared by reducing copper acetate supported on graphite oxide using diethylene glycol as both solvent and reducing agent. The Cu(2)O/RGO composite exhibits excellent catalytic activity and remarkable tolerance to methanol and CO in the oxygen reduction reaction. This journal is © The Royal Society of Chemistry 2012

  5. Immobilization of Acetobacter sp. CCTCC M209061 for efficient asymmetric reduction of ketones and biocatalyst recycling

    Directory of Open Access Journals (Sweden)

    Chen Xiao-Hong

    2012-09-01

    Full Text Available Abstract Background The bacterium Acetobacter sp. CCTCC M209061 is a promising whole-cell biocatalyst with exclusive anti-Prelog stereoselectivity for the reduction of prochiral ketones that can be used to make valuable chiral alcohols such as (R-4-(trimethylsilyl-3-butyn-2-ol. Although it has promising catalytic properties, its stability and reusability are relatively poor compared to other biocatalysts. Hence, we explored various materials for immobilizing the active cells, in order to improve the operational stability of biocatalyst. Results It was found that Ca-alginate give the best immobilized biocatalyst, which was then coated with chitosan to further improve its mechanical strength and swelling-resistance properties. Conditions were optimized for formation of reusable immobilized beads which can be used for repeated batch asymmetric reduction of 4′-chloroacetophenone. The optimized immobilized biocatalyst was very promising, with a specific activity of 85% that of the free-cell biocatalyst (34.66 μmol/min/g dw of cells for immobilized catalyst vs 40.54 μmol/min/g for free cells in the asymmetric reduction of 4′-chloroacetophenone. The immobilized cells showed better thermal stability, pH stability, solvent tolerance and storability compared with free cells. After 25 cycles reaction, the immobilized beads still retained >50% catalytic activity, which was 3.5 times higher than degree of retention of activity by free cells reused in a similar way. The cells could be recultured in the beads to regain full activity and perform a further 25 cycles of the reduction reaction. The external mass transfer resistances were negligible as deduced from Damkohler modulus Da η ∅ Conclusions Ca-alginate coated with chitosan is a highly effective material for immobilization of Acetobacter sp. CCTCC M209061 cells for repeated use in the asymmetric reduction of ketones. Only a small cost in terms of the slightly lower catalytic activity compared to

  6. Combination of magnetic parameters: an efficient way to discriminate soil-contamination sources (south France)

    International Nuclear Information System (INIS)

    Lecoanet, H.; Leveque, F.; Ambrosi, J.-P.

    2003-01-01

    Biplots combining magnetic parameters allow identification of different pollutant emission sources. - Biplots combining magnetic parameters allow to identification and differentiation different pollutant emission sources. A major problem in soil pollution is the characterization of the relative contributions of different anthropogenic particles sources. This paper demonstrates the efficiency of magnetic techniques to provide identification and differentiation of contaminating emission sources. About 100 soil samples were collected across a mixed agricultural and industrial area (Crau plain/Berre-Fos basin) in southern France. Nine soil profiles were realized. They are aligned along a transect, from the Mediterranean cost to the north. Measurements of initial magnetic susceptibility (χ) and remanent magnetization (ARM, IRM) have been carried out at room temperature. Several ratios of magnetic parameters were calculated and tested. Bivariate analyses allow to characterize different pollution sources and graphic results suggest three dominant contributions originated from road traffic, airport and steel industry. Moreover, magnetic grain-size discrimination between surface-soil samples and bottom-soil samples is obtained. An increase of hard magnetic components from topsoil towards the bottom of the profiles is evidenced

  7. An efficient laser vaporization source for chemically modified metal clusters characterized by thermodynamics and kinetics

    Science.gov (United States)

    Masubuchi, Tsugunosuke; Eckhard, Jan F.; Lange, Kathrin; Visser, Bradley; Tschurl, Martin; Heiz, Ulrich

    2018-02-01

    A laser vaporization cluster source that has a room for cluster aggregation and a reactor volume, each equipped with a pulsed valve, is presented for the efficient gas-phase production of chemically modified metal clusters. The performance of the cluster source is evaluated through the production of Ta and Ta oxide cluster cations, TaxOy+ (y ≥ 0). It is demonstrated that the cluster source produces TaxOy+ over a wide mass range, the metal-to-oxygen ratio of which can easily be controlled by changing the pulse duration that influences the amount of reactant O2 introduced into the cluster source. Reaction kinetic modeling shows that the generation of the oxides takes place under thermalized conditions at less than 300 K, whereas metal cluster cores are presumably created with excess heat. These characteristics are also advantageous to yield "reaction intermediates" of interest via reactions between clusters and reactive molecules in the cluster source, which may subsequently be mass selected for their reactivity measurements.

  8. Energy-Efficiency and Air-Pollutant Emissions-Reduction Opportunities for the Ammonia Industry in China

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ding [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Wenying [Tsinghua Univ., Beijing (China)

    2015-06-01

    As one of the most energy-intensive and polluting industries, ammonia production is responsible for significant carbon dioxide (CO2) and air-pollutant emissions. Although many energy-efficiency measures have been proposed by the Chinese government to mitigate greenhouse gas emissions and improve air quality, lack of understanding of the cost-effectiveness of such improvements has been a barrier to implementing these measures. Assessing the costs, benefits, and cost-effectiveness of different energy-efficiency measures is essential to advancing this understanding. In this study, a bottom-up energy conservation supply curve model is developed to estimate the potential for energy savings and emissions reductions from 26 energy-efficiency measures that could be applied in China’s ammonia industry. Cost-effective implementation of these measures saves a potential 271.5 petajoules/year for fuel and 5,443 gigawatt-hours/year for electricity, equal to 14% of fuel and 14% of electricity consumed in China’s ammonia industry in 2012. These reductions could mitigate 26.7 million tonnes of CO2 emissions. This study also quantifies the co-benefits of reducing air-pollutant emissions and water use that would result from saving energy in China’s ammonia industry. This quantitative analysis advances our understanding of the cost-effectiveness of energy-efficiency measures and can be used to augment efforts to reduce energy use and environmental impacts.

  9. Fe Isolated Single Atoms on S, N Codoped Carbon by Copolymer Pyrolysis Strategy for Highly Efficient Oxygen Reduction Reaction.

    Science.gov (United States)

    Li, Qiheng; Chen, Wenxing; Xiao, Hai; Gong, Yue; Li, Zhi; Zheng, Lirong; Zheng, Xusheng; Yan, Wensheng; Cheong, Weng-Chon; Shen, Rongan; Fu, Ninghua; Gu, Lin; Zhuang, Zhongbin; Chen, Chen; Wang, Dingsheng; Peng, Qing; Li, Jun; Li, Yadong

    2018-06-01

    Heteroatom-doped Fe-NC catalyst has emerged as one of the most promising candidates to replace noble metal-based catalysts for highly efficient oxygen reduction reaction (ORR). However, delicate controls over their structure parameters to optimize the catalytic efficiency and molecular-level understandings of the catalytic mechanism are still challenging. Herein, a novel pyrrole-thiophene copolymer pyrolysis strategy to synthesize Fe-isolated single atoms on sulfur and nitrogen-codoped carbon (Fe-ISA/SNC) with controllable S, N doping is rationally designed. The catalytic efficiency of Fe-ISA/SNC shows a volcano-type curve with the increase of sulfur doping. The optimized Fe-ISA/SNC exhibits a half-wave potential of 0.896 V (vs reversible hydrogen electrode (RHE)), which is more positive than those of Fe-isolated single atoms on nitrogen codoped carbon (Fe-ISA/NC, 0.839 V), commercial Pt/C (0.841 V), and most reported nonprecious metal catalysts. Fe-ISA/SNC is methanol tolerable and shows negligible activity decay in alkaline condition during 15 000 voltage cycles. X-ray absorption fine structure analysis and density functional theory calculations reveal that the incorporated sulfur engineers the charges on N atoms surrounding the Fe reactive center. The enriched charge facilitates the rate-limiting reductive release of OH* and therefore improved the overall ORR efficiency. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Efficient all solid-state UV source for satellite-based lidar applications.

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Darrell Jewell; Smith, Arlee Virgil

    2003-07-01

    A satellite-based UV-DIAL measurement system would allow continuous global monitoring of ozone concentration in the upper atmosphere. However such systems remain difficult to implement because aerosol-scattering return signals for satellite-based lidars are very weak. A suitable system must produce high-energy UV pulses at multiple wavelengths with very high efficiency. For example, a nanosecond system operating at 10 Hz must generate approximately 1 J per pulse at 308-320 nm. An efficient space-qualified wavelength-agile system based on a single UV source that can meet this requirement is probably not available using current laser technology. As an alternative, we're pursuing a multi-source approach employing all-solid-state modules that individually generate 300-320 nm light with pulse energies in the range of 50-200 mJ, with transform-limited bandwidths and good beam quality. Pulses from the individual sources can be incoherently summed to obtain the required single-pulse energy. These sources use sum-frequency mixing of the 532 nm second harmonic of an Nd:YAG pump laser with 731-803 nm light derived from a recently-developed, state-of-the-art, nanosecond optical parametric oscillator. Two source configurations are under development, one using extra-cavity sum-frequency mixing, and the other intra-cavity sum-frequency mixing. In either configuration, we hope to obtain sum-frequency mixing efficiency approaching 60% by carefully matching the spatial and temporal properties of the laser and OPO pulses. This ideal balance of green and near-IR photons requires an injection-seeded Nd:YAG pump-laser with very high beam quality, and an OPO exhibiting unusually high conversion efficiency and exceptional signal beam quality. The OPO employs a singly-resonant high-Fresnel-number image-rotating self-injection-seeded nonplanar-ring cavity that achieves pump depletion > 65% and produces signal beams with M{sup 2} {approx} 3 at pulse energies exceeding 50 mJ. Pump beam

  11. Fast and efficient charge breeding of the Californium rare isotope breeder upgrade electron beam ion source

    International Nuclear Information System (INIS)

    Ostroumov, P. N.; Barcikowski, A.; Dickerson, C. A.; Perry, A.; Sharamentov, S. I.; Vondrasek, R. C.; Zinkann, G. P.; Pikin, A. I.

    2015-01-01

    The Electron Beam Ion Source (EBIS), developed to breed Californium Rare Isotope Breeder Upgrade (CARIBU) radioactive beams at Argonne Tandem Linac Accelerator System (ATLAS), is being tested off-line. A unique property of the EBIS is a combination of short breeding times, high repetition rates, and a large acceptance. Overall, we have implemented many innovative features during the design and construction of the CARIBU EBIS as compared to the existing EBIS breeders. The off-line charge breeding tests are being performed using a surface ionization source that produces singly charged cesium ions. The main goal of the off-line commissioning is to demonstrate stable operation of the EBIS at a 10 Hz repetition rate and a breeding efficiency into single charge state higher than 15%. These goals have been successfully achieved and exceeded. We have measured (20% ± 0.7%) breeding efficiency into the single charge state of 28+ cesium ions with the breeding time of 28 ms. In general, the current CARIBU EBIS operational parameters can provide charge breeding of any ions in the full mass range of periodic table with high efficiency, short breeding times, and sufficiently low charge-to-mass ratio, 1/6.3 for the heaviest masses, for further acceleration in ATLAS. In this paper, we discuss the parameters of the EBIS and the charge breeding results in a pulsed injection mode with repetition rates up to 10 Hz

  12. Prospects for energy efficiency improvement and reduction of emissions and life cycle costs for natural gas vehicles

    Science.gov (United States)

    Kozlov, A. V.; Terenchenko, A. S.; Luksho, V. A.; Karpukhin, K. E.

    2017-01-01

    This work is devoted to the experimental investigation of the possibilities to reduce greenhouse gas emissions and to increase energy efficiency of engines that use natural gas as the main fuel and the analysis of economic efficiency of use of dual fuel engines in vehicles compared to conventional diesel. The results of experimental investigation of a 190 kW dual-fuel engine are presented; it is shown that quantitative and qualitative working process control may ensure thermal efficiency at the same level as that of the diesel engine and in certain conditions 5...8% higher. The prospects for reduction of greenhouse gas emissions have been assessed. The technical and economic evaluation of use of dual fuel engines in heavy-duty vehicles has been performed, taking into account the total life cycle. It is shown that it is possible to reduce life cycle costs by two times.

  13. Immobilization of Acetobacter sp. CCTCC M209061 for efficient asymmetric reduction of ketones and biocatalyst recycling.

    Science.gov (United States)

    Chen, Xiao-Hong; Wang, Xiao-Ting; Lou, Wen-Yong; Li, Ying; Wu, Hong; Zong, Min-Hua; Smith, Thomas J; Chen, Xin-De

    2012-09-04

    The bacterium Acetobacter sp. CCTCC M209061 is a promising whole-cell biocatalyst with exclusive anti-Prelog stereoselectivity for the reduction of prochiral ketones that can be used to make valuable chiral alcohols such as (R)-4-(trimethylsilyl)-3-butyn-2-ol. Although it has promising catalytic properties, its stability and reusability are relatively poor compared to other biocatalysts. Hence, we explored various materials for immobilizing the active cells, in order to improve the operational stability of biocatalyst. It was found that Ca-alginate give the best immobilized biocatalyst, which was then coated with chitosan to further improve its mechanical strength and swelling-resistance properties. Conditions were optimized for formation of reusable immobilized beads which can be used for repeated batch asymmetric reduction of 4'-chloroacetophenone. The optimized immobilized biocatalyst was very promising, with a specific activity of 85% that of the free-cell biocatalyst (34.66 μmol/min/g dw of cells for immobilized catalyst vs 40.54 μmol/min/g for free cells in the asymmetric reduction of 4'-chloroacetophenone). The immobilized cells showed better thermal stability, pH stability, solvent tolerance and storability compared with free cells. After 25 cycles reaction, the immobilized beads still retained >50% catalytic activity, which was 3.5 times higher than degree of retention of activity by free cells reused in a similar way. The cells could be recultured in the beads to regain full activity and perform a further 25 cycles of the reduction reaction. The external mass transfer resistances were negligible as deduced from Damkohler modulus Da internal mass transfer restriction affected the reduction action but was not the principal rate-controlling step according to effectiveness factors η < 1 and Thiele modulus 0.3<∅ <1. Ca-alginate coated with chitosan is a highly effective material for immobilization of Acetobacter sp. CCTCC M209061 cells for repeated use in

  14. An Efficient SF-ISF Approach for the Slepian-Wolf Source Coding Problem

    Directory of Open Access Journals (Sweden)

    Tu Zhenyu

    2005-01-01

    Full Text Available A simple but powerful scheme exploiting the binning concept for asymmetric lossless distributed source coding is proposed. The novelty in the proposed scheme is the introduction of a syndrome former (SF in the source encoder and an inverse syndrome former (ISF in the source decoder to efficiently exploit an existing linear channel code without the need to modify the code structure or the decoding strategy. For most channel codes, the construction of SF-ISF pairs is a light task. For parallelly and serially concatenated codes and particularly parallel and serial turbo codes where this appear less obvious, an efficient way for constructing linear complexity SF-ISF pairs is demonstrated. It is shown that the proposed SF-ISF approach is simple, provenly optimal, and generally applicable to any linear channel code. Simulation using conventional and asymmetric turbo codes demonstrates a compression rate that is only 0.06 bit/symbol from the theoretical limit, which is among the best results reported so far.

  15. Improved heating efficiency with High-Intensity Focused Ultrasound using a new ultrasound source excitation.

    Science.gov (United States)

    Bigelow, Timothy A

    2009-01-01

    High-Intensity Focused Ultrasound (HIFU) is quickly becoming one of the best methods to thermally ablate tissue noninvasively. Unlike RF or Laser ablation, the tissue can be destroyed without inserting any probes into the body minimizing the risk of secondary complications such as infections. In this study, the heating efficiency of HIFU sources is improved by altering the excitation of the ultrasound source to take advantage of nonlinear propagation. For ultrasound, the phase velocity of the ultrasound wave depends on the amplitude of the wave resulting in the generation of higher harmonics. These higher harmonics are more efficiently converted into heat in the body due to the frequency dependence of the ultrasound absorption in tissue. In our study, the generation of the higher harmonics by nonlinear propagation is enhanced by transmitting an ultrasound wave with both the fundamental and a higher harmonic component included. Computer simulations demonstrated up to a 300% increase in temperature increase compared to transmitting at only the fundamental for the same acoustic power transmitted by the source.

  16. Radioactivity decontamination efficiency of ceramic filter in an incineration volume reduction system of radioactive waste

    International Nuclear Information System (INIS)

    Kanbe, Hiromi; Mayuzumi, Masami; Yoshiki, Sinya; Sema, Toru; Koyama, Hiroaki; Ono, Tetsuo; Nagae, Madoka; Takaoku, Yoshinobu; Hozumi, Masahiro.

    1987-01-01

    The small pilot facility of a cyclone type suspension incineration system of radioactive waste was set up in order to evaluate the decontamination efficiency of a high efficiency ceramic filter. The evaluation was made by use of 54 Mn, 59 Fe, 60 Co, 65 Zn and 137 Cs. 1. The decontamination factor by one line of ceramic filter for every species were over 10 5 . 2. The decontamination factor increased by one oder when water vapor exists in off-gas. The same tendency was also observed when iron dioxide existed at the incineration of cation exchange resin. (author)

  17. [Prediction of the efficiency of endoscopic lung volume reduction by valves in severe emphysema].

    Science.gov (United States)

    Bocquillon, V; Briault, A; Reymond, E; Arbib, F; Jankowski, A; Ferretti, G; Pison, C

    2016-11-01

    In severe emphysema, endoscopic lung volume reduction with valves is an alternative to surgery with less morbidity and mortality. In 2015, selection of patients who will respond to this technique is based on emphysema heterogeneity, a complete fissure visible on the CT-scan and absence of collateral ventilation between lobes. Our case report highlights that individualized prediction is possible. A 58-year-old woman had severe, disabling pulmonary emphysema. A high resolution thoracic computed tomography scan showed that the emphysema was heterogeneous, predominantly in the upper lobes, integrity of the left greater fissure and no collateral ventilation with the left lower lobe. A valve was inserted in the left upper lobe bronchus. At one year, clinical and functional benefits were significant with complete atelectasis of the treated lobe. The success of endoscopic lung volume reduction with a valve can be predicted, an example of personalized medicine. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  18. Increasing the Energy Efficiency of Aluminum-Reduction Cells Using Modified Cathodes

    Science.gov (United States)

    Jianping, Peng; Yang, Song; Yuezhong, Di; Yaowu, Wang; Naixiang, Feng

    2017-10-01

    A cathode with an inclined surface (5°) and increased bar collector height (230 mm high) was incorporated into two 300-kA industrial aluminum-reduction cells. The voltage of the cells with the modified cathode was reduced by approximately 200 mV when compared with that of a conventional cell with a flat cathode. Through the use of simulations, the reduction in the cell voltage was attributed to the cathode modification (40 mV) and a reduced electrolyte level of 0.5 cm (160 mV). As a result of reduced anode cathode distance (ACD), the ledge toe was extended to the anode shadow by 12 cm. This caused a large inverted horizontal current and a velocity increase. The ledge profile returned to the desired position when the cells were insulated more effectively, and the metal velocity and metal crest in the modified cells were reduced accordingly.

  19. Role of transpiration reduction during center-pivot sprinkler irrigation in application efficiency

    OpenAIRE

    Urrego Pereira, Yenny Fernanda; Cavero Campo, José; Medina Pueyo, Eva Teresa; Martínez-Cob, Antonio

    2013-01-01

    The magnitude and duration of corn transpiration reduction during center-pivot sprinkler irrigation was analyzed on a commercial plot. The irrigation event was defined as the period during which the pivot arm was passing over the transect AC and water droplets were moistening the plants (moist treatment). Corn transpiration rates were measured at three spots of that transect and simultaneously at another spot (dry treatment) located approximately 270 m east from the transect AC. Corn transpir...

  20. ZVI-Clay remediation of a chlorinated solvent source zone, Skuldelev, Denmark: 1. Site description and contaminant source mass reduction

    DEFF Research Database (Denmark)

    Fjordbøge, Annika Sidelmann; Riis, Charlotte; Christensen, Anders G.

    2012-01-01

    Field investigations on the effects of ZVI-Clay soil mixing were conducted at a small DNAPL source zone with PCE as the parent compound. In a one-year monitoring program, soil samples were collected at three horizontal sampling planes (2.5, 5.0 and 7.5m bgs.). PCE was found to have a pseudo first...

  1. Improving Quality and Efficiency for Intussusception Management After Successful Enema Reduction.

    Science.gov (United States)

    Raval, Mehul V; Minneci, Peter C; Deans, Katherine J; Kurtovic, Kelli J; Dietrich, Ann; Bates, D Gregory; Rangel, Shawn J; Moss, R Lawrence; Kenney, Brian D

    2015-11-01

    The purpose of this project was to implement a protocol facilitating discharge from the emergency department (ED) after successful radiologic ileocolic intussusception reduction in a pediatric referral center. A multidisciplinary team identified drivers for successful quality improvement including educational brochures, a standardized radiologic report, an observation period in the ER with oral hydration challenges, and follow-up phone calls the day after discharge. Patient outcomes were tracked, and quarterly feedback was provided. Of 80 patients identified over a 24-month period, 34 (42.5%) did not qualify for discharge home due to need for surgical intervention (n = 9), specific radiologic findings (n = 11), need for additional intravenous hydration (n = 4), or other reasons (n = 7). Of 46 patients who qualified for discharge, 30 (65.2%) were successfully sent home from the ED. One patient returned with recurrent symptoms that required repeat enema reduction. Sixteen patients were observed and discharged within 23 hours. Adherence with discharge from the ED improved over time. Discharge from the ED was associated with cost savings and improved net margins at the hospital level for each encounter. A sustainable multidisciplinary quality improvement project to discharge intussusception patients from the ED after air-contrast enema reduction was successfully integrated in a high-volume referral center through education, standardized radiologic reporting, and protocoled follow-up. Copyright © 2015 by the American Academy of Pediatrics.

  2. A dimension reduction strategy for improving the efficiency of computer-aided detection for CT colonography

    Science.gov (United States)

    Song, Bowen; Zhang, Guopeng; Wang, Huafeng; Zhu, Wei; Liang, Zhengrong

    2013-02-01

    Various types of features, e.g., geometric features, texture features, projection features etc., have been introduced for polyp detection and differentiation tasks via computer aided detection and diagnosis (CAD) for computed tomography colonography (CTC). Although these features together cover more information of the data, some of them are statistically highly-related to others, which made the feature set redundant and burdened the computation task of CAD. In this paper, we proposed a new dimension reduction method which combines hierarchical clustering and principal component analysis (PCA) for false positives (FPs) reduction task. First, we group all the features based on their similarity using hierarchical clustering, and then PCA is employed within each group. Different numbers of principal components are selected from each group to form the final feature set. Support vector machine is used to perform the classification. The results show that when three principal components were chosen from each group we can achieve an area under the curve of receiver operating characteristics of 0.905, which is as high as the original dataset. Meanwhile, the computation time is reduced by 70% and the feature set size is reduce by 77%. It can be concluded that the proposed method captures the most important information of the feature set and the classification accuracy is not affected after the dimension reduction. The result is promising and further investigation, such as automatically threshold setting, are worthwhile and are under progress.

  3. Rational Design of a Hierarchical Tin Dendrite Electrode for Efficient Electrochemical Reduction of CO2.

    Science.gov (United States)

    Won, Da Hye; Choi, Chang Hyuck; Chung, Jaehoon; Chung, Min Wook; Kim, Eun-Hee; Woo, Seong Ihl

    2015-09-21

    Catalysis is a key technology for the synthesis of renewable fuels through electrochemical reduction of CO2 . However, successful CO2 reduction still suffers from the lack of affordable catalyst design and understanding the factors governing catalysis. Herein, we demonstrate that the CO2 conversion selectivity on Sn (or SnOx /Sn) electrodes is correlated to the native oxygen content at the subsurface. Electrochemical analyses show that the reduced Sn electrode with abundant oxygen species effectively stabilizes a CO2 (.-) intermediate rather than the clean Sn surface, and consequently results in enhanced formate production in the CO2 reduction. Based on this design strategy, a hierarchical Sn dendrite electrode with high oxygen content, consisting of a multi-branched conifer-like structure with an enlarged surface area, was synthesized. The electrode exhibits a superior formate production rate (228.6 μmol h(-1)  cm(-2) ) at -1.36 VRHE without any considerable catalytic degradation over 18 h of operation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Energy-Saving Melting and Revert Reduction (E-SMARRT): Energy Efficiency Instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Frank [Iowa State Univ., Ames, IA (United States); Frank, Matthew [Iowa State Univ., Ames, IA (United States)

    2013-12-31

    As with any manufacturing operation, the metalcasting processes have several sources of variation. Additionally, the metalcasting industry routinely produces a wide variety of complex shaped components, which often exacerbates the problem of determining the source of variation. The goals of this project were to develop better tools and strategies to collect and manage process and product information. Based on industry feedback, five areas were selected based on the amount of variation caused by this source or the potential for improvement in terms of energy, emissions and competitiveness. These five areas were: 1. Heat Treatment Control Strategies 2. Semi-Automated Grinding 3. Surface Mapping Software 4. Study of Impact of Repairs via Weld Gouges 5. Rapid Pattern Making Machine. This project collectively looked at areas of the steel casting production process which could help reduce the rework, scrap and energy consumption required. Through these efforts, casting producers are better equipped to control their processes and specify processes that better meet their customers’ needs.

  5. The Crowding-Out Effects of Garbage Fees and Voluntary Source Separation Programs on Waste Reduction: Evidence from China

    Directory of Open Access Journals (Sweden)

    Hongyun Han

    2016-07-01

    Full Text Available This paper examines how and to what degree government policies of garbage fees and voluntary source separation programs, with free indoor containers and garbage bags, can affect the effectiveness of municipal solid waste (MSW management, in the sense of achieving a desirable reduction of per capita MSW generation. Based on city-level panel data for years 1998–2012 in China, our empirical analysis indicates that per capita MSW generated is increasing with per capita disposable income, average household size, education levels of households, and the lagged per capita MSW. While both garbage fees and source separation programs have separately led to reductions in per capita waste generation, the interaction of the two policies has resulted in an increase in per capita waste generation due to the following crowding-out effects: Firstly, the positive effect of income dominates the negative effect of the garbage fee. Secondly, there are crowding-out effects of mandatory charging system and the subsidized voluntary source separation on per capita MSW generation. Thirdly, small subsidies and tax punishments have reduced the intrinsic motivation for voluntary source separation of MSW. Thus, compatible fee charging system, higher levels of subsidies, and well-designed public information and education campaigns are required to promote household waste source separation and reduction.

  6. Geothermal source heat pumps under energy services companies finance scheme to increase energy efficiency and production in stockbreeding facilities

    International Nuclear Information System (INIS)

    Borge-Diez, David; Colmenar-Santos, Antonio; Pérez-Molina, Clara; López-Rey, África

    2015-01-01

    In Europe energy services are underutilized in terms of their potential to improve energy efficiency and reduce external energy dependence. Agricultural and stockbreeding sectors have high potential to improve their energy efficiency. This paper presents an energy model for geothermal source heat pumps in stockbreeding facilities and an analysis of an energy services business case. The proposed solution combines both energy cost reduction and productivity increases and improves energy services company financing scheme. CO 2 emissions drop by 89%, reducing carbon footprint and improving added value for the product. For the two different evaluated scenarios, one including winter heating and one including heating and cooling, high IRR (internal return rate) values are obtained. A sensitivity analysis reveals that the IRR ranges from 10.25% to 22.02%, making the investment attractive. To make the research highly extensible, a sensitivity analysis for different locations and climatic conditions is presented, showing a direct relationship between financial parameters and climatic conditions. A Monte Carlo simulation is performed showing that initial fuel cost and initial investment are the most decisive in the financial results. This work proves that energy services based on geothermal energy can be profitable in these sectors and can increase sustainability, reduce CO 2 emissions and improve carbon footprint. - Highlights: • Geothermal heat pumps are studied to promote industrial energy services. • Geothermal energy in farming facilities improves global competitiveness. • Research shows profitability of low enthalpy geothermal energy services. • Climatic conditions sensitivity analysis reveals IRR ranges from 10.25% to 22.02%. • Added market value for the product as carbon footprint reduction, are achieved

  7. An efficient selective reduction of nitroarenes catalyzed by reusable silver-adsorbed waste nanocomposite

    CSIR Research Space (South Africa)

    Giri, S

    2017-07-01

    Full Text Available Silver nanocomposites (AgNCs) were produced by adsorption onto an electron-rich polypyrrole-mercaptoacetic acid (PPy-MAA) composite, known to be a highly efficient adsorbent for the removal of Ag+ ions from aqueous media in the remediation of metal...

  8. Efficient image enhancement using sparse source separation in the Retinex theory

    Science.gov (United States)

    Yoon, Jongsu; Choi, Jangwon; Choe, Yoonsik

    2017-11-01

    Color constancy is the feature of the human vision system (HVS) that ensures the relative constancy of the perceived color of objects under varying illumination conditions. The Retinex theory of machine vision systems is based on the HVS. Among Retinex algorithms, the physics-based algorithms are efficient; however, they generally do not satisfy the local characteristics of the original Retinex theory because they eliminate global illumination from their optimization. We apply the sparse source separation technique to the Retinex theory to present a physics-based algorithm that satisfies the locality characteristic of the original Retinex theory. Previous Retinex algorithms have limited use in image enhancement because the total variation Retinex results in an overly enhanced image and the sparse source separation Retinex cannot completely restore the original image. In contrast, our proposed method preserves the image edge and can very nearly replicate the original image without any special operation.

  9. Efficient and tunable high-order harmonic light sources for photoelectron spectroscopy at surfaces

    International Nuclear Information System (INIS)

    Chiang, Cheng-Tien; Huth, Michael; Trützschler, Andreas; Schumann, Frank O.; Kirschner, Jürgen; Widdra, Wolf

    2015-01-01

    Highlights: • An overview of photoelectron spectroscopy using high-order harmonics is presented. • Photoemission spectra on Ag(0 0 1) using megahertz harmonics are shown. • A gas recycling system for harmonic generation is presented. • Non-stop operation of megahertz harmonics up to 76 h is demonstrated. • The bandwidth and pulse duration of the harmonics are discussed. - Abstract: With the recent progress in high-order harmonic generation (HHG) using femtosecond lasers, laboratory photoelectron spectroscopy with an ultrafast, widely tunable vacuum-ultraviolet light source has become available. Despite the well-established technique of HHG-based photoemission experiments at kilohertz repetition rates, the efficiency of these setups can be intrinsically limited by the space-charge effects. Here we present recent developments of compact HHG light sources for photoelectron spectroscopy at high repetition rates up to megahertz, and examples for angle-resolved photoemission experiments are demonstrated.

  10. Energy efficiency of growing ram lambs fed concentrate-based diets with different roughage sources.

    Science.gov (United States)

    Galvani, D B; Pires, A V; Susin, I; Gouvêa, V N; Berndt, A; Chagas, L J; Dórea, J R R; Abdalla, A L; Tedeschi, L O

    2014-01-01

    Poor-quality roughages are widely used as fiber sources in concentrate-based diets for ruminants. Because roughage quality is associated with the efficiency of energy use in forage-based diets, the objective of this study was to determine whether differing the roughage source in concentrate-based diets could change the energy requirements of growing lambs. Eighty-four 1/2 Dorper × 1/2 Santa Inês ram lambs (18.0 ± 3.3 kg BW) were individually penned and divided into 2 groups according to primary source of dietary roughage: low-quality roughage (LQR; sugarcane bagasse) or medium-quality roughage (MQR; coastcross hay). Diets were formulated to be isonitrogenous (2.6% N) and to meet 20% of physically effective NDF. After a 10-d ad libitum adaptation period, 7 lambs from each group were randomly selected and slaughtered (baseline). Twenty-one lambs in each diet group were fed ad libitum and slaughtered at 25, 35, or 45 kg BW. The remaining 28 lambs (14 from each diet group) were submitted to 1 of 2 levels of feed restriction: 70% or 50% of the ad libitum intake. Retentions of body fat, N, and energy were determined. Additionally, 6 ram lambs (44.3 ± 5.6 kg BW) were kept in metabolic cages and used in a 6 × 6 Latin square experiment designed to establish the ME content of the 2 diets at the 3 levels of DM intake. There was no effect of intake level on diet ME content, but it was greater in the diet with LQR than in the diet with MQR (3.18 vs. 2.94 Mcal/kg, respectively; P energy concentrations (kcal/kg of empty BW) because of a larger visceral fat deposition (P source of forage in a concentrate-based diet for growing lambs did not change NEm and the efficiency of ME use for maintenance, which averaged 71.6 kcal/kg(0.75) of shrunk BW and 0.63, respectively. On the other hand, the greater nonfibrous carbohydrate content of the diet with LQR resulted in a 17% better efficiency of ME use for gain (P energy retention as fat (P < 0.01). This increased nutritional

  11. Effect of different polyphenol sources on the efficiency of ellagic acid release by Aspergillus niger.

    Science.gov (United States)

    Sepúlveda, Leonardo; de la Cruz, Reynaldo; Buenrostro, José Juan; Ascacio-Valdés, Juan Alberto; Aguilera-Carbó, Antonio Francisco; Prado, Arely; Rodríguez-Herrera, Raúl; Aguilar, Cristóbal Noé

    2016-01-01

    Fungal hydrolysis of ellagitannins produces hexahydroxydiphenic acid, which is considered an intermediate molecule in ellagic acid release. Ellagic acid has important and desirable beneficial health properties. The aim of this work was to identify the effect of different sources of ellagitannins on the efficiency of ellagic acid release by Aspergillus niger. Three strains of A. niger (GH1, PSH and HT4) were assessed for ellagic acid release from different polyphenol sources: cranberry, creosote bush, and pomegranate used as substrate. Polyurethane foam was used as support for solid-state culture in column reactors. Ellagitannase activity was measured for each of the treatments. Ellagic acid was quantified by high performance liquid chromatography. When pomegranate polyphenols were used, a maximum value of ellagic acid (350.21 mg/g) was reached with A. niger HT4 in solid-state culture. The highest amount of ellagitannase (5176.81 U/l) was obtained at 8h of culture when cranberry polyphenols and strain A. niger PSH were used. Results demonstrated the effect of different polyphenol sources and A. niger strains on ellagic acid release. It was observed that the best source for releasing ellagic acid was pomegranate polyphenols and A. niger HT4 strain, which has the ability to degrade these compounds for obtaining a potent bioactive molecule such as ellagic acid. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Transportation Energy Futures Series: Effects of Travel Reduction and Efficient Driving on Transportation: Energy Use and Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D.; Brown, A.; DeFlorio, J.; McKenzie, E.; Tao, W.; Vimmerstedt, L.

    2013-03-01

    Since the 1970s, numerous transportation strategies have been formulated to change the behavior of drivers or travelers by reducing trips, shifting travel to more efficient modes, or improving the efficiency of existing modes. This report summarizes findings documented in existing literature to identify strategies with the greatest potential impact. The estimated effects of implementing the most significant and aggressive individual driver behavior modification strategies range from less than 1% to a few percent reduction in transportation energy use and GHG emissions. Combined strategies result in reductions of 7% to 15% by 2030. Pricing, ridesharing, eco-driving, and speed limit reduction/enforcement strategies are widely judged to have the greatest estimated potential effect, but lack the widespread public acceptance needed to accomplish maximum results. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  13. Transportation Energy Futures Series. Effects of Travel Reduction and Efficient Driving on Transportation. Energy Use and Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Porter, C. D. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); Brown, A. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); DeFlorio, J. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); McKenzie, E. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); Tao, W. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States); Vimmerstedt, L. [National Renewable Energy Lab. (NREL) and Cambridge Systematics, Golden, CO (United States)

    2013-03-01

    Since the 1970s, numerous transportation strategies have been formulated to change the behavior of drivers or travelers by reducing trips, shifting travel to more efficient modes, or improving the efficiency of existing modes. This report summarizes findings documented in existing literature to identify strategies with the greatest potential impact. The estimated effects of implementing the most significant and aggressive individual driver behavior modification strategies range from less than 1% to a few percent reduction in transportation energy use and GHG emissions. Combined strategies result in reductions of 7% to 15% by 2030. Pricing, ridesharing, eco-driving, and speed limit reduction/enforcement strategies are widely judged to have the greatest estimated potential effect, but lack the widespread public acceptance needed to accomplish maximum results. This is one of a series of reports produced as a result of the Transportation Energy Futures (TEF) project, a Department of Energy-sponsored multi-agency project initiated to pinpoint underexplored strategies for abating GHGs and reducing petroleum dependence related to transportation.

  14. Interconnected nitrogen and sulfur dual-doped porous carbon as efficient electrocatalyst for triiodide reduction in dye-sensitized solar cells

    Science.gov (United States)

    Li, Zhao; Yang, Wang; Xu, Xiuwen; Tang, Yushu; Zeng, Ziwei; Yang, Fan; Zhang, Liqiang; Ning, Guoqing; Xu, Chunming; Li, Yongfeng

    2016-09-01

    Exploiting cost-effective and efficient counter electrodes (CEs) for the reduction of triiodide (I3-) has been a persistent objective for the development of dye-sensitized solar cells (DSSCs). Here, we propose a strategy for the synthesis of nitrogen and sulfur dual-doped porous carbon (N/S-PC) via a thermal annealing approach by using melamine as N source, and basic magnesium sulfate (BMS) whiskers as S source and templates. Benefiting from the high surface area, unique interconnected structural feature and synergistic effects of N/S dual-doping, the N/S-PC shows excellent electrocatalytic activity toward I3- reduction, which has simultaneously been confirmed by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The DSSC devices with N/S-PC CEs exhibit a PCE up to 7.41%, which is higher than that of DSSC devices with single heteroatom (N or S) doped CEs and even Pt CEs (7.14%).

  15. Silver nanoparticles supported on alumina-​a highly efficient and selective nanocatalyst for imine reduction

    DEFF Research Database (Denmark)

    Poreddy, Raju; Garcia-Suarez, Eduardo J.; Riisager, Anders

    2014-01-01

    in the synthesis of secondary amines from primary amines in a tandem reaction protocol (oxidation–imination–reduction) using air and molecular hydrogen as oxidizing and reducing agents, respectively. The reported synthesis is performed under mild reaction conditions, which complies with the demands of modern...... organic synthesis. Due to the mild reaction conditions and high conversion as well as high selectivity, we consider that the utilization of silver nanoparticles supported on alumina represents an attractive and environmentally friendly alternative to the current synthesis of N-alkyl amines....

  16. Equating Efficiency with Reduction: A Self-Deception in Energy Policy

    DEFF Research Database (Denmark)

    Wilhite, Harold; Nørgaard, Jørgen

    2004-01-01

    power, mobility and so on). The policy makers at the centre of the policy discourse on energy sustainability suffer from a form for self-deception which revolves around the equation of ‘efficiency’ with ‘reduction’ and ‘sustainability’, i.e., the untenable contention that technological and market...... and infrastructure for homes, businesses, transport, health and public services, so that it is neither ethical nor even practical to argue for restrictions in overall energy growth in these and other developing countries. This places the onus for deep reductions in energy use on Europe, North America and the other...

  17. Noise reduction efficiency of Helmholtz resonator in simulated channel of HVAC system

    Directory of Open Access Journals (Sweden)

    Hossein Ali Yousefi Rizi

    2014-01-01

    Conclusions: This research showed that the designed Helmholtz resonators at a certain frequency of low-frequency sound demonstrated the soundest decrease. The increase in the Helmholtz resonators′ chamber volume and their neck′s pass area are negatively associated with the rate of sound resonance. As a result, of determining the effective frequency range of the Helmholtz resonator, the designed resonator could be applied as an effective and efficient instrument of removing or decreasing noise.

  18. International Experience with Key Program Elements of IndustrialEnergy Efficiency or Greenhouse Gas Emissions Reduction Target-SettingPrograms

    Energy Technology Data Exchange (ETDEWEB)

    Price, Lynn; Galitsky, Christina; Kramer, Klaas Jan

    2008-02-02

    Target-setting agreements, also known as voluntary ornegotiated agreements, have been used by a number of governments as amechanism for promoting energy efficiency within the industrial sector. Arecent survey of such target-setting agreement programs identified 23energy efficiency or GHG emissions reduction voluntary agreement programsin 18 countries. International best practice related to target-settingagreement programs calls for establishment of a coordinated set ofpolicies that provide strong economic incentives as well as technical andfinancial support to participating industries. The key program elementsof a target-setting program are the target-setting process,identification of energy-saving technologies and measures usingenergy-energy efficiency guidebooks and benchmarking as well as byconducting energy-efficiency audits, development of an energy-savingsaction plan, development and implementation of energy managementprotocols, development of incentives and supporting policies, monitoringprogress toward targets, and program evaluation. This report firstprovides a description of three key target-setting agreement programs andthen describes international experience with the key program elementsthat comprise such programs using information from the three keytarget-setting programs as well as from other international programsrelated to industrial energy efficiency or GHG emissionsreductions.

  19. Demonstration of improved vehicle fuel efficiency through innovative tire design, materials, and weight reduction technologies

    Energy Technology Data Exchange (ETDEWEB)

    Donley, Tim [Cooper Tire & Rubber Company Incorporated, Findlay, OH (United States)

    2014-12-31

    Cooper completed an investigation into new tire technology using a novel approach to develop and demonstrate a new class of fuel efficient tires using innovative materials technology and tire design concepts. The objective of this work was to develop a new class of fuel efficient tires, focused on the “replacement market” that would improve overall passenger vehicle fuel efficiency by 3% while lowering the overall tire weight by 20%. A further goal of this project was to accomplish the objectives while maintaining the traction and wear performance of the control tire. This program was designed to build on what has already been accomplished in the tire industry for rolling resistance based on the knowledge and general principles developed over the past decades. Cooper’s CS4 (Figure #1) premium broadline tire was chosen as the control tire for this program. For Cooper to achieve the goals of this project, the development of multiple technologies was necessary. Six technologies were chosen that are not currently being used in the tire industry at any significant level, but that showed excellent prospects in preliminary research. This development was divided into two phases. Phase I investigated six different technologies as individual components. Phase II then took a holistic approach by combining all the technologies that showed positive results during phase one development.

  20. Gold Decorated Graphene for Rapid Dye Reduction and Efficient Electro Catalytic Oxidation of Ethanol

    Science.gov (United States)

    Siddhardha, R. S.; Kumar v, Lakshman; Kaniyoor, A.; Podila, R.; Kumar, V. S.; Venkataramaniah, K.; Ramaprabhu, S.; Rao, A.; Ramamurthy, S. S.; Clemson University Team; Sri Sathya Sai Institute of Higher Learning Team; IITMadras Team

    2013-03-01

    A well known disadvantage in fabrication of metal-graphene composite is the use of surfactants that strongly adsorb on the surface and reduce the performance of the catalyst. Here, we demonstrate a novel one pot synthesis of gold nanoparticles (AuNPs) by laser ablation of gold strip and simultaneous decoration of these on functionalized graphene derivatives. Not only the impregnation of AuNPs was linker free, but also the synthesis by itself was surfactant free. This resulted in in-situ decoration of pristine AuNPs on functionalized graphene derivatives. These materials were well characterized and tested for catalytic applications pertaining to dye reduction and electrooxidation. The catalytic reduction rates are 1.4 x 102 and 9.4x102 times faster for Rhodamine B and Methylene Blue dyes respectively, compared to earlier reports. The enhanced rate involves synergistic interplay of electronic relay between AuNPs and the dye, also charge transfer between the graphene system and dye. In addition, the onset potential for ethanol oxidation was found to be more negative ~ 100 mV, an indication of its promising application in direct ethanol fuel cells.

  1. Efficient Catalytic Reduction of Hexavalent Chromium With Pd-decorated Carbon Nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Dang; Choi, Hyun Chul [Chonnam National University, Gwangju (Korea, Republic of)

    2016-05-15

    Heavy metal pollution is currently a serious environmental issue. Chromium (Cr) and chromium compounds are commonly found in wastewater discharged by various industries such as wood preservation, leather tanning, electroplating, metal finishing, and the production of chemicals. Pd nanoparticles can easily be introduced into CNTs by performing DCC-activated amidation. Our TEM and XRD results indicate that well-dispersed metallic Pd nanoparticles are anchored on the surface of the amidated CNTs. The XPS results suggest that the Pd content of the sample is approximately 9.8 atomic %. In comparison with the commercial Pd catalyst, the prepared Pd-CNTs were demonstrated to exhibit good catalytic activity in the reduction of 4-NP by NaBH4. Moreover, the Pd-CNT catalyst can easily be separated by performing a simple filtration and reused over at least 10 cycles. This Pd-CNT catalyst is therefore believed to have significant potential for use as a reusable catalyst in the reduction of Cr(Vi)

  2. Ground source heat pumps versus high efficiency natural gas furnaces in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, J.

    2003-02-02

    For the past twenty years or so, the heating and cooling of numerous buildings in northern Europe has been accomplished using ground source heat pumps (GSHPs), while in North America they have been in use for approximately ten years. In the Prairies, natural gas furnaces dominate, while GSHP are more popular in eastern Canada. The author noted that natural gas furnaces have an efficiency of 80 per cent or less, while high efficiency natural gas (HENG) furnaces, more expensive, have an efficiency in the 90 per cent range. A brief outline of the principles behind GSHPs was provided. The Coefficient of Performance (COP) of GSHP reaches up to 500 per cent depending whether the unit is cooling or heating. The amount of heat produced by a heating system expressed as a percentage of the energy input required to operate the system is the definition used for the efficiency. In those cases where it is possible to amortize the initial costs, pay now or obtain a subsidy, the installation of GSHP is advantageous. Several factors affect the total cost of heating a building, such as the airtightness of the building and its insulation, the coldness of the climate, and the inside controlled temperature setting. The author then examined the cost of operating a GSHP versus a natural gas furnace. In most examples studied, the cost of operating a GSHP was less than the cost of operating a natural gas furnace. The Total Equivalent Warming Impact (TEWI) of GSHPs and HENG furnaces was examined. The author concluded that the cost of heating by GSHP in Alberta will be lower than the cost of heating by HENG which requires a separate air conditioning unit for the summer months, with additional improvements in efficiency and insulation. 7 refs., 4 tabs.

  3. Efficient electrochemical reduction of nitrate to nitrogen using Ti/IrO2-Pt anode and different cathodes

    International Nuclear Information System (INIS)

    Li Miao; Feng Chuanping; Zhang Zhenya; Sugiura, Norio

    2009-01-01

    Electrochemical reduction of nitrate using Fe, Cu, and Ti as cathodes and Ti/IrO 2 -Pt as anode in an undivided and unbuffered cell was studied. In the presence of appropriate amount of NaCl, both cathodic reduction of nitrate and anodic oxidation of the by-products of ammonia and nitrite were achieved by all cathodes under a proper condition. Both in the absence and presence of NaCl, the order of nitrate removal rate was Fe > Cu > Ti. The nitrate removal was 87% and selectivity to nitrogen was 100% in 3 h with Fe cathode in the presence of NaCl. Ti/IrO 2 -Pt anode played an important role during nitrate reduction, especially in the presence of NaCl, at which by-products could efficiently be oxidized. Moreover, atomic force microscopy (AFM) investigation shown Ti/IrO 2 -Pt anode was suitable for nitration reduction and the surface roughness of all cathodes increased. The concentrations of Fe, Cu, and Ti in the electrolyte were less than 0.15, 0.12 and 0.09 mg/L after 3 h electrolysis, respectively.

  4. Research on numerical method for multiple pollution source discharge and optimal reduction program

    Science.gov (United States)

    Li, Mingchang; Dai, Mingxin; Zhou, Bin; Zou, Bin

    2018-03-01

    In this paper, the optimal method for reduction program is proposed by the nonlinear optimal algorithms named that genetic algorithm. The four main rivers in Jiangsu province, China are selected for reducing the environmental pollution in nearshore district. Dissolved inorganic nitrogen (DIN) is studied as the only pollutant. The environmental status and standard in the nearshore district is used to reduce the discharge of multiple river pollutant. The research results of reduction program are the basis of marine environmental management.

  5. An electrically driven cavity-enhanced source of indistinguishable photons with 61% overall efficiency

    Directory of Open Access Journals (Sweden)

    A. Schlehahn

    2016-04-01

    Full Text Available We report on an electrically driven efficient source of indistinguishable photons operated at pulse-repetition rates f up to 1.2 GHz. The quantum light source is based on a p-i-n-doped micropillar cavity with integrated self-organized quantum dots, which exploits cavity quantum electrodynamics effects in the weak coupling regime to enhance the emission of a single quantum emitter coupled to the cavity mode. We achieve an overall single-photon extraction efficiency of (61 ± 11 % for a device triggered electrically at f = 625 MHz. Analyzing the suppression of multi-photon emission events as a function of excitation repetition rate, we observe single-photon emission associated with g(2HBT(0 values between 0.076 and 0.227 for f ranging from 373 MHz to 1.2 GHz. Hong-Ou-Mandel-type two-photon interference experiments under pulsed current injection at 487 MHz reveal a photon-indistinguishability of (41.1 ± 9.5 % at a single-photon emission rate of (92 ± 23 MHz.

  6. Infrared reduction, an efficient method to control the non-linear optical property of graphene oxide in femtosecond regime

    Science.gov (United States)

    Bhattacharya, S.; Maiti, R.; Saha, S.; Das, A. C.; Mondal, S.; Ray, S. K.; Bhaktha, S. B. N.; Datta, P. K.

    2016-04-01

    Graphene Oxide (GO) has been prepared by modified Hummers method and it has been reduced using an IR bulb (800-2000 nm). Both as grown GO and reduced graphene oxide (RGO) have been characterized using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Raman spectra shows well documented Dband and G-band for both the samples while blue shift of G-band confirms chemical functionalization of graphene with different oxygen functional group. The XPS result shows that the as-prepared GO contains 52% of sp2 hybridized carbon due to the C=C bonds and 33% of carbon atoms due to the C-O bonds. As for RGO, increment of the atomic % of the sp2 hybridized carbon atom to 83% and rapid decrease in atomic % of C=O bonds confirm an efficient reduction with infrared radiation. UV-Visible absorption spectrum also confirms increment of conjugation with increased reduction. Non-linear optical properties of both GO and RGO are measured using single beam open aperture Z-Scan technique in femtosecond regime. Intensity dependent nonlinear phenomena are observed. Depending upon the intensity, both saturable absorption and two photon absorption contribute to the non-linearity of both the samples. Saturation dominates at low intensity (~ 127 GW/cm2) while two photon absorption become prominent at higher intensities (from 217 GW/cm2 to 302 GW/cm2). We have calculated the two-photon absorption co-efficient and saturation intensity for both the samples. The value of two photon absorption co-efficient (for GO~ 0.0022-0.0037 cm/GW and for RGO~ 0.0128-0.0143 cm/GW) and the saturation intensity (for GO~57 GW/cm2 and for RGO~ 194GW/cm2) is increased with reduction. Increase in two photon absorption coefficient with increasing intensity can also suggest that there may be multi-photon absorption is taking place.

  7. Efficient 'One Pot' Nitro Reduction-Protection of γ-Nitro Aliphatic Methyl Esters

    OpenAIRE

    Díaz-Coutiño, Francisco D.; Escalante, Jaime

    2009-01-01

    A simple and efficient protocol has been developed for the direct conversion of γ-nitro aliphatic methyl esters to N-(tert-butoxycarbonyl)amine methyl esters using NH4+HCO2- and Pd/C in the presence of (Boc)2O. There was a significant decrease in the reaction time under these conditions, increased yields and the purity of the products using this 'one pot' procedure. Un protocolo simple y eficiente de síntesis ha sido desarrollado para la conversión directa de metil ésteres de γ-nitro alifá...

  8. Controllable synthesis of Co3O4 nanocrystals as efficient catalysts for oxygen reduction reaction

    Science.gov (United States)

    Li, Baoying; Zhang, Yihe; Du, Ruifeng; Liu, Lei; Yu, Xuelian

    2018-03-01

    The electrochemical oxygen reduction reaction (ORR) has received great attention due to its importance in fuel cells and metal-air batteries. Here, we present a simple approach to prepare non-noble metal catalyst-Co3O4 nanocrystals (NCs). The particle size and shape were simply controlled by different types and concentrations of metal precursor. Furthermore, different sizes and shapes of Co3O4 NCs are explored as electrocatalysts for ORR, and it has been observed that particles with a similar shape, and smaller particle size led to greater catalytic current densities because of the greater surface area. For particles with a comparable size, the shape or crystalline structure governed the activity of the electrocatalytic reactions. Most importantly, the 9 nm-Co3O4 were demonstrated to act as low-cost catalysts for the ORR with a similar performance to that of Pt catalysts.

  9. Laser-induced efficient reduction of Cr(VI) catalyzed by ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Qamar, M. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Gondal, M.A., E-mail: magondal@kfupm.edu.sa [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Laser Research Group, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Yamani, Z.H. [Center of Excellence in Nanotechnology, King Fahd University of Petroleum and Minerals, KFUPM Box 741, Dhahran 31261 (Saudi Arabia); Laser Research Group, Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2011-03-15

    The present study demonstrates the complete removal of Cr(VI) in aqueous suspensions of zinc oxide nanoparticles using a novel laser-induced photocatalytic process without the use of any additive. The study showed that {approx}95% Cr(VI) was removed within short time (60 min) of laser exposure in the presence of ZnO. However, the removal of chromium using conventional setup under identical conditions was found to be negligible. Effect of critical parameters, such as laser energy, catalyst concentration, chromium concentration, and added electron donor and acceptor on the photocatalytic reduction process was also investigated. The data regarding temporal behavior of metal removal was fitted to first-order kinetic and reaction rate was computed.

  10. Efficiency Analysis of Technological Methods for Reduction of NOx Emissions while Burning Hydrocarbon Fuels in Heat and Power Plants

    Directory of Open Access Journals (Sweden)

    S. M. Kabishov

    2013-01-01

    Full Text Available The paper contains a comparative efficiency analysis pertaining to application of existing technological methods for suppression of nitric oxide formation in heating boilers of heat generators. A special attention has been given to investigation of NOx  emission reduction while burning hydrocarbon fuel with the help of oxygen-enriched air. The calculations have demonstrated that while enriching oxidizer with the help of oxygen up to 50 % (by volume it is possible to reduce volume of NOx formation (while burning fuel unit by 21 %.

  11. Condensing gas boilers for energy efficiency and reduction of CO2 and NOx

    International Nuclear Information System (INIS)

    Stewardson, E.

    1994-01-01

    The objectives of the study are: 1) to demonstrate the effectiveness of condensing gas boiler hot water system in reducing energy costs and pollution; 2) to illustrate the importance of marketing this technology to uninformed end users. The development of condensing boilers in the European Community, the materials used, product designs, key performance measures, and the types of applications suited to these products are outlined. Using calculations from a body of work produced by the Chartered Institute of Building Service Engineers in Britain, it is demonstrated how seasonal efficiency differs from combustion efficiency, and how the added capital cost for these boilers may be recovered within an acceptable commercial pay back period from fuel cost savings. Applying current NO x and CO 2 information from a body of the CE Technical Committees, the author show how these products can reduce pollution levels both from CO 2 and NO x . An example of marketing these products to a largely uninformed end user customer market is cited. 2 refs., 3 tabs., 12 figs. (orig.)

  12. Combustion efficiency: Greenhouse gas emission reductions from the power generation sector

    Energy Technology Data Exchange (ETDEWEB)

    Kane, R.; South, D.W.; Fish, A.L. [Argonne National Laboratory, Upton, IL (United States)

    1993-12-31

    Concern for the possibility of an enhanced greenhouse effect and global climate change (GCC) has often been associated with energy use in general, and fossil fuel combustion in particular, because of associated emissions of CO{sub 2} and other greenhouse gases (GHG). Therefore, energy policies play a significant role in determining greenhouse gas emissions. The generation of electricity and power from more efficient fossil energy technologies provides an opportunity to significantly lower GHG emissions, together with other pollutants. The U.S. government oversees a broad-based program to facilitate the development, demonstration, and deployment of these technologies. Advanced fossil technologies offer other benefits as well, in that they permit continued use of widely available fuels such as coal. An international perspective is critical for assessing the role of these fuels, since countries differ in terms of their ability to maximize these benefits. Often, new technologies are considered the domain of industrialized countries. Yet more efficient technologies may have their greatest potential - to concurrently permit the utilization of indigenous fuels and to lower global GHG emissions in developing countries, especially those in the Asia-Pacific region.

  13. Exergy analysis on throttle reduction efficiency based on real gas equations

    International Nuclear Information System (INIS)

    Luo, Yuxi; Wang, Xuanyin

    2010-01-01

    This paper proposes an approach to calculate the efficiency of throttling in which the exergy (available energy) is used to evaluate the energy conversion processes. In the exergy calculation for real gases, a difficult part of integration can be removed by judiciously advised thermodynamic paths; the compressibility factor is calculated by using Peng-Robinson (P-R) equation. It is found that the largest deviation between the exergies calculated by the real gas equation and ideal gas assumption is about 1%. Because the exergy is a function of the pressure and temperature, the Joule-Thomson coefficients are used to calculate the temperature changes of throttling, based on the compressibility factors of the Soave-Redlich-Kwong (S-R-K) and P-R equations, and the temperature decreases are compared with those calculated by empirical formula. The result shows that the heat exergy contributes very little in throttling. The simple equation of ideal gas is suggested to calculate the efficiency of throttling for air at atmospheric temperatures.

  14. An extended dual input dual output three level Z source inverter with improved switch loss reduction technique

    Directory of Open Access Journals (Sweden)

    N.B. Deshmukh

    2016-12-01

    Full Text Available Multilevel inverter (MLI is a proven technology used for industrial applications due to low output total harmonic distortion (THD, high power handling capability and low active device rating. Dual output inverter is a recent trend associated with inverter topologies for specialized applications. This paper deals with three phase three level dual input dual output inverter topology with minimum active device count. Reduction in switch count leads to reduction in losses and improves reliability. Both the input sources share power equally as neutral point current ripple is maintained low. For further reduction in switching losses at higher switching frequencies, the concept of “no switching zone” or discontinuous pulse width modulation (DPWM has been put forth recently. This paper proposes modification in the placement of “no switching zone” in order to optimize switching losses and output THD (output filtering requirements for low power factor load. This study also proposes novel graphical approach to analyze the loss reduction along with its effect on output THD. The sinusoidal PWM (SPWM is used which gives satisfactory switching loss reduction without complex calculations. Moreover, the proposed topology is generalized to provide dual output at higher voltage levels. It is seen that the components reduction phenomenon becomes more pronounced as number of levels goes on increasing. The proposed converter is simulated in MATLAB software environment and results are obtained.

  15. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    Science.gov (United States)

    Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

    2013-11-01

    This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

  16. What Do Capacity Deployment Rates Tell Us about the Efficiency of Electricity Generation from Renewable Energy Sources Support Measures in Greece?

    Directory of Open Access Journals (Sweden)

    Sotiris Papadelis

    2016-01-01

    Full Text Available The efficiency of fiscal support for electricity generation from renewable energy sources (RES-E is a multifaceted notion that cannot be adequately described by a single metric. Efficiency is related to the ability of a policy measure to support deployment without creating negative feedback effects. These negative effects may stem from saturation of the grid’s ability to absorb an increased amount of RES-E power, the inability of regulatory bodies to cope with the larger workload due to the increased number of projects requesting permits or from rent-seeking behavior. Furthermore, the primary rationale for feed-in tariffs (FITs and other fiscal support schemes is that increased deployment of RES-E technologies will lead to reductions in costs and increases in efficiency. As a result, the efficiency of an RES-E support policy should be also judged by its ability to capitalize on cost reductions. Overall, we present an approach to facilitate ongoing assessments of the efficiency of support measures for RES-E deployment. We demonstrate the proposed approach using the FIT support policy in Greece as a case study. In particular, the RES-E support policy in Greece has been recently revised through tariff cuts and a moratorium on new production licenses. We aim to demonstrate that if publicly available data are appropriately monitored, a policy revision can take place in a timelier and less disruptive manner.

  17. MARKAL Application for Analysis of Energy Efficiency in Economic Activities of the Republic of Moldova and Feasible use of Renewable Energy Sources

    OpenAIRE

    Robu, Sergiu; Bikova, Elena; Siakkis, Philip; Giannakidis, George

    2010-01-01

    The paper presents results of analyses of energy efficiency measures and renewable energy sources implementation in the Republic of Moldova using MARKAL model. Detailed analyses of four scenarios are presented for: Reference Scenario; Energy Efficiency Scenario; Renewable Energy Sources Scenario; Energy Efficiency&Renewable Energy Scenario. Energy savings and costs are identified for implementation of renewable energy sources and Energy efficiency measures.

  18. Efficient radiologic reading environment by using an open-source macro program as connection software.

    Science.gov (United States)

    Lee, Young Han

    2012-01-01

    The objectives are (1) to introduce an easy open-source macro program as connection software and (2) to illustrate the practical usages in radiologic reading environment by simulating the radiologic reading process. The simulation is a set of radiologic reading process to do a practical task in the radiologic reading room. The principal processes are: (1) to view radiologic images on the Picture Archiving and Communicating System (PACS), (2) to connect the HIS/EMR (Hospital Information System/Electronic Medical Record) system, (3) to make an automatic radiologic reporting system, and (4) to record and recall information of interesting cases. This simulation environment was designed by using open-source macro program as connection software. The simulation performed well on the Window-based PACS workstation. Radiologists practiced the steps of the simulation comfortably by utilizing the macro-powered radiologic environment. This macro program could automate several manual cumbersome steps in the radiologic reading process. This program successfully acts as connection software for the PACS software, EMR/HIS, spreadsheet, and other various input devices in the radiologic reading environment. A user-friendly efficient radiologic reading environment could be established by utilizing open-source macro program as connection software. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  19. Efficient radiologic reading environment by using an open-source macro program as connection software

    International Nuclear Information System (INIS)

    Lee, Young Han

    2012-01-01

    Purpose: The objectives are (1) to introduce an easy open-source macro program as connection software and (2) to illustrate the practical usages in radiologic reading environment by simulating the radiologic reading process. Materials and methods: The simulation is a set of radiologic reading process to do a practical task in the radiologic reading room. The principal processes are: (1) to view radiologic images on the Picture Archiving and Communicating System (PACS), (2) to connect the HIS/EMR (Hospital Information System/Electronic Medical Record) system, (3) to make an automatic radiologic reporting system, and (4) to record and recall information of interesting cases. This simulation environment was designed by using open-source macro program as connection software. Results: The simulation performed well on the Window-based PACS workstation. Radiologists practiced the steps of the simulation comfortably by utilizing the macro-powered radiologic environment. This macro program could automate several manual cumbersome steps in the radiologic reading process. This program successfully acts as connection software for the PACS software, EMR/HIS, spreadsheet, and other various input devices in the radiologic reading environment. Conclusion: A user-friendly efficient radiologic reading environment could be established by utilizing open-source macro program as connection software.

  20. DrSPINE - New approach to data reduction and analysis for neutron spin echo experiments from pulsed and reactor sources

    International Nuclear Information System (INIS)

    Zolnierczuk, P.A.; Ohl, M.; Holderer, O.; Monkenbusch, M.

    2015-01-01

    Neutron spin echo (NSE) method at a pulsed neutron source presents new challenges to the data reduction and analysis as compared to the instruments installed at reactor sources. The main advantage of the pulsed source NSE is the ability to resolve the neutron wavelength and collect neutrons over a wider bandwidth. This allows us to more precisely determine the symmetry phase and measure the data for several Q-values at the same time. Based on the experience gained at the SNS NSE - the first, and to date the only one, NSE instrument installed at a pulsed spallation source, we propose a novel and unified approach to the NSE data processing called DrSPINE. The goals of the DrSPINE project are: -) exploit better symmetry phase determination due to the broader bandwidth at a pulsed source; -) take advantage of larger Q coverage for TOF instruments; -) use objective statistical criteria to get the echo fits right; -) provide robust reduction with report generation; -) incorporate absolute instrument calibration; and -) allow for background subtraction. The software must be able to read the data from various instruments, perform data integrity, consistency and compatibility checks and combine the data from compatible sets, partial scans, etc. We chose to provide a console-based interface with the ability to process macros (scripts) for batch evaluation. And last and not the least, a good software package has to provide adequate documentation. DrSPINE software is currently under development

  1. Breast cancer prevention knowledge, beliefs, and information sources between non-Hispanic and Hispanic college women for risk reduction focus.

    Science.gov (United States)

    Kratzke, Cynthia; Amatya, Anup; Vilchis, Hugo

    2015-02-01

    Although growing research focuses on breast cancer screenings, little is known about breast cancer prevention with risk reduction awareness for ethnic differences among college-age women. This study examined breast cancer prevention knowledge, beliefs, and information sources between non-Hispanic and Hispanic college women. Using a cross-sectional study, women at a university in the Southwest completed a 51-item survey about breast cancer risk factors, beliefs, and media and interpersonal information sources. The study was guided by McGuire's Input Output Persuasion Model. Of the 546 participants, non-Hispanic college women (n = 277) and Hispanic college women (n = 269) reported similar basic knowledge levels of modifiable breast cancer risk factors for alcohol consumption (52 %), obesity (72 %), childbearing after age 35 (63 %), and menopausal hormone therapy (68 %) using bivariate analyses. Most common information sources were Internet (75 %), magazines (69 %), provider (76 %) and friends (61 %). Least common sources were radio (44 %), newspapers (34 %), and mothers (36 %). Non-Hispanic college women with breast cancer family history were more likely to receive information from providers, friends, and mothers. Hispanic college women with a breast cancer family history were more likely to receive information from their mothers. Breast cancer prevention education for college women is needed to include risk reduction for modifiable health behavior changes as a new focus. Health professionals may target college women with more information sources including the Internet or apps.

  2. Study on Laws, Regulations and Standards on Energy Efficiency, Energy Conserving and Emission Reduction of Industrial Boilers in EU

    Science.gov (United States)

    Liu, Ren; Zhao, Yuejin; Chen, Haihong; Liang, Xiuying; Yang, Ming

    2017-12-01

    Industrial boilers are widely applied in such fields as factory power, building heating, and people’s lives; China is the world’s largest producer and user of industrial boilers, with very high annual energy consumption; clear requirements have been put forward by China on the energy efficiency since the “11th Five-year Plan” with the hope to save energy and reduce emission by means of energy efficiency standards and regulations on the supervision and control of various special equipment. So far, the energy efficiency of industrial boilers in China has been improved significantly but there is still a gap with the EU states. This paper analyzes the policies of energy efficiency, implementation models and methods of supervision and implementation at the EU level from laws, regulations, directives as well as standards; the paper also puts forward suggestions of energy conserving and emission reduction on the improvement of energy conserving capacity of industrial boilers in China through studying the legislations and measures of the developed countries in energy conserving of boilers.

  3. Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Melting Efficiency Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Principal Investigator Kent Peaslee; Co-PI’s: Von Richards, Jeffrey Smith

    2012-07-31

    Steel foundries melt recycled scrap in electric furnaces and typically consume 35-100% excess energy from the theoretical energy requirement required to pour metal castings. This excess melting energy is multiplied by yield losses during casting and finishing operations resulting in the embodied energy in a cast product typically being three to six times the theoretical energy requirement. The purpose of this research project was to study steel foundry melting operations to understand energy use and requirements for casting operations, define variations in energy consumption, determine technologies and practices that are successful in reducing melting energy and develop new melting techniques and tools to improve the energy efficiency of melting in steel foundry operations.

  4. The contribution of energy efficiency and renewability to the reduction of CO2 emissions

    International Nuclear Information System (INIS)

    Paredes, J.A.; Mateo, I.

    1995-01-01

    The European Commission has proposed a series of measures, among which the imposition of a tax on the consumption of energy and CO 2 emissions. Different organizations, among them Eurelectric, have opposed this tax, arguing that there exist alternative solutions, such as the adoption of voluntary commitments between companies/national governments, to reduce CO 2 emissions and which at the same time have a much lower cost/benefit ratio: the effects of the increased use of natural gas in electricity generation, improvements in energy efficiency and the promotion and development of cogeneration and renewable energies on CO 2 emissions on a national level (Spain), as well as applications of the same principles within a particular company (Union Fenosa). 3 tabs

  5. Global threat reduction initiative efforts to address transportation challenges associated with the recovery of disused radioactive sealed sources - 10460

    International Nuclear Information System (INIS)

    Whitworth, Julie; Abeyta, Cristy L.; Griffin, Justin M.; Matzke, James L.; Pearson, Michael W.; Cuthbertson, Abigail; Rawl, Richard; Singley, Paul

    2010-01-01

    Proper disposition of disused radioactive sources is essential for their safe and secure management and necessary to preclude their use in malicious activities. Without affordable, timely transportation options, disused sealed sources remain in storage at hundreds of sites throughout the country and around the world. While secure storage is a temporary measure, the longer sources remain disused or unwanted the chances increase that they will become unsecured or abandoned. The Global Threat Reduction Initiative's Off-Site Source Recovery Project (GTRIlOSRP), recovers thousands of disused and unwanted sealed sources annually as part of GTRl's larger mission to reduce and protect high risk nuclear and radiological materials located at civilian sites worldwide. Faced with decreasing availability of certified transportation containers to support movement of disused and unwanted neutron- and beta/gamma-emitting radioactive sealed sources, GTRIlOSRP has initiated actions to ensure the continued success of the project in timely recovery and management of sealed radioactive sources. Efforts described in this paper to enhance transportation capabilities include: (sm b ullet) Addition of authorized content to existing and planned Type B containers to support the movement of non-special form and other Type B-quantity sealed sources; (sm b ullet) Procurement of vendor services for the design, development, testing and certification of a new Type B container to support transportation of irradiators, teletherapy heads or sources removed from these devices using remote handling capabilities such as the IAEA portable hot cell facility; (sm b ullet) Expansion of shielded Type A container inventory for transportation of gamma-emitting sources in activity ranges requiring use of shielding for conformity with transportation requirements; (sm b ullet) Approval of the S300 Type A fissile container for transport of Pu-239 sealed sources internationally; (sm b ullet) Technology transfer of

  6. Furnace devices aerodynamics optimization for fuel combustion efficiency improvement and nitrogen oxide emission reduction

    Science.gov (United States)

    Volkov, E. P.; Prokhorov, V. B.; Arkhipov, A. M.; Chernov, S. L.; Kirichkov, V. S.; Kaverin, A. A.

    2017-11-01

    MPEI conducts researches on physical and mathematical models of furnace chambers for improvement of power-generation equipment fuel combustion efficiency and ecological safety. Results of these researches are general principles of furnace aerodynamics arrangement for straight-flow burners and various fuels. It has been shown, that staged combustion arrangement with early heating and igniting with torch distribution in all furnace volume allows to obtain low carbon in fly ash and nitrogen oxide emission and also to improve boiler operation reliability with expand load adjustment range. For solid fuel combustion efficiency improvement it is practical to use high-placed and strongly down-tilted straight-flow burners, which increases high-temperature zone residence time for fuel particles. In some cases, for this combustion scheme it is possible to avoid slag-tap removal (STR) combustion and to use Dry-bottom ash removal (DBAR) combustion with tolerable carbon in fly ash level. It is worth noting that boilers with STR have very high nitrogen oxide emission levels (1200-1800 mg/m3) and narrow load adjustment range, which is determined by liquid slag output stability, so most industrially-developed countries don’t use this technology. Final decision about overhaul of boiler unit is made with regard to physical and mathematical modeling results for furnace and zonal thermal calculations for furnace and boiler as a whole. Overhaul of boilers to provide staged combustion and straight-flow burners and nozzles allows ensuring regulatory nitrogen oxide emission levels and corresponding best available technology criteria, which is especially relevant due to changes in Russian environmental regulation.

  7. Scalable preparation of sized-controlled Co-N-C electrocatalyst for efficient oxygen reduction reaction

    Science.gov (United States)

    Ai, Kelong; Li, Zelun; Cui, Xiaoqiang

    2017-11-01

    Heat-treated metal-nitrogen-carbon (M-N-C) materials are emerging as promising non-precious catalysts to replace expensive Pt-based materials for oxygen reduction reaction (ORR) in energy conversion and storage devices. Despite recent progress, their activity and durability are still far from satisfactory. The activity site and particle size are among the most important factors for the ORR activity of M-N-C catalysts. Extensive efforts have been made to reveal the correlation of active site and activity. However, it remains unclear to what extent the particle size will influence the ORR activity of M-N-C materials. Moreover, to the best of our knowledge, controllable synthesis of M-N-C catalysts with high-density activity sites remains elusive. Herein, we develop a straightforward method to produce a monodisperse and size-controlled Co-N-C (Nano-P-ZIF-67) electrocatalyst, and systemically investigate its catalytic mechanisms. Only by optimizing the particle size, Nano-P-ZIF-67 outperforms the commercial 20 wt% Pt/C regarding all evaluating indicators for ORR catalysts in alkaline media including higher catalytic activity, durability, and stronger methanol tolerance. Nano-P-ZIF-67 is assembled into a cell, and the cell shows a power density of 45.5 mW/cm2, which is the highest value among currently studied cathode catalysts. We expect Nano-P-ZIF-67 to be a highly interesting candidate for the next generation of ORR catalysts.

  8. Efficient reduction and modularization for large fault trees stored by pages

    International Nuclear Information System (INIS)

    Chen, Shanqi; Wang, Jin; Wang, Jiaqun; Wang, Fang; Hu, Liqin

    2016-01-01

    Highlights: • New fault tree pre-processing methods used in RiskA are presented. • Including the fault tree paging storage, simplification and modularization. • For getting MCS for fault trees containing more than 10,000 gates and events. • Reduce computer resources needs (RAM) and improve computation speed. - Abstract: Fault Tree Analysis (FTA), an indispensable tool used in Probabilistic Risk Assessment (PRA), has been used throughout the commercial nuclear power industry for safety and reliability analyses. However, large fault tree analysis, such as those used in nuclear power plant requires significant computer resources, which makes the analysis of PRA model inefficient and time consuming. This paper describes a fault tree pre-processing method used in the reliability and probabilistic safety assessment program RiskA that is capable of generating minimal cutsets for fault trees containing more than 10,000 gates and basic events. The novel feature of this method is not only that Boolean reduction rules are used but also that a new objective of simplification is proposed. Moreover, since the method aims to find more fault tree modules by the linear-time algorithm, it can optimize fault tree modularization, which further reduces the computational time of large fault tree analysis.

  9. Effect of coffee reduction on constituent concentration in an energy-efficient process of ultrasonic extraction

    Directory of Open Access Journals (Sweden)

    Wang Cheng-Chi

    2015-01-01

    Full Text Available Coffee is one of the popular beverage; its constituents include caffeine, oxidation resistant aromatic constituents, protein, tannin, and fat. It is indicated in literatures that a proper amount of coffee stimulates the brain and enhances memory, but excessive coffee causes negative results, such as coronary artery disease, high blood pressure, heart disease and kidney disease. This study used high-performance ultrasonic process to discuss the effect of pulverized coffee reduction on the constituent concentration. It further compared the constituent concentrations obtained in different extraction periods. The experimental results show that the coffee aroma constituents can be extracted effectively by ultrasonic process without any organic solvent, and the constituent concentration does not decrease with the addition of pulverized coffee. Therefore, the consumption of pulverized coffee can be reduced greatly by using the proposed. The time of extraction process can be shortened, so as to save energy. The most important point is to reduce the enterprises manufacturing cost and to increase the profit.

  10. Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6

    Energy Technology Data Exchange (ETDEWEB)

    Erin K. Field; Robin Gerlach; Sridhar Viamajala; Laura K. Jennings; Alfred B. Cunningham; Brent M. Peyton; William A. Apel

    2011-09-01

    The reduction of hexavalent chromium, Cr(VI), to trivalent chromium, Cr(III), can be an important aspect of remediation processes at Department of Energy (DOE) and other contaminated sites. Cellulomonas species are found at several Cr(VI) contaminated and uncontaminated locations at the DOE site in Hanford, Washington. Members of this genus have demonstrated the ability to effectively reduce Cr(VI) to Cr(III) fermentatively and therefore play a potential role in hexavalent chromium remediation at this site. Batch studies were conducted with Cellulomonas sp. strain ES6 to assess the influence of various carbon sources, iron minerals, and electron shuttling compounds on Cr(VI) reduction. These chemical species are likely to be present in these terrestrial environments during in situ bioremediation. Results indicated that there were a number of interactions between these compounds that influenced Cr(VI) reduction rates. The type of carbon source as well as the type of electron shuttle present influenced Cr(VI) reduction rates. When an electron shuttle, such as anthraquinone-2,6-disulfonate (AQDS), was present in the system, reduction rates increased significantly. Biologically reduced AQDS (AHDS) reduced Cr(VI) almost instantaneously. The presence of iron minerals and their concentrations did not significantly influence Cr(VI) reduction rates. However, strain ES6 or AQDS could directly reduce surface-associated Fe(III) to Fe(II) which was capable of reducing Cr(VI) at a near instantaneous rate. These results suggest the rate limiting step in these systems is the transfer of electrons from strain ES6 to the intermediate or terminal electron acceptor whether that is Cr(VI), Fe(III), or AQDS.

  11. Influence of Carbon Sources and Electron Shuttles on Ferric Iron Reduction by Cellulomonas sp. Strain ES6

    Energy Technology Data Exchange (ETDEWEB)

    Dr Robin Gerlach; Erin K. Field; Sridhar Viamajala; Brent M. Peyton; William A. Apel; Al B. Cunningham

    2011-09-01

    Microbially reduced iron minerals can reductively transform a variety of contaminants including heavy metals, radionuclides, chlorinated aliphatics, and nitroaromatics. A number of Cellulomonas spp. strains, including strain ES6, isolated from aquifer samples obtained at the U.S. Department of Energy's Hanford site in Washington, have been shown to be capable of reducing Cr(VI), TNT, natural organic matter, and soluble ferric iron [Fe(III)]. This research investigated the ability of Cellulomonas sp. strain ES6 to reduce solid phase and dissolved Fe(III) utilizing different carbon sources and various electron shuttling compounds. Results suggest that Fe(III) reduction by and growth of strain ES6 was dependent upon the type of electron donor, the form of iron present, and the presence of synthetic or natural organic matter, such as anthraquinone-2,6-disulfonate (AQDS) or humic substances. This research suggests that Cellulomonas sp. strain ES6 could play a significant role in metal reduction in the Hanford subsurface and that the choice of carbon source and organic matter addition can allow for independent control of growth and iron reduction activity.

  12. Cr(Vi) reduction capacity of activated sludge as affected by nitrogen and carbon sources, microbial acclimation and cell multiplication

    International Nuclear Information System (INIS)

    Ferro Orozco, A.M.; Contreras, E.M.; Zaritzky, N.E.

    2010-01-01

    The objectives of the present work were: (i) to analyze the capacity of activated sludge to reduce hexavalent chromium using different carbon sources as electron donors in batch reactors, (ii) to determine the relationship between biomass growth and the amount of Cr(VI) reduced considering the effect of the nitrogen to carbon source ratio, and (iii) to determine the effect of the Cr(VI) acclimation stage on the performance of the biological chromium reduction assessing the stability of the Cr(VI) reduction capacity of the activated sludge. The highest specific Cr(VI) removal rate (q Cr ) was attained with cheese whey or lactose as electron donors decreasing in the following order: cheese whey ∼ lactose > glucose > citrate > acetate. Batch assays with different nitrogen to carbon source ratio demonstrated that biological Cr(VI) reduction is associated to the cell multiplication phase; as a result, maximum Cr(VI) removal rates occur when there is no substrate limitation. The biomass can be acclimated to the presence of Cr(VI) and generate new cells that maintain the ability to reduce chromate. Therefore, the activated sludge process could be applied to a continuous Cr(VI) removal process.

  13. Reduction in photosynthetic efficiency of Cladophora glomerata, induced by overlying canopies of Lemna spp.

    Science.gov (United States)

    Parr, L B; Perkins, R G; Mason, C F

    2002-04-01

    The duckweeds Lemna minor L. and L. minuscula Herter reduced PSII quantum efficiency (F'q/F'm) of the filamentous green alga Cladophora glomerata Kützing by up to 42% over seven days when floating above mats of C. glomerata in containers. Dissolved oxygen (DO) increased by 23% at 30 degrees C in containers with C. glomerata over controls. But when the water surface in the containers was covered with Lemna spp. floating above C. glomerata, DO was 83% lower at 30 degrees C over seven days than in control samples with no duckweed or alga. Dissolved oxygen was lower beneath a thick mat (1 cm) of either Lemna spp. covering the surface than under a thin layer (single-frond canopy). PAM fluorimetry showed that maximum PSII efficiency (Fv/Fm) of C. glomerata in containers was reduced under a canopy of L. minor by 17% over seven days, and under L. minuscula by 22%. F'q/F'm of C. glomerata in containers exposed to 51 micromol m(-2) s(-1) PPFD decreased under a canopy of L. minor by 16% over seven days, and under L. minuscula by 19% compared to controls. When light response curves were compared, F'q/F'm was significantly reduced under canopies of L. minor at the highest temperatures tested (28 degrees C and 30 degrees C). L. minor significantly reduced relative electron transport rate (rel. ETR) of the controls by up to 71% at 30 degrees C. Relative electron transport rate did not reach light saturation point (Esat) except at 28 degrees and 30 degrees C under mats of L. minor. Whereas the highest rate of production (rel. ETRmax) and Esat increased with temperature in controls, under a canopy of Lemna, decreases were observed. It is suggested that, during periods of high summer temperature and irradiance, shading inhibits oxygenic photosynthesis in mats of C. glomerata beneath canopies of Lenma spp. This results in less oxygen being produced by the C. glomerata (oxygen produced by Lemna spp. is not released into the water), and this may further inhibit the C. glomerata by

  14. Tracking Poverty Reduction in Bhutan: Income Deprivation Alongside Deprivation in Other Sources of Happiness

    Science.gov (United States)

    Santos, Maria Emma

    2013-01-01

    This paper analyses poverty reduction in Bhutan between two points in time--2003 and 2007--from a multidimensional perspective. The measures estimated include consumption expenditure as well as other indicators which are directly (when possible) or indirectly associated to valuable functionings, namely, health, education, access to electricity,…

  15. REDUCTION IN ASTHMA MORBIDITY IN CHILDREN AS A RESULT OF HOME REMEDIATION AIMED AT MOISTURE SOURCES

    Science.gov (United States)

    Objective: Home dampness, presence of mold and allergens have been associated with asthma morbidity. We examined changes in asthma morbidity in children as a result of home remediation aimed at moisture sources.Design: Prospective, randomized controlled trial.Part...

  16. Dodecahedral W@WC Composite as Efficient Catalyst for Hydrogen Evolution and Nitrobenzene Reduction Reactions.

    Science.gov (United States)

    Chen, Zhao-Yang; Duan, Long-Fa; Sheng, Tian; Lin, Xiao; Chen, Ya-Feng; Chu, You-Qun; Sun, Shi-Gang; Lin, Wen-Feng

    2017-06-21

    Core-shell composites with strong phase-phase contact could provide an incentive for catalytic activity. A simple, yet efficient, H 2 O-mediated method has been developed to synthesize a mesoscopic core-shell W@WC architecture with a dodecahedral microstructure, via a one-pot reaction. The H 2 O plays an important role in the resistance of carbon diffusion, resulting in the formation of the W core and W-terminated WC shell. Density functional theory (DFT) calculations reveal that adding W as core reduced the oxygen adsorption energy and provided the W-terminated WC surface. The W@WC exhibits significant electrocatalytic activities toward hydrogen evolution and nitrobenzene electroreduction reactions, which are comparable to those found for commercial Pt/C, and substantially higher than those found for meso- and nano-WC materials. The experimental results were explained by DFT calculations based on the energy profiles in the hydrogen evolution reactions over WC, W@WC, and Pt model surfaces. The W@WC also shows a high thermal stability and thus may serve as a promising more economical alternative to Pt catalysts in these important energy conversion and environmental protection applications. The current approach can also be extended or adapted to various metals and carbides, allowing for the design and fabrication of a wide range of catalytic and other multifunctional composites.

  17. Assessment of Energy Efficiency Improvement and CO2 Emission Reduction Potentials in the Cement Industry in China

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Morrow, William [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Masanet, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sathaye, Jayant [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Xu, Tengfang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-06-15

    China’s annual cement production (i.e., 1,868 Mt) in 2010 accounted for nearly half of the world’s annual cement production in the same year. We identified and analyzed 23 energy efficiency technologies and measures applicable to the processes in the cement industry. The Conservation Supply Curve (CSC) used in this study is an analytical tool that captures both the engineering and the economic perspectives of energy conservation. Using a bottom-up electricity CSC model, the cumulative cost-effective electricity savings potential for the Chinese cement industry for 2010-2030 is estimated to be 251 TWh, and the total technical electricity saving potential is 279 TWh. The CO2 emissions reduction associated with cost-effective electricity savings is 144 Mt CO2 and the CO2 emission reduction associated with technical electricity saving potential is 161 Mt CO2. The fuel CSC model for the cement industry suggests cumulative cost-effective fuel savings potential of 4,326 PJ which is equivalent to the total technical potential with associated CO2 emission reductions of 406 Mt CO2. In addition, a sensitivity analysis with respect to the discount rate used is conducted to assess the effect of changes in this parameter on the results. We also developed a scenario in which instead of only implementing the international technologies in 2010-2030, we implement both international and Chinese domestic technologies during the analysis period and calculate the saving and cost of conserved energy accordingly. The result of this study gives a comprehensive and easy to understand perspective to the Chinese cement industry and policy makers about the energy efficiency potential and its associated cost.

  18. Three-dimensional iron, nitrogen-doped carbon foams as efficient electrocatalysts for oxygen reduction reaction in alkaline solution

    International Nuclear Information System (INIS)

    Ma, Yanjiao; Wang, Hui; Feng, Hanqing; Ji, Shan; Mao, Xuefeng; Wang, Rongfang

    2014-01-01

    Graphical abstract: Three-dimentional Fe, N-doped carbon foams prepared by two steps exhibited comparable catalytic activity for oxygen reduction reaction to commercial Pt/C due to the unique structure and the synergistic effect of Fe and N atoms. - Highlights: • Three-dimensional Fe, N-doped carbon foam (3D-CF) were prepared. • 3D-CF exhibits comparable catalytic activity to Pt/C for oxygen reduction reaction. • The enhanced activity of 3D-CF results of its unique structure. - Abstract: Three-dimensional (3D) Fe, N-doped carbon foams (3D-CF) as efficient cathode catalysts for the oxygen reduction reaction (ORR) in alkaline solution are reported. The 3D-CF exhibit interconnected hierarchical pore structure. In addition, Fe, N-doped carbon without porous strucuture (Fe-N-C) and 3D N-doped carbon without Fe (3D-CF’) are prepared to verify the electrocatalytic activity of 3D-CF. The electrocatalytic performance of as-prepared 3D-CF for ORR shows that the onset potential on 3D-CF electrode positively shifts about 41 mV than those of 3D-CF’ and Fe-N-C respectively. In addition, the onset potential on 3D-CF electrode for ORR is about 27 mV more negative than that on commercial Pt/C electrode. 3D-CF also show better methanol tolerance and durability than commercial Pt/C catalyst. These results show that to synthesize 3D hierarchical pores with high specific surface area is an efficient way to improve the ORR performance

  19. State Approaches to Demand Reduction Induced Price Effects: Examining How Energy Efficiency Can Lower Prices for All

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Colin [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hedman, Bruce [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goldberg, Amelie [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-12-01

    Effects (DRIPE) as a real, quantifiable benefit of energy efficiency and demand response programs. DRIPE is a measurement of the value of demand reductions in terms of the decrease in wholesale energy prices, resulting in lower total expenditures on electricity or natural gas across a given grid. Crucially for policymakers and consumer advocates, DRIPE savings accrue not only to the subset of customers who consume less, but to all consumers. Rate-paying customers realize DRIPE savings when price reductions across an electricity or natural gas system are passed on to all retail customers as lower rates (depending upon regulation and market structure, residual savings may be wholly or partially retained by utilities). DRIPE savings, though seemingly small in terms of percent price reductions or dollars per household, can amount to hundreds of millions of dollars per year across entire states or grids. Therefore, accurately assessing DRIPE benefits can help to ensure appropriate programs are designed and implemented for energy efficiency measures. This paper reviews the existing knowledge and experience from select U.S. states regarding DRIPE (including New York and Ohio), and the potential for expanded application of the concept of DRIPE by regulators. Policymakers and public utility commissions have a critical role to play in setting the methodology for determining DRIPE, encouraging its capture by utilities, and allocating DRIPE benefits among utilities, various groups of customers, and/or society at large. While the methodologies for estimating DRIPE benefits are still being perfected, policymakers can follow the examples of states such as Maryland and Vermont in including conservative DRIPE estimates in their resource planning.

  20. Assessment of Energy Efficiency Improvement and CO2 Emission Reduction Potentials in India's Cement Industry

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, III, William R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Xu, Tengfang [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-12-03

    India’s cement industry is the second largest in the world behind China with annual cement production of 168 Mt in 2010 which accounted for slightly greater than six percent of the world’s annual cement production in the same year. To produce that amount of cement, the industry consumed roughly 700 PJ of fuel and 14.7 TWh of electricity. We identified and analyzed 22 energy efficiency technologies and measures applicable to the processes in the Indian cement industry. The Conservation Supply Curve (CSC) used in this study is an analytical tool that captures both the engineering and the economic perspectives of energy conservation. Using a bottom-up electricity CSC model and compared to an electricity price forecast the cumulative cost-effective plant-level electricity savings potential for the Indian cement industry for 2010- 2030 is estimated to be 83 TWh, and the cumulative plant-level technical electricity saving potential is 89 TWh during the same period. The grid-level CO2 emissions reduction associated with cost-effective electricity savings is 82 Mt CO2 and the electric grid-level CO2 emission reduction associated with technical electricity saving potential is 88 Mt CO2. Compared to a fuel price forecast, an estimated cumulative cost-effective fuel savings potential of 1,029 PJ with associated CO2 emission reduction of 97 Mt CO2 during 2010-2030 is possible. In addition, a sensitivity analysis with respect to the discount rate used is conducted to assess the effect of changes in this parameter on the results. The result of this study gives a comprehensive and easy to understand perspective to the Indian cement industry and policy makers about the energy efficiency potential and its associated cost over the next twenty years.

  1. Efficient and automatic image reduction framework for space debris detection based on GPU technology

    Science.gov (United States)

    Diprima, Francesco; Santoni, Fabio; Piergentili, Fabrizio; Fortunato, Vito; Abbattista, Cristoforo; Amoruso, Leonardo

    2018-04-01

    In the last years, the increasing number of space debris has triggered the need of a distributed monitoring system for the prevention of possible space collisions. Space surveillance based on ground telescope allows the monitoring of the traffic of the Resident Space Objects (RSOs) in the Earth orbit. This space debris surveillance has several applications such as orbit prediction and conjunction assessment. In this paper is proposed an optimized and performance-oriented pipeline for sources extraction intended to the automatic detection of space debris in optical data. The detection method is based on the morphological operations and Hough Transform for lines. Near real-time detection is obtained using General Purpose computing on Graphics Processing Units (GPGPU). The high degree of processing parallelism provided by GPGPU allows to split data analysis over thousands of threads in order to process big datasets with a limited computational time. The implementation has been tested on a large and heterogeneous images data set, containing both imaging satellites from different orbit ranges and multiple observation modes (i.e. sidereal and object tracking). These images were taken during an observation campaign performed from the EQUO (EQUatorial Observatory) observatory settled at the Broglio Space Center (BSC) in Kenya, which is part of the ASI-Sapienza Agreement.

  2. Development of a high efficient conventional type cold neutron source using a non-explosive material

    International Nuclear Information System (INIS)

    Kiyanagi, Y.; Satoh, S.

    1999-01-01

    An efficient cold moderator that can be used easily at a small neutron source would be useful for neutron radiography, prompt gamma ray analysis and so on. Non-explosive materials are chosen for a cold moderator since explosive materials such as hydrogen and methane require a safety system. Neutronic performances of coupled moderators of various non-explosive materials are studied so as to develop such a cold moderator since the coupled moderator system is the best to obtain high intensity of cold neutrons. Effect of premoderator is studied and neutron spectra from methanol, ethanol, benzene, mesitylene and benzene methanol are measured around 20 K. The premoderator increased the cold neutron intensity by about 50∼70%. Methanol and mesitylene gave the highest cold neutron intensity. Effect of Be filter-reflector is also studied and a intensity gain of about 20% was obtained below about 5 MeV. (author)

  3. Open source acceleration of wave optics simulations on energy efficient high-performance computing platforms

    Science.gov (United States)

    Beck, Jeffrey; Bos, Jeremy P.

    2017-05-01

    We compare several modifications to the open-source wave optics package, WavePy, intended to improve execution time. Specifically, we compare the relative performance of the Intel MKL, a CPU based OpenCV distribution, and GPU-based version. Performance is compared between distributions both on the same compute platform and between a fully-featured computing workstation and the NVIDIA Jetson TX1 platform. Comparisons are drawn in terms of both execution time and power consumption. We have found that substituting the Fast Fourier Transform operation from OpenCV provides a marked improvement on all platforms. In addition, we show that embedded platforms offer some possibility for extensive improvement in terms of efficiency compared to a fully featured workstation.

  4. Bunch compression efficiency of the femtosecond electron source at Chiang Mai University

    International Nuclear Information System (INIS)

    Thongbai, C.; Kusoljariyakul, K.; Saisut, J.

    2011-01-01

    A femtosecond electron source has been developed at the Plasma and Beam Physics Research Facility (PBP), Chiang Mai University (CMU), Thailand. Ultra-short electron bunches can be produced with a bunch compression system consisting of a thermionic cathode RF-gun, an alpha-magnet as a magnetic bunch compressor, and a linear accelerator as a post acceleration section. To obtain effective bunch compression, it is crucial to provide a proper longitudinal phase-space distribution at the gun exit matched to the subsequent beam transport system. Via beam dynamics calculations and experiments, we investigate the bunch compression efficiency for various RF-gun fields. The particle distribution at the RF-gun exit will be tracked numerically through the alpha-magnet and beam transport. Details of the study and results leading to an optimum condition for our system will be presented.

  5. Bunch compression efficiency of the femtosecond electron source at Chiang Mai University

    Science.gov (United States)

    Thongbai, C.; Kusoljariyakul, K.; Saisut, J.

    2011-07-01

    A femtosecond electron source has been developed at the Plasma and Beam Physics Research Facility (PBP), Chiang Mai University (CMU), Thailand. Ultra-short electron bunches can be produced with a bunch compression system consisting of a thermionic cathode RF-gun, an alpha-magnet as a magnetic bunch compressor, and a linear accelerator as a post acceleration section. To obtain effective bunch compression, it is crucial to provide a proper longitudinal phase-space distribution at the gun exit matched to the subsequent beam transport system. Via beam dynamics calculations and experiments, we investigate the bunch compression efficiency for various RF-gun fields. The particle distribution at the RF-gun exit will be tracked numerically through the alpha-magnet and beam transport. Details of the study and results leading to an optimum condition for our system will be presented.

  6. Carbon-layer-protected cuprous oxide nanowire arrays for efficient water reduction

    KAUST Repository

    Zhang, Zhonghai

    2013-02-26

    In this work, we propose a solution-based carbon precursor coating and subsequent carbonization strategy to form a thin protective carbon layer on unstable semiconductor nanostructures as a solution to the commonly occurring photocorrosion problem of many semiconductors. A proof-of-concept is provided by using glucose as the carbon precursor to form a protective carbon coating onto cuprous oxide (Cu2O) nanowire arrays which were synthesized from copper mesh. The carbon-layer-protected Cu2O nanowire arrays exhibited remarkably improved photostability as well as considerably enhanced photocurrent density. The Cu2O nanowire arrays coated with a carbon layer of 20 nm thickness were found to give an optimal water splitting performance, producing a photocurrent density of -3.95 mA cm-2 and an optimal photocathode efficiency of 0.56% under illumination of AM 1.5G (100 mW cm-2). This is the highest value ever reported for a Cu 2O-based electrode coated with a metal/co-catalyst-free protective layer. The photostability, measured as the percentage of the photocurrent density at the end of 20 min measurement period relative to that at the beginning of the measurement, improved from 12.6% on the bare, nonprotected Cu2O nanowire arrays to 80.7% on the continuous carbon coating protected ones, more than a 6-fold increase. We believe that the facile strategy presented in this work is a general approach that can address the stability issue of many nonstable photoelectrodes and thus has the potential to make a meaningful contribution in the general field of energy conversion. © 2013 American Chemical Society.

  7. A high efficiency bunching system for the TUNL polarized ion source

    International Nuclear Information System (INIS)

    Wender, S.A.

    1981-01-01

    The problem of producing pulsed beams without large beam current losses has been the topic of recent interest particularly in areas where large peak currents are required. In addition, an efficient bunching system will allow the use of pulsed beams when source intensities are limited. The motivation for the development of the authors' high efficiency bunching system arose from their strong interest in neutron physics and the desire to extend their research with experiments requiring polarized neutrons. A common method for the production of polarized neutrons is to bombard a deuterium gas cell with a polarized deuteron beam. The D(→d,n) 3 He reaction has a large cross section and the outgoing neutron has a polarization of approximately 60 % in the energy range between 6 MeV to 16 Mev. Most experiments which involve the detection of neutrons use time-of-flight techniques to determine the neutron energy. An excellent way of providing time-of-flight information is to use pulsed beams. To be useful for time of flight experiments beam pulses must be on the order of a few nanoseconds wide. In addition there must be sufficient time between beam bursts to allow the reaction neutrons to travel from the target to the detector before the next beam burst arrives at the target. For reactions studied at the authors' laboratory, with their flight paths, this time is on the order of 400 ns

  8. Indoor air quality in energy-efficient dwellings: Levels and sources of pollutants.

    Science.gov (United States)

    Derbez, M; Wyart, G; Le Ponner, E; Ramalho, O; Ribéron, J; Mandin, C

    2018-03-01

    Worldwide, public policies are promoting energy-efficient buildings and accelerating the thermal renovation of existing buildings. The effects of these changes on the indoor air quality (IAQ) in these buildings remain insufficiently understood. In this context, a field study was conducted in 72 energy-efficient dwellings to describe the pollutants known to be associated with health concerns. Measured parameters included the concentrations of 19 volatile organic compounds and aldehydes, nitrogen dioxide, particulate matter (PM 2.5 ), radon, temperature, and relative humidity. The air stuffiness index and night-time air exchange rate were calculated from the monitored carbon dioxide (CO 2 ) concentrations. Indoor and outdoor measurements were performed at each dwelling during 1 week in each of the two following seasons: heating and non-heating. Moreover, questionnaires were completed by the occupants to characterize the building, equipment, household, and occupants' habits. Perspective on our results was provided by previous measurements made in low-energy European dwellings. Statistical comparisons with the French housing stock and a pilot study showed higher concentrations of terpenes, that is, alpha-pinene and limonene, and hexaldehyde in our study than in previous studies. Alpha-pinene and hexaldehyde are emitted by wood or wood-based products used for the construction, insulation, decoration, and furnishings of the dwellings, whereas limonene is more associated with discontinuous sources related to human activities. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. DISSOLVED OXYGEN REDUCTION IN THE DIII-D NEUTRAL BEAM ION SOURCE COOLING SYSTEM

    International Nuclear Information System (INIS)

    YIP, H.; BUSATH, J.; HARRISON, S.

    2004-03-01

    OAK-B135 Neutral beam ion sources (NBIS) are critical components for the neutral beam injection system supporting the DIII-D tokamak. The NBIS must be cooled with 3028 (ell)/m (800 gpm) of de-ionized and de-oxygenated water to protect the sources from overheating and failure. These ions sources are currently irreplaceable. Since the water cooled molybdenum components will oxidize in water almost instantaneously in the presence of dissolved oxygen (DO), de-oxygenation is extremely important in the NBIS water system. Under normal beam operation the DO level is kept below 5 ppb. However, during weeknights and weekends when neutral beam is not in operation, the average DO level is maintained below 10 ppb by periodic circulation with a 74.6 kW (100 hp) pump, which consumes significant power. Experimental data indicated evidence of continuous oxygen diffusion through non-metallic hoses in the proximity of the NBIS. Because of the intermittent flow of the cooling water, the DO concentration at the ion source(s) could be even higher than measured downstream, and hence the concern of significant localized oxidation/corrosion. A new 3.73 kW (5 hp) auxiliary system, installed in the summer of 2003, is designed to significantly reduce the peak and the time-average DO levels in the water system and to consume only a fraction of the power

  10. The Reduction of Vertical Interchannel Crosstalk: The Analysis of Localisation Thresholds for Natural Sound Sources

    Directory of Open Access Journals (Sweden)

    Rory Wallis

    2017-03-01

    Full Text Available In subjective listening tests, natural sound sources were presented to subjects as vertically-oriented phantom images from two layers of loudspeakers, ‘height’ and ‘main’. Subjects were required to reduce the amplitude of the height layer until the position of the resultant sound source matched that of the same source presented from the main layer only (the localisation threshold. Delays of 0, 1 and 10 ms were applied to the height layer with respect to the main, with vertical stereophonic and quadraphonic conditions being tested. The results of the study showed that the localisation thresholds obtained were not significantly affected by sound source or presentation method. Instead, the only variable whose effect was significant was interchannel time difference (ICTD. For ICTD of 0 ms, the median threshold was −9.5 dB, which was significantly lower than the −7 dB found for both 1 and 10 ms. The results of the study have implications both for the recording of sound sources for three-dimensional (3D audio reproduction formats and also for the rendering of 3D images.

  11. Quality management: reduction of waiting time and efficiency enhancement in an ENT-university outpatients' department

    Science.gov (United States)

    Helbig, Matthias; Helbig, Silke; Kahla-Witzsch, Heike A; May, Angelika

    2009-01-01

    Background Public health systems are confronted with constantly rising costs. Furthermore, diagnostic as well as treatment services become more and more specialized. These are the reasons for an interdisciplinary project on the one hand aiming at simplification of planning and scheduling patient appointments, on the other hand at fulfilling all requirements of efficiency and treatment quality. Methods As to understanding procedure and problem solving activities, the responsible project group strictly proceeded with four methodical steps: actual state analysis, analysis of causes, correcting measures, and examination of effectiveness. Various methods of quality management, as for instance opinion polls, data collections, and several procedures of problem identification as well as of solution proposals were applied. All activities were realized according to the requirements of the clinic's ISO 9001:2000 certified quality management system. The development of this project is described step by step from planning phase to inauguration into the daily routine of the clinic and subsequent control of effectiveness. Results Five significant problem fields could be identified. After an analysis of causes the major remedial measures were: installation of a patient telephone hotline, standardization of appointment arrangements for all patients, modification of the appointments book considering the reason for coming in planning defined working periods for certain symptoms and treatments, improvement of telephonic counselling, and transition to flexible time planning by daily updates of the appointments book. After implementation of these changes into the clinic's routine success could be demonstrated by significantly reduced waiting times and resulting increased patient satisfaction. Conclusion Systematic scrutiny of the existing organizational structures of the outpatients' department of our clinic by means of actual state analysis and analysis of causes revealed the necessity

  12. Isolation and characterization of yeasts capable of efficient utilization of hemicellulosic hydrolyzate as the carbon source.

    Science.gov (United States)

    Cassa-Barbosa, L A; Procópio, R E L; Matos, I T S R; Filho, S A

    2015-09-28

    Few yeasts have shown the potential to efficiently utilize hemicellulosic hydrolyzate as the carbon source. In this study, microorganisms isolated from the Manaus region in Amazonas, Brazil, were characterized based on their utilization of the pentoses, xylose, and arabinose. The yeasts that showed a potential to assimilate these sugars were selected for the better utilization of lignocellulosic biomass. Two hundred and thirty seven colonies of unicellular microorganisms grown on hemicellulosic hydrolyzate, xylose, arabinose, and yeast nitrogen base selective medium were analyzed. Of these, 231 colonies were subjected to sugar assimilation tests. One hundred and twenty five of these were shown to utilize hydrolyzed hemicellulose, xylose, or arabinose as the carbon source for growth. The colonies that showed the best growth (N = 57) were selected, and their internal transcribed spacer-5.8S rDNA was sequenced. The sequenced strains formed four distinct groups in the phylogenetic tree, and showed a high percentage of similarity with Meyerozyma caribbica, Meyerozyma guilliermondii, Trichosporon mycotoxinivorans, Trichosporon loubieri, Pichia kudriavzevii, Candida lignohabitans, and Candida ethanolica. The discovery of these xylose-fermenting yeasts could attract widespread interest, as these can be used in the cost-effective production of liquid fuel from lignocellulosic materials.

  13. Emerging Energy-efficiency and Carbon Dioxide Emissions-reduction Technologies for the Iron and Steel Industry

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept.. China Energy Group; Price, Lynn [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Analysis and Environmental Impacts Dept.. China Energy Group; Arens, Marlene [Fraunhofer Inst. for Systems and Innovation Research (ISI), Karlsruhe (Germany)

    2013-01-31

    Iron and steel manufacturing is among the most energy-intensive industries and accounts for the largest share, approximately 27 percent, of global carbon dioxide (CO2) emissions from the manufacturing sector. The ongoing increase in world steel demand means that this industry’s energy use and CO2 emissions continue to grow, so there is significant incentive to develop, commercialize and adopt emerging energy-efficiency and CO2 emissions-reduction technologies for steel production. Although studies from around the world have identified a wide range of energy-efficiency technologies applicable to the steel industry that have already been commercialized, information is limited and/or scattered regarding emerging or advanced energy-efficiency and low-carbon technologies that are not yet commercialized. This report consolidates available information on 56 emerging iron and steel industry technologies, with the intent of providing a well-structured database of information on these technologies for engineers, researchers, investors, steel companies, policy makers, and other interested parties. For each technology included, we provide information on energy savings and environmental and other benefits, costs, and commercialization status; we also identify references for more information.

  14. Emerging Energy-efficiency and CO{sub 2} Emission-reduction Technologies for Cement and Concrete Production

    Energy Technology Data Exchange (ETDEWEB)

    Hasanbeigi, Ali; Price, Lynn; Lin, Elina

    2012-04-06

    Globally, the cement industry accounts for approximately 5 percent of current anthropogenic carbon dioxide (CO{sub 2}) emissions. World cement demand and production are increasing significantly, leading to an increase in this industry's absolute energy use and CO{sub 2} emissions. Development of new energy-efficiency and CO{sub 2} emission-reduction technologies and their deployment in the market will be key for the cement industry's mid- and long-term climate change mitigation strategies. This report is an initial effort to compile available information on process description, energy savings, environmental and other benefits, costs, commercialization status, and references for emerging technologies to reduce the cement industry's energy use and CO{sub 2} emissions. Although studies from around the world identify a variety of sector-specific and cross-cutting energy-efficiency technologies for the cement industry that have already been commercialized, information is scarce and/or scattered regarding emerging or advanced energy-efficiency and low-carbon technologies that are not yet commercialized. This report consolidates available information on nineteen emerging technologies for the cement industry, with the goal of providing engineers, researchers, investors, cement companies, policy makers, and other interested parties with easy access to a well-structured database of information on these technologies.

  15. Combining IPPC and emission trading: An assessment of energy efficiency and CO2 reduction potentials in the Austrian paper industry

    International Nuclear Information System (INIS)

    Starzer, Otto; Dworak, Oliver

    2005-01-01

    In the frame of an innovative project partnership E.V.A. - the Austrian Energy Agency accompanied the Austrian paper industry for the last 2.5 years in developing a branch specific climate change strategy. Within the scope of this project an assessment of the energy efficiency status of the branch was carried out as well as an evaluation of still realisable energy savings and CO 2 reduction potentials. The paper presents the methodology applied, which combines a top down approach (benchmarking and best practice) with a bottom up approach (on-site interviews and energy audits), supported by a huge data collection process. Within the benchmarking process all Austrian paper industry installations affected by the EU emission trading directive were benchmarked against their respective IPPC/BAT values. Furthermore an extensive list of best practice examples derived from existing or ongoing studies was compared with the energy efficiency measures already carried out by the companies ('early actions'). These theory-oriented findings were complemented by several on-site interviews with the respective energy managers as well as by detailed energy audits carried out by a consulting company, covering in total more than 80% of the Austrian paper industry's CO 2 emissions. The paper concludes with the main results of the project, presenting the pros and cons of working with IPPC documents and BAT values in terms of energy efficiency assessments. Recommendations are presented on how to improve the allocation exercise for the next emission trading period from 2008 to 2012

  16. Synthesis of 32P labelled phosphate sources with different solubility and their efficient s as fertilizers

    International Nuclear Information System (INIS)

    De Luca, Edgar Fernando; Boaretto, Antonio Enedi; Muraoka, Takashi

    1999-01-01

    The study was carried out at the Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo (CENA/USP), Brazil. With the objective to determine, by the isotopic tracer, the P recovery by rice (Oriza sativa) plants and eucalypt (Eucalyptus grandis) seedlings from the P sources with different solubilities, an experiment was carried out in greenhouse, using Quartzpsamment soil samples, which is very poor in P content. Monocalcium, bicalcium, and tricalcium phosphate, Ca(H2 32 PO4).H2O, CaH 32 PO4.2H2O and Ca3(32 PO4)2, respectively were obtained in laboratory. Their solubilities and the X-ray difratometry and differential thermal analysis comproved that the laboratory procedures were adequate for obtaining the desired compounds. These products were applied in the soil as fertilizers. Plants were harvested 60 days after growth period, digested and analysed for total P and 32 P counting through Cerenkov effect. The P recovery from the sources varied from 14.1% [Ca(H2 32 PO4).H2O] to 17.0% [CaH 32 PO4.2H2O] for eucalypt, and from 15.0% [Ca3(32 PO4)2] to 22.2% [CaH 32 PO4.2H2O] for rice. The rice plants showed better ability to absorb P from the laboratory prepared sources, but the eucalypt presented higher P nutritional efficiency index. The difference method, used for determining the P recovery, underestimated the eucalypt and rice plant ability to absorb this nutrient compared to the isotopic method

  17. Joint Source Location and Focal Mechanism Inversion: efficiency, accuracy and applications

    Science.gov (United States)

    Liang, C.; Yu, Y.

    2017-12-01

    The analysis of induced seismicity has become a common practice to evaluate the results of hydraulic fracturing treatment. Liang et al (2016) proposed a joint Source Scanning Algorithms (jSSA for short) to obtain microseismic events and focal mechanisms simultaneously. The jSSA is superior over traditional SSA in many aspects, but the computation cost is too significant to be applied in real time monitoring. In this study, we have developed several scanning schemas to reduce computation time. A multi-stage scanning schema is proved to be able to improve the efficiency significantly while also retain its accuracy. A series of tests have been carried out by using both real field data and synthetic data to evaluate the accuracy of the method and its dependence on noise level, source depths, focal mechanisms and other factors. The surface-based arrays have better constraints on horizontal location errors (0.5). For sources with varying rakes, dips, strikes and depths, the errors are mostly controlled by the partition of positive and negative polarities in different quadrants. More evenly partitioned polarities in different quadrants yield better results in both locations and focal mechanisms. Nevertheless, even with bad resolutions for some FMs, the optimized jSSA method can still improve location accuracies significantly. Based on much more densely distributed events and focal mechanisms, a gridded stress inversion is conducted to get a evenly distributed stress field. The full potential of the jSSA has yet to be explored in different directions, especially in earthquake seismology as seismic array becoming incleasingly dense.

  18. Facile preparation of three-dimensional Co1-xS/sulfur and nitrogen-codoped graphene/carbon foam for highly efficient oxygen reduction reaction

    Science.gov (United States)

    Liang, Hui; Li, Chenwei; Chen, Tao; Cui, Liang; Han, Jingrui; Peng, Zhi; Liu, Jingquan

    2018-02-01

    Because of the urgent need for renewable resources, oxygen reduction reaction (ORR) has been widely studied. Finding efficient and low cost non-precious metal catalyst is increasingly critical. In this study, melamine foam is used as template to obtain porous sulfur and nitrogen-codoped graphene/carbon foam with uniformly distributed cobalt sulfide nanoparticles (Co1-xS/SNG/CF) which is prepared by a simple infiltration-drying-sulfuration method. It is noteworthy that melamine foam not only works as a three-dimensional support skeleton, but also provides a nitrogen source without any environmental pollution. Such Co1-xS/SNG/CF catalyst shows excellent oxygen reduction catalytic performance with an onset potential of only 0.99 V, which is the same as that of Pt/C catalyst (Eonset = 0.99 V). Furthermore, the stability and methanol tolerance of Co1-xS/SNG/CF are more outstanding than those of Pt/C catalyst. Our work manifests a facile method to prepare S and N-codoped 3D graphene network decorated with Co1-xS nanoparticles, which may be utilized as potential alternative to the expensive Pt/C catalysts toward ORR.

  19. Evaluation of virus reduction efficiency in wastewater treatment unit processes as a credit value in the multiple-barrier system for wastewater reclamation and reuse

    OpenAIRE

    Ito, Toshihiro; Kato, Tsuyoshi; Hasegawa, Makoto; Katayama, Hiroyuki; Ishii, Satoshi; Okabe, Satoshi; Sano, Daisuke

    2016-01-01

    The virus reduction efficiency of each unit process is commonly determined based on the ratio of virus concentration in influent to that in effluent of a unit, but the virus concentration in wastewater has often fallen below the analytical quantification limit, which does not allow us to calculate the concentration ratio at each sampling event. In this study, left-censored datasets of norovirus (genogroup I and II), and adenovirus were used to calculate the virus reduction efficiency in unit ...

  20. Specific power reduction of an ion source due to heating and cathode sputtering of electrodes

    International Nuclear Information System (INIS)

    Hamilton, G.U.; Semashko, N.N.

    The potentialities and limitations of the water-cooled ion-optical system of the ion source designed for continuous operation of the high-power neutral beam injector are determined. The following problems are analyzed: thermal expansion and deformation of electrodes, electrode sputtering as a result of bombardment, and heat transfer to turbulent flow of water

  1. Effects of different sources of protein on digestive characteristics, microbial efficiency, and nutrient flow in dairy goats

    Directory of Open Access Journals (Sweden)

    Nivea Regina de Oliveira Felisberto

    2011-10-01

    Full Text Available Diets formulated with protein sources presenting different resistance to ruminal degradation were compared by evaluating ruminal parameters, production and microbial efficiency and nutrients flow to the omasum in goats. Eight rumen cannulated non-lactating, non-pregnant goats were distributed in a 4 × 4 Latin square design with two replicates. Treatments consisted of four diets where different sources of plant protein accounted for the major protein source named soybean meal, source of higher ruminal degradability, and three other sources of higher resistance of degradation: roasted soybean, corn gluten meal, and cottonseed cake. Amounts of rumen protein were similar among rations; however, flows of dry matter, protein and non-fiber carbohydrate to omasum were higher for diets with protein source with reduced rumen degradation rate. Higher values of rumen ammonia were obtained by using ration with soybean meal as major source of protein. Higher values of pH were obtained for rations with roasted soybean e cottonseed cake. Regarding kinetic of transit, similar values were found among rations. Diets with protein sources presenting reduced ruminal degradation increase nutrients flow to the omasum in goats and alter digestive parameters such as pH and ammonia without compromising bacteria growth and efficiency, which grants their use for dairy goats with similar efficiency to rations using more degradable sources of protein.

  2. CO2 Tax or Fee as a Single Economic Instrument for Climate Protection Policy Promoting Renewable Energy Sources and Enhancing Energy Efficiency

    International Nuclear Information System (INIS)

    Granic, G.; Horvath, L.; Jelavic, B.; Juric, Z.; Kulisic, B.; Vuk, B.

    2013-01-01

    This paper presents the analysis of the current implementation of the policy to reduce CO 2 emissions through four practically independent processes: energy market, emission market, support for renewable energy sources through feed-in tariffs (FIT) and support scheme for enhancing energy efficiency. The conclusion is that in this system, some elements of which appear to be controversial, it is not possible to reach the goal - a radical reduction of CO 2 emissions by 80% in total and 95% in electricity production until 2050, which the EU has set as emission reduction targets for this period. Therefore, a new system is now proposed that is based on a single objective function, CO 2 emissions. The process would be managed through taxes or fees on CO 2 , while the raised revenues would be returned to projects aimed at reducing CO 2 emissions, projects for enhancing energy efficiency, renewable energy sources projects and projects reducing emissions from fossil fuels. The paper outlines the basis of the concept of CO 2 tax or fee as a key measure to stimulate the lowering of emissions and gives an analysis of the impact of different rates of tax or fee on CO 2 emissions on the energy price. A critical analysis of the new model's impact on development of renewable energy sources and on improving energy efficiency in buildings was carried out. Also, there is an analysis of the impact of the new model on transport development. The introduction of the new model should clear the energy market from administrative limitations and privileged positions of renewable sources and should bring all back in the frame of market economy, no matter what source of energy for production of electricity we are dealing with. One limitation to the new model is translation of the current situation in to the new system, especially in the field of renewable energy sources and their protected position under the already concluded long-term contracts. The paper also elaborates the basis for the

  3. Evaluation of non-point source pollution reduction by applying best management practices using a SWAT model and QuickBird high resolution satellite imagery.

    Science.gov (United States)

    Lee, MiSeon; Park, GeunAe; Park, MinJi; Park, JongYoon; Lee, JiWan; Kim, SeongJoon

    2010-01-01

    This study evaluated the reduction effect of non-point source pollution by applying best management practices (BMPs) to a 1.21 km2 small agricultural watershed using a SWAT (Soil and Water Assessment Tool) model. Two meter QuickBird land use data were prepared for the watershed. The SWAT was calibrated and validated using daily streamflow and monthly water quality (total phosphorus (TP), total nitrogen (TN), and suspended solids (SS)) records from 1999 to 2000 and from 2001 to 2002. The average Nash and Sutcliffe model efficiency was 0.63 for the streamflow and the coefficients of determination were 0.88, 0.72, and 0.68 for SS, TN, and TP, respectively. Four BMP scenarios viz. the application of vegetation filter strip and riparian buffer system, the regulation of Universal Soil Loss Equation P factor, and the fertilizing control amount for crops were applied and analyzed.

  4. Efficient and Selective Reduction of Aromatic Nitro Compounds to Aromatic Amines by NbCl{sub 5}/Indium System

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Byung Woo; Kim, Duckil; Kim, Hyung Min; Kang, Sung Ho [Korea Univ., Seoul (Korea, Republic of)

    2012-09-15

    Aromatic amines find applicability in diverse fields including dyes, pharmaceuticals, agrochemicals, and photographic materials. To date, there are a variety of methods, which can be used to convert aromatic nitro compounds to their corresponding amines. Some of them include Cp{sub 2}TiCl{sub 2}/In, Al/NH{sub 4}Cl, (NH{sub 4}){sub 2}SO{sub 4}/NaBH{sub 4}, NiCl{sub 2}6H{sub 2}O/In, HI, Sm/I{sub 2}, In/NH{sub 4}Cl, B{sub 4}H{sub 10}/Pd/C, Co{sub 2}(CO){sub 8}/H{sub 2}O and In/HCl. However, most methods still lack the desired chemo-selectivity when other reducible functional groups are present in the nitroarene and often require long reaction times, or harsh reaction conditions. Consequently, efficient and selective methods for the reduction of aromatic nitro compounds continue to be developed. It has been reported that NbCl{sub 5}/Zn system is used as a reagent for reducing sulfoxides, epoxides, and amine N-oxides.12 Because of the close resemblance of indium to zinc in several respects, including first ionization potential, we considered that NbCl{sub 5}/In system can be an efficient reducing agent for the conversion of aromatic nitro compounds to the corresponding amines. Recently, indium metal has attracted much attention for its unique properties such as low toxicity and high stability in water and air compared with other metals. In continuation of our interest in exploring the utility of metal-metal salt system in organic synthesis, we would like to report an efficient and chemo-selective method for the reduction of various aromatic nitro compounds to the corresponding amines by treatment with NbCl{sub 5}/In system (eq. 1). The new reduction system was generated by the addition of indium powder to a stirred solution of niobium(V) chloride in THF under sonication. The generation of low-valent niobium species was examined at room temperature with an excess of indium metal. The observations suggest that this procedure can be applied for the chemo

  5. Personalized Energy Reduction Cyber-Physical System (PERCS): A gamified end-user platform for energy efficiency and demand response.

    Energy Technology Data Exchange (ETDEWEB)

    Sintov, Nicole; Orosz, Michael; Schultz, P. Wesley

    2015-01-01

    The mission of the Personalized Energy Reduction Cyber-physical System (PERCS) is to create new possibilities for improving building operating efficiency, enhancing grid reliability, avoiding costly power interruptions, and mitigating greenhouse gas emissions. PERCS proposes to achieve these outcomes by engaging building occupants as partners in a user-centered smart service platform. Using a non-intrusive load monitoring approach, PERCS uses a single sensing point in each home to capture smart electric meter data in real time. The household energy signal is disaggregated into individual load signatures of common appliances (e.g., air conditioners), yielding near real-time appliance-level energy information. Users interact with PERCS via a mobile phone platform that provides household- and appliance-level energy feedback, tailored recommendations, and a competitive game tied to energy use and behavioral changes. PERCS challenges traditional energy management approaches by directly engaging occupant as key elements in a technological system.

  6. A bio-inspired N-doped porous carbon electrocatalyst with hierarchical superstructure for efficient oxygen reduction reaction

    Science.gov (United States)

    Miao, Yue-E.; Yan, Jiajie; Ouyang, Yue; Lu, Hengyi; Lai, Feili; Wu, Yue; Liu, Tianxi

    2018-06-01

    The bio-inspired hierarchical "grape cluster" superstructure provides an effective integration of one-dimensional carbon nanofibers (CNF) with isolated carbonaceous nanoparticles into three-dimensional (3D) conductive frameworks for efficient electron and mass transfer. Herein, a 3D N-doped porous carbon electrocatalyst consisting of carbon nanofibers with grape-like N-doped hollow carbon particles (CNF@NC) has been prepared through a simple electrospinning strategy combined with in-situ growth and carbonization processes. Such a bio-inspired hierarchically organized conductive network largely facilitates both the mass diffusion and electron transfer during the oxygen reduction reactions (ORR). Therefore, the metal-free CNF@NC catalyst demonstrates superior catalytic activity with an absolute four-electron transfer mechanism, strong methanol tolerance and good long-term stability towards ORR in alkaline media.

  7. Synthesis of AuPd alloyed nanoparticles via room-temperature electron reduction with argon glow discharge as electron source.

    Science.gov (United States)

    Yang, Manman; Wang, Zongyuan; Wang, Wei; Liu, Chang-Jun

    2014-01-01

    Argon glow discharge has been employed as a cheap, environmentally friendly, and convenient electron source for simultaneous reduction of HAuCl4 and PdCl2 on the anodic aluminum oxide (AAO) substrate. The thermal imaging confirms that the synthesis is operated at room temperature. The reduction is conducted with a short time (30 min) under the pressure of approximately 100 Pa. This room-temperature electron reduction operates in a dry way and requires neither hydrogen nor extra heating nor chemical reducing agent. The analyses using X-ray photoelectron spectroscopy (XPS) confirm all the metallic ions have been reduced. The characterization with X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) shows that AuPd alloyed nanoparticles are formed. There also exist some highly dispersed Au and Pd monometallic particles that cannot be detected by XRD and transmission electron microscopy (TEM) because of their small particle sizes. The observed AuPd alloyed nanoparticles are spherical with an average size of 14 nm. No core-shell structure can be observed. The room-temperature electron reduction can be operated in a larger scale. It is an easy way for the synthesis of AuPd alloyed nanoparticles.

  8. Contaminant Flux Reduction Barriers for Managing Difficult-to-Treat Source Zones in Unconsolidated Media

    Science.gov (United States)

    2017-06-20

    estimated viscosity of 3-4 cP.  Solutions-IES Novel Silica Gel/Veg-Oil Grout: 5 wt- % of emulsified vegetable oil (EVO), 10 wt-% of sodium...site must have a lower low permeability unit such as a clay to prevent up flow; and a four sided barrier is recommended (three sided barriers are...depth to groundwater (ង ft)  Transmissive zone preferably with an underlying clay layer  Good accessibility to source zone  Availability of

  9. Biogenic Hydrogen Conversion of De-Oiled Jatropha Waste via Anaerobic Sequencing Batch Reactor Operation: Process Performance, Microbial Insights, and CO2 Reduction Efficiency

    Directory of Open Access Journals (Sweden)

    Gopalakrishnan Kumar

    2014-01-01

    Full Text Available We report the semicontinuous, direct (anaerobic sequencing batch reactor operation hydrogen fermentation of de-oiled jatropha waste (DJW. The effect of hydraulic retention time (HRT was studied and results show that the stable and peak hydrogen production rate of 1.48 L/L*d and hydrogen yield of 8.7 mL H2/g volatile solid added were attained when the reactor was operated at HRT 2 days (d with a DJW concentration of 200 g/L, temperature 55°C, and pH 6.5. Reduced HRT enhanced the production performance until 1.75 d. Further reduction has lowered the process efficiency in terms of biogas production and hydrogen gas content. The effluent from hydrogen fermentor was utilized for methane fermentation in batch reactors using pig slurry and cow dung as seed sources. The results revealed that pig slurry was a feasible seed source for methane generation. Peak methane production rate of 0.43 L CH4/L*d and methane yield of 20.5 mL CH4/g COD were observed at substrate concentration of 10 g COD/L, temperature 30°C, and pH 7.0. PCR-DGGE analysis revealed that combination of celluloytic and fermentative bacteria were present in the hydrogen producing ASBR.

  10. Undertaking high impact strategies: The role of national efficiency measures in long-term energy and emission reduction in steel making

    International Nuclear Information System (INIS)

    Xu, Tengfang; Karali, Nihan; Sathaye, Jayant

    2014-01-01

    Highlights: • Evaluate long-term effects of national energy efficiency in steel making. • Use bottom-up optimization for projection in China, India and the U.S. • The effects include changes in steel production, energy use, emissions, and costs. • Three emission targets induce different structural changes and investments. • Projected energy and CO 2 intensity declines in each country from 2010 to 2050. - Abstract: In this paper, we applied bottom-up linear optimization modeling to analyze long-term national impacts of implementing energy efficiency measures on energy savings, CO 2 -emission reduction, production, and costs of steel making in China, India, and the U.S. We first established two base scenarios representing business-as-usual steel production for each country from 2010 to 2050; Base scenario (in which no efficiency measure is available) and Base-E scenario (in which efficiency measures are available), and model scenarios representing various emission-reduction targets that affects production, annual energy use and costs with the goal of cost minimization. A higher emission-reduction target generally induces larger structural changes and increased investments in nation-wide efficiency measures, in addition to autonomous improvement expected in the Base scenario. Given the same emission-reduction target compared to the base scenario, intensity of annual energy use and emissions exhibits declining trends in each country from year 2010 to 2050. While a higher emission-reduction target result in more energy reduction from the base scenario, such reduction can become more expensive to achieve. The results advance our understanding of long-term effects of national energy efficiency applications under different sets of emission-reduction targets for steel sectors in the three major economies, and provide useful implications for high impact strategies to manage production structures, production costs, energy use, and emission reduction in steel making

  11. Rapid and efficient photocatalytic reduction of hexavalent chromium by using “water dispersible” TiO2 nanoparticles

    International Nuclear Information System (INIS)

    Wang, Lei; Kang, Shi-Zhao; Li, Xiangqing; Qin, Lixia; Yan, Hao; Mu, Jin

    2016-01-01

    In the present work, “water dispersible” TiO 2 nanoparticles were prepared, and meanwhile, their photocatalytic activity was systematically tested for the reduction of aqueous Cr(VI) ions. It is found that the as-prepared “water dispersible” TiO 2 nanoparticles are a highly efficient photocatalyst for the reduction of Cr(VI) ions in water under UV irradiation, and suitable for the remediation of Cr(VI) ions wastewater with low concentration. Compared with commercial TiO 2 nanoparticles (P25), the “water dispersible” TiO 2 nanoparticles exhibit 3.8-fold higher photocatalytic activity. 100% Cr (VI) ions can be reduced into Cr(III) ions within 10 min when the Cr (VI) ions initial concentration is 10 mg L −1 . Moreover, the electrical energy consumption can be obviously decreased using the “water dispersible” TiO 2 nanoparticles. These results suggest that the “water dispersible” TiO 2 nanoparticles are a promising photocatalyst for rapid removal of Cr (VI) in environmental therapy. - Highlights: • “Water dispersible” TiO 2 nanoparticles with high photocatalytic activity. • 100% Cr (VI) (10 mg L −1 ) can be reduced within 10 min. • Obvious decrease of electrical energy consumption.

  12. Highly efficient visible light photocatalytic reduction of CO2 to hydrocarbon fuels by Cu-nanoparticle decorated graphene oxide.

    Science.gov (United States)

    Shown, Indrajit; Hsu, Hsin-Cheng; Chang, Yu-Chung; Lin, Chang-Hui; Roy, Pradip Kumar; Ganguly, Abhijit; Wang, Chen-Hao; Chang, Jan-Kai; Wu, Chih-I; Chen, Li-Chyong; Chen, Kuei-Hsien

    2014-11-12

    The production of renewable solar fuel through CO2 photoreduction, namely artificial photosynthesis, has gained tremendous attention in recent times due to the limited availability of fossil-fuel resources and global climate change caused by rising anthropogenic CO2 in the atmosphere. In this study, graphene oxide (GO) decorated with copper nanoparticles (Cu-NPs), hereafter referred to as Cu/GO, has been used to enhance photocatalytic CO2 reduction under visible-light. A rapid one-pot microwave process was used to prepare the Cu/GO hybrids with various Cu contents. The attributes of metallic copper nanoparticles (∼4-5 nm in size) in the GO hybrid are shown to significantly enhance the photocatalytic activity of GO, primarily through the suppression of electron-hole pair recombination, further reduction of GO's bandgap, and modification of its work function. X-ray photoemission spectroscopy studies indicate a charge transfer from GO to Cu. A strong interaction is observed between the metal content of the Cu/GO hybrids and the rates of formation and selectivity of the products. A factor of greater than 60 times enhancement in CO2 to fuel catalytic efficiency has been demonstrated using Cu/GO-2 (10 wt % Cu) compared with that using pristine GO.

  13. Efficiency and Effectiveness in the Collection and Analysis of S&T Open Source Information

    International Nuclear Information System (INIS)

    Pericou-Cayere, M.; Lemaire, P.; Pace, J.-M.; Baude, S.; Samson, N.

    2015-01-01

    While looking for information in scientific database, we are overwhelmed by the amount of information that we encounter. In this big data collection, getting information with added-value could be strategic for nuclear verification. In our study, we have worked about ''best practices'' in collecting, processing and analyzing open source scientific and technical information. First, we were insistent on working with information authenticated by referees such as scientific publications (structured information). Analysis of this structured data is made with bibliometric tools. Several steps are carried out: collecting data related to the paradigm, creating a database to store data generated by bibliographic research, analyzing data with selected tools. With analysis of bibliographic data only, we are able to get: · a panoramic view of countries that publish in the paradigm, · co-publication networks, · organizations that contribute to scientific publications, · countries with which a country collaborates, · areas of interest of a country, . . . So we are able to identify a target. On a second phase, we can focus on a target (countries for example). Working with non-structured data (i.e., press release, social networks, full text analysis of publications) is in progress and needs other tools to be added to the process, as we will discuss in this paper. In information analysis, methodology and expert analysis are important. Software analysis is just a tool to achieve our goal. This presentation deals with concrete measures that improve the efficiency and effectiveness in the use of open source S&T information and in the management of that information over time. Examples are shown. (author)

  14. Phytoscreening as an efficient tool to delineate chlorinated solvent sources at a chlor-alkali facility.

    Science.gov (United States)

    Yung, Loïc; Lagron, Jérôme; Cazaux, David; Limmer, Matt; Chalot, Michel

    2017-05-01

    Chlorinated ethenes (CE) are among the most common volatile organic compounds (VOC) that contaminate groundwater, currently representing a major source of pollution worldwide. Phytoscreening has been developed and employed through different applications at numerous sites, where it was generally useful for detection of subsurface chlorinated solvents. We aimed at delineating subsurface CE contamination at a chlor-alkali facility using tree core data that we compared with soil data. For this investigation a total of 170 trees from experimental zones was sampled and analyzed for perchloroethene (PCE) and trichloroethene (TCE) concentrations, measured by solid phase microextraction gas chromatography coupled to mass spectrometry. Within the panel of tree genera sampled, Quercus and Ulmus appeared to be efficient biomonitors of subjacent TCE and PCE contamination, in addition to the well known and widely used Populus and Salix genera. Among the 28 trees located above the dense non-aqueous phase liquid (DNAPL) phase zone, 19 tree cores contained detectable amounts of CE, with concentrations ranging from 3 to 3000 μg L -1 . Our tree core dataset was found to be well related to soil gas sampling results, although the tree coring data were more informative. Our data further emphasized the need for choosing the relevant tree species and sampling periods, as well as taking into consideration the nature of the soil and its heterogeneity. Overall, this low-invasive screening method appeared useful to delineate contaminants at a small-scale site impacted by multiple sources of chlorinated solvents. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Highly efficient removal of trace thallium from contaminated source waters with ferrate: Role of in situ formed ferric nanoparticle.

    Science.gov (United States)

    Liu, Yulei; Wang, Lu; Wang, Xianshi; Huang, Zhuangsong; Xu, Chengbiao; Yang, Tao; Zhao, Xiaodan; Qi, Jingyao; Ma, Jun

    2017-11-01

    Thallium (Tl) is highly toxic to mammals and relevant pollution cases are increasing world-widely. Convenient and efficient method for the removal of trace Tl from contaminated source water is imperative. Here, the removal of trace Tl by K 2 FeO 4 [Fe(VI)] was investigated for the first time, with the exploration of reaction mechanisms. Six different types of water treatment agents (powdered activated carbon, Al 2 (SO 4 ) 3 , FeCl 3 , δ-MnO 2 , MnO 2 nano-particles, and K 2 FeO 4 ) were used for the removal of Tl in spiked river water, and K 2 FeO 4 showed excellent removal performance. Over 92% of Tl (1 μg/L) was removed within 5 min by applying 2.5 mg/L of K 2 FeO 4 (pH 7.0, 20 °C). XPS analysis revealed that in the reaction of Tl(I) with K 2 FeO 4 , Tl(I) was oxidized to Tl(III), and removed by the K 2 FeO 4 reduced ferric particles. The removal of Tl by in situ formed and ex situ formed ferric particle was examined respectively, and the results revealed that the removal of trace Tl could be attributed to the combination of adsorption and coprecipitation processes. The hydrodynamic size of the reduced particle from K 2 FeO 4 ranged from 10 nm to 100 nm, and its surface was negatively charged under neutral pH condition. These factors were conducive for the efficient removal of Tl by K 2 FeO 4 . The effects of solution pH, coexisting ions (Na + , Ca 2+ , and HCO 3 - ), humic acid, solution temperature, and reductive environment on the removal and desorption of Tl were investigated, and the elimination of Tl in polluted river water and reservoir water was performed. These results suggest that K 2 FeO 4 could be an efficient and convenient agent on trace Tl removal. Copyright © 2017. Published by Elsevier Ltd.

  16. Transforming waste biomass with an intrinsically porous network structure into porous nitrogen-doped graphene for highly efficient oxygen reduction.

    Science.gov (United States)

    Zhou, Huang; Zhang, Jian; Amiinu, Ibrahim Saana; Zhang, Chenyu; Liu, Xiaobo; Tu, Wenmao; Pan, Mu; Mu, Shichun

    2016-04-21

    Porous nitrogen-doped graphene with a very high surface area (1152 m(2) g(-1)) is synthesized by a novel strategy using intrinsically porous biomass (soybean shells) as a carbon and nitrogen source via calcination and KOH activation. To redouble the oxygen reduction reaction (ORR) activity by tuning the doped-nitrogen content and type, ammonia (NH3) is injected during thermal treatment. Interestingly, this biomass-derived graphene catalyst exhibits the unique properties of mesoporosity and high pyridine-nitrogen content, which contribute to the excellent oxygen reduction performance. As a result, the onset and half-wave potentials of the new metal-free non-platinum catalyst reach -0.009 V and -0.202 V (vs. SCE), respectively, which is very close to the catalytic activity of the commercial Pt/C catalyst in alkaline media. Moreover, our catalyst has a higher ORR stability and stronger CO and CH3OH tolerance than Pt/C in alkaline media. Importantly, in acidic media, the catalyst also exhibits good ORR performance and higher ORR stability compared to Pt/C.

  17. Reduced Graphene Oxide-Immobilized Tris(bipyridine)ruthenium(II) Complex for Efficient Visible-Light-Driven Reductive Dehalogenation Reaction.

    Science.gov (United States)

    Li, Xiaoyan; Hao, Zhongkai; Zhang, Fang; Li, Hexing

    2016-05-18

    A sodium benzenesulfonate (PhSO3Na)-functionalized reduced graphene oxide was synthesized via a two-step aryl diazonium coupling and subsequent NaCl ion-exchange procedure, which was used as a support to immobilize tris(bipyridine)ruthenium(II) complex (Ru(bpy)3Cl2) by coordination reaction. This elaborated Ru(bpy)3-rGO catalyst exhibited excellent catalytic efficiency in visible-light-driven reductive dehalogenation reactions under mild conditions, even for ary chloride. Meanwhile, it showed the comparable reactivity with the corresponding homogeneous Ru(bpy)3Cl2 catalyst. This high catalytic performance could be attributed to the unique two-dimensional sheet-like structure of Ru(bpy)3-rGO, which efficiently diminished diffusion resistance of the reactants. Meanwhile, the nonconjugated PhSO3Na-linkage between Ru(II) complex and the support and the very low electrical conductivity of the catalyst inhibited energy/electron transfer from Ru(II) complex to rGO support, resulting in the decreased support-induced quenching effect. Furthermore, it could be easily recycled at least five times without significant loss of catalytic reactivity.

  18. Papers of the Canadian Energy Pipeline Association's 7. annual climate change workshop : energy efficiency and greenhouse gas reduction opportunities

    International Nuclear Information System (INIS)

    2003-01-01

    This conference focused on the role that Canadian pipeline companies will play in addressing greenhouse gas emissions. Ninety-five per cent of Canada's oil and gas is transported by pipeline. The Canadian Energy Pipeline Association (CEPA) is a national association representing all the major crude oil and natural gas transportation companies in Canada which operate 100,000 kilometres of pipeline in the country. CEPA's ongoing commitment to climate change includes a commitment to participate in the climate change process, share best management practices, develop energy efficient technology, and position Canadian companies so that they can be part of the solution. It was emphasized that a strong commitment to an effective innovation strategy will be crucial to a successful long term energy policy that meets both economic and environmental objectives. One of the key messages at the conference was that Canada's climate change policies should be consistent with those of the United States, its major trading partner, to ensure that Canada is not placed at a competitive disadvantage within North American and world energy markets. It was also noted that greenhouse gas emissions should be reduced in all consuming and producing sectors of the economy through energy efficiency practices and not through reductions in Canadian industry output for domestic or export markets. Five presentations were indexed separately for inclusion in the database. tabs., figs

  19. Manganese dioxide-supported silver bismuthate as an efficient electrocatalyst for oxygen reduction reaction in zinc-oxygen batteries

    International Nuclear Information System (INIS)

    Sun, Yanzhi; Yang, Meng; Pan, Junqing; Wang, Pingyuan; Li, Wei; Wan, Pingyu

    2016-01-01

    In this paper, we present a new efficient composite electrocatalyst, manganese dioxide-supported silver bismuthate (Ag 4 Bi 2 O 5 /MnO 2 ), for oxygen reduction reaction (ORR) in alkaline media. The new electrocatalyst was characterized with scanning electron microscope (SEM), powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Electrochemical measurements indicate that the Ag 4 Bi 2 O 5 /MnO 2 composite is a very efficient electrocatalyst for ORR in alkaline media. The physical and electrochemical characterization results suggest that the high activity is ascribed to the support effects from MnO 2 and the synergetic effects among Ag 4 Bi 2 O 5 and MnO 2 . The analysis of rotating disk electrode (RDE) results shows that the ORR occurs via a four-electron pathway on the surface of the Ag 4 Bi 2 O 5 /MnO 2 electrocatalyst. This electrocatalyst was further tested in a designed zinc–oxygen (Zn–O 2 ) battery. This battery can offer a discharge time of 225 h at 120 mA cm −2 , increasing by more than 492% as compared with pure MnO 2 electrocatalyst. It demonstrates that this inexpensive Ag 4 Bi 2 O 5 /MnO 2 electrocatalyst is a viable alternative to platinum electrocatalyst for energy conversion devices.

  20. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hansang, E-mail: hslee80@kiu.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jung, Seungmin [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of); Cho, Yoonsung [Department of Electric and Energy Engineering, Catholic University of Daegu, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-702 (Korea, Republic of); Yoon, Donghee [Department of New and Renewable Energy, Kyungil University, Hayang-eup, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of)

    2013-11-15

    Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

  1. Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

    International Nuclear Information System (INIS)

    Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

    2013-01-01

    Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed

  2. Voluntary agreements in the field of energy efficiency and emission reduction: Review and analysis of experiences in the European Union

    International Nuclear Information System (INIS)

    Rezessy, Silvia; Bertoldi, Paolo

    2011-01-01

    A number of Member States of the EU have introduced voluntary agreements (VAs) that aim to deliver energy savings and emission reductions via increased energy efficiency in different end-use sectors, mainly targeting industry. Where there is a successful track record of cooperation between public authorities and the private sector, VAs can offer advantages to public authorities in comparison to legislation, most importantly better flexibility when introduced or updated, greater acceptance by industry, possibility for tailor-made solutions e.g. at the level of industrial sectors and opportunity to overcome the information asymmetry between public authorities and private actors. Nevertheless, VAs have been criticized for lack of specific obligations and lenient targets, as well as for deficiencies in compliance monitoring and self-reporting and difficulty in establishing the policy additionality of VA activity. This paper analyses the design of existing VAs in terms of general framework, targets and sectors, obligations and commitments, motivation to join, reporting and monitoring provisions, and results of existing VAs as reported by national authorities. The paper summarizes the key characteristics of voluntary agreements and gives recommendations for the successful application of this policy tool. - Highlights: → Analyze the design of voluntary agreements (VAs) for energy efficiency. → Study national-level VAs in the European Union. → Analyze their general framework and results delivered. → Summarize the key characteristics of VAs. → Give recommendations for the successful application of this policy tool.

  3. Development of Abdominal Compression Belt and Evaluation of the Efficiency for the Reduction of Respiratory Motion in SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Seon Bung; Kim, Il Hwan; Kim, Woong; Im, Hyeong Seo; Gang, Jin Mook; Jeong, Seong Min; Kim, Gi Hwan; Lee, Ah Ram [Dept. of Radiation and Oncology, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Cho, Yura [Dept. of Cyberknife, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2011-03-15

    It's essential to minimize the tumor motion and identify the exact location of the lesions to achieve the improvement in radiation therapy efficiency during SBRT. In this study, we made the established compression belt to reduce respiratory motion and evaluated the usefulness of clinical application in SBRT. We analyzed the merits and demerits of the established compression belt to reduce the respiratory motion and improved the reproducibility and precision in use. To evaluate the usefulness of improved compression belt for respiratory motion reduction in SBRT, firstly, we reviewed the spiral CT images acquired in inspiration and expiration states of 8 lung cancer cases, respectively, and analyzed the three dimensional tumor motion related to respiration. To evaluate isodose distribution, secondly, we also made the special phantom using EBT2 film (Gafchronic, ISP, USA) and we prepared the robot (Cartesian Robot-2 Axis, FARARCM4H, Samsung Mechatronics, Korea) to reproduce three dimensional tumor motion. And analysis was made for isodose curves and two dimensional isodose profiles with reproducibility of respiratory motion on the basis of CT images. A respiratory motion reduction compression belt (Velcro type) that has convenient use and good reproducibility was developed. The moving differences of three dimensional tumor motion of lung cancer cases analyzed by CT images were mean 3.2 mm, 4.3 mm and 13 mm each in LR, AP and CC directions. The result of characteristic change in dose distribution using the phantom and rectangular coordinates robot showed that the distortion of isodose has great differences, mean length was 4.2 mm; the differences were 8.0% and 16.8% each for cranio-caudal and 8.1% and 10.9% each for left-right directions in underdose below the prescribed dose. In this study, we could develop the convenient and efficient compression belt that can make the organs' motion minimize. With this compression belt, we confirmed that underdose due to

  4. Development of Abdominal Compression Belt and Evaluation of the Efficiency for the Reduction of Respiratory Motion in SBRT

    International Nuclear Information System (INIS)

    Hwang, Seon Bung; Kim, Il Hwan; Kim, Woong; Im, Hyeong Seo; Gang, Jin Mook; Jeong, Seong Min; Kim, Gi Hwan; Lee, Ah Ram; Cho, Yura

    2011-01-01

    It's essential to minimize the tumor motion and identify the exact location of the lesions to achieve the improvement in radiation therapy efficiency during SBRT. In this study, we made the established compression belt to reduce respiratory motion and evaluated the usefulness of clinical application in SBRT. We analyzed the merits and demerits of the established compression belt to reduce the respiratory motion and improved the reproducibility and precision in use. To evaluate the usefulness of improved compression belt for respiratory motion reduction in SBRT, firstly, we reviewed the spiral CT images acquired in inspiration and expiration states of 8 lung cancer cases, respectively, and analyzed the three dimensional tumor motion related to respiration. To evaluate isodose distribution, secondly, we also made the special phantom using EBT2 film (Gafchronic, ISP, USA) and we prepared the robot (Cartesian Robot-2 Axis, FARARCM4H, Samsung Mechatronics, Korea) to reproduce three dimensional tumor motion. And analysis was made for isodose curves and two dimensional isodose profiles with reproducibility of respiratory motion on the basis of CT images. A respiratory motion reduction compression belt (Velcro type) that has convenient use and good reproducibility was developed. The moving differences of three dimensional tumor motion of lung cancer cases analyzed by CT images were mean 3.2 mm, 4.3 mm and 13 mm each in LR, AP and CC directions. The result of characteristic change in dose distribution using the phantom and rectangular coordinates robot showed that the distortion of isodose has great differences, mean length was 4.2 mm; the differences were 8.0% and 16.8% each for cranio-caudal and 8.1% and 10.9% each for left-right directions in underdose below the prescribed dose. In this study, we could develop the convenient and efficient compression belt that can make the organs' motion minimize. With this compression belt, we confirmed that underdose due to respiration

  5. Quad Cities Unit 2 Main Steam Line Acoustic Source Identification and Load Reduction

    International Nuclear Information System (INIS)

    DeBoo, Guy; Ramsden, Kevin; Gesior, Roman

    2006-01-01

    The Quad Cities Units 1 and 2 have a history of steam line vibration issues. The implementation of an Extended Power Up-rate resulted in significant increases in steam line vibration as well as acoustic loading of the steam dryers, which led to equipment failures and fatigue cracking of the dryers. This paper discusses the results of extensive data collection on the Quad Cities Unit 2 replacement dryer and the Main Steam Lines. This data was taken with the intent of identifying acoustic sources in the steam system. Review of the data confirmed that vortex shedding coupled column resonance in the relief and safety valve stub pipes were the principal sources of large magnitude acoustic loads in the main steam system. Modifications were developed in sub-scale testing to alter the acoustic properties of the valve standpipes and add acoustic damping to the system. The modifications developed and installed consisted of acoustic side branches that were attached to the Electromatic Relief Valve (ERV) and Main Steam Safety Valve (MSSV) attachment pipes. Subsequent post-modification testing was performed in plant to confirm the effectiveness of the modifications. The modifications have been demonstrated to reduce vibration loads at full Extended Power Up-rate (EPU) conditions to levels below those at Original Licensed Thermal Power (OLTP). (authors)

  6. Developing a Vacuum Electrospray Source To Implement Efficient Atmospheric Sampling for Miniature Ion Trap Mass Spectrometer.

    Science.gov (United States)

    Yu, Quan; Zhang, Qian; Lu, Xinqiong; Qian, Xiang; Ni, Kai; Wang, Xiaohao

    2017-12-05

    The performance of a miniature mass spectrometer in atmospheric analysis is closely related to the design of its sampling system. In this study, a simplified vacuum electrospray ionization (VESI) source was developed based on a combination of several techniques, including the discontinuous atmospheric pressure interface, direct capillary sampling, and pneumatic-assisted electrospray. Pulsed air was used as a vital factor to facilitate the operation of electrospray ionization in the vacuum chamber. This VESI device can be used as an efficient atmospheric sampling interface when coupled with a miniature rectilinear ion trap (RIT) mass spectrometer. The developed VESI-RIT instrument enables regular ESI analysis of liquid, and its qualitative and quantitative capabilities have been characterized by using various solution samples. A limit of detection of 8 ppb could be attained for arginine in a methanol solution. In addition, extractive electrospray ionization of organic compounds can be implemented by using the same VESI device, as long as the gas analytes are injected with the pulsed auxiliary air. This methodology can extend the use of the proposed VESI technique to rapid and online analysis of gaseous and volatile samples.

  7. Hake fish bone as a calcium source for efficient bone mineralization.

    Science.gov (United States)

    Flammini, Lisa; Martuzzi, Francesca; Vivo, Valentina; Ghirri, Alessia; Salomi, Enrico; Bignetti, Enrico; Barocelli, Elisabetta

    2016-01-01

    Calcium is recognized as an essential nutritional factor for bone health. An adequate intake is important to achieve or maintain optimal bone mass in particular during growth and old age. The aim of the present study was to evaluate the efficiency of hake fish bone (HBF) as a calcium source for bone mineralization: in vitro on osteosarcoma SaOS-2 cells, cultured in Ca-free osteogenic medium (OM) and in vivo on young growing rats fed a low-calcium diet. Lithotame (L), a Ca supplement derived from Lithothamnium calcareum, was used as control. In vitro experiments showed that HBF supplementation provided bone mineralization similar to standard OM, whereas L supplementation showed lower activity. In vivo low-Ca HBF-added and L-added diet similarly affected bone deposition. Physico-chemical parameters concerning bone mineralization, such as femur breaking force, tibia density and calcium/phosphorus mineral content, had beneficial effects from both Ca supplementations, in the absence of any evident adverse effect. We conclude HBF derived from by-product from the fish industry is a good calcium supplier with comparable efficacy to L.

  8. Malbranchea cinnamomea: A thermophilic fungal source of catalytically efficient lignocellulolytic glycosyl hydrolases and metal dependent enzymes.

    Science.gov (United States)

    Mahajan, Chhavi; Basotra, Neha; Singh, Surender; Di Falco, Marcos; Tsang, Adrian; Chadha, B S

    2016-01-01

    This study reports thermophilic fungus Malbranchea cinnamomea as an important source of lignocellulolytic enzymes. The secretome analysis using LC-MS/MS orbitrap showed that fungus produced a spectrum of glycosyl hydrolases (cellulase/hemicellulase), polysaccharide lyases (PL) and carbohydrate esterases (CE) in addition to cellobiose dehydrogenase (CDH) indicating the presence of functional classical and oxidative cellulolytic mechanisms. The protein fractions in the secretome resolved by ion exchange chromatography were analyzed for ability to hydrolyze alkali treated carrot grass (ATCG) in the presence of Mn(2+)/Cu(2+). This strategy in tandem with peptide mass fingerprinting led to identification of metal dependent protein hydrolases with no apparent hydrolytic activity, however, showed 5.7 folds higher saccharification in presence of Mn(2+). Furthermore, adding different protein fractions to commercial cellulase (Novozymes: Cellic CTec2) resulted in enhanced hydrolysis of ATCG ranging between 1.57 and 3.43 folds indicating the enzymes from M. cinnamomea as catalytically efficient. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. TU-H-CAMPUS-IeP1-01: Bias and Computational Efficiency of Variance Reduction Methods for the Monte Carlo Simulation of Imaging Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, D; Badano, A [Division of Imaging, Diagnostics and Software Reliability, OSEL/CDRH, Food & Drug Administration, MD (United States); Sempau, J [Technical University of Catalonia, Barcelona (Spain)

    2016-06-15

    Purpose: Variance reduction techniques (VRTs) are employed in Monte Carlo simulations to obtain estimates with reduced statistical uncertainty for a given simulation time. In this work, we study the bias and efficiency of a VRT for estimating the response of imaging detectors. Methods: We implemented Directed Sampling (DS), preferentially directing a fraction of emitted optical photons directly towards the detector by altering the isotropic model. The weight of each optical photon is appropriately modified to maintain simulation estimates unbiased. We use a Monte Carlo tool called fastDETECT2 (part of the hybridMANTIS open-source package) for optical transport, modified for VRT. The weight of each photon is calculated as the ratio of original probability (no VRT) and the new probability for a particular direction. For our analysis of bias and efficiency, we use pulse height spectra, point response functions, and Swank factors. We obtain results for a variety of cases including analog (no VRT, isotropic distribution), and DS with 0.2 and 0.8 optical photons directed towards the sensor plane. We used 10,000, 25-keV primaries. Results: The Swank factor for all cases in our simplified model converged fast (within the first 100 primaries) to a stable value of 0.9. The root mean square error per pixel for DS VRT for the point response function between analog and VRT cases was approximately 5e-4. Conclusion: Our preliminary results suggest that DS VRT does not affect the estimate of the mean for the Swank factor. Our findings indicate that it may be possible to design VRTs for imaging detector simulations to increase computational efficiency without introducing bias.

  10. Stratospheric ozone reduction and its relation to natural and man made sources

    Energy Technology Data Exchange (ETDEWEB)

    Isaksen, I S [Oslo Univ. (Norway). Dept. of Geophysics

    1996-12-31

    Approximately 90 % of the total ozone mass is in the stratosphere (between approximately 12 and 50 km), the rest is in the troposphere (below 12 km). The global distribution of ozone in the stratosphere and its variation over time have been studied extensively over several decades. These studies include observations by ground based instruments (e.g. Dobson instruments), instruments on airborne platforms (e.g. ozone sondes) and on satellites, and model studies which simulate the chemical and dynamical behaviour of the stratosphere. These studies have given good information about the processes which determine the ozone distribution, and how man made emissions affect the distribution. Observations have revealed that there are large year to year variations in stratospheric ozone above a particular location. These variations are difficult to predict as they are connected to irregular weather patterns. However, the observations have shown that there has been a long term decrease in stratospheric ozone on a global scale during the last two decades. The decrease has been most pronounced during the last five to six years and is seen both in the Northern and the Southern Hemispheres. The strong decrease in stratospheric ozone over the Antarctic continent, which has been observed since the mid 80s, and which has reduced the total ozone column with more than 50 % compared with earlier observations, is proven to be a result of increased man made emissions of CFCs. There are also mounting evidences that Northern Hemispheric ozone reductions observed since 1980 are connected to man made emissions of CFCs

  11. Stratospheric ozone reduction and its relation to natural and man made sources

    Energy Technology Data Exchange (ETDEWEB)

    Isaksen, I.S. [Oslo Univ. (Norway). Dept. of Geophysics

    1995-12-31

    Approximately 90 % of the total ozone mass is in the stratosphere (between approximately 12 and 50 km), the rest is in the troposphere (below 12 km). The global distribution of ozone in the stratosphere and its variation over time have been studied extensively over several decades. These studies include observations by ground based instruments (e.g. Dobson instruments), instruments on airborne platforms (e.g. ozone sondes) and on satellites, and model studies which simulate the chemical and dynamical behaviour of the stratosphere. These studies have given good information about the processes which determine the ozone distribution, and how man made emissions affect the distribution. Observations have revealed that there are large year to year variations in stratospheric ozone above a particular location. These variations are difficult to predict as they are connected to irregular weather patterns. However, the observations have shown that there has been a long term decrease in stratospheric ozone on a global scale during the last two decades. The decrease has been most pronounced during the last five to six years and is seen both in the Northern and the Southern Hemispheres. The strong decrease in stratospheric ozone over the Antarctic continent, which has been observed since the mid 80s, and which has reduced the total ozone column with more than 50 % compared with earlier observations, is proven to be a result of increased man made emissions of CFCs. There are also mounting evidences that Northern Hemispheric ozone reductions observed since 1980 are connected to man made emissions of CFCs

  12. Study The Validity of The Direct Mathematical Method For Calculation The Total Efficiency Using Point And Disk Sources

    International Nuclear Information System (INIS)

    Hagag, O.M.; Nafee, S.S.; Naeem, M.A.; El Khatib, A.M.

    2011-01-01

    The direct mathematical method has been developed for calculating the total efficiency of many cylindrical gamma detectors, especially HPGe and NaI detector. Different source geometries are considered (point and disk). Further into account is taken of gamma attenuation from detector window or any interfacing absorbing layer. Results are compared with published experimental data to study the validity of the direct mathematical method to calculate total efficiency for any gamma detector size.

  13. Some successful financing mechanisms for energy efficiency projects (EE) and projects using renewable energy sources (RES) - the experience of Bulgaria

    International Nuclear Information System (INIS)

    Uzunova, Boriana

    2004-01-01

    The paper analysis some of the most promising financial mechanisms for energy efficiency (EE) and renewable energy sources (RES) projects in Bulgaria - the TPF mechanism, the KIDS Fund, delivered by the EBRD fund the EE fund of the WB, established on the floor of the EE act, as well as a number of some of the pre accession and European energy programs used for financing this area. All data its rich intensive international and in -home work in the are of energy efficiency and renewable energy sources. (Author)

  14. Accessing Secondary Markets as a Capital Source for Energy Efficiency Finance Programs: Program Design Considerations for Policymakers and Administrators

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Martin, E. Fadrhonc [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Thompson, P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Goldman, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-02-01

    Estimates of the total opportunity for investment in cost-effective energy efficiency in the United States are typically in the range of several hundred billion dollars (Choi Granade, et al., 2009 and Fulton & Brandenburg, 2012).1,2 To access this potential, many state policymakers and utility regulators have established aggressive energy efficiency savings targets. Current levels of taxpayer and utility bill-payer funding for energy efficiency is only a small fraction of the total investment needed to meet these targets (SEE Action Financing Solutions Working Group, 2013). Given this challenge, some energy efficiency program administrators are working to access private capital sources with the aim of amplifying the funds available for investment. In this context, efficient access to secondary market capital has been advanced as one important enabler of the energy efficiency industry “at scale.”3 The question of what role secondary markets can play in bringing energy efficiency to scale is largely untested despite extensive attention from media, technical publications, advocates, and others. Only a handful of transactions of energy efficiency loan products have been executed to date, and it is too soon to draw robust conclusions from these deals. At the same time, energy efficiency program administrators and policymakers face very real decisions regarding whether and how to access secondary markets as part of their energy efficiency deployment strategy.

  15. Phonon limit to simultaneous near-unity efficiency and indistinguishability in semiconductor single photon sources

    DEFF Research Database (Denmark)

    McCutcheon, Dara P. S.; Iles-Smith, Jake; Nazir, Ahsan

    2016-01-01

    inverse relationship, where indistinguishability and efficiency cannot be simultaneously increased. For cavities, the frequency selectivity of the Purcell enhancement results in a more subtle trade-off, where indistinguishability and efficiency can be simultaneously increased, though by the same mechanism...

  16. TSUNAMIGENIC SOURCE MECHANISM AND EFFICIENCY OF THE MARCH 11, 2011 SANRIKU EARTHQUAKE IN JAPAN

    Directory of Open Access Journals (Sweden)

    George Pararas-Carayannis

    2011-01-01

    Full Text Available The great Tohoku earthquake of March 11, 2011 generated a very destructive and anomalously high tsunami. To understand its source mechanism, an examination was undertaken of the seismotectonics of the region and of the earthquake’ focal mechanism, energy release, rupture patterns and spatial and temporal sequencing and clustering of major aftershocks. It was determined that the great tsunami resulted from a combination of crustal deformations of the ocean floor due to up-thrust tectonic motions, augmented by additional uplift due to the quake’s slow and long rupturing process, as well as to large coseismic lateral movements which compressed and deformed the compacted sediments along the accretionary prism of the overriding plane. The deformation occurred randomly and non-uniformly along parallel normal faults and along oblique, en-echelon faults to the earthquake’s overall rupture direction – the latter failing in a sequential bookshelf manner with variable slip angles. As the 1992 Nicaragua and the 2004 Sumatra earthquakes demonstrated, such bookshelf failures of sedimentary layers could contribute to anomalously high tsunamis. As with the 1896 tsunami, additional ocean floor deformation and uplift of the sediments was responsible for the higher waves generated by the 2011 earthquake. The efficiency of tsunami generation was greater along the shallow eastern segment of the fault off the Miyagi Prefecture where most of the energy release of the earthquake and the deformations occurred, while the segment off the Ibaraki Prefecture – where the rupture process was rapid – released less seismic energy, resulted in less compaction and deformation of sedimentary layers and thus to a tsunami of lesser offshore height. The greater tsunamigenic efficiency of the 2011 earthquake and high degree of the tsunami’s destructiveness along Honshu’s coastlines resulted from vertical crustal displacements of more than 10 meters due to up

  17. 3D graphene preparation via covalent amide functionalization for efficient metal-free electrocatalysis in oxygen reduction

    Science.gov (United States)

    Ahmed, Mohammad Shamsuddin; Kim, Young-Bae

    2017-02-01

    3D and porous reduced graphene oxide (rGO) catalysts have been prepared with sp3-hybridized 1,4-diaminobutane (sp3-DABu, rGO-sp3-rGO) and sp2-hybridized 1,4-diaminobenzene (sp2-DABe, rGO-sp2-rGO) through a covalent amidation and have employed as a metal-free electrocatalyst for oxygen reduction reaction (ORR) in alkaline media. Both compounds have used as a junction between functionalized rGO layers to improve electrical conductivity and impart electrocatalytic activity to the ORR resulting from the interlayer charge transfer. The successful amidation and the subsequent reduction in the process of catalyst preparation have confirmed by X-ray photoelectron spectroscopy. A hierarchical porous structure is also confirmed by surface morphological analysis. Specific surface area and thermal stability have increased after successful the amidation by sp3-DABu. The investigated ORR mechanism reveals that both functionalized rGO is better ORR active than nonfunctionalized rGO due to pyridinic-like N content and rGO-sp3-rGO is better ORR active than rGO-sp2-rGO due to higher pyridinic-like N content and π-electron interaction-free interlayer charge transfer. Thus, the rGO-sp3-rGO has proven as an efficient metal-free electrocatalyst with better electrocatalytic activity, stability, and tolerance to the crossover effect than the commercially available Pt/C for ORR.

  18. A survey on radon reduction efficiency of zeolite and bentonite in a chamber with artificially elevated radon concentration

    International Nuclear Information System (INIS)

    Mortazavi, S.M.J.

    2007-01-01

    Complete text of publication follows. Objective: Zeolite which is made of a special crystalline structure is a naturally occurring mineral group and can be used in radioactive waste management for site remediation /decontamination. There are a wide variety of naturally occurring and synthetic zeolites, each with a unique structure. The cations in zeolite are highly mobile and can be exchanged for other cationic species. On the other hand, bentonite forms from weathering of volcanic ash. This material may be used as an engineering barrier to enclose nuclear waste. In this study, radon reducing properties of zeolite and bentonite have been investigated. Methods: Using radioactive lantern mantle, a radon prone area with radon levels reaching the EPA's action level (200 Bq/m 3 ) was designed. Two sets of identical chambers (cylindrical chambers, diameter 10 cm, height 16 cm) were used in this study. No zeolite/bentonite was used in the 1 st set of the chambers. A thin layer of either zeolite or bentonite powder was applied to the base of the first set of chambers. An unburned radioactive lantern mantle (activity 800 Bq) was placed in all chambers (both sets) to artificially increase the radon level inside the chamber and simulate the condition of a radon prone area. Radon level monitoring was performed by using a PRASSI portable radon gas survey meter. Results: After placing the cap on its place, the radon levels inside the 1 st set of the chambers were 871.9, 770.3, 769.2 and 635.7 Bq/m 3 after 15, 30, 45 and 60 minutes respectively. Zeolite significantly decreased the radon concentration inside the chambers and radon levels were 367.9, 435.4, 399.0 and 435.4 Bq/m 3 after 15, 30, 45 and 60 minutes. The observed reduction in the radon level was statistically significant. As the radon concentrations in identical chambers with Bentonite were 550.7, 526.5, 536.2 and 479.8 Bq/m 3 after 15, 30, 45 and 60 minutes respectively, it is evident that zeolite is more efficient in

  19. Efficient Inversion of Mult-frequency and Multi-Source Electromagnetic Data

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Egbert

    2007-03-22

    The project covered by this report focused on development of efficient but robust non-linear inversion algorithms for electromagnetic induction data, in particular for data collected with multiple receivers, and multiple transmitters, a situation extremely common in eophysical EM subsurface imaging methods. A key observation is that for such multi-transmitter problems each step in commonly used linearized iterative limited memory search schemes such as conjugate gradients (CG) requires solution of forward and adjoint EM problems for each of the N frequencies or sources, essentially generating data sensitivities for an N dimensional data-subspace. These multiple sensitivities allow a good approximation to the full Jacobian of the data mapping to be built up in many fewer search steps than would be required by application of textbook optimization methods, which take no account of the multiplicity of forward problems that must be solved for each search step. We have applied this idea to a develop a hybrid inversion scheme that combines features of the iterative limited memory type methods with a Newton-type approach using a partial calculation of the Jacobian. Initial tests on 2D problems show that the new approach produces results essentially identical to a Newton type Occam minimum structure inversion, while running more rapidly than an iterative (fixed regularization parameter) CG style inversion. Memory requirements, while greater than for something like CG, are modest enough that even in 3D the scheme should allow 3D inverse problems to be solved on a common desktop PC, at least for modest (~ 100 sites, 15-20 frequencies) data sets. A secondary focus of the research has been development of a modular system for EM inversion, using an object oriented approach. This system has proven useful for more rapid prototyping of inversion algorithms, in particular allowing initial development and testing to be conducted with two-dimensional example problems, before

  20. Efficiency improvement and exergy destruction reduction by combining a power and a multi-effect boiling desalination plant

    Directory of Open Access Journals (Sweden)

    A. A. Alsairafi

    2013-06-01

    Full Text Available Electric power and desalted seawater demand is increasing in Kuwait mainly due to residential and industrial growth, especially in summer season. In the past six years, Kuwait citizens have been facing the problem of automated power and water disconnection because of the electricity and water production is lower than the consumption. A common idea for resolving such a problem is to build new power plants but this solution is not practical due to environmental issues. Another choice but more engineer challenging approach for resolving this problem is to improve the efficiency and performance of the already existing power plants. Currently, there are six power plants in Kuwait; four of them have both stand-alone gas-turbine and steam-turbine power plants, one is steam power plant and one is gas turbine power plant. Combined power and desalination plant are more attractive in Kuwait since they have higher thermal efficiency than traditional ones and both electric power and process heat (e.g., desalting can be produced simultaneously. The relatively low temperature multi-effect desalination (MED process (around 75oC saturated temperature as the heat source is thermodynamically the most efficient of all thermal distillation processes (source, and consumes about 2 kWh/m3 pumping energy. In this study, factors affecting the performance of a combined power and MED-desalination plant have been studied. This includes the atmospheric humidity, compressor inlet air temperature, top brine temperature, desalination unit capacity, cooling water temperature, and the number of evaporation stages of the MED unit. A first- and second-law analysis of the proposed system was carried out under several operating conditions. As an example, a 125 MW Siemens V94.2 gas turbine of Al-Zour gas turbine power plant in Kuwait has been selected. It is found that the overall thermal efficiency of the proposed system increases significantly as the desalination unit capacity

  1. Core-Shell Structuring of Pure Metallic Aerogels towards Highly Efficient Platinum Utilization for the Oxygen Reduction Reaction.

    Science.gov (United States)

    Cai, Bin; Hübner, René; Sasaki, Kotaro; Zhang, Yuanzhe; Su, Dong; Ziegler, Christoph; Vukmirovic, Miomir B; Rellinghaus, Bernd; Adzic, Radoslav R; Eychmüller, Alexander

    2018-03-05

    The development of core-shell structures remains a fundamental challenge for pure metallic aerogels. Here we report the synthesis of Pd x Au-Pt core-shell aerogels composed of an ultrathin Pt shell and a composition-tunable Pd x Au alloy core. The universality of this strategy ensures the extension of core compositions to Pd transition-metal alloys. The core-shell aerogels exhibited largely improved Pt utilization efficiencies for the oxygen reduction reaction and their activities show a volcano-type relationship as a function of the lattice parameter of the core substrate. The maximum mass and specific activities are 5.25 A mg Pt -1 and 2.53 mA cm -2 , which are 18.7 and 4.1 times higher than those of Pt/C, respectively, demonstrating the superiority of the core-shell metallic aerogels. The proposed core-based activity descriptor provides a new possible strategy for the design of future core-shell electrocatalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Tailored Combination of Low Dimensional Catalysts for Efficient Oxygen Reduction and Evolution in Li-O2 Batteries.

    Science.gov (United States)

    Yoon, Ki Ro; Kim, Dae Sik; Ryu, Won-Hee; Song, Sung Ho; Youn, Doo-Young; Jung, Ji-Won; Jeon, Seokwoo; Park, Yong Joon; Kim, Il-Doo

    2016-08-23

    The development of efficient bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is a key issue pertaining high performance Li-O2 batteries. Here, we propose a heterogeneous electrocatalyst consisting of LaMnO3 nanofibers (NFs) functionalized with RuO2 nanoparticles (NPs) and non-oxidized graphene nanoflakes (GNFs). The Li-O2 cell employing the tailored catalysts delivers an excellent electrochemical performance, affording significantly reduced discharge/charge voltage gaps (1.0 V at 400 mA g(-1) ), and superior cyclability for over 320 cycles. The outstanding performance arises from (1) the networked LaMnO3 NFs providing ORR/OER sites without severe aggregation, (2) the synergistic coupling of RuO2 NPs for further improving the OER activity and the electrical conductivity on the surface of the LaMnO3 NFs, and (3) the use of GNFs providing a fast electronic pathway as well as improved ORR kinetics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. N-doped graphene coupled with Co nanoparticles as an efficient electrocatalyst for oxygen reduction in alkaline media

    Science.gov (United States)

    Zhang, Geng; Lu, Wangting; Cao, Feifei; Xiao, Zhidong; Zheng, Xinsheng

    2016-01-01

    Development of low-cost and highly efficient electrocatalysts for oxygen reduction reaction (ORR) is still a great challenge for the large-scale application of fuel cells and metal-air batteries. Herein, a noble metal-free ORR electrocatalyst in the form of N-doped graphene coupled with part of Co nanoparticles encased in N-doped graphitic shells (named as SUCo-0.03-800) is prepared by facile one-step pyrolysis of the mixture of sucrose, urea and cobalt nitrate. The novel structure is confirmed by High Resolution-TEM, XRD, XPS and Raman spectroscopy. SUCo-0.03-800 presents comparable ORR catalytic activity to commercial Pt/C catalyst with a dominating four-electron pathway under alkaline conditions, and both of its mass activity and volume activity also outperform Co-free N-doped graphene and other Co/N-C hybrids with higher Co content, which may probably be ascribed to the high specific surface area, novel structure and synergistic effect between encased Co nanoparticles and N-doped graphitic shell. Additionally, SUCo-0.03-800 also shows outstanding stability and improved selectivity towards ORR, making it a promising alternative to Pt with potential application in fuel cells and metal-air batteries.

  4. Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source

    Science.gov (United States)

    Jain, P.; Recchia, M.; Cavenago, M.; Fantz, U.; Gaio, E.; Kraus, W.; Maistrello, A.; Veltri, P.

    2018-04-01

    Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (˜9.4 W cm-3) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).

  5. Alaska earthquake source for the SAFRR tsunami scenario: Chapter B in The SAFRR (Science Application for Risk Reduction) Tsunami Scenario

    Science.gov (United States)

    Kirby, Stephen; Scholl, David; von Huene, Roland E.; Wells, Ray

    2013-01-01

    Tsunami modeling has shown that tsunami sources located along the Alaska Peninsula segment of the Aleutian-Alaska subduction zone have the greatest impacts on southern California shorelines by raising the highest tsunami waves for a given source seismic moment. The most probable sector for a Mw ~ 9 source within this subduction segment is between Kodiak Island and the Shumagin Islands in what we call the Semidi subduction sector; these bounds represent the southwestern limit of the 1964 Mw 9.2 Alaska earthquake rupture and the northeastern edge of the Shumagin sector that recent Global Positioning System (GPS) observations indicate is currently creeping. Geological and geophysical features in the Semidi sector that are thought to be relevant to the potential for large magnitude, long-rupture-runout interplate thrust earthquakes are remarkably similar to those in northeastern Japan, where the destructive Mw 9.1 tsunamigenic earthquake of 11 March 2011 occurred. In this report we propose and justify the selection of a tsunami source seaward of the Alaska Peninsula for use in the Tsunami Scenario that is part of the U.S. Geological Survey (USGS) Science Application for Risk Reduction (SAFRR) Project. This tsunami source should have the potential to raise damaging tsunami waves on the California coast, especially at the ports of Los Angeles and Long Beach. Accordingly, we have summarized and abstracted slip distribution from the source literature on the 2011 event, the best characterized for any subduction earthquake, and applied this synoptic slip distribution to the similar megathrust geometry of the Semidi sector. The resulting slip model has an average slip of 18.6 m and a moment magnitude of Mw = 9.1. The 2011 Tohoku earthquake was not anticipated, despite Japan having the best seismic and geodetic networks in the world and the best historical record in the world over the past 1,500 years. What was lacking was adequate paleogeologic data on prehistoric earthquakes

  6. Modeling and Design of High-Efficiency Single-Photon Sources

    DEFF Research Database (Denmark)

    Gregersen, Niels; Nielsen, Per Kær; Mørk, Jesper

    2013-01-01

    be electrically driven. Several design strategies addressing these requirements have been proposed. In the cavity-based source, light emission is controlled using resonant cavity quantum electrodynamics effects, whereas in the waveguide-based source, broadband electric field screening effects are employed......Solid-state sources capable of emitting single photons on demand are of great interest in quantum information applications. Ideally, such a source should emit exactly one photon into the collection optics per trigger, the emitted photons should be indistinguishable, and the source should...

  7. Analysis of efficiency of pollution reduction measures in rural basin using MIKE Basin model. Case study: Olšava River Basin

    Directory of Open Access Journals (Sweden)

    Kaiglová Jana

    2014-03-01

    Full Text Available This paper presents the results of testing the applicability of the MIKE Basin model for simulating the efficiency of scenarios for reducing water pollution. The model has been tested on the Olšava River Basin (520 km2 which is a typical rural region with a heterogeneous mix of pollution sources with variable topography and land use. The study proved that the model can be calibrated successfully using even the limited amount of data typically available in rural basins. The scenarios of pollution reduction were based on implementation and intensification of municipal wastewater treatment and conversion of arable land on fields under the risk of soil erosion to permanent grassland. The application of simulation results of these scenarios with proposed measures proved decreasing concentrations in downstream monitoring stations. Due to the practical applicability of proposed measures, these could lead to fulfilment of the water pollution limits required by the Czech and EU legislation. However, there are factors of uncertainty that are discussed that may delay or limit the effect of adopted measures in small rural basins.

  8. Fast and efficient method for reduction of carbonyl compounds with NaBH{sub 4} /wet SiO{sub 2} under solvent free condition

    Energy Technology Data Exchange (ETDEWEB)

    Zeynizadeh, Behzad; Bahyar, Tarifeh [Urmia University, Urmia (Iran, Islamic Republic of). Faculty of Sciences. Dept. of Chemistry]. E-mail: b.zeynizadeh@mail.urmia.ac.ir

    2005-11-15

    Reduction of structurally different carbonyl compounds such as aldehydes, ketones, {alpha},{beta}-unsaturated enals and enones, {alpha}-diketones and acyloins were accomplished efficiently by sodium borohydride in the presence of wet SiO{sub 2} (30% m/m) under solvent free condition. The reactions were performed at room tempere or 75-80 deg C with high to excellent yields of the corresponding products. The chemoselective reduction of aldehydes over ketones was achieved successfully with this reducing system. (author)

  9. Fast and efficient method for reduction of carbonyl compounds with NaBH4 /wet SiO2 under solvent free condition

    International Nuclear Information System (INIS)

    Zeynizadeh, Behzad; Bahyar, Tarifeh

    2005-01-01

    Reduction of structurally different carbonyl compounds such as aldehydes, ketones, α,β-unsaturated enals and enones, α-diketones and acyloins were accomplished efficiently by sodium borohydride in the presence of wet SiO 2 (30% m/m) under solvent free condition. The reactions were performed at room temperature or 75-80 deg C with high to excellent yields of the corresponding products. The chemoselective reduction of aldehydes over ketones was achieved successfully with this reducing system. (author)

  10. Realization of high efficiency in a plasma-assisted microwave source with two-dimensional electron motion

    International Nuclear Information System (INIS)

    Shkvarunets, A.G.; Carmel, Y.; Nusinovich, G.S.; Abu-elfadl, T.M.; Rodgers, J.; Antonsen, T.M. Jr.; Granatstein, V.; Goebel, D.M.

    2002-01-01

    Conventional microwave sources utilize a strong axial magnetic field to guide an electron beam through an interaction region. A plasma-assisted slow wave microwave oscillator (Pasotron) can operate without an external magnetic field because the presence of ions neutralizes the space charge in the beam, permits the self-pinch forces to provide beam propagation, and allows for the radial motion of electrons under the action of transverse fields of the wave. While the inherent efficiency of conventional microwave sources with 1D electron flow is limited to 15%-20%, it is shown in this work that both the calculated and measured inherent efficiency of devices with 2D electron flow can be higher than 50%. Both in situ diagnostics and analysis confirmed that the enhanced efficiency is due to the fact that rf forces dominate the beam dynamics

  11. [Effects of phosphorus sources on phosphorus fractions in rhizosphere soil of wild barley genotypes with high phosphorus utilization efficiency].

    Science.gov (United States)

    Cai, Qiu-Yan; Zhang, Xi-Zhou; Li, Ting-Xuan; Chen, Guang-Deng

    2014-11-01

    High P-efficiency (IS-22-30, IS-22-25) and low P-efficiency (IS-07-07) wild barley cultivars were chosen to evaluate characteristics of phosphorus uptake and utilization, and properties of phosphorus fractions in rhizosphere and non-rhizosphere in a pot experiment with 0 (CK) and 30 mg P · kg(-1) supplied as only Pi (KH2PO4), only Po (phytate) or Pi + Po (KH2PO4+ phytate). The results showed that dry matter and phosphorus accumulation of wild barley in the different treatments was ranked as Pi > Pi + Po > Po > CK. In addition, dry matter yield and phosphorus uptake of wild barley with high P-efficiency exhibited significantly greater than that with low P-efficiency. The concentration of soil available phosphorus was significantly different after application of different phosphorus sources, which was presented as Pi > Pi + Po > Po. The concentration of soil available phosphorus in high P-efficiency wild barley was significantly higher than that of low P-efficiency in the rhizosphere soil. There was a deficit in rhizosphere available phosphorus of high P-efficiency wild barley, especially in Pi and Pi+Po treatments. The inorganic phosphorus fractions increased with the increasing Pi treatment, and the concentrations of inorganic phosphorus fractions in soil were sorted as follows: Ca10-P > O-P > Fe-P > Al-P > Ca2-P > Ca8-P. The contents of Ca2-P and Ca8-P for high P-efficiency wild barley showed deficits in rhizosphere soil under each phosphorus source treatment. In addition, enrichment of Al-P and Fe-P was observed in Pi treatment in rhizosphere soil. The concentrations of organic phosphorus fractions in soil were sorted as follows: moderate labile organic phosphorus > moderate resistant, resistant organic phosphorus > labile organic phosphorus. The labile and moderate labile organic phosphorus enriched in rhizosphere soil and the greatest enrichment appeared in Pi treatment. Furthermore, the concentrations of moderate resistant organic phosphorus and resistant

  12. Energy efficiency the definitive guide to the cheapest, cleanest, fastest source of energy

    CERN Document Server

    Fawkes, Steven

    2013-01-01

    Energy risk has reappeared on the corporate and social agenda with a bang and the complexity of the issues has increased many-fold since the days of the last great wave of concern following the oil crises of the 1970s. Steven Fawkes' Energy Efficiency is a comprehensive guide for managers and policy-makers to the fundamental questions underpinning energy-efficiency and our responses to it: ¢ what do we really mean by energy efficiency? ¢ what is the potential (in different dimensions)? ¢ why it is important? ¢ what management processes lead to optimisation of energy efficiency? ¢ what technolo

  13. Reduction of Methane Emission during Slurry Storage by the Addition of Effective Microorganisms and Excessive Carbon Source from Brewing Sugar.

    Science.gov (United States)

    Bastami, Mohd Saufi B; Jones, Davey L; Chadwick, David R

    2016-11-01

    Storing livestock manure is the primary stage of manure management where microbial processes and chemical reactions result in the release of methane (CH), nitrous oxide (NO), ammonia (NH), and carbon dioxide (CO). This study examined the reduction of CH emissions from slurry storage under two temperatures (cool [10°C] and warm [30°C]) when a glucose-rich substrate (brewing sugar) and activated effective microorganisms were applied at 10% (w/w) and 5% (v/w), respectively. Brewing sugar addition influenced microbial anaerobic respiration, resulting in a reduction of slurry pH to <5.0, through "self-acidification" caused by lactic acid production. Subsequently, CH emissions were significantly reduced by 87 and 99% in the cool and warm environments, respectively. The effective microorganism treatment did not change the chemical characteristics of the slurry but reduced CH emissions by 17 and 27% ( < 0.05) in the cool and warm environments, respectively. These results suggest that self-acidification after addition of a carbon source may be a promising alternative to slurry acidification using concentrated acids. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  14. Modelling of Efficiency Change as a Source of Economic Growth in Agriculture

    Directory of Open Access Journals (Sweden)

    Bezat-Jarzębowska Agnieszka

    2016-12-01

    Full Text Available In the paper, the subject of economic growth in agriculture was raised. One of the determinants of this process, namely an efficiency change was under the assessment. The aim of the paper was to evaluate the changes of efficiency in the Polish agriculture. In the study, a stochastic parametric production function was used.

  15. CO2 emission reduction potential of large-scale energy efficiency measures in power generation from fossil fuels in China, India, Brazil, Indonesia and South Africa

    OpenAIRE

    Boehme, Benn J.; Krey, Matthias

    2005-01-01

    We quantify the theoretical potential for energy-efficiency CDM projects using best available technology in coal, natural gas or oil fuelled power generation in China, India, Brazil, Indonesia and South Africa, looking at new power plants or retrofit measures. We then discuss the likelihood of the potential emission reductions materialising under CDM. Our results are very sensitive to choices of baseline and project efficiencies and the level of electricity generation from potential emission ...

  16. CO2 reduction in the Danish transportation sector. Working paper 10: Energy efficiency of the private cars - a package of control measures

    International Nuclear Information System (INIS)

    1997-03-01

    Average requirements to automotive fuel efficiency in new cars and differentiation of registration and weight taxes according to fuel consumption by a car result in fewer new cars due to very high registration tax and lower driving costs per km, which is against the CO 2 reduction measure. More efficient car manufacturing would eventually lead to a lower registration tax. Higher tax on fuels is another solution to the problem. (EG)

  17. Experimental validation of the intrinsic spatial efficiency method over a wide range of sizes for cylindrical sources

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Ramŕez, Pablo, E-mail: rapeitor@ug.uchile.cl; Larroquette, Philippe [Departamento de Física, Facultad de Ciencias, Universidad de Chile (Chile); Camilla, S. [Departamento de Física, Universidad Tecnológica Metropolitana (Chile)

    2016-07-07

    The intrinsic spatial efficiency method is a new absolute method to determine the efficiency of a gamma spectroscopy system for any extended source. In the original work the method was experimentally demonstrated and validated for homogeneous cylindrical sources containing {sup 137}Cs, whose sizes varied over a small range (29.5 mm radius and 15.0 to 25.9 mm height). In this work we present an extension of the validation over a wide range of sizes. The dimensions of the cylindrical sources vary between 10 to 40 mm height and 8 to 30 mm radius. The cylindrical sources were prepared using the reference material IAEA-372, which had a specific activity of 11320 Bq/kg at july 2006. The obtained results were better for the sources with 29 mm radius showing relative bias lesser than 5% and for the sources with 10 mm height showing relative bias lesser than 6%. In comparison with the obtained results in the work where we present the method, the majority of these results show an excellent agreement.

  18. An unsaturated metal site-promoted approach to construct strongly coupled noble metal/HNb3O8 nanosheets for efficient thermo/photo-catalytic reduction.

    Science.gov (United States)

    Shen, Lijuan; Xia, Yuzhou; Lin, Sen; Liang, Shijing; Wu, Ling

    2017-10-05

    Creating two-dimensional (2D) crystal-metal heterostructures with an ultrathin thickness has spurred increasing research endeavors in catalysis because of its fascinating opportunities in tuning the electronic state at the surface and enhancing the chemical reactivity. Here we report a novel and facile Nb 4+ -assisted strategy for the in situ growth of highly dispersed Pd nanoparticles (NPs) on monolayer HNb 3 O 8 nanosheets (HNb 3 O 8 NS) constituting a 2D Pd/HNb 3 O 8 NS heterostructure composite without using extra reducing agents and stabilizing agents. The Pd NP formation is directed via a redox reaction between an oxidative Pd salt precursor (H 2 PdCl 4 ) and reductive unsaturated surface metal (Nb 4+ ) sites induced by light irradiation on monolayer HNb 3 O 8 NS. The periodic arrangement of metal Nb nodes on HNb 3 O 8 NS leads to a homogeneous distribution of Pd NPs. Density functional theory (DFT) calculations reveal that the direct redox reaction between the Nb 4+ and Pd 2+ ions leads to a strong chemical interaction between the formed Pd metal NPs and the monolayer HNb 3 O 8 support. Consequently, the as-obtained Pd/HNb 3 O 8 composite serves as a highly efficient bifunctional catalyst in both heterogeneous thermocatalytic and photocatalytic selective reduction of aromatic nitro compounds in water under ambient conditions. The achieved high activity originates from the unique 2D nanosheet configuration and in situ Pd incorporation, which leads to a large active surface area, strong metal-support interaction and enhanced charge transport capability. Moreover, this facile Nb 4+ -assisted synthetic route has demonstrated to be general, which can be applied to load other metals such as Au and Pt on monolayer HNb 3 O 8 NS. It is anticipated that this work can extend the facile preparation of noble metal/nanosheet 2D heterostructures, as well as promote the simultaneous capture of duple renewable thermal and photon energy sources to drive an energy efficient

  19. Taming a Tiger in the City: Comparison of Motorized Backpack Applications and Source Reduction Against the Asian Tiger Mosquito, Aedes albopictus

    Science.gov (United States)

    2014-06-01

    TAMING A TIGER IN THE CITY: COMPARISON OF MOTORIZED BACKPACK APPLICATIONS AND SOURCE REDUCTION AGAINST THE ASIAN TIGER MOSQUITO, AEDES ALBOPICTUS...FONSECA2 AND ARY FARAJOLLAHI2,3,7 ABSTRACT. We evaluated 2 strategies to manage Aedes albopictus: 1) motorized backpack applications and 2) source...the community level. KEY WORDS Bacillus thuringiensis israelensis, Bti, methoprene, hand applications, backpack applications INTRODUCTION Aedes

  20. SU-F-T-368: Improved HPGe Detector Precise Efficiency Calibration with Monte Carlo Simulations and Radioactive Sources

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Y. John [Vanderbilt University, Vanderbilt-Ingram Cancer Center, Nashville, TN 37232 (United States)

    2016-06-15

    Purpose: To obtain an improved precise gamma efficiency calibration curve of HPGe (High Purity Germanium) detector with a new comprehensive approach. Methods: Both of radioactive sources and Monte Carlo simulation (CYLTRAN) are used to determine HPGe gamma efficiency for energy range of 0–8 MeV. The HPGe is a GMX coaxial 280 cm{sup 3} N-type 70% gamma detector. Using Momentum Achromat Recoil Spectrometer (MARS) at the K500 superconducting cyclotron of Texas A&M University, the radioactive nucleus {sup 24} Al was produced and separated. This nucleus has positron decays followed by gamma transitions up to 8 MeV from {sup 24} Mg excited states which is used to do HPGe efficiency calibration. Results: With {sup 24} Al gamma energy spectrum up to 8MeV, the efficiency for γ ray 7.07 MeV at 4.9 cm distance away from the radioactive source {sup 24} Al was obtained at a value of 0.194(4)%, by carefully considering various factors such as positron annihilation, peak summing effect, beta detector efficiency and internal conversion effect. The Monte Carlo simulation (CYLTRAN) gave a value of 0.189%, which was in agreement with the experimental measurements. Applying to different energy points, then a precise efficiency calibration curve of HPGe detector up to 7.07 MeV at 4.9 cm distance away from the source {sup 24} Al was obtained. Using the same data analysis procedure, the efficiency for the 7.07 MeV gamma ray at 15.1 cm from the source {sup 24} Al was obtained at a value of 0.0387(6)%. MC simulation got a similar value of 0.0395%. This discrepancy led us to assign an uncertainty of 3% to the efficiency at 15.1 cm up to 7.07 MeV. The MC calculations also reproduced the intensity of observed single-and double-escape peaks, providing that the effects of positron annihilation-in-flight were incorporated. Conclusion: The precision improved gamma efficiency calibration curve provides more accurate radiation detection and dose calculation for cancer radiotherapy treatment.

  1. Efficient Location of Research Reference Sources in the Field of Dance.

    Science.gov (United States)

    Kissinger, Pat; Jay, Danielle

    More than 45 basic dance reference research sources that would be useful to students, scholars, teachers, historians, and therapists are discussed in this bibliographic essay. Aspects of dance covered include choreography, criticism, teaching principles, aesthetic theory, dance therapy, and history. Sources are grouped by type: dictionaries and…

  2. Near-unity efficiency, single-photon sources based on tapered photonic nanowires

    DEFF Research Database (Denmark)

    Bleuse, Joël; Munsch, Mathieu; Claudon, Julien

    2012-01-01

    Single-photon emission from excitons in InAs Quantum Dots (QD) embedded in GaAs Tapered Photonic Wires (TPW) already demonstrated a 0.72 collection efficiency, with TPWs were the apex is the sharp end of the cone. Going to alternate designs, still based on the idea of the adiabatic deconfinement...... of the quasi-Gaussian emission mode, but with inverted TPW where the apex is the cone's base, leads to even larger efficiencies. In addition, these inverted TPWs make the electric pumping of the emitters compatible with these large efficiencies....

  3. An analytical calculation of the peak efficiency for cylindrical sources perpendicular to the detector axis in gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Julio C. [Autoridad Regulatoria Nuclear, Laboratorio de Espectrometria Gamma-CTBTO, Av. Del Libertador 8250, C1429BNP Buenos Aires (Argentina)], E-mail: jaguiar@sede.arn.gov.ar

    2008-08-15

    An analytical expression for the so-called full-energy peak efficiency {epsilon}(E) for cylindrical source with perpendicular axis to an HPGe detector is derived, using point-source measurements. The formula covers different measuring distances, matrix compositions, densities and gamma-ray energies; the only assumption is that the radioactivity is homogeneously distributed within the source. The term for the photon self-attenuation is included in the calculation. Measurements were made using three different sized cylindrical sources of {sup 241}Am, {sup 57}Co, {sup 137}Cs, {sup 54}Mn, and {sup 60}Co with corresponding peaks of 59.5, 122, 662, 835, 1173, and 1332 keV, respectively, and one measurement of radioactive waste drum for 662, 1173, and 1332 keV.

  4. Efficient source for the production of ultradense deuterium D(-1) for laser-induced fusion (ICF)

    International Nuclear Information System (INIS)

    Andersson, Patrik U.; Loenn, Benny; Holmlid, Leif

    2011-01-01

    A novel source which simplifies the study of ultradense deuterium D(-1) is now described. This means one step further toward deuterium fusion energy production. The source uses internal gas feed and D(-1) can now be studied without time-of-flight spectral overlap from the related dense phase D(1). The main aim here is to understand the material production parameters, and thus a relatively weak laser with focused intensity ≤10 12 W cm -2 is employed for analyzing the D(-1) material. The properties of the D(-1) material at the source are studied as a function of laser focus position outside the emitter, deuterium gas feed, laser pulse repetition frequency and laser power, and temperature of the source. These parameters influence the D(-1) cluster size, the ionization mode, and the laser fragmentation patterns.

  5. Efficient source for the production of ultradense deuterium D(-1) for laser-induced fusion (ICF)

    Science.gov (United States)

    Andersson, Patrik U.; Lönn, Benny; Holmlid, Leif

    2011-01-01

    A novel source which simplifies the study of ultradense deuterium D(-1) is now described. This means one step further toward deuterium fusion energy production. The source uses internal gas feed and D(-1) can now be studied without time-of-flight spectral overlap from the related dense phase D(1). The main aim here is to understand the material production parameters, and thus a relatively weak laser with focused intensity ≤1012 W cm-2 is employed for analyzing the D(-1) material. The properties of the D(-1) material at the source are studied as a function of laser focus position outside the emitter, deuterium gas feed, laser pulse repetition frequency and laser power, and temperature of the source. These parameters influence the D(-1) cluster size, the ionization mode, and the laser fragmentation patterns.

  6. Fuel-efficiency of hydrogen and heat storage technologies for integration of fluctuating renewable energy sources

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Lund, Henrik

    2005-01-01

    This paper presents the methodology and results of analysing the use of different energy storage technologies in the task of integration of fluctuating renewable energy sources (RES) into the electricity supply. The analysis is done on the complete electricity system including renewable energy...... sources as well as power plants and CHP (Combined heat and power production). Emphasis is put on the need for ancillary services. Devices to store electricity as well as devices to store heat can be used to help the integration of fluctuating sources. Electricity storage technologies can be used...... to relocate electricity production directly from the sources, while heat storage devices can be used to relocate the electricity production from CHP plants and hereby improve the ability to integrate RES. The analyses are done by advanced computer modelling and the results are given as diagrams showing...

  7. Effect of Amount of Carbon on the Reduction Efficiency of Iron Ore-Coal Composite Pellets in Multi-layer Bed Rotary Hearth Furnace (RHF)

    Science.gov (United States)

    Mishra, Srinibash; Roy, Gour Gopal

    2016-08-01

    The effect of carbon-to-hematite molar ratio has been studied on the reduction efficiency of iron ore-coal composite pellet reduced at 1523 K (1250 °C) for 20 minutes in a laboratory scale multi-layer bed rotary hearth furnace (RHF). Reduced pellets have been characterized through weight loss measurement, estimation of porosity, shrinkage, qualitative and quantitative phase analysis by XRD. Performance parameters such as the degree of reduction, metallization, carbon efficiency, productivity, and compressive strength have been calculated to compare the process efficacy at different carbon levels in the pellets. Pellets with optimum carbon-to-hematite ratio (C/Fe2O3 molar ratio = 1.66) that is much below the stoichiometric carbon required for direct reduction of hematite yielded maximum reduction, better carbon utilization, and productivity for all three layers. Top layer exhibited maximum reduction at comparatively lower carbon level (C/Fe2O3 molar ratio 2.33). Correlation between degree of reduction and metallization indicated non-isothermal kinetics influenced by heat and mass transfer in multi-layer bed RHF. Compressive strength of the partially reduced pellet with optimum carbon content (C/Fe2O3 molar ratio = 1.66) showed that they could be potentially used as an alternate feed in a blast furnace or any other smelting reactor.

  8. Numerical investigation of the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir: a case study of the Daming geothermal field in China.

    Science.gov (United States)

    Guo, Xuyang; Song, Hongqing; Killough, John; Du, Li; Sun, Pengguang

    2018-02-01

    The utilization of geothermal energy is clean and has great potential worldwide, and it is important to utilize geothermal energy in a sustainable manner. Mathematical modeling studies of geothermal reservoirs are important as they evaluate and quantify the complex multi-physical effects in geothermal reservoirs. However, previous modeling efforts lack the study focusing on the emission reduction efficiency and the deformation at geothermal wellbores caused by geothermal water extraction/circulation. Emission efficiency is rather relevant in geothermal projects introduced in areas characterized by elevated air pollution where the utilization of geothermal energy is as an alternative to burning fossil fuels. Deformation at geothermal wellbores is also relevant as significant deformation caused by water extraction can lead to geothermal wellbore instability and can consequently decrease the effectiveness of the heat extraction process in geothermal wells. In this study, the efficiency of emission reduction and heat extraction in a sedimentary geothermal reservoir in Daming County, China, are numerically investigated based on a coupled multi-physical model. Relationships between the efficiency of emission reduction and heat extraction, deformation at geothermal well locations, and geothermal field parameters including well spacing, heat production rate, re-injection temperature, rock stiffness, and geothermal well placement patterns are analyzed. Results show that, although large heat production rates and low re-injection temperatures can lead to decreased heat production in the last 8 years of heat extraction, they still improve the overall heat production capacity and emission reduction capacity. Also, the emission reduction capacity is positively correlated with the heat production capacity. Deformation at geothermal wellbore locations is alleviated by smaller well spacing, lower heat production rates, and smaller numbers of injectors in the well pattern, and by

  9. Feasibility of efficient room-temperature solid-state sources of indistinguishable single photons using ultrasmall mode volume cavities

    Science.gov (United States)

    Wein, Stephen; Lauk, Nikolai; Ghobadi, Roohollah; Simon, Christoph

    2018-05-01

    Highly efficient sources of indistinguishable single photons that can operate at room temperature would be very beneficial for many applications in quantum technology. We show that the implementation of such sources is a realistic goal using solid-state emitters and ultrasmall mode volume cavities. We derive and analyze an expression for photon indistinguishability that accounts for relevant detrimental effects, such as plasmon-induced quenching and pure dephasing. We then provide the general cavity and emitter conditions required to achieve efficient indistinguishable photon emission and also discuss constraints due to phonon sideband emission. Using these conditions, we propose that a nanodiamond negatively charged silicon-vacancy center combined with a plasmonic-Fabry-Pérot hybrid cavity is an excellent candidate system.

  10. IN VITRO FERMENTATION EFFICIENCY OF MIXTURES OF Cynodon nlemfuensis, Leucaena leucocephala AND TWO ENERGY SOURCES (MAIZE OR SUGAR CANE MOLASSES

    Directory of Open Access Journals (Sweden)

    Juan Martin Estrada-Liévano

    2009-07-01

    Full Text Available The in vitro fermentation efficiency of Cynodon nlemfuensis forage (star grass and Leucaena leucocephala foliage (leucaena and two energy sources (i.e. maize and sugar cane molasses mixture was evaluated. Mixture samples (1 g DM were incubated for 24 h. All the mixtures were added with 500 mg of polyetilenglycol (PEG. Adding molasses to star grass increased dry matter true digestibility and carbohydrate fermentation (P

  11. Evaluation of efficiency of P sources for rice using /sup 32/P as tracer

    Energy Technology Data Exchange (ETDEWEB)

    Sadanandan, A K [Central Plantation Crops Research Inst., Spice Farm, Peruvanuamuzhi, Kerala (India); Mohanty, S K; Patnaik, S; Dash, R N [Central Rice Research Inst., Cuttack (India); Mistry, K B

    1981-10-01

    /sup 32/P tracer studies were conducted in micro-plot and pot experiments to evaluate the efficiency of ammonium nitrate phosphates containing 30, 50 and 70% of the P in the water-soluble form and tri- and tetra-ammonium polyphosphates, in comparison with water-soluble phosphate for rice grown on a light-textured acid alluvials oil. Ammonium nitrate phosphate containing 50% of the P in the water-soluble form was as efficient as water-soluble phosphates on this soil in respect of dry-matter production, P uptake and utilization of applied P.

  12. Evaluation of efficiency of P sources for rice using 32P as tracer

    International Nuclear Information System (INIS)

    Sadanandan, A.K.; Mohanty, S.K.; Patnaik, S.; Dash, R.N.; Mistry, K.B.

    1981-01-01

    32 P tracer studies were conducted in micro-plot and pot experiments to evaluate the efficiency of ammonium nitrate phosphates containing 30, 50 and 70% of the P in the water-soluble form and tri- and tetra-ammonium polyphosphates, in comparison with water-soluble phosphate for rice grown on a light-textured acid alluvials oil. Ammonium nitrate phosphate containing 50% of the P in the water-soluble form was as efficient as water-soluble phosphates on this soil in respect of dry-matter production, P uptake and utilization of applied P. (author)

  13. CO2 reduction in the Danish transportation sector. Working paper 5: Technological improvement of energy efficiency. Average requirements to energy efficiency of the new vehicles. Subsidies to research and development

    International Nuclear Information System (INIS)

    1997-03-01

    The road traffic is expected to be responsible for 9/10 of the total CO 2 emission from transportation sector in 2005. Especially private cars contribute more than half of the total CO 2 emission. Cars are not produced in Denmark, so energy efficiency of the new models depends entirely on the foreign manufacturers. Measurements of energy efficiency on test facilities show usually slightly better efficiency than on-the-road results. Efficiency estimates are based on test results. Within 10-15 years the whole car park will show essential efficiency improvement due to exchanging to newer models. Shadow price of CO 2 emission reduction is defined. (EG) Prepared for Trafikministeriet. 27 refs

  14. An efficient central DOA tracking algorithm for multiple incoherently distributed sources

    Science.gov (United States)

    Hassen, Sonia Ben; Samet, Abdelaziz

    2015-12-01

    In this paper, we develop a new tracking method for the direction of arrival (DOA) parameters assuming multiple incoherently distributed (ID) sources. The new approach is based on a simple covariance fitting optimization technique exploiting the central and noncentral moments of the source angular power densities to estimate the central DOAs. The current estimates are treated as measurements provided to the Kalman filter that model the dynamic property of directional changes for the moving sources. Then, the covariance-fitting-based algorithm and the Kalman filtering theory are combined to formulate an adaptive tracking algorithm. Our algorithm is compared to the fast approximated power iteration-total least square-estimation of signal parameters via rotational invariance technique (FAPI-TLS-ESPRIT) algorithm using the TLS-ESPRIT method and the subspace updating via FAPI-algorithm. It will be shown that the proposed algorithm offers an excellent DOA tracking performance and outperforms the FAPI-TLS-ESPRIT method especially at low signal-to-noise ratio (SNR) values. Moreover, the performances of the two methods increase as the SNR values increase. This increase is more prominent with the FAPI-TLS-ESPRIT method. However, their performances degrade when the number of sources increases. It will be also proved that our method depends on the form of the angular distribution function when tracking the central DOAs. Finally, it will be shown that the more the sources are spaced, the more the proposed method can exactly track the DOAs.

  15. Efficient full waveform inversion using the excitation representation of the source wavefield

    KAUST Repository

    Kalita, Mahesh

    2017-05-16

    Full waveform inversion (FWI) is an iterative method of data-fitting, aiming at high-resolution recovery of the unknown model parameters. However, its conventional implementation is a cumbersome process, requiring a long computational time and large memory space/disk storage. One of the reasons for this computational limitation is the gradient calculation step. Based on the adjoint state method, it involves the temporal cross-correlation of the forward propagated sourcewavefield with the backward propagated residuals, inwhichwe usually need to store the source wavefield, or include an extra extrapolation step to propagate the source wavefield from its storage at the boundary. We propose, alternatively, an amplitude excitation gradient calculation based on the excitation imaging condition concept that represents the source wavefield history by a single, specifically the most energetic arrival. An excitation based Born modelling allows us to derive the adjoint operation. In this case, the source wavelet is injected by a cross-correlation step applied to the data residual directly. Representing the source wavefield through the excitation amplitude and time, we reduce the large requirements for both storage and the computational time. We demonstrate the application of this approach on a two-layer model with an anomaly, the Marmousi II model and a marine data set acquired by CGG.

  16. Design of a novel high efficiency antenna for helicon plasma sources

    Science.gov (United States)

    Fazelpour, S.; Chakhmachi, A.; Iraji, D.

    2018-06-01

    A new configuration for an antenna, which increases the absorption power and plasma density, is proposed for helicon plasma sources. The influence of the electromagnetic wave pattern symmetry on the plasma density and absorption power in a helicon plasma source with a common antenna (Nagoya) is analysed by using the standard COMSOL Multiphysics 5.3 software. In contrast to the theoretical model prediction, the electromagnetic wave does not represent a symmetric pattern for the common Nagoya antenna. In this work, a new configuration for an antenna is proposed which refines the asymmetries of the wave pattern in helicon plasma sources. The plasma parameters such as plasma density and absorption rate for a common Nagoya antenna and our proposed antenna under the same conditions are studied using simulations. In addition, the plasma density of seven operational helicon plasma source devices, having a common Nagoya antenna, is compared with the simulation results of our proposed antenna and the common Nagoya antenna. The simulation results show that the density of the plasma, which is produced by using our proposed antenna, is approximately twice in comparison to the plasma density produced by using the common Nagoya antenna. In fact, the simulation results indicate that the electric and magnetic fields symmetry of the helicon wave plays a vital role in increasing wave-particle coupling. As a result, wave-particle energy exchange and the plasma density of helicon plasma sources will be increased.

  17. Influence of Bernstein modes on the efficiency of electron cyclotron resonance x-ray source

    International Nuclear Information System (INIS)

    Andreev, V. V.; Nikitin, G.V.; Savanovich, V.Yu.; Umnov, A.M.; Elizarov, L.I.; Serebrennikov, K.S.; Vostrikova, E.A.

    2006-01-01

    The article considers the factors influencing the temperature of hot electron component in an electron cyclotron resonance (ECR) x-ray source. In such sources the electron heating occurs often due to extraordinary electromagnetic wave propagating perpendicularly to the magnetic field. In this case the possibility of the absorption of Bernstein modes is regarded as an additional mechanism of electron heating. The Bernstein modes in an ECR x-ray source can arise due to either linear transformation or parametric instability of external transversal wave. The article briefly reviews also the further experiments which will be carried out to study the influence of Bernstein modes on the increase of hot electron temperature and consequently of x-ray emission

  18. Efficient fiber-coupled single-photon sources based on quantum dots

    DEFF Research Database (Denmark)

    Daveau, Raphaël Sura

    refrigeration with coupled quantum wells. Many photonic quantum information processing applications would benet from a highbrightness, ber-coupled source of triggered single photons. This thesis presents a study of such sources based on quantum dots coupled to unidirectional photonic-crystal waveguide devices.......6 %. This latter method opens a promising future for increasing the eciency and reliability of planar chip-based single-photon sources. Refrigeration of a solid-state system with light has potential applications for cooling small-scale electronic and photonic circuits. We show theoretically that two coupled...... semiconductor quantum wells are ecient cooling media because they support long-lived indirect electron-hole pairs. These pairs can be thermally excited to distinct higher-energy states with faster radiative recombination, thereby creating an ecient escape channel to remove thermal energy from the system. From...

  19. Dependence of NaI(Tl) detector intrinsic efficiency on source ...

    Indian Academy of Sciences (India)

    on source–detector distance, energy and off-axis distance: Their ... This d/R value at which minimum efficiency occurs approaches zero as off- axis distance ... It should be noted at this point that from the point of view of radiation protection ...

  20. Highly efficient electron gun with a single-atom electron source

    International Nuclear Information System (INIS)

    Ishikawa, Tsuyoshi; Urata, Tomohiro; Cho, Boklae; Rokuta, Eiji; Oshima, Chuhei; Terui, Yoshinori; Saito, Hidekazu; Yonezawa, Akira; Tsong, Tien T.

    2007-01-01

    The authors have demonstrated highly collimated electron-beam emission from a practical electron gun with a single-atom electron source; ∼80% of the total emission current entered the electron optics. This ratio was two or three orders of magnitude higher than those of the conventional electron sources such as a cold field emission gun and a Zr/O/W Schottky gun. At the pressure of less than 1x10 -9 Pa, the authors observed stable emission of 20 nA, which generates the specimen current of 5 pA required for scanning electron microscopes

  1. Efficient 'water window' soft x-ray high-Z plasma source

    International Nuclear Information System (INIS)

    Higashiguchi, T; Otsuka, T; Jiang, W; Endo, A; Li, B; Dunne, P; O'Sullivan, G

    2013-01-01

    Unresolved transition array (UTA) is scalable to shorter wavelengths, and we demonstrate a table-top broadband emission 'water window' soft x-ray source based on laser-produced plasmas. Resonance emission from multiply charged ions merges to produce intense UTAs in the 2 to 4 nm region, extending below the carbon K edge (4.37 nm). An outline of a microscope design for single-shot live cell imaging is proposed based on a bismuth (Bi) plasma UTA source, coupled to multilayer mirror optics

  2. Feasibility study of broadband efficient ''water window'' source

    Energy Technology Data Exchange (ETDEWEB)

    Higashiguchi, Takeshi; Yugami, Noboru [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Japan Science and Technology Agency, CREST, 4-1-8 Honcho, Kanagawa, Saitama 332-0012 (Japan); Otsuka, Takamitsu [Department of Advanced Interdisciplinary Sciences, Center for Optical Research and Education (CORE), and Optical Technology Innovation Center (OpTIC), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585 (Japan); Jiang Weihua [Department of Electrical Engineering, Nagaoka University of Technology, Kami-tomiokamachi 1603-1, Nagaoka, Niigata 940-2188 (Japan); Endo, Akira [Research Institute for Science and Engineering, Waseda University, Okubo 3-4-1, Shinjuku, Tokyo 169-8555 (Japan); Li Bowen; Dunne, Padraig; O' Sullivan, Gerry [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)

    2012-01-02

    We demonstrate a table-top broadband emission water window source based on laser-produced high-Z plasmas. Resonance emission from multiply charged ions merges to produce intense unresolved transition arrays (UTAs) in the 2-4 nm region, extending below the carbon K edge (4.37 nm). Arrays resulting from n=4-n=4 transitions are overlaid with n=4-n=5 emission and shift to shorter wavelength with increasing atomic number. An outline of a microscope design for single-shot live cell imaging is proposed based on a bismuth plasma UTA source, coupled to multilayer mirror optics.

  3. The impedance of energy efficiency of a coaxial magnetized plasma source used for spheromak formation and sustainment

    International Nuclear Information System (INIS)

    Barnes, C.W.; Jarboe, T.R.; Marklin, G.J.; Knox, S.O.; Henins, I.

    1989-01-01

    Electrostatic (dc) helicity injection has previously been shown to successfully sustain the magnetic fields of spheromaks and tokamaks. The magnitude of the injected magnetic helicity balances (within experimental error) the flux lost be resistive decay of the toroidal equilibrium. The problem of optimizing this current drive scheme hence involves maximizing the injected helicity (the voltage-connecting-flux product) while minimizing the current (which multiplied by the voltage represents the energy input and also possible damage to the electrodes). The impedance (voltage-to-current ratio) and energy efficiency of a dc helicity injection experiment are studied on the CTX spheromak. Over several years changes were made in the physical geometry of the coaxial magnetized plasmas source as well as changes in the external electrical circuit. The source could be operated over a wide range of external charging voltage (and hence current), applied axial flux, and source gas flow rate. A database of resulting voltage, helicity injection, efficiency, electron density, and rotation has been created. These experimental results are compared to an ideal magnetohydrodynamic theory of magnetic flux flow. The theory is parameterized by the dimensionless Hall parameter, the ratio of electric to mass current. For a constant Hall parameter the theory explains why the voltage depends quadratically on the current at constant flux. The theory also explains the approximately linear dependence of the impedance-to-current ratio on the current-to-flux ratio of the source. 9 refs., 6 figs

  4. Towards efficient next generation light sources: combined solution processed and evaporated layers for OLEDs

    Science.gov (United States)

    Hartmann, D.; Sarfert, W.; Meier, S.; Bolink, H.; García Santamaría, S.; Wecker, J.

    2010-05-01

    Typically high efficient OLED device structures are based on a multitude of stacked thin organic layers prepared by thermal evaporation. For lighting applications these efficient device stacks have to be up-scaled to large areas which is clearly challenging in terms of high through-put processing at low-cost. One promising approach to meet cost-efficiency, high through-put and high light output is the combination of solution and evaporation processing. Moreover, the objective is to substitute as many thermally evaporated layers as possible by solution processing without sacrificing the device performance. Hence, starting from the anode side, evaporated layers of an efficient white light emitting OLED stack are stepwise replaced by solution processable polymer and small molecule layers. In doing so different solutionprocessable hole injection layers (= polymer HILs) are integrated into small molecule devices and evaluated with regard to their electro-optical performance as well as to their planarizing properties, meaning the ability to cover ITO spikes, defects and dust particles. Thereby two approaches are followed whereas in case of the "single HIL" approach only one polymer HIL is coated and in case of the "combined HIL" concept the coated polymer HIL is combined with a thin evaporated HIL. These HIL architectures are studied in unipolar as well as bipolar devices. As a result the combined HIL approach facilitates a better control over the hole current, an improved device stability as well as an improved current and power efficiency compared to a single HIL as well as pure small molecule based OLED stacks. Furthermore, emitting layers based on guest/host small molecules are fabricated from solution and integrated into a white hybrid stack (WHS). Up to three evaporated layers were successfully replaced by solution-processing showing comparable white light emission spectra like an evaporated small molecule reference stack and lifetime values of several 100 h.

  5. Efficiency in the reduction of chromium by a wild bacterium in a Batch treatment type using residual water substrate from the municipality of Pasto, Colombia

    Directory of Open Access Journals (Sweden)

    Deisy Lorena Guerrero Ceballos

    2017-05-01

    Full Text Available Objective: To evaluate the efficiency in the reduction of chromium in a Batch treatment type, using municipal residual water substrate inoculated with a wild bacterium. Materials and methods: The reduction percentage of hexavalent chromium of three wild bacteria previously isolated from residual water from the Pasto River was verified at laboratory scale (Bacillus thuringiensis, Bacillus amyloliquefaciens and Paenibacillus sp.; the isolated that showed the highest percentage of reduction of Cr was selected and was subjected to different treatments. The analysis of results was done using descriptive statistics. Results: B. thuringiensis, B. amyloliquefaciens, and Paenibacillus sp., presented percentages of reduction of Cr (VI of 82,01%; 80,85% and 79,27%, respectively. It was determined that the third treatment (nonsterile water from the Pasto River with B. thuringiensis presented significant differences with regard to the other (p = 0.0001 α = 0.05, concluding that B. thuringiensis reduces in greater proportion the Cr (VI. The results found in this research are promising in the field of bioremediation of contaminated effluents with Chrome since they may be taken as the basis for implementing strategies of bioremediation on a large scale. Conclusion: The bacteria B. thuringiensis presented high efficiency in the reduction of hexavalent chromium (99.42% when implemented in a treatment at laboratory scale of residual nonsterile water.

  6. Improving the efficiency of a fluorescent Xe dielectric barrier light source using short pulse excitation

    International Nuclear Information System (INIS)

    Beleznai, Sz; Mihajlik, G; Richter, P; Maros, I; Balazs, L

    2008-01-01

    Operation of a Xe dielectric barrier discharge lamp producing 147-172 nm VUV radiation is investigated both theoretically and experimentally. Xe gas pressure varies between 100 and 300 mbar, and the glass body of the lamp is coated with LAP (green) phosphor to convert radiation into the visible part of the spectrum. Simulation results predict improved discharge efficiencies reaching 67% when excited by a fast rise-time, short pulse (∼200 ns) driving waveform. In this case most power deposited into the plasma efficiently produces Xe 2 * excimers, while other energy dissipation processes (ion heating, e-Xe elastic collision) are kept at a low rate. Simulation and experimental results are compared in terms of discharge efficacy and show good agreement. A lamp efficacy value as high as 80 lm W -1 is demonstrated experimentally

  7. Packaging as source of efficient and sustainable advantages in supply chain management. An analysis of briks

    Directory of Open Access Journals (Sweden)

    Jesus García-Arca

    2014-01-01

    Full Text Available In higher competitive markets, the suitable supply chain management (particularly, in logistic processes and the adoptionof sustainability programs are strategic points in companies. In this context, no many companies have devoted special attentionto the impact of packaging design on logistic efficiency and sustainability.Thus, the integration of logistics and the packaging design has been conceptualized in the term «packaging logistics», par ticularly emphasizing its operational and organizational impact on supply chain performance. Going beyond, authors consider that a greater emphasis should be given to the important strategic connotations to do with packaging design,in many cases this being one of the supports of competitive advantages in the supply chain management from an overall perspective of efficiency and sustainability.To illustrate this statement, in this paper, not only the conceptual field of this concept is developed, but also in its application, analysing a case study in dairy sector, particularly, focused on brik products .

  8. Energy-Efficiency Analysis of Per-Subcarrier Antenna Selection with Peak-Power Reduction in MIMO-OFDM Wireless Systems

    Directory of Open Access Journals (Sweden)

    Ngoc Phuc Le

    2014-01-01

    Full Text Available The use of per-subcarrier antenna subset selection in OFDM wireless systems offers higher system capacity and/or improved link reliability. However, the implementation of the conventional per-subcarrier selection scheme may result in significant fluctuations of the average power and peak power across antennas, which affects the potential benefits of the system. In this paper, power efficiency of high-power amplifiers and energy efficiency in per-subcarrier antenna selection MIMO-OFDM systems are investigated. To deliver the maximum overall power efficiency, we propose a two-step strategy for data-subcarrier allocation. This strategy consists of an equal allocation of data subcarriers based on linear optimization and peak-power reduction via cross-antenna permutations. For analysis, we derive the CCDF (complementary cumulative distribution function of the power efficiency as well as the analytical expressions of the average power efficiency. It is proved from the power-efficiency perspective that the proposed allocation scheme outperforms the conventional scheme. We also show that the improvement in the power efficiency translates into an improved capacity and, in turn, increases energy efficiency of the proposed system. Simulation results are provided to validate our analyses.

  9. Comparison of the Efficiencies of Zero-Valent Iron Nanoparticles and Stabilized Iron Nanoparticles for Nitrate Reduction from Polluted Waters

    Directory of Open Access Journals (Sweden)

    Fatemeh Nooralivand

    2015-12-01

    Full Text Available The present study was conducted to evaluate the feasibility of zero-valent iron nanoparticles (ZVIN for the removal of nitrate from aqueous solutions. For this purpose, bare zero-valent iron nanoparticles (bare-ZVIN and CMC-ZVIN were synthesized using the borohydride reduction method and their morphological characteristics were examined via scanning electron microscopy (SEM, X-ray diffraction (XRD, and Fourier Transmission Infrared Spectroscopy (FTIR. The effects of pH of the aqueous solution, initial nitrate concentration, ZVIN concentration, and contact time on nitrate reduction were investigated as operational parameters and the kinetics of nitrate reduction was studied in batch experiments. The results showed that 93.65% of nitrate was removed by stabilized nanoparticles at pH=6 while non-stabilized nanoparticles at pH=2 were able to remove 85.55% of the nitrate.Furthermore, nitrate reduction was enhanced by increasing ZVIN concentration and contact time while it was decreased as a result of increasing initial nitrate concentration. The major product of nitrate reduction at an acidic pH was found to be ammonium; at an alkaline pH, however, nitrate was converted to nitrogen and nitrite production dropped to less than 2%. Kinetic analysis demonstrated that denitrification of nitrate by the nanoparticles fitted well with first-order and second-order reaction models. The results also demonstrated that the stabilized ZVI nanoparticles were more effective than bare-ZVIN for nitrate reduction in aqueous solutions.

  10. Electric power supply and the influence of changes on renewable sources' utilisation and energy efficiency

    International Nuclear Information System (INIS)

    Kurek, J.

    2000-01-01

    Changes expected to occur at the electricity market min the Republic of Croatia will have a considerable influence on the development of renewable sources and on the interest in the rationalisation of electricity consumption. If this area and its significance within the total, not only energy-related but also social relations, is stimulated by the law, the influence will be a positive one. Post-liberalisation experience of developed European countries presented in this paper implies arising problems, which can be partly avoided by means of anticipated legislative alternations. Special attention is paid to the possibility of introducing additional work places through a new market approachz, renewable sources' utilisation and consumption rationalisation. (author)

  11. Energy management for cost reduction in the production. TEEM - Total Energy Efficiency Management; Energiemanagement zur Kostensenkung in der Produktion. TEEM - Total Energy Efficiency Management

    Energy Technology Data Exchange (ETDEWEB)

    Westkaemper, Engelbert; Verl, Alexander (eds.)

    2009-07-01

    Within the workshop of the Fraunhofer Institute for Manufacturing Engineering and Automation IPA (Stuttgart, Federal Republic of Germany) at 6th October, 2009, in Stuttgart the following lectures were held: (1) Presentation of Fraunhofer Institute for Manufacturing Engineering and Automation IPA (Engelbert Westkaemper); (2) TEEM - Total Energy Efficiency Management - ''With energy management to an energy efficient production'' (Alexander Schloske); (3) DIN EN 16001 Introduction of an energy management system - utilization and advantages for companies (Sylvia Wahren); (4) Analysis of the energy efficiency with power flow - Support and implementation at factory planning and optimization of production (Klaus Erlach); (5) Total Energy Efficiency Management - Approaches at the company Kaercher in injection moulding for example (Axel Leschtar); (6) Modelling the embodied product energy (Shahin Rahimifard); (7) Acquisition of energy data in the production - Technologies and possibilities (Joachim Neher); (8) Active energy management by means of an ''energy control centre'' - Analysis of the real situation and upgrading measures in the production using coating plants as an example (Wolfgang Klein); (9) Visualisation and simulation of energy values in the digital factory (Carmen Constantinescu, Axel Bruns).

  12. The development of magnetic ion-source with high ionisation efficiency

    NARCIS (Netherlands)

    Veenstra, P.C.; Milatz, J.M.W.

    1950-01-01

    Starting from the principle given by A. Th. F i n k e l s t e i n l) , M. yon Ardenne2) 3) and W. Maas4), further development of the magnetic ion-source has been undertaken. The instrument has been designed especially for use with a 800 kV neutron generator described by W. M a a s 4) and under

  13. Application of source biasing technique for energy efficient DECODER circuit design: memory array application

    Science.gov (United States)

    Gupta, Neha; Parihar, Priyanka; Neema, Vaibhav

    2018-04-01

    Researchers have proposed many circuit techniques to reduce leakage power dissipation in memory cells. If we want to reduce the overall power in the memory system, we have to work on the input circuitry of memory architecture i.e. row and column decoder. In this research work, low leakage power with a high speed row and column decoder for memory array application is designed and four new techniques are proposed. In this work, the comparison of cluster DECODER, body bias DECODER, source bias DECODER, and source coupling DECODER are designed and analyzed for memory array application. Simulation is performed for the comparative analysis of different DECODER design parameters at 180 nm GPDK technology file using the CADENCE tool. Simulation results show that the proposed source bias DECODER circuit technique decreases the leakage current by 99.92% and static energy by 99.92% at a supply voltage of 1.2 V. The proposed circuit also improves dynamic power dissipation by 5.69%, dynamic PDP/EDP 65.03% and delay 57.25% at 1.2 V supply voltage.

  14. Phosphate fertilizers with varying water-solubilities applied to Amazonian soils: I. agronomic efficiency of P sources

    International Nuclear Information System (INIS)

    Brasil, E.C.; Muraoka, T.; Boaretto, A.E.; Scivittaro, W.B.

    2002-01-01

    The relative agronomic efficiency of four phosphate sources (triple superphosphate, ordinary Yoorin thermophosphate, coarse Yoorin thermophosphate and North Carolina phosphate rock) were evaluated, in a pot experiment carried out under greenhouse conditions, using five soils (medium texture Yellow Latosol, clayey Yellow Latosol, very clayey Yellow Latosol, clayey Red-Yellow Podzolic and very clayey Red-Yellow Podzolic) from Para State, Brazil. The soils received three rates of phosphorus (40, 80 and 120 mg P/kg of soil) plus the control (0P) treatment. A randomized block design with three replicates was used. Two consecutive crops (cowpea and rice) were used as test plants. The results showed that the best dry matter yield and P uptake for cowpea were obtained in soils fertilized with triple superphosphate. The agronomic efficiency index of ordinary Yoorin was superior to the coarse Yoorin and North Carolina phosphate rock for the cowpea grown as first crop. The indices were similar for all phosphate sources for the subsequent rice crop. The best residual effect was obtained with North Carolina phosphate rock and coarse Yoorin. The larger particle size of coarse thermophosphate resulted in a decreased P efficiency. (author)

  15. From Goals to Action: The Efforts for Increasing Energy Efficiency and Integration of Renewable Sources in Eskilstuna, Sweden

    Directory of Open Access Journals (Sweden)

    Iana Vassileva

    2015-07-01

    Full Text Available Cities’ energy usage accounts for two thirds of global primary energy consumption. Energy efficiency in urban areas is, therefore, one of the most important topics to consider when dealing with urban sustainability. This paper evaluates the goals for increasing energy efficiency and use of renewable energy sources in the areas of transportation, buildings and consumers’ awareness, as stated in the Climate action plan, for the municipality of Eskilstuna, Sweden. The efforts of the municipality to successfully reach their energy efficiency goals, are described in this paper including future perspectives. The results show that although the municipality counts with the advantage of owning and working together with the local housing company and energy provider, in order to reach the established goals, additional strategies need to be considered. For an increased use of renewable energy sources, analysis of rooftops suitable for photovoltaic (PV installation should be carried out as well as the integration of goals for self-consumption. In the transport field, the city needs to prepare for large-scale electric vehicle (EV market penetration and to consider different bike or car sharing options. Finally, more specific awareness campaigns are needed to engage the citizens in reducing their energy consumption and living a more sustainable life.

  16. Sources

    International Nuclear Information System (INIS)

    Duffy, L.P.

    1991-01-01

    This paper discusses the sources of radiation in the narrow perspective of radioactivity and the even narrow perspective of those sources that concern environmental management and restoration activities at DOE facilities, as well as a few related sources. Sources of irritation, Sources of inflammatory jingoism, and Sources of information. First, the sources of irritation fall into three categories: No reliable scientific ombudsman to speak without bias and prejudice for the public good, Technical jargon with unclear definitions exists within the radioactive nomenclature, and Scientific community keeps a low-profile with regard to public information. The next area of personal concern are the sources of inflammation. This include such things as: Plutonium being described as the most dangerous substance known to man, The amount of plutonium required to make a bomb, Talk of transuranic waste containing plutonium and its health affects, TMI-2 and Chernobyl being described as Siamese twins, Inadequate information on low-level disposal sites and current regulatory requirements under 10 CFR 61, Enhanced engineered waste disposal not being presented to the public accurately. Numerous sources of disinformation regarding low level radiation high-level radiation, Elusive nature of the scientific community, The Federal and State Health Agencies resources to address comparative risk, and Regulatory agencies speaking out without the support of the scientific community

  17. Automated system for efficient microwave power coupling in an S-band ECR ion source driven under different operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Muguira, L., E-mail: lmuguira@essbilbao.org [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain); Portilla, J. [University of Basque Country (UPV/EHU), Department of Electricity and Electronics, Science and Technology Faculty, 48940 Leioa (Bizkaia) (Spain); Gonzalez, P.J.; Garmendia, N.; Feuchtwanger, J. [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain); Etxebarria, V. [University of Basque Country (UPV/EHU), Department of Electricity and Electronics, Science and Technology Faculty, 48940 Leioa (Bizkaia) (Spain); Eguiraun, M.; Arredondo, I.; Miracoli, R.; Belver, D. [ESS-Bilbao, Edificio Rectorado, Vivero de Empresas, 48940 Leioa (Bizkaia) (Spain)

    2014-03-21

    This article presents an automated system for optimizing the microwave power coupling to the plasma generated in a proton/deuteron Electron Cyclotron Resonance (ECR) source, based on a specific model of a rectangular waveguide triple-stub tuner and the integrated measurement and control electronics, helping to get stable plasma states. The control and improvement of the RF power absorption into the plasma is a complex process, essential for the ion source development and optimization under different operating conditions. A model and a matching algorithm for the triple-stub tuner have been developed and, besides, different methods to accurately measure the power transfer in a waveguide RF system have been studied and deployed in the ESS-Bilbao ion source system. The different parts have been integrated through a controller, which allows to run an automatic plasma matching system in closed loop. The behavior of the system implemented for low and high power regimes has been tested under different conditions: with several load impedances, with plasma inside the chamber, in continuous wave and pulsed wave operation modes, demonstrating power absorption typically over 90% in all the ion source configurations. The developed system allows to achieve significant improvement in the ECR ion source power absorption efficiency, both in continuous and pulsed mode. The automatic tuning unit enhances the system operation finding an optimum solution much faster than manually, also behaving as an adaptive system able to respond in few pulses to ion source configuration changes to maintain the power coupling as high as possible. - Highlights: • An automated system optimizing plasma and microwave power interaction is presented. • A model and a matching algorithm for the triple-stub tuner have been developed. • Different methods to measure the power transfer have been studied and deployed. • The system works for low or high power regimes under different ion source conditions.

  18. Automated system for efficient microwave power coupling in an S-band ECR ion source driven under different operating conditions

    International Nuclear Information System (INIS)

    Muguira, L.; Portilla, J.; Gonzalez, P.J.; Garmendia, N.; Feuchtwanger, J.; Etxebarria, V.; Eguiraun, M.; Arredondo, I.; Miracoli, R.; Belver, D.

    2014-01-01

    This article presents an automated system for optimizing the microwave power coupling to the plasma generated in a proton/deuteron Electron Cyclotron Resonance (ECR) source, based on a specific model of a rectangular waveguide triple-stub tuner and the integrated measurement and control electronics, helping to get stable plasma states. The control and improvement of the RF power absorption into the plasma is a complex process, essential for the ion source development and optimization under different operating conditions. A model and a matching algorithm for the triple-stub tuner have been developed and, besides, different methods to accurately measure the power transfer in a waveguide RF system have been studied and deployed in the ESS-Bilbao ion source system. The different parts have been integrated through a controller, which allows to run an automatic plasma matching system in closed loop. The behavior of the system implemented for low and high power regimes has been tested under different conditions: with several load impedances, with plasma inside the chamber, in continuous wave and pulsed wave operation modes, demonstrating power absorption typically over 90% in all the ion source configurations. The developed system allows to achieve significant improvement in the ECR ion source power absorption efficiency, both in continuous and pulsed mode. The automatic tuning unit enhances the system operation finding an optimum solution much faster than manually, also behaving as an adaptive system able to respond in few pulses to ion source configuration changes to maintain the power coupling as high as possible. - Highlights: • An automated system optimizing plasma and microwave power interaction is presented. • A model and a matching algorithm for the triple-stub tuner have been developed. • Different methods to measure the power transfer have been studied and deployed. • The system works for low or high power regimes under different ion source conditions.

  19. Efficient Electrocatalytic Reduction of CO2 by Nitrogen-Doped Nanoporous Carbon/Carbon Nanotube Membranes - A Step Towards the Electrochemical CO2 Refinery

    KAUST Repository

    Wang, Hong; Jia, Jia; Song, Pengfei; Wang, Qiang; Li, Debao; Min, Shixiong; Qian, Chenxi; Wang, Lu; Li, Young Feng; Ma, Chun; Wu, Tao; Yuan, Jiayin; Antonietti, Markus; Ozin, Geoffrey A.

    2017-01-01

    The search for earth abundant, efficient and stable electrocatalysts that can enable the chemical reduction of CO2 to value-added chemicals and fuels at an industrially relevant scale, is a high priority for the development of a global network of renewable energy conversion and storage systems that can meaningfully impact greenhouse gas induced climate change. Here we introduce a straightforward, low cost, scalable and technologically relevant method to manufacture an all-carbon, electroactive, nitrogen-doped nanoporous carbon-carbon nanotube composite membrane. The membrane is demonstrated to function as a binder-free, high-performance electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency for the production of formate is 81%. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long-term stability.

  20. Efficient Electrocatalytic Reduction of CO2 by Nitrogen-Doped Nanoporous Carbon/Carbon Nanotube Membranes - A Step Towards the Electrochemical CO2 Refinery

    KAUST Repository

    Wang, Hong

    2017-05-12

    The search for earth abundant, efficient and stable electrocatalysts that can enable the chemical reduction of CO2 to value-added chemicals and fuels at an industrially relevant scale, is a high priority for the development of a global network of renewable energy conversion and storage systems that can meaningfully impact greenhouse gas induced climate change. Here we introduce a straightforward, low cost, scalable and technologically relevant method to manufacture an all-carbon, electroactive, nitrogen-doped nanoporous carbon-carbon nanotube composite membrane. The membrane is demonstrated to function as a binder-free, high-performance electrode for the electrocatalytic reduction of CO2 to formate. The Faradaic efficiency for the production of formate is 81%. Furthermore, the robust structural and electrochemical properties of the membrane endow it with excellent long-term stability.

  1. NOVEL SOURCES OF FUNGAL CELLULASES OF THERMOPHILIC / THERMOTOLERANT FOR EFFICIENT DEINKING OF COMPOSITE PAPER WASTE

    Directory of Open Access Journals (Sweden)

    Rohit Soni

    2008-02-01

    Full Text Available Twenty thermophilic/thermotolerant fungal strains were isolated from compositing soils and screened for production of different enzymes (Endoglucanases, β-glucosidase, Fpase and xylanases to assess their deinking efficiency. Three isolates, Aspergillus sp. AMA, Aspergillus terreus AN1, and Myceliophthora fergusii T4I, identified on the basis of morphological and sequencing of amplified ITS1-5.8S-ITS2 rDNA region, showed significant deinking of composite waste paper (70% magazine and 30% Xerox copier/ laser print paper waste as well as improved properties (brightness, tensile strength, tear index of recycled paper sheets. The chosen strains Aspergillus sp. AMA, Aspergillus terreus AN1 and Myceliophthora fergusii T4I, showed 53, 52.7, and 40.32% deinking with increase in brightness by 4.32, 3.56, and 3.01 % ISO, respectively. These cultures were found to produce multiple endoglucanases and were characterized to lack a cellulose binding module (CBD, which may be responsible for their better deinking efficiency.

  2. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    International Nuclear Information System (INIS)

    Sloan Roberts, F.; Anderson, Scott L.

    2013-01-01

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a “soft” photoionization source for gas-phase mass spectrometry

  3. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: A modular vacuum ultraviolet source

    Energy Technology Data Exchange (ETDEWEB)

    Sloan Roberts, F.; Anderson, Scott L. [Department of Chemistry, University of Utah, 315 S. 1400 E., Salt Lake City, Utah 84112 (United States)

    2013-12-15

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a “soft” photoionization source for gas-phase mass spectrometry.

  4. Note: Hollow cathode lamp with integral, high optical efficiency isolation valve: a modular vacuum ultraviolet source.

    Science.gov (United States)

    Roberts, F Sloan; Anderson, Scott L

    2013-12-01

    The design and operating conditions of a hollow cathode discharge lamp for the generation of vacuum ultraviolet radiation, suitable for ultrahigh vacuum (UHV) application, are described in detail. The design is easily constructed, and modular, allowing it to be adapted to different experimental requirements. A thin isolation valve is built into one of the differential pumping stages, isolating the discharge section from the UHV section, both for vacuum safety and to allow lamp maintenance without venting the UHV chamber. The lamp has been used both for ultraviolet photoelectron spectroscopy of surfaces and as a "soft" photoionization source for gas-phase mass spectrometry.

  5. Efficiency and stability of a phosphor-conversion white light source using a blue laser diode

    Directory of Open Access Journals (Sweden)

    G. Ledru

    2014-10-01

    Full Text Available A white light source using direct phosphor-conversion excited by a blue laser diode is presented. In this preliminary study we have investigated the influence of phosphor’s thickness and operating current of the laser diode over the (x, y chromaticity coordinates, Correlated Color Temperature (CCT and Color Rendering Index (CRI. The best values found were 4000 K and 94. A 40 lm/W luminous efficacy was achieved together with a CRI close to 90 for an operating current of 0.8 A. Those values, to the best of our knowledge, were not previously reported in the literature.

  6. LED arrays as cost effective and efficient light sources for widefield microscopy.

    Directory of Open Access Journals (Sweden)

    Dinu F Albeanu

    Full Text Available New developments in fluorophores as well as in detection methods have fueled the rapid growth of optical imaging in the life sciences. Commercial widefield microscopes generally use arc lamps, excitation/emission filters and shutters for fluorescence imaging. These components can be expensive, difficult to maintain and preclude stable illumination. Here, we describe methods to construct inexpensive and easy-to-use light sources for optical microscopy using light-emitting diodes (LEDs. We also provide examples of its applicability to biological fluorescence imaging.

  7. Technical note: Efficient online source identification algorithm for integration within a contamination event management system

    Science.gov (United States)

    Deuerlein, Jochen; Meyer-Harries, Lea; Guth, Nicolai

    2017-07-01

    Drinking water distribution networks are part of critical infrastructures and are exposed to a number of different risks. One of them is the risk of unintended or deliberate contamination of the drinking water within the pipe network. Over the past decade research has focused on the development of new sensors that are able to detect malicious substances in the network and early warning systems for contamination. In addition to the optimal placement of sensors, the automatic identification of the source of a contamination is an important component of an early warning and event management system for security enhancement of water supply networks. Many publications deal with the algorithmic development; however, only little information exists about the integration within a comprehensive real-time event detection and management system. In the following the analytical solution and the software implementation of a real-time source identification module and its integration within a web-based event management system are described. The development was part of the SAFEWATER project, which was funded under FP 7 of the European Commission.

  8. Study on efficiency of multi-wire tungsten moderator for slow positron source on SPring-8 hard synchrotron radiation

    International Nuclear Information System (INIS)

    Plokhoi, Vladimir; Kandiev, Yadgar; Samarin, Sergey; Malyshkin, Gennady; Baidin, Grigory; Litvinenko, Igor; Nikitin, Valery

    1999-01-01

    The paper provides results of numeric simulations of in-target positron production process, processes of moderation, thermalization, diffusion, and reemission of positrons in high efficiency multi-wire moderator made of tungsten monocrystalline wire with regular wire spacing. The paper looks into dynamics of slow positrons in the moderator's vacuum gaps taking into account of external fields. The possibility for using multi-wire moderator with non-regular structure - multi-layer w ire felt m oderator is discussed. According to maximal estimate the multi-wire moderators can reach very high efficiency of fast-slow positron transformation ∼ 10 -2 . Using such moderator the intensity of slow positron source on hard synchrotron radiation of Spring-8 can reach the level of ∼10 11 e + /s. (author)

  9. BPS, energy efficiency and renewable energy sources for buildings greening and zero energy cities planning harmony and ethics of sustainability

    Energy Technology Data Exchange (ETDEWEB)

    Todorovic, Marija S. [University of Belgrade, Serbia and Southeast University (China)

    2011-07-01

    Traditional village houses now use renewable materials and energy sources and this paper presents the intrinsic harmony of these buildings' greening and their sustainability. The paper covers building technical systems, sustainable energy supply, and the importance of renewable raw materials (RMS) for sustainable development. This study investigated the role of building dynamic behavior and optimized energy efficiency in reducing thermal loads significantly. A preliminary design for sustainable energy efficient settlements with net zero energy buildings is proposed and a comprehensive multidisciplinary engineering study was done which identified the technical feasibility of sustainable village energy and water supplies using solar or wind technologies. Overall, through analysis of sustainability definitions and possible ways to achieve sustainability, the study demonstrated that this can only be brought about by interdisciplinary interaction and finding the right balance between materiality and spirituality, science and art, and between technological development and concern for cultural and other human values.

  10. Efficient power generation from large 7500C heat sources. Application to coal-fired and nuclear power station

    International Nuclear Information System (INIS)

    Tilliette, Z.P.; Pierre, B.

    1980-03-01

    Considering the future concern about a more efficient, rational use of heat sources, and also about a greater location flexibility of power plants owing to dry cooling possibility, closed gas cycles can offer new solutions for fossil or nuclear energy. An efficient heat conversion into power is obtained by the combination of a main non-intercooled helium cycle with a flexible, superheated, low pressure bottoming steam cycle. Emphasis is placed on the matching of the two cycle; for that, a recuperator by-pass arrangement is used. The operation of the main gas turbocompressor does not depend upon the operation of the small steam cycle. Results are given for a conservative turbine inlet temperature of 750 0 C. Applications are made to a coal-fired power plant and to a gas turbine, gas-cooled nuclear reactor. Overall net plant efficiencies of 39 per cent and 46 per cent respectively are reached. For a cycle top temperature equal to 850 0 C, corresponding net efficiencies would be 42 and 49 per cent

  11. Energy Efficiency Modelling of Residential Air Source Heat Pump Water Heater

    Directory of Open Access Journals (Sweden)

    Cong Toan Tran

    2016-03-01

    Full Text Available The heat pump water heater is one of the most energy efficient technologies for heating water for household use. The present work proposes a simplified model of coefficient of performance and examines its predictive capability. The model is based on polynomial functions where the variables are temperatures and the coefficients are derived from the Australian standard test data, using regression technics. The model enables to estimate the coefficient of performance of the same heat pump water heater under other test standards (i.e. US, Japanese, European and Korean standards. The resulting estimations over a heat-up phase and a full test cycle including a draw off pattern are in close agreement with the measured data. Thus the model allows manufacturers to avoid the need to carry out physical tests for some standards and to reduce product cost. The limitations of the methodology proposed are also discussed.

  12. The solvent management plan as a source of eco-efficiency indicators

    International Nuclear Information System (INIS)

    D'Amico, Flaviano; Valardi, Maria; Buleandra, Marian Mihai; Tanase, Ion

    2006-01-01

    Reducing emissions of VOCs (volatil organic compounds) is a top-priority environmental goal, because when they react in the atmosphere with NO X , CO and solar radiation, they form tropospheric ozone, a pollutant that has a large environmental impact and contributes to world climate change. The most innovative part of the solvent directive concerns the Solvent Management Plan (SMP): a very useful tool, especially for small and medium-sized enterprises. With relatively small changes, the SMP can be turned into a Solvent Management System (SMS) having the features of an Environmental Management System. By applying an SMP-SMS, a great number of indicators can be developed, analysed and used to improve eco-efficiency; furthermore, the SMP-SMS can help local authorities in charge of environmental control procedures, in decision-making processes [it

  13. Experimental characterization and Monte Carlo simulation of Si(Li) detector efficiency by radioactive sources and PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Mesradi, M. [Institut Pluridisciplinaire Hubert-Curien, UMR 7178 CNRS/IN2P3 et Universite Louis Pasteur, 23 rue du Loess, BP 28, F-67037 Strasbourg Cedex 2 (France); Elanique, A. [Departement de Physique, FS/BP 8106, Universite Ibn Zohr, Agadir, Maroc (Morocco); Nourreddine, A. [Institut Pluridisciplinaire Hubert-Curien, UMR 7178 CNRS/IN2P3 et Universite Louis Pasteur, 23 rue du Loess, BP 28, F-67037 Strasbourg Cedex 2 (France)], E-mail: abdelmjid.nourreddine@ires.in2p3.fr; Pape, A.; Raiser, D.; Sellam, A. [Institut Pluridisciplinaire Hubert-Curien, UMR 7178 CNRS/IN2P3 et Universite Louis Pasteur, 23 rue du Loess, BP 28, F-67037 Strasbourg Cedex 2 (France)

    2008-06-15

    This work relates to the study and characterization of the response function of an X-ray spectrometry system. The intrinsic efficiency of a Si(Li) detector has been simulated with the Monte Carlo codes MCNP and GEANT4 in the photon energy range of 2.6-59.5 keV. After finding it necessary to take a radiograph of the detector inside its cryostat to learn the correct dimensions, agreement within 10% between the simulations and experimental measurements with several point-like sources and PIXE results was obtained.

  14. Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source.

    Science.gov (United States)

    Higashiguchi, Takeshi; Hamada, Masaya; Kubodera, Shoichi

    2007-03-01

    A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 microm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2 x 10(11) Wcm(2) with a spot diameter of 175 microm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal.

  15. Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source

    Science.gov (United States)

    Higashiguchi, Takeshi; Hamada, Masaya; Kubodera, Shoichi

    2007-03-01

    A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 μm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2×1011 W/cm2 with a spot diameter of 175 μm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal.

  16. Development of a liquid tin microjet target for an efficient laser-produced plasma extreme ultraviolet source

    International Nuclear Information System (INIS)

    Higashiguchi, Takeshi; Hamada, Masaya; Kubodera, Shoichi

    2007-01-01

    A regenerative tin liquid microjet target was developed for a high average power extreme ultraviolet (EUV) source. The diameter of the target was smaller than 160 μm and good vacuum lower than 0.5 Pa was maintained during the operation. A maximum EUV conversion efficiency of 1.8% at the Nd:yttrium-aluminum-garnet laser intensity of around 2x10 11 W/cm 2 with a spot diameter of 175 μm (full width at half maximum) was observed. The angular distribution of the EUV emission remained almost isotropic, whereas suprathermal ions mainly emerged toward the target normal

  17. The photonic nanowire: an emerging platform for highly efficient single-photon sources for quantum information applications

    DEFF Research Database (Denmark)

    Gregersen, Niels; Munsch, Mathieu; Malik, Nitin S.

    2013-01-01

    Efficient coupling between a localized quantum emitter and a well defined optical channel represents a powerful route to realize single-photon sources and spin-photon interfaces. The tailored fiber-like photonic nanowire embedding a single quantum dot has recently demonstrated an appealing...... potential. However, the device requires a delicate, sharp needle-like taper with performance sensitive to minute geometrical details. To overcome this limitation we demonstrate the photonic trumpet, exploiting an opposite tapering strategy. The trumpet features a strongly Gaussian far-field emission...

  18. Pd@Pt Core–Shell Nanoparticles with Branched Dandelion-like Morphology as Highly Efficient Catalysts for Olefin Reduction

    Science.gov (United States)

    A facile synthesis based on the addition of ascorbic acid to a mixture of Na2PdCl4, K2PtCl6, and Pluronic P123 results in highly branched core–shell nanoparticles (NPs) with a micro–mesoporous dandelion-like morphology comprising Pd core and Pt shell. The slow reduction kinetics ...

  19. Mixed Cd-Zn sulfides / Pt-TiO2 composites : bottlenecks limiting efficiency of photocatalytic water reduction

    NARCIS (Netherlands)

    Litke, A.; Weber, Th.; Hofmann, J.P.; Hensen, E.J.M.

    2016-01-01

    Visible-light driven photocatalytic water reduction on composite materials consisting of platinized titania (Pt-TiO2) and transition metal sulfides (CdS or Cd0.5Zn0.5S) was investigated in detail. Sulfides were prepared by hydrothermal synthesis and room-temperature precipitation. The parameters

  20. An easy and efficient method to produce {gamma}-amino alcohols by reduction of {beta}-enamino ketones

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Maria Ines N.C.; Braga, Antonio C.H. [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: herrera@iqm.unicamp.br

    2004-12-01

    Reduction of {beta}-enamino ketones 2 with NaBH{sub 4} in glacial acetic acid gave {gamma}-amino alcohols 1 in 70% to 98% yield with diastereomeric excesses, preferentially the syn product, from 44% to 90%. The stereochemistry of these compounds was confirmed by analysis of their tetrahydro-1,3-oxazine derivatives 3. (author)

  1. Reductive Deprotection of Monolayer Protected Nanoclusters: An Efficient Route to Supported Ultrasmall Au Nanocatalysts for Selective Oxidation

    Czech Academy of Sciences Publication Activity Database

    Das, S.; Goswami, A.; Hesari, M.; Al-Sharab, J. F.; Mikmeková, Eliška; Maran, F.; Asefa, T.

    2014-01-01

    Roč. 10, č. 8 (2014), s. 1473-1478 ISSN 1613-6810 R&D Projects: GA MŠk(CZ) LO1212 Keywords : gold nanoclusters * selective oxidation * heterogeneous nanocatalysis * styrene oxidation * borohydride reduction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 8.368, year: 2014

  2. Removal efficiency and economic cost comparison of hydrated electron-mediated reductive pathways for treatment of bromate

    DEFF Research Database (Denmark)

    Nawaz, Shah; Shah, Noor S.; Khan, Javed Ali

    2017-01-01

    Bromate, a potential carcinogen, is a well known highly persistent and environmentally recalcitrant contaminant. UV-254/sulfite-based advanced reductive pathways (ARPs) were proposed to eliminate bromate successfully from water. Experiments with N2, N2O, 2-chlorophenol, inorganic ions, and differ...

  3. Computationally efficient near-field source localization using third-order moments

    Science.gov (United States)

    Chen, Jian; Liu, Guohong; Sun, Xiaoying

    2014-12-01

    In this paper, a third-order moment-based estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm is proposed for passive localization of near-field sources. By properly choosing sensor outputs of the symmetric uniform linear array, two special third-order moment matrices are constructed, in which the steering matrix is the function of electric angle γ, while the rotational factor is the function of electric angles γ and ϕ. With the singular value decomposition (SVD) operation, all direction-of-arrivals (DOAs) are estimated from a polynomial rooting version. After substituting the DOA information into the steering matrix, the rotational factor is determined via the total least squares (TLS) version, and the related range estimations are performed. Compared with the high-order ESPRIT method, the proposed algorithm requires a lower computational burden, and it avoids the parameter-match procedure. Computer simulations are carried out to demonstrate the performance of the proposed algorithm.

  4. Design of the miniaturized free electron laser module as an efficient source of the THz waves

    International Nuclear Information System (INIS)

    Kim, Young Chul; Ahn, Seong Joon; Kim, Ho Seob; Kim, Dae-Wook; Ahn, Seungjoon

    2011-01-01

    Since the tremendous potential of the THz wave for the bio-technological applications has been found, there has been a lot of interest paid to development of the THz-wave sources. The miniaturized free electron laser (FEL) module based on the microcolumn can be a very convenient THz wave emitter because of its compactness. In this work, we tried to design the miniaturized FEL module to achieve the optimized electron beam (e-beam) trajectory in the module by using 3D simulation tool. We found that the accelerator bias, the length and radius of the limiting aperture were important parameters to obtain the strong and parallel e-beam. We have also proposed the ring-type grids to get more symmetrical behavior of the e-beam in the wiggler.

  5. Design of the miniaturized free electron laser module as an efficient source of the THz waves

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Chul [Department of Optometry, Eulji University, 212 Yangji-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do 461-713 (Korea, Republic of); Ahn, Seong Joon [Department of I and C Engineering, Sun Moon University, Tangjeong-myeon, Asan-si, Chungnam 336-708 (Korea, Republic of); Kim, Ho Seob; Kim, Dae-Wook [Department of Information Display, Sun Moon University, 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of); Ahn, Seungjoon, E-mail: sjan@sunmoon.ac.kr [Department of Information Display, Sun Moon University, 100 Kalsan-ri, Tangjeong-myun, Asan-si, Chungnam 336-708 (Korea, Republic of)

    2011-10-21

    Since the tremendous potential of the THz wave for the bio-technological applications has been found, there has been a lot of interest paid to development of the THz-wave sources. The miniaturized free electron laser (FEL) module based on the microcolumn can be a very convenient THz wave emitter because of its compactness. In this work, we tried to design the miniaturized FEL module to achieve the optimized electron beam (e-beam) trajectory in the module by using 3D simulation tool. We found that the accelerator bias, the length and radius of the limiting aperture were important parameters to obtain the strong and parallel e-beam. We have also proposed the ring-type grids to get more symmetrical behavior of the e-beam in the wiggler.

  6. Using learning curves on energy-efficient technologies to estimate future energy savings and emission reduction potentials in the U.S. iron and steel industry

    Energy Technology Data Exchange (ETDEWEB)

    Karali, Nihan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Park, Won Young [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); McNeil, Michael A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-06-18

    Increasing concerns on non-sustainable energy use and climate change spur a growing research interest in energy efficiency potentials in various critical areas such as industrial production. This paper focuses on learning curve aspects of energy efficiency measures in the U.S iron and steel sector. A number of early-stage efficient technologies (i.e., emerging or demonstration technologies) are technically feasible and have the potential to make a significant contribution to energy saving and CO2 emissions reduction, but fall short economically to be included. However, they may also have the cost effective potential for significant cost reduction and/or performance improvement in the future under learning effects such as ‘learning-by-doing’. The investigation is carried out using ISEEM, a technology oriented, linear optimization model. We investigated how steel demand is balanced with/without the availability learning curve, compared to a Reference scenario. The retrofit (or investment in some cases) costs of energy efficient technologies decline in the scenario where learning curve is applied. The analysis also addresses market penetration of energy efficient technologies, energy saving, and CO2 emissions in the U.S. iron and steel sector with/without learning impact. Accordingly, the study helps those who use energy models better manage the price barriers preventing unrealistic diffusion of energy-efficiency technologies, better understand the market and learning system involved, predict future achievable learning rates more accurately, and project future savings via energy-efficiency technologies with presence of learning. We conclude from our analysis that, most of the existing energy efficiency technologies that are currently used in the U.S. iron and steel sector are cost effective. Penetration levels increases through the years, even though there is no price reduction. However, demonstration technologies are not economically

  7. sources

    Directory of Open Access Journals (Sweden)

    Shu-Yin Chiang

    2002-01-01

    Full Text Available In this paper, we study the simplified models of the ATM (Asynchronous Transfer Mode multiplexer network with Bernoulli random traffic sources. Based on the model, the performance measures are analyzed by the different output service schemes.

  8. The sustainability and efficient use of renewable energy sources in rural areas

    Science.gov (United States)

    Adetunji, Kayode E.; Akinlabi, Akindeji O.; Joseph, Meera K.

    2018-04-01

    The energy system in African countries is mostly dependent on coal, gas, and oil, which in turns leads to environmental challenges and an imbalance of energy usage in some area of the countries. Given that, a mostly rural area in Africa suffers from the unsustainable energy system, thus it necessary to integrate renewable energy into the rural area for social and economic development. A sustainable energy system built on a clean energy such as renewable energy based on the availability of the natural resource is the main focus of this paper. Renewable energy is a solution for service delivery and when deployed everyone would be able to access electricity power, particularly in the remote area (which can be a suburb or rural environment) where the absence of national power grids. Renewable energy opens new opportunities for an economic development and sustainable solution to employ for energy efficiency, energy delivery, and energy management by the people and upon that a platform to promote environmental friendliness. In this paper, we explored the reasons for switching to renewable energy, saving energy and the awareness of potential and use of renewable energy in the rural area. IBM's SPSS is used for the quantitative data analysis. The results showed that sustainability of the National utility grid to the rural area is low, with over 80 percent of participants agreeing to disruption of power supply. The Positivity of the rural peoples' awareness of renewable also brought about the conclusion and recommendations from this paper.

  9. Gasdynamics of relativistically expanding gamma-ray burst sources - Kinematics, energetics, magnetic fields, and efficiency

    Science.gov (United States)

    Meszaros, P.; Laguna, P.; Rees, M. J.

    1993-01-01

    We calculate both analytically and numerically the evolution of highly relativistic fireballs through the stages of free expansion and coasting, and determine the dependence of the thermodynamic and radiation variables in the comoving and laboratory flames. The dynamics and the comoving geometry change at the (lab) expansion factors r/r(0) greater than eta and r/r(0) greater than eta-squared, respectively, where eta = E(0)/M(0)c-squared is the initial Lorentz factor. In the lab, the gas appears concentrated in a thin shell of width r(0) until r/r(0) of less than about eta-squared, and increases linearly after that. Magnetic fields may have been important in the original impulsive event. We discuss their effect on the fireball dynamics and also consider their effects on the radiation emitted when the fireball runs into an external medium and is decelerated. The inverse synchro-Compton mechanism can then yield high radiative efficiency in the reverse shock (and through turbulent instabilities and mixing also in the forward blast wave), producing a burst of nonthermal radiation mainly in the MeV to GeV range. The energy and duration depend on eta, the magnetic field strength, and the external density, and can match the range of properties observed in cosmic gamma-ray bursts.

  10. Energy-efficient operation of a booster RF system for Taiwan light source operated in top-up mode

    International Nuclear Information System (INIS)

    Yeh, Meng-Shu; Wang, Chaoen; Chang, Lung-Hai; Chung, Fu-Tsai; Yu, Tsung-Chi; Lin, Ming-Chyuan; Chen, Ling-Jhen; Yang, Tz-Te; Chang, Mei-Hsia; Lin, Yu-Han; Tsai, Ming-Hsun; Lo, Chih-Hung; Liu, Zong-Kai

    2015-01-01

    Contemporary light sources operate in a top-up mode to maintain their photon intensity quasi-constant so as to improve significantly the thermal stability of the photon beam and to maximize ultimately the average photon flux at a designed maximum operational beam current. Operating in a top-up mode requires frequent beam injection from the synchrotron booster to the storage ring of the light source, but the injection intervals occupy only a tiny portion of the operational time of the integrated machine. To maintain a high operational reliability, the booster RF system practically operates necessarily under injection conditions around the clock and consumes full electric power whether during top-up injection or not. How to decrease the power consumption of the booster RF system during its stand-by time but not to sacrifice the reliability and availability of the RF system is obviously of fundamental interest for routine operation of the light source in a top-up mode. Here, an energy-efficient operation of a booster RF system adaptive to top-up operation of a light source is proposed that has been developed, realized and integrated into the booster RF system of the Taiwan Light Source (TLS), and routinely operated since the end of year 2008. The klystron cathode current and RF gap voltage of the booster's accelerating RF cavity are both periodically modulated to adapt the injection rhythm during top-up operation, which results in decreased consumption of electric power of the booster RF system by more than 78%. The impact on the reliability and availability of the booster RF system has been carefully monitored during the past five operational years, delivering more than 5000 h scheduled user beam time per year. The booster RF system retains its excellent reliability and availability as previously. Neither a decrease of the service time nor an induced reliability issue from the klystron or any high-power high-voltage component of the transmitter has been

  11. Final Technical Report for Alternative Fuel Source Study-An Energy Efficient and Environmentally Friendly Approach

    Energy Technology Data Exchange (ETDEWEB)

    Zee, Ralph [Auburn University, AL (United States); Schindler, Anton [Auburn University, AL (United States); Duke, Steve [Auburn University, AL (United States); Burch, Thom [Auburn University, AL (United States); Bransby, David [Auburn University, AL (United States); Stafford, Don [Lafarge North America, Inc., Alpharetta, GA (United States)

    2010-08-31

    The objective of this project is to conduct research to determine the feasibility of using alternate fuel sources for the production of cement. Successful completion of this project will also be beneficial to other commercial processes that are highly energy intensive. During this report period, we have completed all the subtasks in the preliminary survey. Literature searches focused on the types of alternative fuels currently used in the cement industry around the world. Information was obtained on the effects of particular alternative fuels on the clinker/cement product and on cement plant emissions. Federal regulations involving use of waste fuels were examined. Information was also obtained about the trace elements likely to be found in alternative fuels, coal, and raw feeds, as well as the effects of various trace elements introduced into system at the feed or fuel stage on the kiln process, the clinker/cement product, and concrete made from the cement. The experimental part of this project involves the feasibility of a variety of alternative materials mainly commercial wastes to substitute for coal in an industrial cement kiln in Lafarge NA and validation of the experimental results with energy conversion consideration.

  12. Image features dependant correlation-weighting function for efficient PRNU based source camera identification.

    Science.gov (United States)

    Tiwari, Mayank; Gupta, Bhupendra

    2018-04-01

    For source camera identification (SCI), photo response non-uniformity (PRNU) has been widely used as the fingerprint of the camera. The PRNU is extracted from the image by applying a de-noising filter then taking the difference between the original image and the de-noised image. However, it is observed that intensity-based features and high-frequency details (edges and texture) of the image, effect quality of the extracted PRNU. This effects correlation calculation and creates problems in SCI. For solving this problem, we propose a weighting function based on image features. We have experimentally identified image features (intensity and high-frequency contents) effect on the estimated PRNU, and then develop a weighting function which gives higher weights to image regions which give reliable PRNU and at the same point it gives comparatively less weights to the image regions which do not give reliable PRNU. Experimental results show that the proposed weighting function is able to improve the accuracy of SCI up to a great extent. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. On sustainable and efficient design of ground-source heat pump systems

    Science.gov (United States)

    Grassi, W.; Conti, P.; Schito, E.; Testi, D.

    2015-11-01

    This paper is mainly aimed at stressing some fundamental features of the GSHP design and is based on a broad research we are performing at the University of Pisa. In particular, we focus the discussion on an environmentally sustainable approach, based on performance optimization during the entire operational life. The proposed methodology aims at investigating design and management strategies to find the optimal level of exploitation of the ground source and refer to other technical means to cover the remaining energy requirements and modulate the power peaks. The method is holistic, considering the system as a whole, rather than focusing only on some components, usually considered as the most important ones. Each subsystem is modeled and coupled to the others in a full set of equations, which is used within an optimization routine to reproduce the operative performances of the overall GSHP system. As a matter of fact, the recommended methodology is a 4-in-1 activity, including sizing of components, lifecycle performance evaluation, optimization process, and feasibility analysis. The paper reviews also some previous works concerning possible applications of the proposed methodology. In conclusion, we describe undergoing research activities and objectives of future works.

  14. The German way to an energy efficient future. Process and cross cutting technology improvements for CO{sub 2} reductions and a competitive economy

    Energy Technology Data Exchange (ETDEWEB)

    Radgen, P.

    1999-07-01

    The aim of the paper is to show how Germany tries to improve the energy efficiency of the economy and reduce carbon dioxide emissions without affecting the competitiveness of the industry. Between 1990 to 1995 Germany has reduced its CO{sub 2} emission from 1029 to 933 million tonnes, which is equivalent to an emission reduction of 9%. To analyse and compare different options to reach the emission reduction target, multiple tools have been developed and can be used to help in setting policy priorities. The IKARUS model and database together with the use of energy efficiency indicators helps to keep the development of energy consumption and emission reduction on track to the reduction target. Voluntary agreements between industry and government had been worked out, to limit the emissions in the energy intensive sectors of the German industry. Results from the monitoring of this efforts will be presented together with a short evaluation of the factors influencing the improvements in energy efficiency. As energy related emissions can be reduced significantly by closing energy and material flows, the effect of recycling of energy intensive materials such as steel, glass, plastics, and paper is discussed. The possible role of renewables as energy carrier and feedstock is evaluated for the production of surfactants. If more oleochemical surfactants could be applied, this will help to reduce the CO{sub 2} emissions from the use of fossil fuels as feedstock. The efficiency improvement by cross cutting technologies will be discussed for furnaces, compressed air systems and electric motors. Most of these improvement potentials are economic at present energy prices, but some barriers for their application has to be overcome. One way to help decision makers in industry is the use of energy benchmarking. Benchmarking helps to analyse the energy efficiency of the own company in comparison to the competitors and to set appropriate targets and to prepare a road map of measures to

  15. A Simple and Computationally Efficient Approach to Multifactor Dimensionality Reduction Analysis of Gene-Gene Interactions for Quantitative Traits

    OpenAIRE

    Gui, Jiang; Moore, Jason H.; Williams, Scott M.; Andrews, Peter; Hillege, Hans L.; van der Harst, Pim; Navis, Gerjan; Van Gilst, Wiek H.; Asselbergs, Folkert W.; Gilbert-Diamond, Diane

    2013-01-01

    We present an extension of the two-class multifactor dimensionality reduction (MDR) algorithm that enables detection and characterization of epistatic SNP-SNP interactions in the context of a quantitative trait. The proposed Quantitative MDR (QMDR) method handles continuous data by modifying MDR's constructive induction algorithm to use a T-test. QMDR replaces the balanced accuracy metric with a T-test statistic as the score to determine the best interaction model. We used a simulation to ide...

  16. Stable silver nanoclusters electrochemically deposited on nitrogen-doped graphene as efficient electrocatalyst for oxygen reduction reaction

    Science.gov (United States)

    Jin, Shi; Chen, Man; Dong, Haifeng; He, Bingyu; Lu, Huiting; Su, Lei; Dai, Wenhao; Zhang, Qiaochu; Zhang, Xueji

    2015-01-01

    Metal nanoclusters exhibit unusually high catalytic activity toward oxygen reduction reaction (ORR) due to their small size and unique electronic structures. However, controllable synthesis of stable metal nanoclusters is a challenge, and the durability of metal clusters suffers from the deficiency of dissolution, aggregation, and sintering during catalysis reactions. Herein, silver nanoclusters (AgNCs) (diameter , which is vital in high performance fuel cells, batteries and nanodevices.

  17. Target-aimed versus wishful-thinking in designing efficient GHG reduction strategies for a metropolitan city: Taipei

    International Nuclear Information System (INIS)

    Liu, C.-M.; Liou, M.-L.; Yeh, S.-C.; Shang, N.-C.

    2009-01-01

    In recent years, many national and local governments claim for a specific GHG (greenhouse gas) reduction goal targeted for many years later. In 2005, the Taipei City government announced that Taipei's total GHG emission in 2015 will reach the same level as that in 2005 and then down to 75% of that level at year 2030. However, based on the estimated energy consumption and GHG emission and the proposed emission reduction plans from the local government, it is clear that these goals are not going to be accomplished. In Taipei, the residential and commercial sector contributes more than 78% of the total GHG emission. Thus, in a business as usual scenario, the total GHG emission in 2030 would be 79% more than that in 2005, far more than the target value proclaimed. As many key factors are uncontrollable by the local government, a target-aimed strategy designing process by looking into changes in Taipei and identifying major targets is proposed in this study. It is demonstrated that such a universally applicable approach will give more confidence to the public on working toward the expected GHG reduction goal

  18. Efficient reduction of graphene oxide film by low temperature heat treatment and its effect on electrical conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xuebing; Chen, Zheng [Jingdezhen Ceramic Institute, Jingdezhen (China). Key Lab. of Inorganic Membrane; Yu, Yun [Shanghai Institute of Ceramics, Shanghai (China). Key Lab. of Inorganic Coating Materials; Zhang, Xiaozhen; Wang, Yongqing; Zhou, Jianer [Jingdezhen Ceramic Institute, Jingdezhen (China). Dept. of Materials Engineering

    2018-03-01

    Graphene-based conductive films have already attracted great attention due to their unique and outstanding physical properties. In this work, in order to develop a novel, effective method to produce these films with good electrical conductivity, a simple and green method is reported to rapidly and effectively reduce graphene oxide film using a low temperature heat treatment. The reduction of graphene oxide film is verified by XRD, FT-IR and Raman spectroscopy. Compared with graphene oxide film, the obtained reduced graphene oxide film has better electrical conductivity and its sheet resistance decreases from 25.3 kΩ x sq{sup -1} to 3.3 kΩ x sq{sup -1} after the heat treatment from 160 to 230 C. The mechanism of thermal reduction of the graphene oxide film mainly results from the removal of the oxygen-containing functional groups and the structural changes. All these results indicate that the low temperature heat treatment is a suitable and effective method for the reduction of graphene oxide film.

  19. Congestion reduction through efficient empty container movement : a research report from the National Center for Sustainable Transportation.

    Science.gov (United States)

    2017-08-01

    In 2015, the Ports of Los Angeles and Long Beach moved 15.3 million twenty-foot Equivalent Units (TEU). There is a significant body of work on moving loaded containers efficiently, however there has been little research on the movement of empty conta...

  20. Presence of renewable sources of energy, cogeneration, energy efficiency and distributed generation in the International Nuclear Information System (INIS)

    International Nuclear Information System (INIS)

    Pares Ferrer, Marianela; Oviedo Rivero, Irayda; Gonzalez Garcia, Alejandro

    2011-01-01

    The International Nuclear Information System (INIS) it was created in 1970 by the International Atomic Energy Agency (OIEA) with the objective of propitiating the exchange of scientific information and technique on the peaceful uses of the energy atomic. INIS processes most of scientific literature and technique in engineering matters nuclear, safeguard and non proliferation and applications in agriculture and health that it generates in the world and it contributes to create a repository of nuclear information for present and future generations. Additionally it includes economic aspects and environmental of other energy sources that facilitate comparative studies for the taking of decisions. The database INIS, is its main informative product and it counts with more than 3 million registrations. One of the services that lends the Center of Administration of the Information and Development of the Energy (CUBAENERGIA), like center INIS in Cuba, is the search of information on the peaceful use of the science and nuclear technology in the Countries Members and the registration of information on their applications in Cuba. More recently, it extends this service to the Renewable Sources application of Energy in the country; as part of the works of administration of the information that it carries out for the National Group of Renewable Energy, Cogeneration, Saving and Energy Efficiency, created in the 2007 and coordinated by the MINBAS with the participation of institutions belonging to Organisms of the Administration Central of the State. In this work the results of a preliminary study are presented on the witnesses in the INIS of the Renewable Sources of Energy, the Cogeneration, Energy Efficiency, and the Distributed Generation. As well as of the application of metric tools to the opposing registrations for the case of the Distributed generation, that which allowed to characterize their historical evolution, the participation for countries in their development and

  1. Combustion system optimization of a P-62 lignite boiler in ContourGlobal Maritsa East 3 with NOx-reduction and efficiency improvement

    International Nuclear Information System (INIS)

    Petkov, Ch.; Thierbach, Hans-Ulrich; Totev, T.

    2013-01-01

    Steinmueller Engineering GmbH, Gummersbach, Germany, successfully concluded in consortium with Siemens EOOD, Sofia, the combustion system modification of a P62 lignite fired boiler in TPP ContourGlobal Maritsa East 3, which was targeting mainly the reduction of the NOx emissions below 180 mg/Nm 3 at 6 % O 2 . The modification is part of an EPC contract covering the design, fabrication, installation and commissioning works needed to upgrade the boilers at the power station. The Modification concept involves optimization of PF- and Vapor distribution, replacement of the coal burners, installation of new Over-fire air (OFA) system and Side-wall air (SWA) system and minor modification of the existing control system to allow control of the OFAflow. The main results of the modification are: Reduction of the NOx emissions (at ESP exit) from approximately 390 g/Nm³ to below 180 mg/Nm³ at 6% O 2 , Efficiency increase of the furnace by reduction of the excess air ratio from 1.2 to 1.15 (at furnace outlet) and overall increase of the boiler efficiency. (authors)

  2. A Co3O4-CDots-C3N4 three component electrocatalyst design concept for efficient and tunable CO2 reduction to syngas.

    Science.gov (United States)

    Guo, Sijie; Zhao, Siqi; Wu, Xiuqin; Li, Hao; Zhou, Yunjie; Zhu, Cheng; Yang, Nianjun; Jiang, Xin; Gao, Jin; Bai, Liang; Liu, Yang; Lifshitz, Yeshayahu; Lee, Shuit-Tong; Kang, Zhenhui

    2017-11-28

    Syngas, a CO and H 2 mixture mostly generated from non-renewable fossil fuels, is an essential feedstock for production of liquid fuels. Electrochemical reduction of CO 2 and H + /H 2 O is an alternative renewable route to produce syngas. Here we introduce the concept of coupling a hydrogen evolution reaction (HER) catalyst with a CDots/C 3 N 4 composite (a CO 2 reduction catalyst) to achieve a cheap, stable, selective and efficient route for tunable syngas production. Co 3 O 4 , MoS 2 , Au and Pt serve as the HER component. The Co 3 O 4 -CDots-C 3 N 4 electrocatalyst is found to be the most efficient among the combinations studied. The H 2 /CO ratio of the produced syngas is tunable from 0.07:1 to 4:1 by controlling the potential. This catalyst is highly stable for syngas generation (over 100 h) with no other products besides CO and H 2 . Insight into the mechanisms balancing between CO 2 reduction and H 2 evolution when applying the HER-CDots-C 3 N 4 catalyst concept is provided.

  3. Metal-free and Oxygen-free Graphene as Oxygen Reduction Catalysts for Highly Efficient Fuel Cells

    Science.gov (United States)

    2013-06-30

    analysis was carried out by a TA instrument with a heating rate of 10 °C in N2. The Raman spectra were collected on a Raman spectrometer (Renishaw...kinematics viscosity for KOH (v = 0.01 cm 2 s -1 ) and CO2 is concentration of O2 in the solution (CO2 = 1.2 × 10 -6 mol cm -3 ). The constant 0.2 is...functionalizing graphene to impart electrocatalytic activity for oxygen reduction reaction (ORR) in fuel cells. Raman and X-ray photoelectron spectroscopic

  4. Graphene hydrogels with embedded metal nanoparticles as efficient catalysts in 4-nitrophenol reduction and methylene blue decolorization

    Directory of Open Access Journals (Sweden)

    Żelechowska Kamila

    2016-12-01

    Full Text Available Synthesis and characterization of the graphene hydrogels with three different metallic nanoparticles, that is Au, Ag and Cu, respectively is presented. Synthesized in a one-pot approach graphene hydrogels with embedded metallic nanoparticles were tested as heterogeneous catalysts in a model reaction of 4-nitrophenol reduction. The highest activity was obtained for graphene hydrogel with Cu nanoparticles and additional reaction of methylene blued degradation was evaluated using this system. The obtained outstanding catalytic activity arises from the synergistic effect of graphene and metallic nanoparticles. The hydrogel form of the catalyst benefits in the easiness in separation from the reaction mixture (for example using tweezers and reusability.

  5. Global Emissions of Nitrous Oxide: Key Source Sectors, their Future Activities and Technical Opportunities for Emission Reduction

    Science.gov (United States)

    Winiwarter, W.; Höglund-Isaksson, L.; Klimont, Z.; Schöpp, W.; Amann, M.

    2017-12-01

    Nitrous oxide originates primarily from natural biogeochemical processes, but its atmospheric concentrations have been strongly affected by human activities. According to IPCC, it is the third largest contributor to the anthropogenic greenhouse gas emissions (after carbon dioxide and methane). Deep decarbonization scenarios, which are able to constrain global temperature increase within 1.5°C, require strategies to cut methane and nitrous oxide emissions on top of phasing out carbon dioxide emissions. Employing the Greenhouse gas and Air pollution INteractions and Synergies (GAINS) model, we have estimated global emissions of nitrous oxide until 2050. Using explicitly defined emission reduction technologies we demonstrate that, by 2030, about 26% ± 9% of the emissions can be avoided assuming full implementation of currently existing reduction technologies. Nearly a quarter of this mitigation can be achieved at marginal costs lower than 10 Euro/t CO2-eq with the chemical industry sector offering important reductions. Overall, the largest emitter of nitrous oxide, agriculture, also provides the largest emission abatement potentials. Emission reduction may be achieved by precision farming methods (variable rate technology) as well as by agrochemistry (nitrification inhibitors). Regionally, the largest emission reductions are achievable where intensive agriculture and industry are prevalent (production and application of mineral fertilizers): Centrally Planned Asia including China, North and Latin America, and South Asia including India. Further deep cuts in nitrous oxide emissions will require extending reduction efforts beyond strictly technological solutions, i.e., considering behavioral changes, including widespread adoption of "healthy diets" minimizing excess protein consumption.

  6. Energy-Efficient and Environmentally Friendly Solid Oxide Membrane Electrolysis Process for Magnesium Oxide Reduction: Experiment and Modeling

    Science.gov (United States)

    Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

    2014-06-01

    This paper reports a solid oxide membrane (SOM) electrolysis experiment using an LSM(La0.8Sr0.2MnO3-δ)-Inconel inert anode current collector for production of magnesium and oxygen directly from magnesium oxide at 1423 K (1150 °C). The electrochemical performance of the SOM cell was evaluated by means of various electrochemical techniques including electrochemical impedance spectroscopy, potentiodynamic scan, and electrolysis. Electronic transference numbers of the flux were measured to assess the magnesium dissolution in the flux during SOM electrolysis. The effects of magnesium solubility in the flux on the current efficiency and the SOM stability during electrolysis are discussed. An inverse correlation between the electronic transference number of the flux and the current efficiency of the SOM electrolysis was observed. Based on the experimental results, a new equivalent circuit of the SOM electrolysis process is presented. A general electrochemical polarization model of SOM process for magnesium and oxygen gas production is developed, and the maximum allowable applied potential to avoid zirconia dissociation is calculated as well. The modeling results suggest that a high electronic resistance of the flux and a relatively low electronic resistance of SOM are required to achieve membrane stability, high current efficiency, and high production rates of magnesium and oxygen.

  7. Use of an external source (60Co) for 32P detection efficiency determination by the Cerenkov effect, in soil extracts

    International Nuclear Information System (INIS)

    Nascimento Filho, V.F. do.

    1975-03-01

    The detection of 32 P in aqueous extracts is usually made with the aid of a Geiger-Muller detector, with thin window and sample on a planchet. Presently the technique is being developed of detection of high energy beta particles emitters ( 32 P, 42 K, 86 Rb) through the Cerenkov effect, using a commercial liquid scintillation system. This technique, despite being approximately 30 times more sensitive, has the inconvenience of varying the detection efficiency, mainly for color samples (soil extracts, for instance). From this stems the need for determining the detection efficiency for each sample. The internal standardization and channels ratio methods show a series of drawbacks, mainly the non-reutilization of the samples (1st method) and statistical uncertainty for low activity samples (2nd method). The elimination of these dreawbacks can be achieved through the utilization of the external standardization method. A 60 Co source with 1,4 μCi activity has been adapted to the sample elevator of the detector system, and a comparison was made with the channels ratio method to evaluate the efficiency of 32 P detection in soil extracts (P extraction and fractionation). The external standardization method showed to be more accurate, besides being influenced to a lesser degree by high voltage variation, sample volume and vial types. In the case of large samples, it is advisable to carry out detection in vials filled up to their full capacity; in the case of small samples, the whole volume should be transferred to the vials and completed up to 9 ml for nylon vials,10 ml for glass vials and 11 to 14 ml for polyethilene vials. On the other hand, plastic vials showed higher detection efficiency than ones. As to background radiation, the lowest rates were given by nylon vials and the highest by Beckman glass vials [pt

  8. Assessment of GHG Emission Reduction Potential from Source-separated Organic Waste (SOW) Management: Case Study in a Higher Educational Institution in Malaysia

    International Nuclear Information System (INIS)

    Ng, C.G.; Sumiani Yusoff

    2015-01-01

    In Malaysia, the greenhouse gases (GHGs) emissions reduction via composting of source-separated organic waste (SOW) in municipal solid waste (MSW) has not been assessed. Assessment of GHG emissions reduction via composting of SOW is important as environmental impacts from waste management are waste-specific and local-specific. The study presents the case study for potential carbon reduction via composting of SOW in University of Malaya (UM). In this study, a series of calculations were used to evaluate the GHG emission of different SOW management scenarios. The calculations based on IPCC calculation methods (AM0025) include GHGs emissions from land filling, fuel consumption in transportation and SOW composting activity. The methods were applied to assess the GHG emissions from five alternative SOW management scenarios in UM. From the baseline scenario (S0), a total of 1,636.18 tCO2e was generated. In conjunction with target of 22 % recycling rate, as shown in S1, 14 % reduction in potential GHG emission can be achieved. The carbon reduction can be further enhanced by increasing the SOW composting capacity. The net GHG emission for S1, S2, S3 and S4 were 1,399.52, 1,161.29, 857.70 and 1,060.48 tCO2e, respectively. In general, waste diversion for composting proved a significant net GHG emission reduction as shown in S3 (47 %), S4 (35 %) and S2 (29 %). Despite the emission due to direct on-site activity, the significant reduction in methane generation at landfill has reduced the net GHG emission. The emission source of each scenario was studied and analysed. (author)

  9. Leakage Reduction in Water Distribution Systems with Efficient Placement and Control of Pressure Reducing Valves Using Soft Computing Techniques

    Directory of Open Access Journals (Sweden)

    A. Gupta

    2017-04-01

    Full Text Available Reduction of leakages in a water distribution system (WDS is one of the major concerns of water industries. Leakages depend on pressure, hence installing pressure reducing valves (PRVs in the water network is a successful techniques for reducing leakages. Determining the number of valves, their locations, and optimal control setting are the challenges faced. This paper presents a new algorithm-based rule for determining the location of valves in a WDS having a variable demand pattern, which results in more favorable optimization of PRV localization than that caused by previous techniques. A multiobjective genetic algorithm (NSGA-II was used to determine the optimized control value of PRVs and to minimize the leakage rate in the WDS. Minimum required pressure was maintained at all nodes to avoid pressure deficiency at any node. Proposed methodology is applied in a benchmark WDS and after using PRVs, the average leakage rate was reduced by 6.05 l/s (20.64%, which is more favorable than the rate obtained with the existing techniques used for leakage control in the WDS. Compared with earlier studies, a lower number of PRVs was required for optimization, thus the proposed algorithm tends to provide a more cost-effective solution. In conclusion, the proposed algorithm leads to more favorable optimized localization and control of PRV with improved leakage reduction rate.

  10. Electrochemically reduced graphene-oxide supported bimetallic nanoparticles highly efficient for oxygen reduction reaction with excellent methanol tolerance

    Science.gov (United States)

    Yasmin, Sabina; Cho, Sung; Jeon, Seungwon

    2018-03-01

    We report a simple and facile method for the fabrication of bimetallic nanoparticles on electrochemically reduced graphene oxide (ErGO) for electrocatalytic oxygen reduction reaction (ORR) in alkaline media. First, reduced graphene oxide supported palladium and manganese oxide nanoparticle (rGO/Pd-Mn2O3) catalyst was synthesized via a simple chemical method at room temperature; then, it was electrochemically reduced for oxidation reduction reaction (ORR) in alkaline media. The chemical composition and morphological properties of ErGO/Pd-Mn2O3 was characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The TEM images reveals that, nano-sized Pd and Mn2O3 particles were disperse on the ErGO sheet without aggregation. The as-prepared ErGO/Pd-Mn2O3 was employed for ORR in alkaline media which shows higher ORR activity with more positive onset and half-wave potential, respectively. Remarkably, ErGO/Pd-Mn2O3 reduced oxygen via four-electron transfer pathway with negligible amount of intermediate peroxide species (HO2-). Furthermore, the higher stability and excellent methanol tolerance of the ErGO/Pd-Mn2O3 compared to commercial Pt/C (20 wt%) catalyst, indicating its suitability for fuel cells.

  11. Core hydrophobicity tuning of a self-assembled particle results in efficient lipid reduction and favorable organ distribution.

    Science.gov (United States)

    Banik, Bhabatosh; Wen, Ru; Marrache, Sean; Kumar, Anil; Kolishetti, Nagesh; Howerth, Elizabeth W; Dhar, Shanta

    2017-12-21

    Atherosclerosis, the deadliest disease in the United States, arises due to the build up of plaques in the arteries as a result of excessive cholesterol deposition and an impaired cholesterol removal process. High density lipoproteins (HDL), popularly known as "good cholesterol", are naturally occurring nano-sized particles that, along with apolipoproteins, are deployed to maintain cholesterol homeostasis in the body. Both cholesterol efflux, from the fat-laden macrophages in the arteries, and intracellular lipid transport, to deliver cholesterol to the mitochondria of liver cells for metabolism, hold key responsibilities to maintain healthy lipid levels inside the body. We designed a library of nine mitochondria targeted polymer-lipid hybrid nanoparticles (NPs), comprised of completely synthetic yet biodegradable components, that are capable of performing HDL-like functions. Using this library, we optimized a superior mitochondria targeted NP candidate, which can show favourable organ distribution, therapeutic potential, and non-toxic properties. Two targeted NP formulations with optimum NP size, zeta potential, and cholesterol binding and release properties were identified. Lipid reduction and anti-oxidative properties of these two NPs demonstrated cholesterol removal ability. In vivo therapeutic evaluation of the targeted-NP formulations in apolipoprotein E knockout (apoE - / - ) mice indicated lipid reduction and anti-inflammatory properties compared to non-targeted NPs. This synthetic targeted NP with potential abilities to participate in both extra- and intracellular cholesterol transport might potentiate therapeutic interventions for heart diseases.

  12. MIL-100-Fe derived N-doped Fe/Fe3C@C electrocatalysts for efficient oxygen reduction reaction

    Science.gov (United States)

    Guo, Dakai; Han, Sancan; Wang, Jiacheng; Zhu, Yufang

    2018-03-01

    N-doped porous Fe/Fe3C@C electrocatalysts were prepared by the pyrolysis of the hexamethylenetetramine (HMT)-incorporated MIL-100-Fe at different temperatures (700-1000 °C) under N2 atmosphere. Rotary evaporation of MIL-100-Fe and HMT solution could make more N-enriched HMT molecules enter into the pores of MIL-100-Fe, thus improving nitrogen contents of the final pyrolyzed samples. All pyrolyzed samples show porous textures with middle specific surface areas. The X-ray photoelectron spectroscopy (XPS) results demonstrate the successful introduction of N atoms into carbon framework. Sample Fe-N2-800 prepared by annealing the precursors with the HMT/MIL-100-Fe weight ratio of 2 at 800 °C exhibits the best electrocatalytic activity towards the oxygen reduction reaction (ORR) in terms of onset potential and current density because of high graphitic N and pyridinic N content. The enwrapped Fe/Fe3C nanoparticles and Fe-Nx active sites in these samples could also boost the ORR activity synergistically. Moreover, sample Fe-N2-800 demonstrates a dominant four electron reduction process, as well as excellent long-term operation stability and methanol crossover resistance. Thus, the N-doped Fe/Fe3C@C composites derived from the HMT-incorporated MIL-100-Fe are promising electrocatalysts to replace Pt/C for ORR in practical applications.

  13. N- and S-doped high surface area carbon derived from soya chunks as scalable and efficient electrocatalysts for oxygen reduction

    Science.gov (United States)

    Rana, Moumita; Arora, Gunjan; Gautam, Ujjal K.

    2015-02-01

    Highly stable, cost-effective electrocatalysts facilitating oxygen reduction are crucial for the commercialization of membrane-based fuel cell and battery technologies. Herein, we demonstrate that protein-rich soya chunks with a high content of N, S and P atoms are an excellent precursor for heteroatom-doped highly graphitized carbon materials. The materials are nanoporous, with a surface area exceeding 1000 m2 g-1, and they are tunable in doping quantities. These materials exhibit highly efficient catalytic performance toward oxygen reduction reaction (ORR) with an onset potential of -0.045 V and a half-wave potential of -0.211 V (versus a saturated calomel electrode) in a basic medium, which is comparable to commercial Pt catalysts and is better than other recently developed metal-free carbon-based catalysts. These exhibit complete methanol tolerance and a performance degradation of merely ˜5% as compared to ˜14% for a commercial Pt/C catalyst after continuous use for 3000 s at the highest reduction current. We found that the fraction of graphitic N increases at a higher graphitization temperature, leading to the near complete reduction of oxygen. It is believed that due to the easy availability of the precursor and the possibility of genetic engineering to homogeneously control the heteroatom distribution, the synthetic strategy is easily scalable, with further improvement in performance.

  14. Mobile Technology Applications for Manufacturing, Reduction of Muda (Waste and the Effect on Manufacturing Economy and Efficiency

    Directory of Open Access Journals (Sweden)

    Angela M Huenerfauth

    2014-10-01

    Full Text Available Mobile devices in the manufacturing setting offer mobility and information whenever and wherever it is needed; these advantages allow for a more efficient workflow and allow the user to make more informed decisions. Due to these advantages, companies are reducing muda (waste by using mobile devices (implementing Lean Manufacturing and therefore saving money. Some of the mobile applications discussed in this paper are the following: Augmented Reality for assembly training, pruefcubing, remotely-monitored shop floors, statistical process control (SPC, and change requests for construction, and the two types of muda (waste reduced by these mobile applications are “unnecessary / excess motion and defects.”

  15. Pharmaceuticals, hormones and bisphenol A in untreated source and finished drinking water in Ontario, Canada - Occurrence and treatment efficiency

    International Nuclear Information System (INIS)

    Kleywegt, Sonya; Pileggi, Vince; Yang, Paul; Hao Chunyan; Zhao Xiaoming; Rocks, Carline; Thach, Serei; Cheung, Patrick; Whitehead, Brian

    2011-01-01

    The Ontario Ministry of the Environment (MOE) conducted a survey in 2006 on emerging organic contaminants (EOCs) which included pharmaceuticals, hormones and bisphenol A (BPA). The survey collected 258 samples over a 16 month period from selected source waters and 17 drinking water systems (DWSs), and analyzed them for 48 EOCs using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and isotope dilution mass spectrometry (IDMS) for the highest precision and accuracy of analytical data possible. 27 of the 48 target EOCs were detected in source water, finished drinking water, or both. DWSs using river and lake source water accounted for > 90% detections. Of the 27 EOCs found, we also reported the first detection of two antibiotics roxithromycin and enrofloxacin in environmental samples. The most frequently detected compounds (≥ 10%) in finished drinking water were carbamazepine (CBZ), gemfibrozil (GFB), ibuprofen (IBU), and BPA; with their concentrations accurately determined by using IDMS and calculated to be 4 to 10 times lower than those measured in the source water. Comparison of plant specific data allowed us to determine removal efficiency (RE) of these four most frequently detected compounds in Ontario DWSs. The RE of CBZ was determined to be from 71 to 93% for DWSs using granulated activated carbon (GAC); and was 75% for DWSs using GAC followed by ultraviolet irradiation (UV). The observed RE of GFB was between 44 and 55% in DWSs using GAC and increased to 82% when GAC was followed by UV. The use of GAC or GAC followed by UV provided an RE improvement of BPA from 80 to 99%. These detected concentration levels are well below the predicted no effect concentration or total allowable concentration reported in the literature. Additional targeted, site specific comparative research is required to fully assess the effectiveness of Ontario DWSs to remove particular compounds of concern. - Research Highlights: → Occurrence and typical range of 45 selected

  16. Pharmaceuticals, hormones and bisphenol A in untreated source and finished drinking water in Ontario, Canada - Occurrence and treatment efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Kleywegt, Sonya; Pileggi, Vince [Standards Development Branch, Ontario Ministry of the Environment, 40 St. Clair Avenue West, Toronto, Ontario, M4V 1M2 (Canada); Yang, Paul, E-mail: paul.yang@ontario.ca [Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Hao Chunyan; Zhao Xiaoming [Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Rocks, Carline [Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Thach, Serei [Laboratory Services Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada); Cheung, Patrick; Whitehead, Brian [Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Etobicoke, Ontario, M9P 3V6 (Canada)

    2011-03-15

    The Ontario Ministry of the Environment (MOE) conducted a survey in 2006 on emerging organic contaminants (EOCs) which included pharmaceuticals, hormones and bisphenol A (BPA). The survey collected 258 samples over a 16 month period from selected source waters and 17 drinking water systems (DWSs), and analyzed them for 48 EOCs using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and isotope dilution mass spectrometry (IDMS) for the highest precision and accuracy of analytical data possible. 27 of the 48 target EOCs were detected in source water, finished drinking water, or both. DWSs using river and lake source water accounted for > 90% detections. Of the 27 EOCs found, we also reported the first detection of two antibiotics roxithromycin and enrofloxacin in environmental samples. The most frequently detected compounds ({>=} 10%) in finished drinking water were carbamazepine (CBZ), gemfibrozil (GFB), ibuprofen (IBU), and BPA; with their concentrations accurately determined by using IDMS and calculated to be 4 to 10 times lower than those measured in the source water. Comparison of plant specific data allowed us to determine removal efficiency (RE) of these four most frequently detected compounds in Ontario DWSs. The RE of CBZ was determined to be from 71 to 93% for DWSs using granulated activated carbon (GAC); and was 75% for DWSs using GAC followed by ultraviolet irradiation (UV). The observed RE of GFB was between 44 and 55% in DWSs using GAC and increased to 82% when GAC was followed by UV. The use of GAC or GAC followed by UV provided an RE improvement of BPA from 80 to 99%. These detected concentration levels are well below the predicted no effect concentration or total allowable concentration reported in the literature. Additional targeted, site specific comparative research is required to fully assess the effectiveness of Ontario DWSs to remove particular compounds of concern. - Research Highlights: {yields} Occurrence and typical range of 45

  17. Wind speed reductions by large-scale wind turbine deployments lower turbine efficiencies and set low wind power potentials

    Science.gov (United States)

    Miller, Lee; Kleidon, Axel

    2017-04-01

    Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power potentials that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m-2) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m-2) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m-2 of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power.

  18. Use of Open Source Hardware and Software Platforms to Quantify Spectrally Dependent Differences in Photochemical Efficiency and Functional Absorption Cross Section within the Dinoflagellate Symbiodinium spp.

    Directory of Open Access Journals (Sweden)

    Kenneth D. Hoadley

    2017-11-01

    Full Text Available Active chlorophyll a fluorescence is an essential tool for understanding photosynthetic activity within cnidarian/dinoflagellate symbioses. Fluorescence measurement is typically achieved by utilizing a blue or red monochromatic excitation light source. However, algal photosynthetic pigments can differ in their absorption spectra, potentially leading to excitation wavelength dependent measurements of maximal and light acclimated PSII photosynthetic quantum yield (Fv/Fm or Fq′/Fm′ and functional absorption cross section (σPSII or σPSII′. Here we utilized an open source hardware development platform to construct a multispectral excitation fluorometer to assess spectrally dependent differences in photochemistry within four different Symbiodinium species (two of each ITS2-type A4 and B1. Multivariate analysis of light acclimated photochemical signatures showed separation between most alga types. These spectrally dependent differences in light acclimated PSII efficiency and PSII functional absorption cross section likely reflect changes in light harvesting compounds, their connectivity to the PSII reaction centers and the balance between photochemical and non-photochemical fluorescence quenching. Additionally, acclimation to low (20 μmol photons m−2 s−1 and high (200 μmol photons m−2 s−1 light conditions was examined in two of these symbionts types (ITS-2 type A4 and B1 As expected, chlorophyll a cell−1 decreased under high light acclimation in both symbionts. However, only A4 saw a subsequent reduction in absorbance whereas cellular volume decreased in the B1 (S. minutum symbiont. In response to high light acclimation, Fv/Fm was significantly lower at all excitation wavelengths for the B1 symbiont where as efficiencies remained the same for A4. However, high-light acclimated Fq′/Fm′ levels decreased in both symbionts, but only when measured using the 615 or 625 nm excitation wavelengths. Non-photochemical quenching within the

  19. Development of mini linac-based positron source and an efficient positronium convertor for positively charged antihydrogen production

    Science.gov (United States)

    Muranaka, T.; Debu, P.; Dupré, P.; Liszkay, L.; Mansoulie, B.; Pérez, P.; Rey, J. M.; Ruiz, N.; Sacquin, Y.; Crivelli, P.; Gendotti, U.; Rubbia, A.

    2010-04-01

    We have installed in Saclay a facility for an intense positron source in November 2008. It is based on a compact 5.5 MeV electron linac connected to a reaction chamber with a tungsten target inside to produce positrons via pair production. The expected production rate for fast positrons is 5·1011 per second. The study of moderation of fast positrons and the construction of a slow positron trap are underway. In parallel, we have investigated an efficient positron-positronium convertor using porous silica materials. These studies are parts of a project to produce positively charged antihydrogen ions aiming to demonstrate the feasibility of a free fall antigravity measurement of neutral antihydrogen.

  20. Development of mini linac-based positron source and an efficient positronium convertor for positively charged antihydrogen production

    International Nuclear Information System (INIS)

    Muranaka, T; Debu, P; Dupre, P; Liszkay, L; Mansoulie, B; Perez, P; Rey, J M; Ruiz, N; Sacquin, Y; Crivelli, P; Gendotti, U; Rubbia, A

    2010-01-01

    We have installed in Saclay a facility for an intense positron source in November 2008. It is based on a compact 5.5 MeV electron linac connected to a reaction chamber with a tungsten target inside to produce positrons via pair production. The expected production rate for fast positrons is 5·10 11 per second. The study of moderation of fast positrons and the construction of a slow positron trap are underway. In parallel, we have investigated an efficient positron-positronium convertor using porous silica materials. These studies are parts of a project to produce positively charged antihydrogen ions aiming to demonstrate the feasibility of a free fall antigravity measurement of neutral antihydrogen.