Barriers for realisation of energy savings in buildings; Barrierer for realisering af energibesparelser i bygninger

Energy Technology Data Exchange (ETDEWEB)

Jensen, O.M.

2004-07-01

Many years' efforts within the energy labelling area have shown large saving potentials in heating and use of electricity in buildings. At the same time it has been proved that these saving potentials, even when economically advantageous, only are cashed to a limited extent. The reason to this is ascribed to barriers that meet the individual building owner who wants to start saving energy. Most barriers are known and a lot of these have been sought overcome for some time. The questions are how many barriers still exist, have new barriers arisen and the character of these barriers. On this background the objective of this survey has been to concretize and study the barriers, which are blocking reasonable energy savings. Focus has especially been on barriers for realisation of heating savings, but through a general evaluation of energy savings of barriers other forms of energy saving methods have been taken into consideration. Special interest has been directed towards houses, typically one family houses, which are affected by the Energy Labelling Scheme. The concept barriers include all kinds of barriers, also barriers that not are acknowledged as barriers by the individual house owner, or that on closer inspection turn out to be something else than actual barriers. This note suggests an alternative inertia model, in order to create an idea of the inertness characteristic of the many house owners who understand the message but fail to act on it. (BA)

Pulse-height response of silicon surface-barrier detectors to high-energy heavy ions

International Nuclear Information System (INIS)

Smith, G.D.

1973-01-01

The pulse-height defect (PHD) of high-energy heavy ions in silicon surface-barrier detectors can be divided into three components: (1) energy loss in the gold-surface layer, (2) a nuclear-stopping defect, and (3) a defect due to recombination of electron-hole pairs in the plasma created by the heavy ion. The plasma recombination portion of the PHD was the subject of this study using the variation of the PHD with (1) the angle of incidence of incoming heavy ions, and (2) changes in the detector bias. The Tandem Van de Graaff accelerator at Argonne National Laboratory was used to produce scattered beam ions ( 32 S, 35 Cl) and heavy target recoils (Ni, Cu, 98 Mo, Ag, Au) at sufficient energies to produce a significant recombination defect. The results confirm the existence of a recombination zone at the front surface of these detectors and the significance of plasma recombination as a portion of the pulse-height defect. (Diss. Abstr. Int., B)

Measurement of leakage and design for the protective barrier of the high energy radiation therapy room

International Nuclear Information System (INIS)

Chu, S.S.; Park, C.Y.

1981-01-01

The logical development of an optimum structural shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV are presented. We obtained following results by comparison in between the precalculating values and actual survey after complete installation of radiogenerating units. 1) The calculating formula for the protective barrier written in NCRP report no. 34(1970) was the most ideal and economic calculating methods for the construction of barrier and to determine thickness for the meeting requirements of the number of patients of 80-100 in daily treatment. 2) The precalculating values of protective barrier are 5 times more protective than that of actual measurement. It is depending on radiation workload and utilization the data most securely. 3) The dose rate during exposure are 2-10 mR/hr at out of the door and the control room. 4) The foul smelling and ozone gas production from long exposure of cancer patients cannot be estimated when the room is ill ventilated. (author)

Highway renewable energy : photovoltaic noise barriers

Science.gov (United States)

2017-07-01

Highway photovoltaic noise barriers (PVNBs) represent the combination of noise barrier systems and photovoltaic systems in order to mitigate traffic noise while simultaneously producing renewable energy. First deployed in Switzerland in 1989, PVNBs a...

Barriers to renewable energy development: A case study of large-scale wind energy in Saskatchewan, Canada

International Nuclear Information System (INIS)

Richards, Garrett; Noble, Bram; Belcher, Ken

2012-01-01

Renewable energy is receiving increased attention as a viable alternative to non-renewable electrical generation, however, meeting global energy demands will require a more ambitious renewable energy program than is currently the case. There have been several reviews of potential technological, economic, social, or public barriers and solutions to renewable energy investment. Although important, there is also need for multi-dimensional analyses of these barriers and identification of the most significant underlying barriers if viable solutions are to be developed. In this paper we apply a theoretical framework to examine stakeholder's perceptions and understanding of the barriers to wind energy development in Saskatchewan, Canada. We identify and examine the most significant underlying barriers to investment in renewable energy and the interactions between those barriers. Results show a number of perceived barriers to wind energy investment, however, these barriers can be explained in large part by knowledge barriers, if not disagreement over whether the current level of investment in wind energy is sufficient. We show that barriers to renewable energy cannot be explained solely by technological, social, political, or economic factors in isolation, and that a multi-dimensional approach, identifying and explaining the underlying sources of these barriers, is necessary to develop viable solutions. - Highlights: ► Meeting future wind energy objectives requires an ambitious investment program. ► A framework is applied to identify and explain perceived barriers to wind energy. ► Stakeholders perceived technological and political barriers as the most significant. ► These could be explained by knowledge barriers and complacency with the status quo. ► Even with additional investment these underlying barriers will constrain progress.

Understanding energy efficiency barriers in Ukraine: Insights from a survey of commercial and industrial firms

International Nuclear Information System (INIS)

Timilsina, Govinda R.; Hochman, Gal; Fedets, Iryna

2016-01-01

Improvement of energy efficiency is an important element of energy policy for a sustainable supply of energy in Ukraine. However, the country is facing several challenges to the large-scale deployment of energy efficient technologies. We conducted a two-stage quota sample survey of 509 commercial and industrial firms of all regions of Ukraine to understand the barriers to energy efficiency improvements. Our study finds that more than two-thirds of the commercial and industrial firms in the country view improvement of energy efficiency very important to their business. However, due to several barriers they are unable to realize the improvements of energy efficiency. Among the 19 potential barriers investigated in the study, the survey results show that high upfront investment requirement, lack of government policies to support energy efficiency improvements, higher cost of capital, and lack of information and awareness are the most critical barriers to the improvement of energy efficiency in the industrial and commercial sectors in Ukraine. - Highlights: • Despite attractiveness, large scale deployment of energy efficiency is lacking. • Several barriers are responsible for slow implementation of energy efficiency. • Understanding the barriers from the field is crucial to design effective policies. • A survey of commercial and industrial firms reveals the key barriers. • Financial barriers are the main hurdles to adopt energy efficient technologies.

Overcoming energy efficiency barriers through systems approach—A conceptual framework

International Nuclear Information System (INIS)

Chai, Kah-Hin; Yeo, Catrina

2012-01-01

In this paper we propose a framework which categorizes energy efficiency barriers based on the stage at which the barriers exist. Barriers to energy efficiency have been widely studied but to our knowledge, except for a few studies, we found inadequate consideration for barrier–barrier interactions when proposing policy measures for improving energy efficiency. Leveraging systems thinking's power as a problem solver which identifies underlying structure that explains (similar) patterns of behavior in a variety of different situations, we attempted to identify patterns of barriers to adoption of energy efficiency measures in industrial companies. Inspired by systems thinking, the proposed framework has four stages, namely, Motivation, Capability, Implementation and Results, as well as a feedback loop. Using a case study, we show that following the four stages will lead to positive feedback for future energy efficiency implementations. The framework highlights the interconnected nature of the barriers and a need for policymakers to address these barriers in a holistic manner. We argue that the overall effectiveness of energy efficiency policies is only as strong as the weakest link in the four-stage framework. This differs from most prior research that addressed barriers in isolation, where a solution is proposed for each of the barriers without considering the relationship between the barriers. Our framework also offers a way to understand the roles and responsibilities of major stakeholders such as governments and energy service companies (ESCOs) in driving energy efficiency. This allows the assessment and identification of weak links in energy efficiency policies. - Highlights: ► We propose a systems approach to overcome energy efficiency barriers. ► Barriers are grouped into Motivation, Capability, Implementation and Results. ► Case study shows that there is a feedback loop from Results to Motivation. ► Current Results will affect future Motivation. �

Energy analysis of vehicle-to-cable barrier impacts.

Science.gov (United States)

2013-06-01

An accident reconstruction technique was developed for estimating the energy absorbed during an impact with a cable barrier system as well as the initial impact velocity. The kinetic energy absorbed during a cable barrier system impact is comprised o...

Structural-morphological variations in pseudo-barrier films of anode aluminium oxide under irradiation with high-energy particles

International Nuclear Information System (INIS)

Chernykh, M.A.; Belov, V.T.

1988-01-01

Comparative study of structural-morphological variations under electron beam effect in pseudo-barrier films of anode aluminium oxide, obtained in seven different solutions and proton or X-rays pre-irradiated to determine structure peculiarities of anode aluminium oxides, is presented. Such study is a matter of interest from the solid-phase transformation theory point of view and for anode aluminium films application under radiation. Stability increase of pseudo-barrier films of anode aluminium oxide to the effect of UEhMV-100 K microscope electron beam at standard modes of operation (75 kV) due to proton or X-rays irradiation is found. Difference in structural-monorphological variations obtained in different solutions of anode aluminium films under high-energy particles irradiation is determined. Strucural-phase microinhomogeneity of amorphous pseudo-barrier films of anode aluminium oxide and its influence on solid-phase transformations character under electron bean of maximal intensity are detected

Technical Barriers, Gaps, and Opportunities Related to Home Energy Upgrade Market Delivery

Energy Technology Data Exchange (ETDEWEB)

Bianchi, M. V. A.

2011-11-01

This report outlines the technical barriers, gaps, and opportunities that arise in executing home energy upgrade market delivery approaches, as identified through research conducted by the U.S. Department of Energy's Building America program. The objective of this report is to outline the technical1 barriers, gaps, and opportunities that arise in executing home energy upgrade market delivery approaches, as identified through research conducted by the U.S. Department of Energy's (DOE) Building America program. This information will be used to provide guidance for new research necessary to enable the success of the approaches. Investigation for this report was conducted via publications related to home energy upgrade market delivery approaches, and a series of interviews with subject matter experts (contractors, consultants, program managers, manufacturers, trade organization representatives, and real estate agents). These experts specified technical barriers and gaps, and offered suggestions for how the technical community might address them. The potential benefits of home energy upgrades are many and varied: reduced energy use and costs; improved comfort, durability, and safety; increased property value; and job creation. Nevertheless, home energy upgrades do not comprise a large part of the overall home improvement market. Residential energy efficiency is the most complex climate intervention option to deliver because the market failures are many and transaction costs are high (Climate Change Capital 2009). The key reasons that energy efficiency investment is not being delivered are: (1) The opportunity is highly fragmented; and (2) The energy efficiency assets are nonstatus, low-visibility investments that are not properly valued. There are significant barriers to mobilizing the investment in home energy upgrades, including the 'hassle factor' (the time and effort required to identify and secure improvement works), access to financing, and the

A novel GaN HEMT with double recessed barrier layer for high efficiency-energy applications

Science.gov (United States)

Jia, Hujun; Luo, Yehui; Wu, Qiuyuan; Yang, Yintang

2017-11-01

In this paper, a novel GaN HEMT with high efficiency-energy characteristic is proposed. Different from the conventional structure, the proposed structure contains double recessed barriers layer (DRBL) beside the gate. The key idea in this work is to improve the microwave output characteristics. The simulated results show that the drain saturation current and peak transconductance of DRBL GaN HEMT is slightly decreased, the transconductance saturation flatness is increased by 0.5 V and the breakdown voltage is also enhanced too. Due to the both recessed barrier layer, the gate-drain/gate-source capacitance is decreased by 6.3% and 11.3%, respectively. The RF simulated results show that the maximum oscillation frequency for DRBL GaN HEMT is increased from 57 GHz to 64 GHz and the saturation power density is 8.7 W/mm at 600 MHz, 6.9 W/mm at 1200 MHz with the higher power added efficiency (PAE). Further investigation show that DRBL GaN HEMT can achieve to 6.4 W/mm and the maximum PAE 83.8% at 2400 MHz. Both are higher than the 5.0 W/mm and 80.3% for the conventional structure. When the operating frequency increases to X band, the DRBL GaN HEMT still exhibits the superior output performances. All the results show that the advantages and the potential capacities of DRBL GaN HEMT at high efficiency-energy are greater than the conventional GaN HEMT.

Efficient sampling over rough energy landscapes with high barriers: A combination of metadynamics with integrated tempering sampling

Energy Technology Data Exchange (ETDEWEB)

Yang, Y. Isaac [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Zhang, Jun; Che, Xing; Yang, Lijiang; Gao, Yi Qin, E-mail: gaoyq@pku.edu.cn [Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Biodynamic Optical Imaging Center, Peking University, Beijing 100871 (China)

2016-03-07

In order to efficiently overcome high free energy barriers embedded in a complex energy landscape and calculate overall thermodynamics properties using molecular dynamics simulations, we developed and implemented a sampling strategy by combining the metadynamics with (selective) integrated tempering sampling (ITS/SITS) method. The dominant local minima on the potential energy surface (PES) are partially exalted by accumulating history-dependent potentials as in metadynamics, and the sampling over the entire PES is further enhanced by ITS/SITS. With this hybrid method, the simulated system can be rapidly driven across the dominant barrier along selected collective coordinates. Then, ITS/SITS ensures a fast convergence of the sampling over the entire PES and an efficient calculation of the overall thermodynamic properties of the simulation system. To test the accuracy and efficiency of this method, we first benchmarked this method in the calculation of ϕ − ψ distribution of alanine dipeptide in explicit solvent. We further applied it to examine the design of template molecules for aromatic meta-C—H activation in solutions and investigate solution conformations of the nonapeptide Bradykinin involving slow cis-trans isomerizations of three proline residues.

Investing in Energy Efficiency. Removing the Barriers

International Nuclear Information System (INIS)

2004-01-01

Investing in improving energy efficiency has the clear advantages of reducing energy costs, improving security of supply and mitigating the environmental impacts of energy use. And still, many viable opportunities for higher energy efficiency are not tapped because of the existence of numerous barriers to such investments. These lost opportunities imply costs to the individual energy consumers and to the society as a whole and they are particularly important in economies in transition. This report identifies various types of barriers for making energy efficiency investments (be they of legal, administrative, institutional or financial nature), mainly in buildings, district heating and efficient lighting. The role of various bodies and organisations for the facilitation of energy efficiency investments is analysed, from public authorities and regulators to banks and international financing institutions

Should we quit our jobs? Challenges, barriers and recommendations for interdisciplinary energy research

International Nuclear Information System (INIS)

Schuitema, Geertje; Sintov, Nicole D.

2017-01-01

Many plea for a better integration of social sciences in energy research, which would imply more comprehensive interdisciplinary energy research. We argue that in order to achieve this, institutional barriers and research challenges need to be recognised and addressed. We identify six challenges and barriers, and provide recommendations for working towards solutions. We conclude that to engage in interdisciplinary research implies extra costs and fewer rewards for all researchers, particularly early and mid-career academics. We propose a new conceptualisation of practices and incentive structures among academic institutions, funding agencies, and publication outlets, and urge all energy researchers to join this debate. - Highlights: • Interdisciplinary energy research currently does not reach its full potential. • Social sciences are underutilised in energy research. • Barriers and challenges need to be addressed to stimulate interdisciplinary energy research. • High costs and small rewards for interdisciplinary (early and mid-career) researchers.

Heavy ion collisions at energies near the Coulomb barrier 1990

International Nuclear Information System (INIS)

Nagarajan, M.A.

1991-01-01

During recent years, detailed experimental and theoretical investigations have been carried out on heavy ion collisions at energies close to the Coulomb barrier. These studies have provided direct evidence of strong couplings between the various reaction channels available at energies near the top of the Coulomb barrier. This field of research has remained the focus of interest and with improved experimental techniques, new detailed high resolution data have been obtained. The workshop on ''Heavy Ion Collisions at Energies Close to the Coulomb Barrier'' was organized with the aim of reviewing the current understanding of the collision dynamics and to discuss future directions in this area of research. The topics discussed at the workshop were broadly classified under the titles: quasielastic reactions; fusion of heavy ions; and shape and spin dependence in heavy ion collisions. The last of these topics was included to review new data obtained with polarized heavy ions and their theoretical interpretations. This volume contains the invited and contributed talks as well as a few short presentations during panel discussions. (author)

Reducing barriers to energy efficiency in the German energy service companies sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Koewener, D.; Schleich, J.

2000-12-01

This report describes the empirical research conducted in the German energy service sector to assess to what extent energy service companies (ESCOs) can help overcome the barriers to energy in the higher education, brewing and mechanical engineering sectors. This report complements the sector for Germany within the BARRIERS project (Sorrell et al., 2000; Schleich/Boede 2000a; Schleich/Boede 2000b; Schleich et al., 2000). The report characterises the German energy service sector, contains a description and analysis of four case studies in the energy service sector, identifies the main barriers and chances for ESCOs in the higher education, brewery and mechanical engineering sectors, and concludes with brief recommendations on how these barriers may be overcome. The results of the study are summarised here under the following headings: Characterising the energy service sector in Germany; - Case studies of energy service companies in Germany; - The role of ESCOs in the case-study sectors; - Policy implications. (orig.)

Renewable energy costs, potentials, barriers: Conceptual issues

International Nuclear Information System (INIS)

Verbruggen, Aviel; Fischedick, Manfred; Moomaw, William; Weir, Tony; Nadai, Alain; Nilsson, Lars J.; Nyboer, John; Sathaye, Jayant

2010-01-01

Renewable energy can become the major energy supply option in low-carbon energy economies. Disruptive transformations in all energy systems are necessary for tapping widely available renewable energy resources. Organizing the energy transition from non-sustainable to renewable energy is often described as the major challenge of the first half of the 21st century. Technological innovation, the economy (costs and prices) and policies have to be aligned to achieve full renewable energy potentials, and barriers impeding that growth need to be removed. These issues are also covered by IPCC's special report on renewable energy and climate change to be completed in 2010. This article focuses on the interrelations among the drivers. It clarifies definitions of costs and prices, and of barriers. After reviewing how the third and fourth assessment reports of IPCC cover mitigation potentials and commenting on definitions of renewable energy potentials in the literature, we propose a consistent set of potentials of renewable energy supplies.

Barriers' and policies' analysis of China's building energy efficiency

International Nuclear Information System (INIS)

Zhang, Yurong; Wang, Yuanfeng

2013-01-01

With the rapid economic growth and the improvement of people's living standards, China's building energy consumption has kept rising during the past 15 years. Under the effort of the Chinese government and the society, China's building energy efficiency has made certain achievements. However, the implementation of building energy efficiency in China is still far from its potential. Based on the analysis of the existing policies implemented in China, the article concluded that the most essential and the most effective ways to promote building energy efficiency is the government's involvement as well as economic and financial incentives. In addition, the main barriers in the process of promoting building energy efficiency in China are identified in six aspects. It has been found that the legal system and administrative issues constitute major barriers, and the lack of financial incentives and the mismatching of market mechanism also hamper the promotion of building energy efficiency. Finally, in view of the existing policies and barriers analysis, three corresponding policy proposals are presented. -- Highlights: •The existing policies implemented in China from three aspects are presented and analysed. •The Government's involvement is the most essential effective way to promote building-energy efficiency. •Six aspects of barriers in promoting building energy efficiency in China are identified. •The legal system and administrative issues constitute the major barriers. •Three policy proposals to further promote building energy efficiency in China are proposed

Energy management action plan: Developing a strategy for overcoming institutional barriers to municipal energy conservation

Energy Technology Data Exchange (ETDEWEB)

1992-12-31

Energy offices working to improve efficiency of local government facilities face not only technical tasks, but institutional barriers, such as budget structures that do not reward efficiency, a low awareness of energy issues, and purchasing procedures based only on minimizing initial cost. The bureau, in working to remove such barriers in San Francisco, has identified 37 institutional barriers in areas such as operations & maintenance, purchasing, and facility design; these barriers were then reorganized into three groupings-- policy & attitudes, budget & incentives, and awareness & information-- and mapped. This map shows that the barriers mutually reinforce each other, and that a holistic approach is required for permanent change. The city`s recreation & parks department was used as a model department, and information about facility energy use was compiled into a departmental energy review. Staff interviews showed how barriers affect conservation. The bureau then generated ideas for projects to remove specific barriers and rated them according to potential impact and the resources required to implement them. Four of the six projects selected focused on maintenance staff: a cost- sharing lighting retrofit program, a boiler efficiency program, a departmental energy tracking system, and a budgetary incentive program for conservation. The other two projects are city-wide: promotion of a new term contract supplying energy-efficient light materials, and publication/distribution of ENERGY NEWS newsletter. A general methodology, the EMAP Strategy Guide, has been created to assist other energy offices in developing EMAPs.

Fusion of 6Li with 159Tb at near-barrier energies

International Nuclear Information System (INIS)

Pradhan, M. K.; Mukherjee, A.; Basu, P.; Goswami, A.; Kshetri, R.; Roy, Subinit; Chowdhury, P. Roy; Sarkar, M. Saha; Palit, R.; Parkar, V. V.; Santra, S.; Ray, M.

2011-01-01

Complete and incomplete fusion cross sections for 6 Li + 159 Tb have been measured at energies around the Coulomb barrier by the γ-ray method. The measurements show that the complete fusion cross sections at above-barrier energies are suppressed by ∼34% compared to coupled-channel calculations. A comparison of the complete fusion cross sections at above-barrier energies with the existing data for 11,10 B + 159 Tb and 7 Li + 159 Tb shows that the extent of suppression is correlated with the α separation energies of the projectiles. It has been argued that the Dy isotopes produced in the reaction 6 Li + 159 Tb at below-barrier energies are primarily due to the d transfer to unbound states of 159 Tb, while both transfer and incomplete fusion processes contribute at above-barrier energies.

Barriers to renewable energy penetration. A framework for analysis

DEFF Research Database (Denmark)

Painuly, Jyoti P.

2001-01-01

Renewable energy has the potential to play an important role in providing energy with sustainability to the vast populations in developing countries who as yet have no access to clean energy. Although economically viable fur several applications, renewable energy has not been able to realise its...... potential due to several barriers to its penetration. A framework has been developed in this paper to identify the barriers to renewable energy penetration acid to suggest measures to overcome them. (C) 2001 Elsevier Science Ltd. All rights reserved....

7Li breakup polarization potential at near barrier energies

International Nuclear Information System (INIS)

Lubian, J. . E-mail lubian@if.uff.br; Correa, T.; Paes, B.; Figueira, J.M.; Abriola, D.; Fernandez Niello, J.O.; Arazi, A.; Capurro, O.A.; de Barbara, E.; Marti, G.V.; Martinez Heinmann, D.; Negri, A.E.; Pacheco, A.J.; Padron, I.; Gomes, P.R.S.

2007-01-01

Inelastic and one neutron transfer cross sections at energies around the Coulomb barrier were used to derive dynamic polarization potential (DPP) for the 7 Li + 27 Al system. The DPP due to breakup, obtained in a simple way, indicates that its real part is repulsive at near barrier energies

Energy barrier to decoherence

International Nuclear Information System (INIS)

Mizel, Ari; Mitchell, M. W.; Cohen, Marvin L.

2001-01-01

We propose a ground-state approach to realizing quantum computers. This scheme is time-independent and inherently defends against decoherence by possessing an energy barrier to excitation. We prove that our time-independent qubits can perform the same algorithms as their time-dependent counterparts. Advantages and disadvantages of the time-independent approach are described. A model involving quantum dots is provided for illustration

On the economic analysis of problems in energy efficiency: Market barriers, market failures, and policy implications

International Nuclear Information System (INIS)

Sanstad, A.H.; Koomey, J.G.; Levine, M.D.

1993-01-01

In his recent paper in The Energy Journal, Ronald Sutherland argues that several so-called ''market barriers'' to energy efficiency frequently cited in the literature are not market failures in the conventional sense and are thus irrelevant for energy policy. We argue that Sutherland has inadequately analyzed the idea of market barrier and misrepresented the policy implications of microeconomics. We find that economic theory, correctly interpreted, does not provide for the categorical dismissal of market barriers. We explore important methodological issues underlying the debate over market barriers, and discuss the importance of reconciling the findings of non-economic social sciences with the economic analysis of energy demand and consumer decision-making. We also scrutinize Sutherland's attempt to apply finance theory to rationalize high implicit discount rates observed in energy-related choices, and find this use of finance theory to be inappropriate

On the economic analysis of problems in energy efficiency: Market barriers, market failures, and policy implications

Energy Technology Data Exchange (ETDEWEB)

Sanstad, A.H.; Koomey, J.G.; Levine, M.D.

1993-01-01

In his recent paper in The Energy Journal, Ronald Sutherland argues that several so-called ``market barriers`` to energy efficiency frequently cited in the literature are not market failures in the conventional sense and are thus irrelevant for energy policy. We argue that Sutherland has inadequately analyzed the idea of market barrier and misrepresented the policy implications of microeconomics. We find that economic theory, correctly interpreted, does not provide for the categorical dismissal of market barriers. We explore important methodological issues underlying the debate over market barriers, and discuss the importance of reconciling the findings of non-economic social sciences with the economic analysis of energy demand and consumer decision-making. We also scrutinize Sutherland`s attempt to apply finance theory to rationalize high implicit discount rates observed in energy-related choices, and find this use of finance theory to be inappropriate.

The role of confined collagen geometry in decreasing nucleation energy barriers to intrafibrillar mineralization.

Science.gov (United States)

Kim, Doyoon; Lee, Byeongdu; Thomopoulos, Stavros; Jun, Young-Shin

2018-03-06

Mineralization of collagen is critical for the mechanical functions of bones and teeth. Calcium phosphate nucleation in collagenous structures follows distinctly different patterns in highly confined gap regions (nanoscale confinement) than in less confined extrafibrillar spaces (microscale confinement). Although the mechanism(s) driving these differences are still largely unknown, differences in the free energy for nucleation may explain these two mineralization behaviors. Here, we report on experimentally obtained nucleation energy barriers to intra- and extrafibrillar mineralization, using in situ X-ray scattering observations and classical nucleation theory. Polyaspartic acid, an extrafibrillar nucleation inhibitor, increases interfacial energies between nuclei and mineralization fluids. In contrast, the confined gap spaces inside collagen fibrils lower the energy barrier by reducing the reactive surface area of nuclei, decreasing the surface energy penalty. The confined gap geometry, therefore, guides the two-dimensional morphology and structure of bioapatite and changes the nucleation pathway by reducing the total energy barrier.

Linear and non-linear energy barriers in systems of interacting single-domain ferromagnetic particles

International Nuclear Information System (INIS)

Petrila, Iulian; Bodale, Ilie; Rotarescu, Cristian; Stancu, Alexandru

2011-01-01

A comparative analysis between linear and non-linear energy barriers used for modeling statistical thermally-excited ferromagnetic systems is presented. The linear energy barrier is obtained by new symmetry considerations about the anisotropy energy and the link with the non-linear energy barrier is also presented. For a relevant analysis we compare the effects of linear and non-linear energy barriers implemented in two different models: Preisach-Neel and Ising-Metropolis. The differences between energy barriers which are reflected in different coercive field dependence of the temperature are also presented. -- Highlights: → The linear energy barrier is obtained from symmetry considerations. → The linear and non-linear energy barriers are calibrated and implemented in Preisach-Neel and Ising-Metropolis models. → The temperature and time effects of the linear and non-linear energy barriers are analyzed.

On the economic analysis of problems in energy efficiency: Market barriers, market failures, and policy implications

Energy Technology Data Exchange (ETDEWEB)

Sanstad, A.H.; Koomey, J.G.; Levine, M.D.

1993-01-01

In his recent paper in The Energy Journal, Ronald Sutherland argues that several so-called market barriers'' to energy efficiency frequently cited in the literature are not market failures in the conventional sense and are thus irrelevant for energy policy. We argue that Sutherland has inadequately analyzed the idea of market barrier and misrepresented the policy implications of microeconomics. We find that economic theory, correctly interpreted, does not provide for the categorical dismissal of market barriers. We explore important methodological issues underlying the debate over market barriers, and discuss the importance of reconciling the findings of non-economic social sciences with the economic analysis of energy demand and consumer decision-making. We also scrutinize Sutherland's attempt to apply finance theory to rationalize high implicit discount rates observed in energy-related choices, and find this use of finance theory to be inappropriate.

Financing energy SMEs in Ghana and Senegal: Outcomes, barriers and prospects

International Nuclear Information System (INIS)

Haselip, James; Desgain, Denis; Mackenzie, Gordon

2014-01-01

The article presents the findings of primary research carried out in Ghana and Senegal, which revisited the main assumptions behind the African Rural Energy Enterprise Development (AREED) initiative (2002–2012), and other donor-backed programmes, designed to promote small and medium-sized energy enterprises (energy SMEs). These assumptions were (1) that the lack of affordable local financing presented the most significant barrier to setting up and expanding energy SMEs, and (2) that these barriers would be overcome by a ‘demonstration effect’ whereby successful businesses, supported by donor-backed programmes, could in turn influence the commercial financial sector to invest in energy SMEs, thus triggering a virtuous circle of growth and profitability. - Highlights: • Analysis of the AREED ‘demonstration effect’ in Senegal and Ghana. • Commercial financial backing for SMEs remains a serious challenge for entrepreneurs. • Structural issues that increase the financial risk of investing in energy SMEs. • High transaction costs of investing in SMEs. • Longer supply chains and slower pay-back periods for capital-intensive technologies

Urban sound energy reduction by means of sound barriers

Science.gov (United States)

Iordache, Vlad; Ionita, Mihai Vlad

2018-02-01

In urban environment, various heating ventilation and air conditioning appliances designed to maintain indoor comfort become urban acoustic pollution vectors due to the sound energy produced by these equipment. The acoustic barriers are the recommended method for the sound energy reduction in urban environment. The current sizing method of these acoustic barriers is too difficult and it is not practical for any 3D location of the noisy equipment and reception point. In this study we will develop based on the same method a new simplified tool for acoustic barriers sizing, maintaining the same precision characteristic to the classical method. Abacuses for acoustic barriers sizing are built that can be used for different 3D locations of the source and the reception points, for several frequencies and several acoustic barrier heights. The study case presented in the article represents a confirmation for the rapidity and ease of use of these abacuses in the design of the acoustic barriers.

Urban sound energy reduction by means of sound barriers

Directory of Open Access Journals (Sweden)

Iordache Vlad

2018-01-01

Full Text Available In urban environment, various heating ventilation and air conditioning appliances designed to maintain indoor comfort become urban acoustic pollution vectors due to the sound energy produced by these equipment. The acoustic barriers are the recommended method for the sound energy reduction in urban environment. The current sizing method of these acoustic barriers is too difficult and it is not practical for any 3D location of the noisy equipment and reception point. In this study we will develop based on the same method a new simplified tool for acoustic barriers sizing, maintaining the same precision characteristic to the classical method. Abacuses for acoustic barriers sizing are built that can be used for different 3D locations of the source and the reception points, for several frequencies and several acoustic barrier heights. The study case presented in the article represents a confirmation for the rapidity and ease of use of these abacuses in the design of the acoustic barriers.

Reducing barriers to energy efficiency in the German brewing sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Schleich, J; Boede, U; Ostertag, K; Radgen, P

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German brewing sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of five case studies of energy management in German breweries. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the brewing sector may be improved. The results of the study for the brewing sector in Germany are summarised in this executive summary under the following headings: - Characterising the brewing sector - Case studies of energy management in the German brewing sector; - Evidence of barriers in the German brewing sector; - The role of energy service companies in the brewing sector; - Policy implications. (orig.)

Reducing barriers to energy efficiency in the German brewing sector. Executive Summary

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.; Ostertag, K.; Radgen, P.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German brewing sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of five case studies of energy management in German breweries. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the brewing sector may be improved. The results of the study for the brewing sector in Germany are summarised in this executive summary under the following headings: - Characterising the brewing sector; - Case studies of energy management in the German brewing sector; - Evidence of barriers in the German brewing sector; - The role of energy service companies in the brewing sector; - Policy implications. (orig.)

Barriers to Industrial Energy Efficiency - Study (Appendix A), June 2015

Energy Technology Data Exchange (ETDEWEB)

None

2015-06-01

This study examines barriers that impede the adoption of energy efficient technologies and practices in the industrial sector, and identifies successful examples and opportunities to overcome these barriers. Three groups of energy efficiency technologies and measures were examined: industrial end-use energy efficiency, industrial demand response, and industrial combined heat and power. This study also includes the estimated economic benefits from hypothetical Federal energy efficiency matching grants, as directed by the Act.

Barriers to Industrial Energy Efficiency - Report to Congress, June 2015

Energy Technology Data Exchange (ETDEWEB)

None

2015-06-01

This report examines barriers that impede the adoption of energy efficient technologies and practices in the industrial sector, and identifies successful examples and opportunities to overcome these barriers. Three groups of energy efficiency technologies and measures were examined: industrial end-use energy efficiency, industrial demand response, and industrial combined heat and power. This report also includes the estimated economic benefits from hypothetical Federal energy efficiency matching grants, as directed by the Act.

Dealing with barriers to energy efficiency and SMEs: Some empirical evidences

International Nuclear Information System (INIS)

Trianni, A.; Cagno, E.

2012-01-01

This paper aims at providing an identification and an analysis of the most relevant barriers to energy efficiency that limit a widespread implementation of the Best Available Technologies and Practices (BAT/Ps) through the investigation of 128 non-energy intensive manufacturing Small and Medium-sized Enterprises (SMEs) in Northern Italy. The study, starting from the existing literature, performs an investigation of the operational difficulties occurring when it has been decided to undertake the process of investing resources in energy efficiency interventions. The most perceived barriers have been analyzed with respect to several important characteristics (among others, sector and firm’s size). This examination shows also that very much attention should be paid to avoid bundling together SMEs of different sizes and sectors, since different behaviors with respect to the perception of the barriers can be observed. The analysis of the sample presents some interesting trends considering the perception of the barriers with respect to previous experience of the enterprises on energy efficiency. The paper also explores, through a preliminary analysis, the correlations among questions in order to understand the dynamics and the possible effects of a given barrier with respect to others. Several suggestions for future research in this important area have been provided. -- Highlights: ► Evidences of different behaviors with respect to energy efficiency among sectors and firm’s size (within SMEs). ► Importance, for energy efficiency barriers, of avoid bundling SMEs as a whole. ► Preliminary investigation of relationships between barriers in order to understand the dynamics.

Energy efficiency barriers in commercial and industrial firms in Ukraine: An empirical analysis

International Nuclear Information System (INIS)

Hochman, Gal; Timilsina, Govinda R.

2017-01-01

Improvement in energy efficiency is one of the main options to reduce energy demand and greenhouse gas emissions. However, large-scale deployment of energy-efficient technologies is constrained by several factors. Employing a survey of 509 industrial and commercial firms throughout Ukraine and a generalized ordered logit model, we quantified the economic, behavioral, and institutional barriers that may impede the deployment of energy-efficient technologies. Our analysis shows that behavioral barriers resulted from lack of information, knowledge, and awareness are major impediments to the adoption of energy-efficient technologies in Ukraine, and that financial barriers may further impede investments in these technologies especially for small firms. This suggests that carefully targeted information provisions and energy audits will enhance Ukrainian firms' investments in energy-efficient technologies to save energy consumption, improve productivity, and reduce carbon emissions from the productive sectors. - Highlights: • Employing a survey of 509 industrial and commercial firms throughout Ukraine • A generalized ordered logit model is used in the analysis. • The paper quantifies the economic, behavioral, and institutional barriers to energy-efficient technologies. • Behavioral barriers are major impediments to the adoption of energy-efficient technologies. • Financial barriers may further impede investments in these technologies especially for small firms.

A path method for finding energy barriers and minimum energy paths in complex micromagnetic systems

International Nuclear Information System (INIS)

Dittrich, R.; Schrefl, T.; Suess, D.; Scholz, W.; Forster, H.; Fidler, J.

2002-01-01

Minimum energy paths and energy barriers are calculated for complex micromagnetic systems. The method is based on the nudged elastic band method and uses finite-element techniques to represent granular structures. The method was found to be robust and fast for both simple test problems as well as for large systems such as patterned granular media. The method is used to estimate the energy barriers in CoCr-based perpendicular recording media

Implementation of renewable energy technologies - Opportunities and barriers. Ghana country study

Energy Technology Data Exchange (ETDEWEB)

Edjekumhene, I.; Atakora, S.B.; Atta-Konadu, R.; Brew-Hammond, A. [Kumasi Inst. og Technology and Environment (Ghana)

2001-07-01

This report presents the experience of Ghana in the development, utilisation and promotion of Renewable Energy Technologies (RETs). The report gives a general overview of the state of RETs, describes past/existing institutional, regulatory and policy framework, identifies key barriers to and opportunities for RETs, and recommends directional changes needed to remove barriers and promote wide-scale adoption of RETs in Ghana. A total of eight RETs - biomass-fired dryers, sawdust stoves, sawdust briquette, biogas, solar crop dryer, solar water heater, solar water pump and small hydro power - are covered in the report. Analyses of barriers to the eight RETs are carried out using a framework approach that categorises barriers into socio-technical, economic and crosscutting barriers. Financial analyses, as opposed to economic analyses, have been carried out for all the selected RETs. The report also incorporates stake holders' perspectives and views on barriers and how they can be removed. Ghana is endowed with several renewable energy resources like solar radiation, small hydro, biomass, and wind. Exploitation of Ghana's renewable energy resources has been carried out under two main policy regimes - PND Law 62 (1983) and the Energy Sector Development Programme (ESDP). Several measures and instruments have been employed in the implementation of renewable energy policies. The main measures used are research and development, information and eduction, and some normative measures (like the passing of PNDC Law 62 and the Energy Commission Law). Some economic instruments, such as subsidies, taxes, pricing, financing and duty waiver/reduction, have been used as well but only to a limited extent. The effective development, implementation and dissemination of all the RETs studied are hampered by several barriers, which can be grouped into three main categories - Socio-technical barriers, economic barriers and crosscutting barriers. Socio-technical barriers refer to

Implementation of renewable energy technologies - Opportunities and barriers. Ghana country study

Energy Technology Data Exchange (ETDEWEB)

Edjekumhene, I; Atakora, S B; Atta-Konadu, R; Brew-Hammond, A [Kumasi Inst. og Technology and Environment (Ghana)

2001-07-01

This report presents the experience of Ghana in the development, utilisation and promotion of Renewable Energy Technologies (RETs). The report gives a general overview of the state of RETs, describes past/existing institutional, regulatory and policy framework, identifies key barriers to and opportunities for RETs, and recommends directional changes needed to remove barriers and promote wide-scale adoption of RETs in Ghana. A total of eight RETs - biomass-fired dryers, sawdust stoves, sawdust briquette, biogas, solar crop dryer, solar water heater, solar water pump and small hydro power - are covered in the report. Analyses of barriers to the eight RETs are carried out using a framework approach that categorises barriers into socio-technical, economic and crosscutting barriers. Financial analyses, as opposed to economic analyses, have been carried out for all the selected RETs. The report also incorporates stake holders' perspectives and views on barriers and how they can be removed. Ghana is endowed with several renewable energy resources like solar radiation, small hydro, biomass, and wind. Exploitation of Ghana's renewable energy resources has been carried out under two main policy regimes - PND Law 62 (1983) and the Energy Sector Development Programme (ESDP). Several measures and instruments have been employed in the implementation of renewable energy policies. The main measures used are research and development, information and eduction, and some normative measures (like the passing of PNDC Law 62 and the Energy Commission Law). Some economic instruments, such as subsidies, taxes, pricing, financing and duty waiver/reduction, have been used as well but only to a limited extent. The effective development, implementation and dissemination of all the RETs studied are hampered by several barriers, which can be grouped into three main categories - Socio-technical barriers, economic barriers and crosscutting barriers. Socio-technical barriers refer to resource

Barriers to the sustainable development of electrical energy in the industrialized nations

International Nuclear Information System (INIS)

Ringel, M.; Leonardi, J.

2003-01-01

The liberalization of the electricity market in the industrialized nations may considered as an opportunity to bring about a diversification of the energy sector which could help overcome the economic barriers to a more sustainable development By allowing new companies to boost their market share, in many countries increases have been obtained in the supply of electricity based on renewable energy or energy services offering greater efficiency. It is now possible to reduce the cost of the measures which encourage the sustainable development of the sector, taking account of those barriers which prevent the expansion of ENR, hold back further gains in energy efficiency and block a reduction in demand An active energy policy will make it possible to overcome the difficulties encountered in various countries. This study highlights the main barriers to the sustainable development of electrical energy and outlines which solutions may be envisaged to overcome these barriers. (authors)

Financing energy SMEs in Ghana and Senegal: Outcomes, barriers and prospects

DEFF Research Database (Denmark)

Haselip, James Arthur; Desgain, Denis DR; Mackenzie, Gordon A.

2014-01-01

enterprises (energy SMEs). These assumptions were (1) that the lack of affordable local financing presented the most significant barrier to setting up and expanding energy SMEs, and (2) that these barriers would be overcome by a ‘demonstration effect’ whereby successful businesses, supported by donor...

Energy SMEs in sub-Saharan Africa: Outcomes, barriers and prospects in Ghana, Senegal, Tanzania and Zambia

DEFF Research Database (Denmark)

Haselip, James Arthur; Desgain, Denis DR; Mackenzie, Gordon A.

a commercially viable energy SME sector, emphasising the lack of strong policy support from governments, poor business skills capacity and the high cost of many RETs as related cause-and-effect barriers. While these issues continue to characterise, to a greater or lesser extent, the energy SMEs sectors......; lack of clearly defined markets; demand-side barriers to purchase relatively high capital-intense energy products. Where numerous energy SMEs are in operation and thus where a valid demonstration effect can be identified, there is a perceived paradox that serves to undermine commercial interest...... in investing in energy SMEs. The paradox is that the donor-supported businesses that were issued with concessional and/or flexible loans serve to demonstrate that these businesses depend upon such concessional terms, i.e., that they could not survive in ‘the real world’. While this assumption is widely...

Reducing barriers to energy efficiency in the German mechanical engineering sector. Executive summary

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German mechanical engineering (ME) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of four case studies of energy management in German companies in the ME sector. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the ME sector may be improved. The results of the study for the ME sector in Germany are summarised in this executive summary under the following headings: - Characterising the mechanical engineering sector; - Case studies of energy management in the German mechanical engineering sector; - Evidence of barriers in the German mechanical engineering sector; - The role of energy service companies in the mechanical engineering sector; - Policy implications. (orig.)

Reducing barriers to energy efficiency in the German higher education sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German higher education (HE) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of six case studies of energy management in German universities. The results are analysed using the theoretical framework developed for the BARRIERS project (Sorrell et al., 2000). The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the sector may be improved. The results of the study for the higher education sector in Germany are summarised in this executive summary under the following headings: - Characterising the higher education sector; - Case studies of energy management in the German higher education sector; - Evidence of barriers in the German higher education sector; - The role of energy service companies in the higher education sector; - Policy implications. (orig.)

Reducing barriers to energy efficiency in the German higher education sector. Executive summary

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German higher education (HE) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of six case studies of energy management in German universities. The results are analysed using the theoretical framework developed for the BARRIERS project (Sorrell et al., 2000). The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the sector may be improved. The results of the study for the higher education sector in Germany are summarised in this executive summary under the following headings: - Characterising the higher education sector; - Case studies of energy management in the German higher education sector; - Evidence of barriers in the German higher education sector; - The role of energy service companies in the higher education sector; - Policy implications. (orig.)

Reducing barriers to energy efficiency in the German mechanical engineering sector. Final report

Energy Technology Data Exchange (ETDEWEB)

Schleich, J.; Boede, U.

2000-12-01

This report describes the empirical research into barriers to energy efficiency in the German mechanical engineering (ME) sector. It is one of nine such reports in the BARRIERS project. The report contains description and analysis of four case studies of energy management in German companies in the ME sector. The results are analysed using the theoretical framework developed for the BARRIERS project. The report also provides brief recommendations on how these barriers to the rational use of energy (RUE) may be overcome and how energy efficiency within the ME sector may be improved. The results of the study for the ME sector in Germany are summarised in this executive summary under the following headings: - Characterising the mechanical engineering sector; - Case studies of energy management in the German mechanical engineering sector; - Evidence of barriers in the German mechanical engineering sector; - The role of energy service companies in the mechanical engineering sector; - Policy implications. (orig.)

Nuclear energy technology transfer: the security barriers

International Nuclear Information System (INIS)

Rinne, R.L.

1975-08-01

The problems presented by security considerations to the transfer of nuclear energy technology are examined. In the case of fusion, the national security barrier associated with the laser and E-beam approaches is discussed; for fission, the international security requirements, due to the possibility of the theft or diversion of special nuclear materials or sabotage of nuclear facilities, are highlighted. The paper outlines the nuclear fuel cycle and terrorist threat, examples of security barriers, and the current approaches to transferring technology. (auth)

Analysis of Relationships among Organizational Barriers to Energy Efficiency Improvement: A Case Study in Indonesia’s Steel Industry

Directory of Open Access Journals (Sweden)

Apriani Soepardi

2018-01-01

Full Text Available The aim of this paper is to analyze and rank the managerial-organizational barriers to energy efficiency improvement from an industry perspective. To that end, this study utilizes the Interpretive Structural Modeling (ISM methodology to identify the contextual relationships among the barriers. In a focus group discussion forum, five practitioners from the steel industry were consulted to identify these mutual linkages. The results indicated that five of the eight barriers proposed are in the linkage category. These barriers include that the energy manager or people in charge of energy management lack influence, there are higher priorities to production activity, there is management resistance to change, there is inadequate management capacity, and there are conflicts of interest within the organization. The management should focus more attention on these barriers, because they have both high driving power and dependency. The findings are intended to help managers from manufacturing sectors identify key barriers and thus develop strategic plans to address these issues.

Anisotropic Lithium Insertion Behavior in Silicon Nanowires: Binding Energy, Diffusion Barrier, and Strain Effect

KAUST Repository

Zhang, Qianfan; Cui, Yi; Wang, Enge

2011-01-01

Silicon nanowires (SiNWs) have recently been shown to be promising as high capacity lithium battery anodes. SiNWs can be grown with their long axis along several different crystallographic directions. Due to distinct atomic configuration and electronic structure of SiNWs with different axial orientations, their lithium insertion behavior could be different. This paper focuses on the characteristics of single Li defects, including binding energy, diffusion barriers, and dependence on uniaxial strain in [110], [100], [111], and [112] SiNWs. Our systematic ab initio study suggests that the Si-Li interaction is weaker when the Si-Li bond direction is aligned close to the SiNW long axis. This results in the [110] and [111] SiNWs having the highest and lowest Li binding energy, respectively, and it makes the diffusion barrier along the SiNW axis lower than other pathways. Under external strain, it was found that [110] and [001] SiNWs are the most and least sensitive, respectively. For diffusion along the axial direction, the barrier increases (decreases) under tension (compression). This feature results in a considerable difference in the magnitude of the energy barrier along different diffusion pathways. © 2011 American Chemical Society.

Anisotropic Lithium Insertion Behavior in Silicon Nanowires: Binding Energy, Diffusion Barrier, and Strain Effect

KAUST Repository

Zhang, Qianfan

2011-05-19

Silicon nanowires (SiNWs) have recently been shown to be promising as high capacity lithium battery anodes. SiNWs can be grown with their long axis along several different crystallographic directions. Due to distinct atomic configuration and electronic structure of SiNWs with different axial orientations, their lithium insertion behavior could be different. This paper focuses on the characteristics of single Li defects, including binding energy, diffusion barriers, and dependence on uniaxial strain in [110], [100], [111], and [112] SiNWs. Our systematic ab initio study suggests that the Si-Li interaction is weaker when the Si-Li bond direction is aligned close to the SiNW long axis. This results in the [110] and [111] SiNWs having the highest and lowest Li binding energy, respectively, and it makes the diffusion barrier along the SiNW axis lower than other pathways. Under external strain, it was found that [110] and [001] SiNWs are the most and least sensitive, respectively. For diffusion along the axial direction, the barrier increases (decreases) under tension (compression). This feature results in a considerable difference in the magnitude of the energy barrier along different diffusion pathways. © 2011 American Chemical Society.

Applications of Skyrme energy-density functional to fusion reactions spanning the fusion barriers

International Nuclear Information System (INIS)

Liu Min; Wang, Ning; Li Zhuxia; Wu Xizhen; Zhao Enguang

2006-01-01

The Skyrme energy density functional has been applied to the study of heavy-ion fusion reactions. The barriers for fusion reactions are calculated by the Skyrme energy density functional with proton and neutron density distributions determined by using restricted density variational (RDV) method within the same energy density functional together with semi-classical approach known as the extended semi-classical Thomas-Fermi method. Based on the fusion barrier obtained, we propose a parametrization of the empirical barrier distribution to take into account the multi-dimensional character of real barrier and then apply it to calculate the fusion excitation functions in terms of barrier penetration concept. A large number of measured fusion excitation functions spanning the fusion barriers can be reproduced well. The competition between suppression and enhancement effects on sub-barrier fusion caused by neutron-shell-closure and excess neutron effects is studied

Addressing and overcoming barriers for energy savings in business

DEFF Research Database (Denmark)

Dirckinck-Holmfeld, Kasper

Energy savings are generally viewed as an effective way to cut GHG emissions, as there are huge potentials for improvements because of several barriers and constraining factors for implementing otherwise profitable solutions. Several different polity tools have been applied to overcome these barr......Energy savings are generally viewed as an effective way to cut GHG emissions, as there are huge potentials for improvements because of several barriers and constraining factors for implementing otherwise profitable solutions. Several different polity tools have been applied to overcome...

Key Barriers to the Implementation of Solar Energy in Nigeria: A Critical Analysis

Science.gov (United States)

Abdullahi, D.; Suresh, S.; Renukappa, S.; Oloke, D.

2017-08-01

Nigeria, potentially, has abundant sunshine throughout the year, making it full thirst for solar energy generation. Even though, the country’s solar energy projects have not realised a fair result over the years, due to many barriers associated with initiatives implementation. Therefore, the entire power sector remains incapacitated to generate, transmit and distribute a clean, affordable and sustainable energy to assist economic growth. The research integrated five African counterpart’s solar energy initiatives, barriers, policies and strategies adopted as a lesson learned to Nigeria. Inadequate solar initiative’s research, lack of technological know-how, short-term policies, lack of awareness and political instability are the major barriers that made the implementation of solar initiatives almost impossible in Nigeria. The shock of the barriers therefore, constitutes a major negative contribution to the crippling of the power sector in the state. Future research will concentrate on initiatives for mitigating solar and other renewable energy barriers.

Li breakup polarization potential at near barrier energies

International Nuclear Information System (INIS)

Lubian, F. J.; Correa, T.; Gomes, P.R.S.; Paes, B; Figueira, J. M.; Abriola, D.; Fernandez, J. O.; Capurro, O. A.; Marti, G.V.; Martinez, D.; Heimann; Negri, A.; Pacheco, A. J.; Padron, I.

2007-01-01

Inelastic and one neutron transfer cross sections at energies around the Coulomb barrier were used to derive dynamic polarization potential (DPP) for the 7 Li + 27 Al system. The DPP due to breakup, obtained in a simple way, indicates that its real part is repulsive at nearbarrier energies. (Author)

Addressing barriers to low carbon energy

International Nuclear Information System (INIS)

Berry, Fiona; Dunstan, Chris

2012-01-01

Full text: Two energy solutions gaining attention are cogeneration and trigeneration, mostly fuelled by natural gas, although other renewable sources can be used, such as sewage, agricultural waste and municipal waste. Trigeneration has become increasingly popular in Australia's urban centres as a relatively cost-effective means to cut the carbon-intensity of energy supply by more than half compared to traditional coal- fired electricity. Some examples of trigeneration projects include the City of Sydney's planned 360 megawatt trigeneration networks by 2030, the University of Technology Sydney's campus master plan and the six star Green Star Commonwealth Bank Place building in Sydney. Trigeneration and cogeneration can present opportunities such as addressing the issue of rising peak demand, which is a major driver for the current $9 billion per annum of network infrastructure spending. They can also face barriers. For example, depending on the current state of the network, additional network costs can be required to accommodate trigeneration. Furthermore, under the current National Electricity Market regulations and conventions, challenges do exist to timely and financially viable connection to the grid. Here we present two examples of barriers to trigeneration and cogeneration and solutions being considered and implemented. The University of Technology Sydney campus master plan is underway, with approximately 100,000sq.m of floor area being built by 2019 and includes plans for trigeneration. During the master planning phase of development, the university considered small trigeneration units in individual buildings in order to reduce the carbon intensity of electricity supply and deliver high ratings under Green Star ratings. When considering connecting trigeneration with the grid at multiple buildings on an individual basis, a number of barriers were encountered by UTS. The largest barrier was appropriate charging for connecting to and using the grid. However

Nucleus-size pinning for determination of nucleation free-energy barriers and nucleus geometry

Science.gov (United States)

Sharma, Abhishek K.; Escobedo, Fernando A.

2018-05-01

Classical Nucleation Theory (CNT) has recently been used in conjunction with a seeding approach to simulate nucleation phenomena at small-to-moderate supersaturation conditions when large free-energy barriers ensue. In this study, the conventional seeding approach [J. R. Espinosa et al., J. Chem. Phys. 144, 034501 (2016)] is improved by a novel, more robust method to estimate nucleation barriers. Inspired by the interfacial pinning approach [U. R. Pedersen, J. Chem. Phys. 139, 104102 (2013)] used before to determine conditions where two phases coexist, the seed of the incipient phase is pinned to a preselected size to iteratively drive the system toward the conditions where the seed becomes a critical nucleus. The proposed technique is first validated by estimating the critical nucleation conditions for the disorder-to-order transition in hard spheres and then applied to simulate and characterize the highly non-trivial (prolate) morphology of the critical crystal nucleus in hard gyrobifastigia. A generalization of CNT is used to account for nucleus asphericity and predict nucleation free-energy barriers for gyrobifastigia. These predictions of nuclei shape and barriers are validated by independent umbrella sampling calculations.

Study of Quasielastic scattering for 7Li+159Tb at around- barrier energies

Directory of Open Access Journals (Sweden)

Mukherjee A.

2017-01-01

Full Text Available Quasielastic scattering cross sections for the reaction 7Li+159Tb have been measured at large backangles, at energies around the Coulomb barrier. The quasielastic barrier distribution has been extracted from the measured quasielastic scattering excitation function, including and excluding α particle contribution. The peak of the quasielastic barrier distribution including α particle contribution shows a shift towards higher energy compared to the peak of the distribution without α particles. The quasielastic barrier distribution when compared to the calculated fusion barrier distribution, appears to show reasonable agreement for the system.

Low-impact, high toughness transportation barriers.

Science.gov (United States)

2012-10-01

Alternatives to existing transportation truck escape ramps and crash barriers are examined using arrays of : wood, bamboo, and fiberglass structural elements that act as energy absorbers as they deform. The : behaviors of each material type are analy...

6,7Li + 28Si total reaction cross sections at near barrier energies

International Nuclear Information System (INIS)

Pakou, A.; Musumarra, A.; Pierroutsakou, D.; Alamanos, N.; Assimakopoulos, P.A.; Divis, N.; Doukelis, G.; Gillibert, A.; Harissopulos, S.; Kalyva, G.; Kokkoris, M.; Lagoyannis, A.; Mertzimekis, T.J.; Nicolis, N.G.; Papachristodoulou, C.; Perdikakis, G.; Roubos, D.; Rusek, K.; Spyrou, S.; Zarkadas, Ch.

2007-01-01

Total reaction cross section measurements for the 6,7 Li + 28 Si systems have been performed at near-barrier energies. The results indicate that, with respect to the potential anomaly at barrier, 6 Li and 7 Li on light targets exhibit similar energy dependence on the imaginary potential. Comparisons are made with 6,7 Li cross sections on light and heavy targets, extracted via previous elastic scattering measurements and also with CDCC calculations. Energy dependent parametrisations are also obtained for total reaction cross sections of 6,7 Li on Si, as well as on any target, at near barrier energies

Sustainability and energy self-sufficiency; overcoming the barriers

Directory of Open Access Journals (Sweden)

Rania Abdel Galil

2015-12-01

Full Text Available Engendering more positive attitudes to renewable energy is by no means a simple feat. Renewable energy technologies are viewed as radical innovations which necessitate substantial changes in production and consumption patterns, hence often met with resistance from both institutions and individuals. Yet action is needed; global energy consumption is expected to rise by 41% and global carbon dioxide emissions by 29%, with most of the demand and rise coming from emerging economies (BP energy outlook 2035. Further, countries need to meet objectives of reduction of GHG under the United Nations Framework Convention on Climate Change. Renewable energy share in the global energy mix needs to significantly increase in order to reach supply sufficiency, energy security, energy equity and environmental sustainability.Meeting demands of energy is critical for the economic and social development of any country; energy must be secure, accessible and affordable at all levels of society, and any negative impact of energy production and energy use on the environment must be minimized. Middle East energy consumption is expected to grow by 69% whilst production to grow by 32%, with 97% of demand still met by fossil fuels by the end of the 2035. Energy investment of $316 billion will be required in the Middle East and North Africa (MENA between 2015 and 2019 to meet its growing demand for power (Apicorp, 2014. Diversifying energy sources is indeed of interest in the MENA region, spurred by growing demand for power and desalinated water, fluctuating fuel price, GHG emission reduction targets, depleting fossil fuel reserves and advances in renewable energy technology. However, there are many barriers that hinder the adoption of renewable energy technologies worldwide, but more so in the MENA region. These barriers are political, economic, social and technological. With a focus on Europe and MENA, it can be said that these barriers have much in common albeit framing

Improving energy efficiency in industrial energy systems an interdisciplinary perspective on barriers, energy audits, energy management, policies, and programs

CERN Document Server

Thollander, Patrik

2012-01-01

Industrial energy efficiency is one of the most important means of reducing the threat of increased global warming. Research however states that despite the existence of numerous technical energy efficiency measures, its deployment is hindered by the existence of various barriers to energy efficiency. The complexity of increasing energy efficiency in manufacturing industry calls for an interdisciplinary approach to the issue. Improving energy efficiency in industrial energy systems applies an interdisciplinary perspective in examining energy efficiency in industrial energy systems, and discuss

How does incomplete fusion show up at slightly above barrier energies?

Directory of Open Access Journals (Sweden)

Prasad R.

2012-02-01

Full Text Available Experimental results on the onset of incomplete fusion at slightly above barrier energies are discussed in this paper. Spin-distributions of evaporation residues populated via complete and/or incomplete fusion of 12C,16O (Elab ≈ 4–7 MeV with 169Tm have been measured to probe associated ℓ–values. Particle (Z=1,2 – γ – coincidence technique has been used for channel selection. Entirely different entry state spin populations have been observed during the de-excitation of complete and incomplete composites. The complete fusion residues are found to be strongly fed over a broad spin range. While, a narrow range feeding for only high spin states has been observed in case of incomplete fusion residues. In the present work, incomplete fusion is shown to be a promising tool to populate high spin states in final reaction products. For better insight into the onset and strength of incomplete fusion, the relative contributions of complete and incomplete fusion have been deduced from the analysis of excitation functions and forward recoil ranges. A significant fraction of ICF has been observed even at energy as low as ≈ 7% above the barrier. The relative strengths of complete and incomplete fusion deduced from the analysis of forward-recoil-ranges and excitation functions complement each other. All the available results are discussed in light of the Morgenstern’s mass-asymmetry systematics. Incomplete fusion fraction is found to be large for more mass-asymmetric systems for individual projectiles, which points towards the projectile structure effect on incomplete fusion fraction. Experimentally measured forward ranges of recoils complement the existence of incomplete fusion at slightly above barrier energies, where more than one linear-momentum-transfer components associated with full- and/or partial-fusion of projectile(s have been observed. Present results conclusively demonstrate the possibility to selectively populate high spin states

Migration energy barriers of symmetric tilt grain boundaries in body-centered cubic metal Fe

International Nuclear Information System (INIS)

Wu, Minghui; Gu, Jianfeng; Jin, Zhaohui

2015-01-01

Graphical abstract: DFT calculated migration energy barrier (left) for symmetric grain boundary in metals is an essential physical property to measure the trend of grain boundary migration, in particular, in terms of the classical homogeneous nucleation model of GB dislocation/disconnection loops (right). - Migration energy barriers of two symmetric tilt grain boundaries in body-centered cubic metal Fe are obtained via first-principles calculations in combination with the nudged elastic band methods. Although the two grain boundaries show similar grain boundary energies, the migration energy barriers are different. Based on a homogeneous nucleation theory of grain-boundary dislocation loops, the calculated energy barrier provides a measure of intrinsic grain-boundary mobility and helps to evaluate effects due to vacancy and interstitial atoms such as carbon

Market failures and barriers as a basis for clean energy policies

International Nuclear Information System (INIS)

Brown, M.A.

2001-01-01

This paper provides compelling evidence that large-scale market failures and barriers prevent consumers in the United States from obtaining energy services at least cost. Assessments of numerous energy policies and programs suggest that public interventions can overcome many of these market obstacles. By articulating these barriers and reviewing the literature on ways of addressing them, this paper provides a strong justification for the policy portfolios that define the ''Scenarios for a Clean Energy Future'', a study conducted by five National Laboratories. These scenarios are described in other papers published in this special issue of Energy Policy. (author)

Energy barriers for diffusion on heterogeneous stepped metal surfaces: Ag/Cu(110)

International Nuclear Information System (INIS)

Sbiaai, K.; Boughaleb, Y.; Mazroui, M.; Hajjaji, A.; Kara, A.

2013-01-01

In this paper we investigated the diffusion of Ag adatom by computing the energy barriers for many elementary diffusive processes which are likely to happen near to the step edge on Cu (110). The barriers are calculated by means of molecular dynamics simulation by using embedded atom potentials. The proximity to steps alters these barriers considerably, and very different results may be expected. In fact, our numerical calculations show that the diffusion via jump process along step edge is predominant for Ag/Cu(110) and the diffusion over the step occurs sometimes, but only via exchange mechanisms. The adatom diffusion across channels is difficult due to the high value of activation energy required (around 1 eV). Furthermore, we found the Ehrlich–Schwoebel barrier for diffusion around 120 meV in order to descend via exchange process and of the order of 170 meV via hopping mode. This aspect may have a strong influence on the growth character. In general our results suggest that, for our metal system, diffusion mechanism may be important for mass transport across the steps. Implications of these findings are discussed. - Highlights: • Study of adatom diffusion near the step edge • The diffusion along channel is enhanced through jump process. • Arrhenius law is satisfied for a wide range of temperature (310–600 K)

Barriers to Energy Efficiency in Swedish Non-Energy-Intensive Micro- and Small-Sized Enterprises—A Case Study of a Local Energy Program

Directory of Open Access Journals (Sweden)

Fredrik Backman

2017-01-01

Full Text Available Improved energy efficiency has become a strategic issue and represents a priority for European competitiveness. Countries adopt various energy policies on local and national levels where energy audit programs are the most common energy end-use efficiency policy for industrial small- and medium-sized enterprises (SMEs. However, studies indicate that cost-efficient energy conservation measures are not always implemented, which can be explained by the existence of barriers to energy efficiency. This paper investigates how Swedish municipalities can support local micro- and small-sized enterprises with improved energy efficiency and the existence of different barriers to the implementation of energy efficiency. Relating this empirical case study to the theoretical barriers outlined in the text, this study found that the major explanatory factors related to non-implementation of cost-effective energy efficiency measures among micro- and small-sized industrial enterprises were bounded rationality (lack of time and/or other priorities, split incentives (having other priorities for capital investments, and imperfect information (slim organization and lack of technical skill. This study also found that information in the form of a report was the main thing that companies gained from working on the project “Energy-Driven Business”. Notably, the study involved companies that had participated in a local energy program and, still, companies face major barriers inhibiting implementation, indicating a need to further study other alternative policy models and how knowledge transfer can be improved.

Barriers and Potential Solutions for Energy Renovation of Buildings in Denmark

Directory of Open Access Journals (Sweden)

Niels I. Meyer

2014-02-01

Full Text Available Buildings account for a substantial part of the total energy consumption. In Denmark this number is about 40 % and this is approximately the same in most industrial countries. On this background there is an urgent need to develop strategies for reducing the energy demand in the building sector. Renovation of existing buildings must have high priority as houses often last for 50 to 100 years, while the time perspective for the desired transformation to low-energy houses is less than 30 years in order to mitigate global warming and avoid irreversible tipping-points. The only sustainable energy supply in the perspective of centuries is renewable energy provided by the sun and exploited in the form of solar heat, solar electricity (PVs, wind power, hydropower, wave power, and some types of biomass etc. A future dominating role of intermittent renewable sources requires new integrated systems thinking on both the supply and demand side for heat, electricity and transport. Implementing such Smart Energy Systems requires integrated strategic energy planning on the national and local level. With the fundamental changes in the energy supply technologies expected during the coming years, it is important to synchronize investments in energy conservation measures with investments in the supply side, in order to avoid overinvestment in supply systems and thus to minimize the total costs of the transformation to Smart Energy Systems. This paper highlights some of the most important barriers for renovation of existing buildings in Denmark and points to policies for overcoming these barriers. Some of the policies have been presented in the reports of a recent Danish research project (CEESA

Barriers to the adoption of energy-saving technologies in the building sector: A survey study of Jing-jin-tang, China

International Nuclear Information System (INIS)

Du, Ping; Zheng, Li-Qun; Xie, Bai-Chen; Mahalingam, Arjun

2014-01-01

The building sector of China currently consumes 20% of the total energy consumption. Studies on barriers to the adoption of building energy-saving technologies are of great significance on implementing policies related to achieving energy-saving goals. This paper studied 15 barriers with the aid of information collected through questionnaires and semi-structured interviews. The respondents were 135 employees working in the Jing-jin-tang area. Based on the results of the factor analysis, the barriers were categorized into five groups: attitudes of stakeholders, policies and regulations, auxiliary resources, profitability, and adaptability of the technologies. Analysis of the entire sample showed that the stakeholders’ reluctance to use was the largest barrier, followed by high initial investment and low profitability. Further analysis showed that the occupation and designation of the respondents and the size of the enterprises that they served influenced their perspectives on the barriers. It was found that architects attributed more importance to the adoption of energy-saving technologies than contractors; barriers confronted by employees of large enterprises and small enterprises were different; managers perceived weaker barriers than frontline employees and were more optimistic about the prospect of building energy-saving technologies. Finally, policy recommendations were proposed based on these in-depth and targeted analyses. - Highlights: • Fifteen barriers to the adoption of energy-saving technologies are discussed. • Surveys are conducted in one of China's most technologically developed area. • The barriers are divided into 5 groups according to the results of factor analysis. • Barriers related to profitability greatly hamper the adoption of the technologies. • Comparative analyses show the background of respondents influence their viewpoints

Institutional distributed energy interconnection barriers

International Nuclear Information System (INIS)

Castelaz, S.A.

2002-01-01

This PowerPoint presentation provided an introduction to Encorp Inc., a leading provider of network technology and infrastructure management solutions for the distributed energy market. Encorp develops and markets software and hardware technology solutions for communications, control and networking of distributed energy. It is developing and implementing real-time, distributed energy-focused solutions for a wide variety of applications through new products and services which are technology neutral, and easily networked. Encorp controls more than 500 MW of distributed power with a total of 127 customers. This paper reviewed 3 barriers (regulatory, contractual/tariffs, and business practices) based on US experience. The challenge remaining is to determine if microgrids can be used effectively, and to determine the limitations of bi-directional power flows. The key issues regarding how end-users can share the costs and maximize on the benefits of distributed energy resources include: standby service charges, departing load charges, regulatory uncertainty, rate class degradation, lack of incentives for utility cost reduction, and lack of ability to create experimental tariffs. tabs., figs

Free energy barriers to evaporation of water in hydrophobic confinement.

Science.gov (United States)

Sharma, Sumit; Debenedetti, Pablo G

2012-11-08

We use umbrella sampling Monte Carlo and forward and reverse forward flux sampling (FFS) simulation techniques to compute the free energy barriers to evaporation of water confined between two hydrophobic surfaces separated by nanoscopic gaps, as a function of the gap width, at 1 bar and 298 K. The evaporation mechanism for small (1 × 1 nm(2)) surfaces is found to be fundamentally different from that for large (3 × 3 nm(2)) surfaces. In the latter case, the evaporation proceeds via the formation of a gap-spanning tubular cavity. The 1 × 1 nm(2) surfaces, in contrast, are too small to accommodate a stable vapor cavity. Accordingly, the associated free energy barriers correspond to the formation of a critical-sized cavity for sufficiently large confining surfaces, and to complete emptying of the gap region for small confining surfaces. The free energy barriers to evaporation were found to be of O(20kT) for 14 Å gaps, and to increase by approximately ~5kT with every 1 Å increase in the gap width. The entropy contribution to the free energy of evaporation was found to be independent of the gap width.

Energy education: breaking up the rational energy use barriers

International Nuclear Information System (INIS)

Dias, R.A.; Mattos, C.R.; Balestieri, J.A.P.

2004-01-01

Human development is associated directly or indirectly with the energy use, and because of this the energetic sources were dealt with in the recent past, as fully available to human necessities. The reality shows that the energy availability, considering the non-renewable sources, is limited, and beyond that, the exploration, the processing and the use of energy impose considerable impacts on the environment. There is not a system which operates with no losses and without imposing changes to the environment. Therefore, the energy conservation incorporates the concepts and the actions applied to the research of sustainable balance between nature and the energy availability and use. Such actions can be presented both in the short term, in which the energy system is close to a collapse, or in the medium/long term, in which those responsible for the energy policies are concerned with the structure of the socio-economic development. Such a situation requires more responsibility in the treatment of energy questions, mainly through education, which represents long-term investments. This paper discusses barriers that are present in the projects applied to energy conservation, by making clear that education is one of the best ways to transform the human behavior in for the rational use of energy

Deep inelastic collisions at near-barrier energies and search for cold donor-fragment production

International Nuclear Information System (INIS)

Chatterjee, M.B.

1992-01-01

Deep inelastic collisions in the near barrier energies of the mass asymmetric systems are of importance since controversial results on energy partition are being reported. Energy dissipation and the partition of dissipated energy among the reaction partners are of interest. Search for cold donor-fragment production at near barrier energies were carried out on a mass asymmetric system like Ni+Pb. (author). 13 refs., 8 figs

Stability of trans-fermium elements at high spin: Measuring the fission barrier of 254No

International Nuclear Information System (INIS)

Henning, Greg

2012-01-01

Super heavy nuclei provide opportunities to study nuclear structure near three simultaneous limits: in charge Z, spin I and excitation energy E*. These nuclei exist only because of a fission barrier, created by shell effects. It is therefore important to determine the fission barrier and its spin dependence B f (I), which gives information on the shell energy E(shell)(I). Theoretical calculations predict different fission barrier heights from B f (I = 0) = 6.8 MeV for a macro-microscopic model to 8.7 MeV for Density Functional Theory calculations using the Gogny or Skyrme interactions. Hence, a measurement of B f provides a test for theories.To investigate the fission barrier, an established method is to measure the rise of fission with excitation energy, characterized by the ratio of decay widths Γ(fission)/Γ(total), using transfer reactions. However, for heavy elements such as 254 No, there is no suitable target for a transfer reaction. We therefore rely on the complementary decay widths ratio Γ γ /Γ(fission) and its spin dependence, deduced from the entry distribution (I, E*).Measurements of the gamma-ray multiplicity and total energy for 254 No have been performed with beam energies of 219 and 223 MeV in the reaction 208 Pb( 48 Ca,2n) at ATLAS (Argonne Tandem Linac Accelerator System). The 254 No gamma rays were detected using the Gammasphere array as a calorimeter - as well as the usual high resolution γ-ray detector. Coincidences with evaporation residues at the Fragment Mass Analyzer focal plane separated 254 No gamma rays from those from fission fragments, which are ≥ 10 6 more intense. From this measurement, the entry distribution - i.e. the initial distribution of I and E* - is constructed. Each point (I,E*) of the entry distribution is a point where gamma decay wins over fission and, therefore, gives information on the fission barrier. The measured entry distributions show an increase in the maximum spin and excitation energy from 219 to 223 Me

Barriers to the adoption of energy-conserving technologies in the textile industry

Energy Technology Data Exchange (ETDEWEB)

Evans, A.R.; Zussman, S.K.

1979-09-01

An overview of the textile industry and a discussion of energy-conserving technologies currently available at the pilot-demonstration stage are presented. Existing and potential barriers to the adoption of these technologies in the textile industry identified are: economic; technical acceptance; conflict between commitments of capital for compliance with environmental and health regulations and for investment in energy conservation measures; and a lack of information and technical expertise. Possible measures to eliminate barriers to the implementation of energy-conserving technologies are discussed. (MCW)

Transition to distributed energy generation in Finland: Prospects and barriers

International Nuclear Information System (INIS)

Ruggiero, Salvatore; Varho, Vilja; Rikkonen, Pasi

2015-01-01

Small-scale distributed energy generation is expected to play an important role in helping Finland increase its energy self-sufficiency. However, the overall strategy to date for promoting distributed energy remains unclear. It is not yet well understood which factors promote the growth of the distributed energy sector and what barriers need to be removed. In this article we present the results of a questionnaire directed at a panel of 26 experts from the distributed energy value chain and 15 semi-structured interviews with industry and non-industry representatives. We investigated, from a sociotechnical transition perspective, the possibilities and challenges of the transition to distributed energy in Finland through 2025. The results show that a shift to a prosperous future for distributed energy is possible if permit procedures, ease of grid connection, and taxation laws are improved in the electricity sector and new business concepts are introduced in the heat sector. In contrast to other European countries, the transition in Finland is expected to take place through a market-based approach favoring investment-focused measures. We conclude that incentive-based schemes alone, whatever they may be, will be insufficient to create significant growth in Finland without institutional change, removal of barriers, and the engagement of key actors. - Highlights: • We examine the possibilities and challenges of the transition to DE in Finland. • Technological niches are emerging both in the heat and electricity sector. • Business model innovation is evident only in the electricity sector. • Removing barriers and developing new business models will accelerate the transition.

Critical energy barrier for capillary condensation in mesopores: Hysteresis and reversibility

International Nuclear Information System (INIS)

Hiratsuka, Tatsumasa; Tanaka, Hideki; Miyahara, Minoru T.

2016-01-01

Capillary condensation in the regime of developing hysteresis occurs at a vapor pressure, P cond , that is less than that of the vapor-like spinodal. This is because the energy barrier for the vapor-liquid transition from a metastable state at P cond becomes equal to the energy fluctuation of the system; however, a detailed mechanism of the spontaneous transition has not been acquired even through extensive experimental and simulation studies. We therefore construct accurate atomistic silica mesopore models for MCM-41 and perform molecular simulations (gauge cell Monte Carlo and grand canonical Monte Carlo) for argon adsorption on the models at subcritical temperatures. A careful comparison between the simulation and experiment reveals that the energy barrier for the capillary condensation has a critical dimensionless value, W c * = 0.175, which corresponds to the thermal fluctuation of the system and depends neither on the mesopore size nor on the temperature. We show that the critical energy barrier W c * controls the capillary condensation pressure P cond and also determines a boundary between the reversible condensation/evaporation regime and the developing hysteresis regime.

Critical energy barrier for capillary condensation in mesopores: Hysteresis and reversibility

Science.gov (United States)

Hiratsuka, Tatsumasa; Tanaka, Hideki; Miyahara, Minoru T.

2016-04-01

Capillary condensation in the regime of developing hysteresis occurs at a vapor pressure, Pcond, that is less than that of the vapor-like spinodal. This is because the energy barrier for the vapor-liquid transition from a metastable state at Pcond becomes equal to the energy fluctuation of the system; however, a detailed mechanism of the spontaneous transition has not been acquired even through extensive experimental and simulation studies. We therefore construct accurate atomistic silica mesopore models for MCM-41 and perform molecular simulations (gauge cell Monte Carlo and grand canonical Monte Carlo) for argon adsorption on the models at subcritical temperatures. A careful comparison between the simulation and experiment reveals that the energy barrier for the capillary condensation has a critical dimensionless value, Wc* = 0.175, which corresponds to the thermal fluctuation of the system and depends neither on the mesopore size nor on the temperature. We show that the critical energy barrier Wc* controls the capillary condensation pressure Pcond and also determines a boundary between the reversible condensation/evaporation regime and the developing hysteresis regime.

Barriers to energy efficiency in shipping: A triangulated approach to investigate the principal agent problem

International Nuclear Information System (INIS)

Rehmatulla, Nishatabbas; Smith, Tristan

2015-01-01

Energy efficiency is a key policy strategy to meet some of the challenges being faced today and to plan for a sustainable future. Numerous empirical studies in various sectors suggest that there are cost-effective measures that are available but not always implemented due to existence of barriers to energy efficiency. Several cost-effective energy efficient options (technologies for new and existing ships and operations) have also been identified for improving energy efficiency of ships. This paper is one of the first to empirically investigate barriers to energy efficiency in the shipping industry using a novel framework and multidisciplinary methods to gauge implementation of cost-effective measures, perception on barriers and observations of barriers. It draws on findings of a survey conducted of shipping companies, content analysis of shipping contracts and analysis of energy efficiency data. Initial results from these methods suggest the existence of the principal agent problem and other market failures and barriers that have also been suggested in other sectors and industries. Given this finding, policies to improve implementation of energy efficiency in shipping need to be carefully considered to improve their efficacy and avoid unintended consequences. -- Highlights: •We provide the first analysis of the principal agent problem in shipping. •We develop a framework that incorporates methodological triangulation. •Our results show the extent to which this barrier is observed and perceived. •The presence of the barrier has implications on the policy most suited to shipping

Reducing Barriers To The Use of High-Efficiency Lighting Systems

Energy Technology Data Exchange (ETDEWEB)

Peter Morante

2005-12-31

With funding from the U.S. Department of Energy (DOE), the Lighting Research Center (LRC) at Rensselaer Polytechnic Institute completed the four-year research project, Reducing Barriers to the Use of High-Efficiency Lighting Systems. The initial objectives were: (1) identifying barriers to widespread penetration of lighting controls in commercial/industrial (C/I) applications that employ fluorescent lamp technologies, and (2) making recommendations to overcome these barriers. The addition of a fourth year expanded the original project objectives to include an examination of the impact on fluorescent lamps from dimming utilizing different lamp electrode heating and dimming ratios. The scope of the project was narrowed to identify barriers to the penetration of lighting controls into commercial-industrial (C/I) applications that employ fluorescent lamp technologies, and to recommend means for overcoming these barriers. Working with lighting manufacturers, specifiers, and installers, the project identified technological and marketing barriers to the widespread use of lighting controls, specifically automatic-off controls, occupancy sensors, photosensors, dimming systems, communication protocols and load-shedding ballasts. The primary barriers identified include cost effectiveness of lighting controls to the building owner, lack of standard communication protocols to allow different part of the control system to communicate effectively, and installation and commissioning issues. Overcoming the identified barriers requires lighting control products on the market to achieve three main goals: (1) Achieve sufficient functionality to meet the key requirements of their main market. (2) Allow significant cost reduction compared to current market standard systems. Cost should consider: hardware capital cost including wiring, design time required by the specifier and the control system manufacturer, installation time required by the electrician, and commissioning time and

Use of a silicon surface-barrier detector for measurement of high-energy end loss electrons in a tandem mirror

International Nuclear Information System (INIS)

Saito, T.; Kiwamoto, Y.; Honda, T.; Kasugai, A.; Kurihara, K.; Miyoshi, S.

1991-01-01

An apparatus for the measurement of high-energy electrons (10--500 keV) with a silicon surface-barrier detector is described. The apparatus has special features. In particular, a fast CAMAC transient digitizer is used to directly record the wave form of a pulse train from the detector and then pulse heights are analyzed with a computer instead of on a conventional pulse height analyzer. With this method the system is capable of detecting electrons with a count rate as high as ∼300--400 kilocounts/s without serious deterioration of performance. Moreover, piled up signals are reliably eliminated from analysis. The system has been applied to measure electron-cyclotron-resonance-heating-induced end loss electrons in the GAMMA 10 tandem mirror and has yielded information relating to electron heating and diffusion in velocity space

Capabilities of silicon Shottki barriers and planar detectors in low-energy proton spectometry

Energy Technology Data Exchange (ETDEWEB)

Verbitskaya, E M; Eremin, V K; Malyarenko, A M; Sakharov, V I; Serenkov, I T; Strokan, N B; Sukhanov, V L

1987-05-12

Dependence of the resolution of surface barrier and planar diffusion silicon detectors on proton energy is investigated. The experiment was conducted at the device, representing the double mass spectrometer with the maximal energy of single-charged ions up to 200 keV. Two advantages of using planar diffusion detectors for light low-energy ion spectrometry is established: high energy resolution and independence of signal amplitude of bias voltage. Background noise represents the main factor dictaiting resolution, but fluctuations of losses in input window are sufficient as well. It was concluded that planar detector application for spectrometry of protons with energy of less than 200 keV would improve the resolution up to 2.2 keV without detector cooling.

Potential and barrier study. Energy efficiency in Norwegian vocational buildings; Potensial- og barrierestudie. Energieffektivisering i norske yrkesbygg

Energy Technology Data Exchange (ETDEWEB)

Boehn, Trond Ivar; Palm, Linn Therese; Bakken, Line; Nossum, Aase; Jordell, Hanne

2012-07-01

On behalf of Enova SF, Multiconsult AS and Analyse og Strategi AS conducted an analysis to identify potential and barriers related to commercial buildings energy performance. The aim of this study was to determine what is the potential for energy efficiency for Norwegian vocational buildings that distinguishes between theoretical, technical, financial and real potential. Technical potential is the percentage of the theoretical potential that is technically feasible. Economic potential is the proportion of technical potential that is economically profitable to implement. Economic potential varies with the energy price. Build a small part of the total potential in 2020. In the calculation of the real potential is taken into account induced potential in terms of that, each year, a percentage actually implementing energy conservation measures (energy efficiency ratio 2%), a percentage rehabilitating / upgrading existing buildings (rehab rate 1.5%), and that a proportion of new buildings built better than regulatory requirements (rate 10%). In real potential for energy efficiency is the proportion of the economic potential that is not natural triggered but which is limited by various barriers. In real potential also varies with energy price. Respondents in our study is particularly concerned with the economic barriers, and least concerned the technical barriers. Attitudes and knowledge barriers are also very important. Lack of knowledge the effects and benefits of energy efficiency means that negative attitudes persist and that myths about the lack of profitability continues to exist. Many believe this is due to lack the knowledge and can be the cause of other types of barriers such as economic barriers. It has been analyzed which part of the real potential bounded by the barriers, and which type of institutions in society that can reduce these barriers with various categories of instrument. Main barriers for existing buildings practical barriers, economic barriers and

Identifying barriers to aboriginal renewable energy deployment in Canada

International Nuclear Information System (INIS)

Krupa, Joel

2012-01-01

As one of the largest and wealthiest countries in the world, Canada stands well-positioned to take advantage of ongoing growth in North American demand for primary energy supply by expanding domestic delivery of renewable energy generation to internationally interconnected electric grids across the country. There are myriad benefits of adopting the renewable energy approach to development—as the province of Ontario has acknowledged through the implementation of their 2009 Green Energy Act—including drastic reductions in carbon emissions, the decommissioning of existing fossil fuel power generation that cause serious public health problems, and opportunities for sustainable development at the community level. One group in particular stands poised to shape these debates. In Canada, historically marginalized Aboriginal peoples remain one of the groups with the greatest potential for meeting these enormous renewable energy deployment needs. Aboriginal involvement in renewable energy generation in Canada has been as diverse as Canada's Aboriginal peoples and groups have already adopted a range of different solutions to meet energy supply needs. However, many significant barriers exist that prevent this diverse cultural group from reaching its full potential. The article identifies some of these shortcomings and analyzes their roots. - Highlights: ► Renewable energy is one of the most important sustainable development opportunities today. ► Aboriginal-led renewable development could dramatically increase Canadian supply. ► Surmountable barriers are identified.

Identifying barriers in the diffusion of renewable energy sources

International Nuclear Information System (INIS)

Eleftheriadis, Iordanis M.; Anagnostopoulou, Evgenia G.

2015-01-01

Rapid diffusion of renewable energy sources (RES) in the electricity power sector is crucial if the EU wants to fulfill its 2050 CO 2 reduction commitments. For this reason, identifying and alleviating all barriers that hinder the development of RES is necessary to the successful deployment of these technologies. This paper discusses the main barriers in the diffusion of wind and photovoltaic (PV) solar power in the Greek electricity sector by drawing on the literature of technological innovation systems and system functions. Furthermore, we provide an explanation of the different diffusion rates between the two technologies. Inadequate financial resources, low grid capacity, delays in the issuance of building permits, opposition from local communities to the construction of wind farms and the lack of a stable institutional framework are among the most important barriers that inhibit the diffusion of the wind and PV solar power. The nature of the barriers identified in this study calls for policy intervention. - Highlights: • Firms in the Greek wind and solar power sectors assess RES barriers. • Lack of financial resources is the most important RES barrier. • Lack of a stable institutional framework negatively affects RES deployment. • The support of the public sector is crucial to the diffusion of RES. •Wind power faces strong legitimization barriers

Controlling Schottky energy barriers in organic electronic devices using self-assembled monolayers

Science.gov (United States)

Campbell, I. H.; Rubin, S.; Zawodzinski, T. A.; Kress, J. D.; Martin, R. L.; Smith, D. L.; Barashkov, N. N.; Ferraris, J. P.

1996-11-01

We demonstrate tuning of Schottky energy barriers in organic electronic devices by utilizing chemically tailored electrodes. The Schottky energy barrier of Ag on poly[2-methoxy, 5-(2'-ethyl-hexyloxy)- 1,4-phenylene was tuned over a range of more than 1 eV by using self-assembled monolayers (SAM's) to attach oriented dipole layers to the Ag prior to device fabrication. Kelvin probe measurements were used to determine the effect of the SAM's on the Ag surface potential. Ab initio Hartree-Fock calculations of the molecular dipole moments successfully describe the surface potential changes. The chemically tailored electrodes were then incorporated in organic diode structures and changes in the metal/organic Schottky energy barriers were measured using an electroabsorption technique. These results demonstrate the use of self-assembled monolayers to control metal/organic interfacial electronic properties. They establish a physical principle for manipulating the relative energy levels between two materials and demonstrate an approach to improve metal/organic contacts in organic electronic devices.

E4 - Energy efficient elevators and escalators. Barriers to and strategies for promoting energy-efficient lift and escalator technologies

Energy Technology Data Exchange (ETDEWEB)

Duetschke, Elisabeth; Hirzel, Simon

2010-02-25

According to prior findings of the E4 project, considerable savings potential exists both for lifts and escalators that could be realized if appropriate technology is implemented. However, energy-efficient technology is slowly diffusing the market - a phenomenon that could be explained by barriers present in the market. A barrier is defined as a mechanism that inhibits a decision or behavior that appears to be both energy-efficient and economically efficient and thereby prevents investment in energy-efficient technologies. This document has two aims. First, it will identify influential barriers in the European lift and escalator market. This analysis is based on the literature as well as a study including interviews as well as group discussions with relevant stakeholders. Second, strategies and measures to overcome the barriers identified in the first step are outlined. Major barriers to the penetration of energy-efficient technologies identified in this paper include a lack of monitoring energy consumption of installations and a lack of awareness of as well as knowledge about energy-efficient technology. Thus, installations and components are usually chosen without a (comprehensive) assessment of their energy consumption and without considering life-cycle approaches. On top of this, split incentives are a regularly occurring barrier. Various stakeholders are influential in the decisionmaking process about an installation or its components. However, those who will later pay for the energy consumption often are not involved in this process. Moreover, it is important to keep in mind that the number of new lifts and escalators installed each year is relatively low compared to the existing stock. Thus, it is very important to discuss enhancement of energy efficiency also for the existing stock. Based on our analyses, several recommendations are developed in this paper that could contribute to a market transformation in the lift and escalator market. First of all, a

Magnetization reversal processes of single nanomagnets and their energy barrier

International Nuclear Information System (INIS)

Krone, P.; Makarov, D.; Albrecht, M.; Schrefl, T.; Suess, D.

2010-01-01

Micromagnetic simulations were performed to investigate the influence of geometry and magnetic anisotropy constant on energy barrier and magnetization reversal mechanism of individual bits important for the bit patterned media concept in magnetic data storage. It is shown that dependency of the energy barrier on magnetic and geometric properties of bits can be described by an analytical approach in the case of quasi-coherent magnetization rotation process. However, when the bit size exceeds a critical size, for which an incoherent magnetization reversal is preferred, the analytical approach becomes invalid and no self-consistent theory is available. By systematically investigating the influence of bit size on the magnetization reversal mode, it was found that the transition from quasi-coherent to incoherent magnetization reversal mode can still be described analytically if an activation volume is considered instead of the bit volume. In this case, the nucleation volume is an important parameter determining thermal stability of the bit. If the volume of the bit is larger than twice the activation volume, the energy barrier stays nearly constant; with further increase in bit size, no gain in thermal stability can be achieved.

Direct measurement of free-energy barrier to nucleation of crystallites in amorphous silicon thin films

Science.gov (United States)

Shi, Frank G.

1994-01-01

A method is introduced to measure the free-energy barrier W(sup *), the activation energy, and activation entropy to nucleation of crystallites in amorphous solids, independent of the energy barrier to growth. The method allows one to determine the temperature dependence of W(sup *), and the effect of the preparation conditions of the initial amorphous phase, the dopants, and the crystallization methds on W(sup *). The method is applied to determine the free-energy barrier to nucleation of crystallites in amorphous silicon (a-Si) thin films. For thermally induced nucleation in a-Si thin films with annealing temperatures in the range of from 824 to 983 K, the free-energy barrier W(sup *) to nucleation of silicon crystals is about 2.0 - 2.1 eV regardless of the preparation conditions of the films. The observation supports the idea that a-Si transforms into an intermediate amorphous state through the structural relaxation prior to the onset of nucleation of crystallites in a-Si. The observation also indicates that the activation entropy may be an insignificant part of the free-energy barrier for the nucleation of crystallites in a-Si. Compared with the free-energy barrier to nucleation of crystallites in undoped a-Si films, a significant reduction is observed in the free-energy barrier to nucleation in Cu-doped a-Si films. For a-Si under irradiation of Xe(2+) at 10(exp 5) eV, the free-energy barrier to ion-induced nucleation of crystallites is shown to be about half of the value associated with thermal-induced nucleation of crystallites in a-Si under the otherwise same conditions, which is much more significant than previously expected. The present method has a general kinetic basis; it thus should be equally applicable to nucleation of crystallites in any amorphous elemental semiconductors and semiconductor alloys, metallic and polymeric glasses, and to nucleation of crystallites in melts and solutions.

Barriers to investments in energy saving technologies. Case study for the industry

NARCIS (Netherlands)

Masselink, Dirk Jan

2007-01-01

To realise future energy saving targets, the government needs to increase energy reduction rates. One option to increase energy savings is found in removing barriers to investments in cost-effective energy saving technologies. Many technologies save energ

Renewable Energy Permitting Barriers in Hawaii: Experience from the Field

Energy Technology Data Exchange (ETDEWEB)

Busche, S.; Donnelly, C.; Atkins, D.; Fields, R.; Black, C.

2013-03-01

This white paper presents a summary of the solicited input from permitting agencies and renewable energy developers on the permitting process in Hawaii to provide stakeholders in Hawaii, particularly those involved in permitting, with information on current permitting barriers that renewable energy developers are experiencing.

Barriers to Building Energy Efficiency (BEE) promotion: A transaction costs perspective

Science.gov (United States)

Qian Kun, Queena

Worldwide, buildings account for a surprisingly high 40% of global energy consumption, and the resulting carbon footprint significantly exceeds that of all forms of transportation combined. Large and attractive opportunities exist to reduce buildings' energy use at lower costs and higher returns than in other sectors. This thesis analyzes the concerns of the market stakeholders, mainly real estate developers and end-users, in terms of transaction costs as they make decisions about investing in Building Energy Efficiency (BEE). It provides a detailed analysis of the current situation and future prospects for BEE adoption by the market's stakeholders. It delineates the market and lays out the economic and institutional barriers to the large-scale deployment of energy-efficient building techniques. The aim of this research is to investigate the barriers raised by transaction costs that hinder market stakeholders from investing in BEES. It explains interactions among stakeholders in general and in the specific case of Hong Kong as they consider transaction costs. It focuses on the influence of transaction costs on the decision-making of the stakeholders during the entire process of real estate development. The objectives are: 1) To establish an analytical framework for understanding the barriers to BEE investment with consideration of transaction costs; 2) To build a theoretical game model of decision making among the BEE market stakeholders; 3) To study the empirical data from questionnaire surveys of building designers and from focused interviews with real estate developers in Hong Kong; 4) To triangulate the study's empirical findings with those of the theoretical model and analytical framework. The study shows that a coherent institutional framework needs to be established to ensure that the design and implementation of BEE policies acknowledge the concerns of market stakeholders by taking transaction costs into consideration. Regulatory and incentive options

Barriers to energy efficiency improvement. Empirical evidence from small-and-medium-sized enterprises in China

Energy Technology Data Exchange (ETDEWEB)

Kostka, Genia; Moslener, Ulf; Andreas, Jan G.

2012-07-01

This paper analyzes barriers for energy efficiency investments for small-and medium-sized enterprises (SMEs) in China. Based on a survey of 480 SMEs in Zhejiang Province, this study assesses financial, informational, and organizational barriers for energy efficiency investments in the SME sector. The conventional view has been that the lack of appropriate financing mechanisms particularly hinders SMEs to adopt cost-effective energy efficiency measures. As such, closing the financing gap for SMEs is seen as a prerequisite in order to promote energy efficiency in the sector. The econometric estimates of this study, however, suggest that access to information is an important determinant of investment outcomes, while this is less clear with respect to financial and organizational factors. More than 40 percent of enterprises in the sample declared that that they are not aware of energy saving equipments or practices in their respective business area, indicating that there are high transaction costs for SMEs to gather, assess, and apply information about energy saving potentials and relevant technologies. One implication is that the Chinese government may assume an active role in fostering the dissemination of energy-efficiency related information in the SME sector. (orig.)

Identifying and prioritizing barriers to implementation of smart energy city projects in Europe: An empirical approach

International Nuclear Information System (INIS)

Mosannenzadeh, Farnaz; Di Nucci, Maria Rosaria; Vettorato, Daniele

2017-01-01

Successful implementation of smart energy city projects in Europe is crucial for a sustainable transition of urban energy systems and the improvement of quality of life for citizens. We aim to develop a systematic classification and analysis of the barriers hindering successful implementation of smart energy city projects. Through an empirical approach, we investigated 43 communities implementing smart and sustainable energy city projects under the Sixth and Seventh Framework Programmes of the European Union. Validated through literature review, we identified 35 barriers categorized in policy, administrative, legal, financial, market, environmental, technical, social, and information-and-awareness dimensions. We prioritized these barriers, using a novel multi-dimensional methodology that simultaneously analyses barriers based on frequency, level of impact, causal relationship among barriers, origin, and scale. The results indicate that the key barriers are lacking or fragmented political support on the long term at the policy level, and lack of good cooperation and acceptance among project partners, insufficient external financial support, lack of skilled and trained personnel, and fragmented ownership at the project level. The outcome of the research should aid policy-makers to better understand and prioritize implementation barriers to develop effective action and policy interventions towards more successful implementation of smart energy city projects. - Highlights: • A solid empirical study on the implementation of European smart energy city projects. • We found 35 barriers in nine dimensions; e.g. policy, legal, financial, and social. • We suggested a new multi-dimensional methodology to prioritize barriers. • Lacking or fragmented political support on the long term is a key barrier. • We provided insights for action for project coordinators and policy makers.

Energy Barriers and Hysteresis in Martensitic Phase Transformations

Science.gov (United States)

2008-08-01

glacial acetic acid (CH3COOH) and 10-15% perchloric acid (HCLO4) by volume, the cathode was stainless steel , the anode was stainless steel or Ti, the...Submitted to Acta Materialia Energy barriers and hysteresis in martensitic phase transformations Zhiyong Zhang, Richard D. James and Stefan Müller...hysteresis based on the growth from a small scale of fully developed austenite martensite needles. In this theory the energy of the transition layer plays a

A novel method for calculating the energy barriers for carbon diffusion in ferrite under heterogeneous stress

Science.gov (United States)

Tchitchekova, Deyana S.; Morthomas, Julien; Ribeiro, Fabienne; Ducher, Roland; Perez, Michel

2014-07-01

A novel method for accurate and efficient evaluation of the change in energy barriers for carbon diffusion in ferrite under heterogeneous stress is introduced. This method, called Linear Combination of Stress States, is based on the knowledge of the effects of simple stresses (uniaxial or shear) on these diffusion barriers. Then, it is assumed that the change in energy barriers under a complex stress can be expressed as a linear combination of these already known simple stress effects. The modifications of energy barriers by either uniaxial traction/compression and shear stress are determined by means of atomistic simulations with the Climbing Image-Nudge Elastic Band method and are stored as a set of functions. The results of this method are compared to the predictions of anisotropic elasticity theory. It is shown that, linear anisotropic elasticity fails to predict the correct energy barrier variation with stress (especially with shear stress) whereas the proposed method provides correct energy barrier variation for stresses up to ˜3 GPa. This study provides a basis for the development of multiscale models of diffusion under non-uniform stress.

A novel method for calculating the energy barriers for carbon diffusion in ferrite under heterogeneous stress

International Nuclear Information System (INIS)

Tchitchekova, Deyana S.; Morthomas, Julien; Perez, Michel; Ribeiro, Fabienne; Ducher, Roland

2014-01-01

A novel method for accurate and efficient evaluation of the change in energy barriers for carbon diffusion in ferrite under heterogeneous stress is introduced. This method, called Linear Combination of Stress States, is based on the knowledge of the effects of simple stresses (uniaxial or shear) on these diffusion barriers. Then, it is assumed that the change in energy barriers under a complex stress can be expressed as a linear combination of these already known simple stress effects. The modifications of energy barriers by either uniaxial traction/compression and shear stress are determined by means of atomistic simulations with the Climbing Image-Nudge Elastic Band method and are stored as a set of functions. The results of this method are compared to the predictions of anisotropic elasticity theory. It is shown that, linear anisotropic elasticity fails to predict the correct energy barrier variation with stress (especially with shear stress) whereas the proposed method provides correct energy barrier variation for stresses up to ∼3 GPa. This study provides a basis for the development of multiscale models of diffusion under non-uniform stress

A novel method for calculating the energy barriers for carbon diffusion in ferrite under heterogeneous stress

Energy Technology Data Exchange (ETDEWEB)

Tchitchekova, Deyana S. [IRSN, PSN, SEMIA, LPTM, Saint-Paul-Lez-Durance (France); Univ. Lyon, INSA Lyon, MATEIS, UMR CNRS 5510, Villeurbanne (France); Morthomas, Julien; Perez, Michel [Univ. Lyon, INSA Lyon, MATEIS, UMR CNRS 5510, Villeurbanne (France); Ribeiro, Fabienne [IRSN, PSN, SEMIA, LPTM, Saint-Paul-Lez-Durance (France); Ducher, Roland [IRSN, PSN, SAG, LETR, Saint-Paul-Lez-Durance (France)

2014-07-21

A novel method for accurate and efficient evaluation of the change in energy barriers for carbon diffusion in ferrite under heterogeneous stress is introduced. This method, called Linear Combination of Stress States, is based on the knowledge of the effects of simple stresses (uniaxial or shear) on these diffusion barriers. Then, it is assumed that the change in energy barriers under a complex stress can be expressed as a linear combination of these already known simple stress effects. The modifications of energy barriers by either uniaxial traction/compression and shear stress are determined by means of atomistic simulations with the Climbing Image-Nudge Elastic Band method and are stored as a set of functions. The results of this method are compared to the predictions of anisotropic elasticity theory. It is shown that, linear anisotropic elasticity fails to predict the correct energy barrier variation with stress (especially with shear stress) whereas the proposed method provides correct energy barrier variation for stresses up to ∼3 GPa. This study provides a basis for the development of multiscale models of diffusion under non-uniform stress.

11Li Breakup on 208 at energies around the Coulomb barrier.

Science.gov (United States)

Fernández-García, J P; Cubero, M; Rodríguez-Gallardo, M; Acosta, L; Alcorta, M; Alvarez, M A G; Borge, M J G; Buchmann, L; Diget, C A; Falou, H A; Fulton, B R; Fynbo, H O U; Galaviz, D; Gómez-Camacho, J; Kanungo, R; Lay, J A; Madurga, M; Martel, I; Moro, A M; Mukha, I; Nilsson, T; Sánchez-Benítez, A M; Shotter, A; Tengblad, O; Walden, P

2013-04-05

The inclusive breakup for the (11)Li + (208)Pb reaction at energies around the Coulomb barrier has been measured for the first time. A sizable yield of (9)Li following the (11)Li dissociation has been observed, even at energies well below the Coulomb barrier. Using the first-order semiclassical perturbation theory of Coulomb excitation it is shown that the breakup probability data measured at small angles can be used to extract effective breakup energy as well as the slope of B(E1) distribution close to the threshold. Four-body continuum-discretized coupled-channels calculations, including both nuclear and Coulomb couplings between the target and projectile to all orders, reproduce the measured inclusive breakup cross sections and support the presence of a dipole resonance in the (11)Li continuum at low excitation energy.

Testing Convergence of Different Free-Energy Methods in a Simple Analytical System with Hidden Barriers

Directory of Open Access Journals (Sweden)

S. Alexis Paz

2018-03-01

Full Text Available In this work, we study the influence of hidden barriers on the convergence behavior of three free-energy calculation methods: well-tempered metadynamics (WTMD, adaptive-biasing forces (ABF, and on-the-fly parameterization (OTFP. We construct a simple two-dimensional potential-energy surfaces (PES that allows for an exact analytical result for the free-energy in any one-dimensional order parameter. Then we chose different CV definitions and PES parameters to create three different systems with increasing sampling challenges. We find that all three methods are not greatly affected by the hidden-barriers in the simplest case considered. The adaptive sampling methods show faster sampling while the auxiliary high-friction requirement of OTFP makes it slower for this case. However, a slight change in the CV definition has a strong impact in the ABF and WTMD performance, illustrating the importance of choosing suitable collective variables.

Building energy efficiency for public hospitals and healthcare facilities in China: Barriers and drivers

International Nuclear Information System (INIS)

Wang, Tao; Li, Xiaodong; Liao, Pin-Chao; Fang, Dongping

2016-01-01

Maximizing energy efficiency within HHFs (hospitals and healthcare facilities) is a major challenge in the field of energy conservation. This paper studies the key barriers to the implementation of energy-efficient technologies in China's public HHFs. For this purpose, a preliminary survey was conducted at the Beijing Municipal Health Bureau in order to assess the energy conservation efforts being made at 20 public HHFs. In the survey, a list of specific barriers to energy efficiency was created and HHF staffs were asked to rank these barriers in the order of importance. The results show that the economic incentives, appropriate technology, as well as enforceable laws and regulations are insufficiently supported by the government, have become the most significant obstacles to the improvement of energy efficiency. To remedy this, policymakers should take a multipronged approach which addresses the hospitals, projects, and technical and operating procedures in order to encourage the full participation and support of all stakeholders involved. Specifically, the government should offer multilevel economic incentives and reward policies; establish practical mandatory targets for building energy efficiency; provide demonstrable best practices in terms of the project, techniques, and operating procedures; and promote awareness of the importance of property risk management. - Highlights: • We developed a checklist of building energy efficiency barriers of HHFs in China. • We took a survey to prioritize the barriers by the staff from 20 public HHFs. • Policy makers should provide multiple-level solutions to all the stakeholders. • Economic incentives, mandatory target, technique supports are critical drivers.

The role of cooperatives in overcoming the barriers to adoption of renewable energy

International Nuclear Information System (INIS)

Viardot, Eric

2013-01-01

Recently, cooperatives have been created to promote the use of renewable energy (RE) most notably in Canada, the US, UK, Denmark or Germany. In order to develop the adoption of RE, the cooperatives have to seek to influence the behaviour of their members so that they switch from the use of traditional fossil energy to RE. This paper examines the various barriers to adoption of RE and the way cooperatives are circumventing those obstacles in order to develop the use of RE. This study surveyed a sample of 9 cooperatives from countries where governments are subsidizing the use of RE. The paper identifies a set of specific barriers to the adoption of RE by consumers. It also reveals that cooperatives effectively contribute to the uptake of RE with community-based social marketing initiatives that are lowering those barriers successfully. Those initiatives are related to educational communication, low prices, local offers with complementary services, and cooperative distribution. The paper put forwards a framework for the assessment of how each of those initiatives contributes to the diminishing of each of the barriers to adoption of RE. - Highlights: • We examine the barriers to adoption of renewable energy by RE cooperatives. • We have identified the main significant barriers to adoption of RE by consumers. • Cooperatives apply community-based marketing initiatives to ease the uptake of RE. • We evaluate how each marketing initiatives diminish the barriers to adoption of RE

Financing Solar Energy Systems with Energy Savings Performance Contracts in the Federal Sector: Results of a Survey on Barriers

Energy Technology Data Exchange (ETDEWEB)

Gee, R. C.; LaPorta, C.

1999-08-17

This report summarizes the findings of an investigation into financing solar energy systems for the Federal sector. The objectives of the investigation were (1) to identify the barriers that impede companies from using Energy Savings Performance Contracts (ESPCs) to develop solar energy projects for Federal facilities, and (2) to clarify the impacts of Federal contracting requirements on energy service companies' use of ESPCs. Twenty-four representatives of energy service companies agreed to be interviewed. Their responses indicate that these are the primary barriers to greater use of ESPCs: the relatively long payback periods for investments in solar technologies; the length of the ESPC process; the cost of certain contractual requirements regarding wages and financing; and a lack of knowledge about the actual cost and reliability of solar systems. The report proposes a number of actions the government could take to remove these barriers, including (1) streamlining and shortening the ESPC process and (2) doing more to inform both government agencies and energy service companies about the costs and benefits of solar systems.

Controlling Schottky energy barriers in organic electronic devices using self-assembled monolayers

Energy Technology Data Exchange (ETDEWEB)

Campbell, I.H.; Rubin, S.; Zawodzinski, T.A.; Kress, J.D.; Martin, R.L.; Smith, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Barashkov, N.N.; Ferraris, J.P. [The University of Texas at Dallas, Richardson, Texas 75083 (United States)

1996-11-01

We demonstrate tuning of Schottky energy barriers in organic electronic devices by utilizing chemically tailored electrodes. The Schottky energy barrier of Ag on poly[2-methoxy], 5-(2{prime}-ethyl-hexyloxy)- 1,4-phenylene was tuned over a range of more than 1 eV by using self-assembled monolayers (SAM{close_quote}s) to attach oriented dipole layers to the Ag prior to device fabrication. Kelvin probe measurements were used to determine the effect of the SAM{close_quote}s on the Ag surface potential. {ital Ab} {ital initio} Hartree-Fock calculations of the molecular dipole moments successfully describe the surface potential changes. The chemically tailored electrodes were then incorporated in organic diode structures and changes in the metal/organic Schottky energy barriers were measured using an electroabsorption technique. These results demonstrate the use of self-assembled monolayers to control metal/organic interfacial electronic properties. They establish a physical principle for manipulating the relative energy levels between two materials and demonstrate an approach to improve metal/organic contacts in organic electronic devices. {copyright} {ital 1996 The American Physical Society.}

Controlling Schottky energy barriers in organic electronic devices using self-assembled monolayers

International Nuclear Information System (INIS)

Campbell, I.H.; Rubin, S.; Zawodzinski, T.A.; Kress, J.D.; Martin, R.L.; Smith, D.L.; Barashkov, N.N.; Ferraris, J.P.

1996-01-01

We demonstrate tuning of Schottky energy barriers in organic electronic devices by utilizing chemically tailored electrodes. The Schottky energy barrier of Ag on poly[2-methoxy], 5-(2'-ethyl-hexyloxy)- 1,4-phenylene was tuned over a range of more than 1 eV by using self-assembled monolayers (SAM close-quote s) to attach oriented dipole layers to the Ag prior to device fabrication. Kelvin probe measurements were used to determine the effect of the SAM close-quote s on the Ag surface potential. Ab initio Hartree-Fock calculations of the molecular dipole moments successfully describe the surface potential changes. The chemically tailored electrodes were then incorporated in organic diode structures and changes in the metal/organic Schottky energy barriers were measured using an electroabsorption technique. These results demonstrate the use of self-assembled monolayers to control metal/organic interfacial electronic properties. They establish a physical principle for manipulating the relative energy levels between two materials and demonstrate an approach to improve metal/organic contacts in organic electronic devices. copyright 1996 The American Physical Society

Barriers and drivers for energy efficiency: Different perspectives from an exploratory study in the Netherlands

International Nuclear Information System (INIS)

Cagno, Enrico; Trianni, Andrea; Abeelen, Christiaan; Worrell, Ernst; Miggiano, Federica

2015-01-01

Highlights: • We investigated the perception of barriers and drivers and mechanisms regulating them. • Firms agree on the most important barriers and drivers. • Firms agree on the most critical decision-making steps and actors promoting drivers. • Major external actors perceive barriers, drivers and mechanisms differently. • Success of voluntary agreements depends on the link to other policy instruments. - Abstract: Increased energy efficiency represents a crucial opportunity for European industrial sustainability, but several barriers still need to be tackled. Thus, it is crucial to understand the existing mismatches between the perception of enterprises and what the major actors promoting energy efficiency believe enterprises suffer from and need within the decision-making process. To do so, we have performed an exploratory investigation analysing a set of manufacturing enterprises participating in the Dutch voluntary agreements. The study involved the major external actors, i.e. the national energy agency, governmental and industrial organisations, to map their views on the decision-making process. Results show that enterprises agree not only on the most important barriers and drivers, but also on the mechanisms underlying them. However, even a general common understanding of the barriers is disputed when major external actors are considered, as they only agree on the primary role of economic barriers. Mismatches appear when considering how single barriers affect the decision-making process and which drivers – and actors promoting them – need to be addressed. Although voluntary agreements represent the most popular instrument on energy efficiency in the Netherlands, they do not seem to be considered by small and medium-sized enterprises as a stimulus for improving energy efficiency. Crucial for future success are the link with other policy instruments, and the degree to which the instruments trigger the right drivers and barriers at the right

Tunnel superpenetrability of potential barriers

International Nuclear Information System (INIS)

Zakhariev, B N.

1982-01-01

The transmission of two particles through the same barrier is considered. The limiting cases are compared when the particles are joined together in a single particle with double mass-energy and potential and when they pass the barrier independently. As an intermediate case a pair of particles bound in a quasideuteron of a finite size is considered. It is shown that long-range collective correlations of particles (of the superfluidity type and others) simplify very much for them passing through high potential barriers. This happens due to the transfer of the additional energy from the particles outside the barriers to those inside it

A novel method of calculating the energy deposition curve of nanosecond pulsed surface dielectric barrier discharge

International Nuclear Information System (INIS)

He, Kun; Wang, Xinying; Lu, Jiayu; Cui, Quansheng; Pang, Lei; Di, Dongxu; Zhang, Qiaogen

2015-01-01

To obtain the energy deposition curve is very important in the fields to which nanosecond pulse dielectric barrier discharges (NPDBDs) are applied. It helps the understanding of the discharge physics and fast gas heating. In this paper, an equivalent circuit model, composed of three capacitances, is introduced and a method of calculating the energy deposition curve is proposed for a nanosecond pulse surface dielectric barrier discharge (NPSDBD) plasma actuator. The capacitance C d and the energy deposition curve E R are determined by mathematically proving that the mapping from C d to E R is bijective and numerically searching one C d that satisfies the requirement for E R to be a monotonically non-decreasing function. It is found that the value of capacitance C d varies with the amplitude of applied pulse voltage due to the change of discharge area and is dependent on the polarity of applied voltage. The bijectiveness of the mapping from C d to E R in nanosecond pulse volumetric dielectric barrier discharge (NPVDBD) is demonstrated and the feasibility of the application of the new method to NPVDBD is validated. This preliminarily shows a high possibility of developing a unified approach to calculate the energy deposition curve in NPDBD. (paper)

Closing the Energy Efficiency Gap: A study linking demographics with barriers to adopting energy efficiency measures in the home

International Nuclear Information System (INIS)

Pelenur, Marcos J.; Cruickshank, Heather J.

2012-01-01

This paper presents a study which linked demographic variables with barriers affecting the adoption of domestic energy efficiency measures in large UK cities. The aim was to better understand the ‘Energy Efficiency Gap’ and improve the effectiveness of future energy efficiency initiatives. The data for this study was collected from 198 general population interviews (1.5–10 min) carried out across multiple locations in Manchester and Cardiff. The demographic variables were statistically linked to the identified barriers using a modified chi-square test of association (first order Rao–Scott corrected to compensate for multiple response data), and the effect size was estimated with an odds-ratio test. The results revealed that strong associations exist between demographics and barriers, specifically for the following variables: sex; marital status; education level; type of dwelling; number of occupants in household; residence (rent/own); and location (Manchester/Cardiff). The results and recommendations were aimed at city policy makers, local councils, and members of the construction/retrofit industry who are all working to improve the energy efficiency of the domestic built environment. -- Highlights: ► 7 demographic variables linked to 8 barriers to adopting energy efficiency measures. ► A modified chi-square test for association was used (first order Rao–Scott corrected). ► Results revealed strong associations between most of the demographics and barriers. ► Data was collected from 198 interviews in the UK cities of Manchester and Cardiff. ► Specific recommendations are presented for regional policy makers and industry.

Examining barrier distributions and, in extension, energy derivative of probabilities for surrogate experiments

International Nuclear Information System (INIS)

Romain, P.; Duarte, H.; Morillon, B.

2012-01-01

The energy derivatives of probabilities are functions suited to a best understanding of certain mechanisms. Applied to compound nuclear reactions, they can bring information on fusion barrier distributions as originally introduced, and also, as presented here, on fission barrier distributions and heights. Extendedly, they permit to access the compound nucleus spin-parity states preferentially populated according to an entrance channel, at a given energy. (authors)

Energy shift and conduction-to-valence band transition mediated by a time-dependent potential barrier in graphene

Science.gov (United States)

Chaves, Andrey; da Costa, D. R.; de Sousa, G. O.; Pereira, J. M.; Farias, G. A.

2015-09-01

We investigate the scattering of a wave packet describing low-energy electrons in graphene by a time-dependent finite-step potential barrier. Our results demonstrate that, after Klein tunneling through the barrier, the electron acquires an extra energy which depends on the rate of change of the barrier height with time. If this rate is negative, the electron loses energy and ends up as a valence band state after leaving the barrier, which effectively behaves as a positively charged quasiparticle.

Barriers to energy efficiency in small industry clusters: Multi-criteria-based prioritization using the analytic hierarchy process

International Nuclear Information System (INIS)

Nagesha, N.; Balachandra, P.

2006-01-01

The small scale industry (SSI) is an important component of Indian economy and a majority of SSI units tend to exist in geographical clusters. Energy efficiency is crucial for the survival and growth of energy intensive SSI clusters, not only to improve their competitiveness through cost reduction but also to minimize adverse environmental impacts. However, this is easier said than done due to the presence of a variety of barriers. The identification of relevant barriers and their appropriate prioritization in such clusters is a prerequisite to effectively tackle them. This paper identifies relevant barriers to energy efficiency and their dimensions in SSI clusters. Further, the barriers are prioritized based on the perceptions and experiences of entrepreneurs, the main stakeholders of SSIs, using the analytic hierarchy process (AHP). The field data from two energy intensive clusters of foundry and brick and tile in Karnataka (a state in India) reveal that the prioritization remained the same despite differences in the relative weights of barrier groups. The financial and economic barrier (FEB) and behavioural and personal barrier (BPB) have emerged as the top two impediments to energy efficiency improvements

Market barriers to energy efficiency: A critical reappraisal of the rationale for public policies to promote energy efficiency

Energy Technology Data Exchange (ETDEWEB)

Golove, W.H.; Eto, J.H. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.

1996-03-01

This report reviews current perspectives on market barriers to energy efficiency. Ratepayer-funded utility energy-efficiency programs are likely to change in scope, size, and nature as the deregulation process proceeds; the authors research focuses on understanding to what extent some form of future intervention may be warranted and how they might judge the success of particular interventions, especially those funded by ratepayers. They find that challenges to the existence of market barriers have, for the most part, failed to provide a testable alternative explanation for evidence suggesting that there is a substantial ``efficiency gap`` between a consumer`s actual investments in energy efficiency and those that appear to be in the consumer`s own interest. They then suggest that differences of opinion about the appropriateness of public policies stem not from disputes about whether market barriers exist, but from different perceptions of the magnitude of the barriers, and the efficacy and (possibly unintended) consequences of policies designed to overcome them. They conclude that there are compelling justifications for future energy-efficiency policies. Nevertheless, in order to succeed, they must be based on a sound understanding of the market problems they seek to correct and a realistic assessment of their likely efficacy. This understanding can only emerge from detailed investigations of the current operation of individual markets.

Barriers to fusion

International Nuclear Information System (INIS)

Berriman, A.C.; Butt, R.D.; Dasgupta, M.; Hinde, D.J.; Morton, C.R.; Newton, J.O.

1999-01-01

The fusion barrier is formed by the combination of the repulsive Coulomb and attractive nuclear forces. Recent research at the Australian National University has shown that when heavy nuclei collide, instead of a single fusion barrier, there is a set of fusion barriers. These arise due to intrinsic properties of the interacting nuclei such deformation, rotations and vibrations. Thus the range of barrier energies depends on the properties of both nuclei. The transfer of matter between nuclei, forming a neck, can also affect the fusion process. High precision data have been used to determine fusion barrier distributions for many nuclear reactions, leading to new insights into the fusion process

High energy ion implantation

International Nuclear Information System (INIS)

Ziegler, J.F.

1985-01-01

High energy ion implantation offers the oppertunity for unique structures in semiconductor processing. The unusual physical properties of such implantations are discussed as well as the special problems in masking and damage annealing. A review is made of proposed circuit structures which involve deep implantation. Examples are: deep buried bipolar collectors fabricated without epitaxy, barrier layers to reduce FET memory sensitivity to soft-fails, CMOS isolation well structures, MeV implantation for customization and correction of completed circuits, and graded reach-throughs to deep active device components. (orig.)

8B + 208Pb Elastic Scattering at Coulomb Barrier Energies

Science.gov (United States)

La Commara, M.; Mazzocco, M.; Boiano, A.; Boiano, C.; Manea, C.; Parascandolo, C.; Pierroutsakou, D.; Signorini, C.; Strano, E.; Torresi, D.; Yamaguchi, H.; Kahl, D.; Di Meo, P.; Grebosz, J.; Imai, N.; Hirayama, Y.; Ishiyama, H.; Iwasa, N.; Jeong, S. C.; Jia, H. M.; Kim, Y. H.; Kimura, S.; Kubono, S.; Lin, C. J.; Miyatake, H.; Mukai, M.; Nakao, T.; Nicoletto, M.; Sakaguchi, Y.; Sánchez-Benítez, A. M.; Soramel, F.; Teranishi, T.; Wakabayashi, Y.; Watanabe, Y. X.; Yang, L.; Yang, Y. Y.

2018-02-01

The scattering process of weakly-bound nuclei at Coulomb barrier energies provides deep insights on the reaction dynamics induced by exotic nuclei. Within this framework, we measured for the first time the scattering process of the short-lived Radioactive Ion Beam (RIB) 8B (Sp = 0.1375 MeV) from a 208Pb target at 50 MeV beam energy. The 8B RIB was produced by means of the in-flight facility CRIB (RIKEN, Japan) with an average intensity on target of 10 kHz and a purity about 25%. Elastically scattering ions were detected in the angular range θc.m. = 10°-160° by means of the detector array EXPADES. A preliminary optical model analysis indicates a total reaction cross section of about 1 b, a value, once reduced, 2-3 times larger than those obtained for the reactions induced by the stable weakly-bound projectiles 6,7Li on a 208Pb target in the energy range around the Coulomb barrier.

11Li Breakup on 208Pb at Energies Around the Coulomb Barrier

DEFF Research Database (Denmark)

Fernández-García, J.P.; Cubero, M.; Rodríguez-Gallardo, M.

2013-01-01

The inclusive breakup for the 11Li+208Pb reaction at energies around the Coulomb barrier has been measured for the first time. A sizable yield of 9Li following the 11Li dissociation has been observed, even at energies well below the Coulomb barrier. Using the first-order semiclassical perturbation...... theory of Coulomb excitation it is shown that the breakup probability data measured at small angles can be used to extract effective breakup energy as well as the slope of B(E1) distribution close to the threshold. Four-body continuum-discretized coupled-channels calculations, including both nuclear...... and Coulomb couplings between the target and projectile to all orders, reproduce the measured inclusive breakup cross sections and support the presence of a dipole resonance in the 11Li continuum at low excitation energy....

Implementation of renewable energy technologies - Opportunities and barriers. Egypt country study

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The project used case studies of renewable energy implementation projects to analyse the reasons for success or failure of specific projects or technologies. In particular the study aimed to identify possibilities for 'removing' the main barriers and thus 'promoting' increased implementation of (RETs), and to 'generalise' the experiences from the case studies and produce results that can be disseminated and utilized further in a planned second phase. The specific objectives for Egypt Country Study were: 1) To determine, on the basis of analysis of the past experience, the barriers against implementation of RETs in Egypt, and to identify the favourable conditions and actions required for such implementation. 2) To apply the knowledge gained and results of the analysis of past projects for a detailed analysis of barriers to a chosen set of potential RETs implementation projects with view to success. 3) To identify specific RET projects for implementation including necessary actions to overcome identified barriers. The case study revealed that; for Domestic Solar Water Heating (DSWH) the main barriers are; the economic barriers followed by the awareness / information barriers, then the Technical and Institution barriers. For the PV rural electrification, the most important barriers are; the economic and financial barriers, the awareness and information barriers then the technical barriers. For the large-scale biogas systems, the main barriers are the institution and capacity, economic, policy and awareness / information respectively. According to the project results the main actions that could be taken to overcome the barriers and make use of the available opportunities are: Economic / Financial: 1) Creation of new financial schemes for the RETs applications components and systems. 2) Reducing the taxes and duties for the components and / or materials needed for Renewable Energy (RE) systems. 3) More government-supported market incentives to encourage further

Implementation of renewable energy technologies - Opportunities and barriers. Egypt country study

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The project used case studies of renewable energy implementation projects to analyse the reasons for success or failure of specific projects or technologies. In particular the study aimed to identify possibilities for 'removing' the main barriers and thus 'promoting' increased implementation of (RETs), and to 'generalise' the experiences from the case studies and produce results that can be disseminated and utilized further in a planned second phase. The specific objectives for Egypt Country Study were: 1) To determine, on the basis of analysis of the past experience, the barriers against implementation of RETs in Egypt, and to identify the favourable conditions and actions required for such implementation. 2) To apply the knowledge gained and results of the analysis of past projects for a detailed analysis of barriers to a chosen set of potential RETs implementation projects with view to success. 3) To identify specific RET projects for implementation including necessary actions to overcome identified barriers. The case study revealed that; for Domestic Solar Water Heating (DSWH) the main barriers are; the economic barriers followed by the awareness / information barriers, then the Technical and Institution barriers. For the PV rural electrification, the most important barriers are; the economic and financial barriers, the awareness and information barriers then the technical barriers. For the large-scale biogas systems, the main barriers are the institution and capacity, economic, policy and awareness / information respectively. According to the project results the main actions that could be taken to overcome the barriers and make use of the available opportunities are: Economic / Financial: 1) Creation of new financial schemes for the RETs applications components and systems. 2) Reducing the taxes and duties for the components and / or materials needed for Renewable Energy (RE) systems. 3) More government-supported market incentives

Overcoming financial barriers to wider use of renewable energy technology in Africa

International Nuclear Information System (INIS)

Davidson, O.R.; Turkson, J.

2001-01-01

Future energy demand in Africa will rise dramatically due to development desires and increased industrial needs. Coping with this demand will pose a serious challenge because of the economic and environmental constraints of the continent. Exploiting its vast renewable energy sources for this purpose will assist greatly, but financial and other barriers to the rapid growth of associated technologies are significant. This paper explores measures that can be implemented to reduce these financial barriers. The analyses, which are based on lessons from experiences in and out of the region, show that replicating and enhancing current initiatives along with the implementation of suggested policy options could substantially increase the use of renewable energy technologies in Africa. (author)

Review of Renewable Energy Technologies in Zambian Households: Capacities and Barriers Affecting Successful Deployment

Directory of Open Access Journals (Sweden)

Priscilla Kachapulula-Mudenda

2018-05-01

Full Text Available Modern renewable energy has been hailed as one of the prerequisites for fostering green growth and the achievement of sustainable development. Despite efforts to promote the use of renewable energy in households, its adoption has remained fairly low, hence the need for an inquiry into household capabilities needed for the acquisition and adoption of renewable energy technologies. This paper reviews the requisite capacities of households for the adoption of renewable energy services and expounds on some of the barriers hampering renewable energy among households. It takes a desk research approach to analyse the capacities which should be possessed by Zambian households and possible barriers constraining the widespread deployment of renewable energy technologies. The findings reveal that there is a need for a broader, multidimensional understanding of access to renewable energy in order for deployment to be effective. Barriers to the successful adoption of clean energy technologies include underserved populations, policy inadequacies; an underexploited renewable energy sector and heavy reliance on a service-challenged hydro-power utility. Since most of the aforementioned challenges are institutional in nature, the paper concludes with a recommendation of a baseline assessment to understand knowledge, perceptions, attitudes and drivers for renewable energy technology adoption among households.

Technical Barriers, Gaps,and Opportunities Related to Home Energy Upgrade Market Delivery

Energy Technology Data Exchange (ETDEWEB)

Bianchi, Marcus V.A. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2011-11-01

This report outlines the technical barriers, gaps, and opportunities that arise in executing home energy upgrade market delivery approaches, as identified through research conducted by the U.S. Department of Energy's Building America program.

Application of diffusion barriers to high modulus fibers

Science.gov (United States)

Veltri, R. D.; Douglas, F. C.; Paradis, E. L.; Galasso, F. S.

1977-01-01

Barrier layers were coated onto high-modulus fibers, and nickel and titanium layers were overcoated as simulated matrix materials. The objective was to coat the high-strength fibers with unreactive selected materials without degrading the fibers. The fibers were tungsten, niobium, and single-crystal sapphire, while the materials used as barrier coating layers were Al2O3, Y2O3, TiC, ZrC, WC with 14% Co, and HfO2. An ion-plating technique was used to coat the fibers. The fibers were subjected to high-temperature heat treatments to evaluate the effectiveness of the barrier layer in preventing fiber-metal interactions. Results indicate that Al2O3, Y2O3, and HfO2 can be used as barrier layers to minimize the nickel-tungsten interaction. Further investigation, including thermal cycling tests at 1090 C, revealed that HfO2 is probably the best of the three.

Summary of Gaps and Barriers for Implementing Residential Building Energy Efficiency Strategies

Energy Technology Data Exchange (ETDEWEB)

2010-08-01

This report presents the key gaps and barriers to implementing residential energy efficiency strategies in the U.S. market, as identified in sessions at the U.S. Department of Energy's Building America 2010 Residential Energy Efficiency Meeting held in Denver, Colorado, on July 20-22, 2010.

Internationalization as a strategy to overcome industry barriers-An assessment of the marine energy industry

International Nuclear Information System (INIS)

Lovdal, Nicolai; Neumann, Frank

2011-01-01

Research on conditions to develop new innovations within emerging renewable energy industries is often done with a national focus. However, recent research on international entrepreneurship has revealed that firms operate on international levels very early in their life time. Thus, based on former research on international entrepreneurship and case examples, we build the propositions that firms in the marine energy industry use internationalization as a strategy to overcome industry barriers. Our primary source of data is a unique dataset from a global survey of all the companies in the marine energy industry who are aiming to commercialize a wave or tidal energy device. This paper is organized in two steps: first we identified the most challenging industry barriers perceived by companies. Second we use these to form propositions which we assess through empirical data. The two most challenging barriers perceived by the companies are need for capital and need for supportive political schemes. Our findings reveal that internationalization certainly is a common strategy to access capital and attractive support schemes in foreign countries. The early internationalization has implications for researchers, managers and policy makers. - Research highlights: → Industry barriers identified as access to capital and supportive political schemes. → International entrepreneurship is used to overcome industry barriers. → Start-ups in emerging energy industries 'shop' national support schemes. → Future research to provide policy advice should adapt to the international reality. → Research based on a worldwide survey of wave and tidal energy device developers.

Internationalization as a strategy to overcome industry barriers-An assessment of the marine energy industry

Energy Technology Data Exchange (ETDEWEB)

Lovdal, Nicolai, E-mail: nicolai.lovdal@iot.ntnu.n [Industrial Economics and Technology Management, Norwegian University of Science and Technology, 7491 Trondheim (Norway); Neumann, Frank, E-mail: frank@wave-energy-centre.or [Wave Energy Centre, Av. Manuel Maia, 36, r/c Dto., 1000-201 Lisboa (Portugal)

2011-03-15

Research on conditions to develop new innovations within emerging renewable energy industries is often done with a national focus. However, recent research on international entrepreneurship has revealed that firms operate on international levels very early in their life time. Thus, based on former research on international entrepreneurship and case examples, we build the propositions that firms in the marine energy industry use internationalization as a strategy to overcome industry barriers. Our primary source of data is a unique dataset from a global survey of all the companies in the marine energy industry who are aiming to commercialize a wave or tidal energy device. This paper is organized in two steps: first we identified the most challenging industry barriers perceived by companies. Second we use these to form propositions which we assess through empirical data. The two most challenging barriers perceived by the companies are need for capital and need for supportive political schemes. Our findings reveal that internationalization certainly is a common strategy to access capital and attractive support schemes in foreign countries. The early internationalization has implications for researchers, managers and policy makers. - Research highlights: {yields} Industry barriers identified as access to capital and supportive political schemes. {yields} International entrepreneurship is used to overcome industry barriers. {yields} Start-ups in emerging energy industries 'shop' national support schemes. {yields} Future research to provide policy advice should adapt to the international reality. {yields} Research based on a worldwide survey of wave and tidal energy device developers.

High efficiency combined heat and power facilities - benefits and barriers

International Nuclear Information System (INIS)

Klein, M.

2001-01-01

There are important linkages between the economy, energy production, the environment and our health. Where thermal energy is needed, distributed Combined Heat and Power facilities, using gas turbines, reciprocating engines and future fuel cells can provide significant improvements to our long term mix of energy production. Local generation can also have benefits in security of energy supply and economic savings. This paper is intended to discuss the relevant air pollution and greenhouse gas emissions from modem CHP plants, the emission prevention and reduction methods available, and their operating experience and cost-effectiveness. Mention is made of recently constructed industrial and commercial plants, and institutional barriers to further development. Solutions described for these barriers include the need for more awareness of opportunities, improved access to the electricity grid, the proper design balance between thermal and electric for CHP systems rather than large combined cycles, improved corporate taxation incentives, and the assessment of all environmental and economic benefits when considering such cleaner sources in a restructured energy market. (author)

Energy SMEs in sub-Saharan Africa: Outcomes, barriers and prospects in Ghana, Senegal, Tanzania and Zambia

Energy Technology Data Exchange (ETDEWEB)

Haselip, J. A.; Desgain, D.; Mackenzie, G. A.

2013-05-15

This report presents the findings of research into the main outcomes of government and donor-backed efforts to promote small and medium-sized energy businesses (energy SMEs) in sub-Saharan Africa. The research follows an outcome analysis methodology. The focus is on four countries: Ghana, Senegal, Tanzania and Zambia and primarily on UNEP's AREED programme (2002-2012). This research focuses on the 'contributing factors' - a deliberately broader term that incorporates the internal 'success factors' - for energy SMEs, about which much has already been written. Indeed, the research findings presented in this report reaffirm most of what has been concluded in previous studies. These studies identified the lack of access to affordable finance as being the predominant, persistent, barrier to establishing and scaling up a commercially viable energy SME sector, emphasising the lack of strong policy support from governments, poor business skills capacity and the high cost of many RETs as related cause-and-effect barriers. While these issues continue to characterise, to a greater or lesser extent, the energy SMEs sectors in the countries studied for this research, it is more relevant to revisit the main assumption behind AREED and other donor-backed programmes designed to promote energy SMEs. The assumption is that the solution to the aforementioned barriers would be overcome by a 'demonstration effect' whereby successful energy SMEs, supported by donor-backed programmes, influence the commercial financial sector to invest in energy SMEs, thus triggering a virtuous circle of growth and profitability. Experiences drawn from a decade of AREED support across four of the project countries reveal both the presence (Ghana, Senegal) and absence, or weak presence, of this demonstration effect (Tanzania, Zambia). This is a central question, and one which was not the focus of previous research, presumably because the answer was not fully apparent prior to 2006 when the last

Removing barriers to women entrepreneurs’ engagement in decentralized sustainable energy solutions for the poor

Directory of Open Access Journals (Sweden)

Yannick Glemarec

2016-01-01

Full Text Available  Rapidly falling renewable technology costs and new business models mean that decentralized energy solutions hold great promise to accelerate universal sustainable energy access. Across developing countries, women are typically the primary household energy managers. Close to their customers, women entrepreneurs have the potential to lower customer acquisition and servicing costs and drive these new decentralized solutions. However, they remain under-represented in the industry. This paper attempts to understand the root causes of this gender gap. It formulates the research hypothesis that market transformation policies intended to reduce investment risks to accelerate energy access may not benefit men and women entrepreneurs equally because of the existing structural barriers that women face. To test this hypothesis, the paper conducts a gender sensitive investment barrier and risk analysis, overlaid onto an existing gender neutral taxonomy of investment barriers and risks for decentralized sustainable energy solutions. A key finding is that for women entrepreneurs, existing structural impediments to gender equality translate into additional investment barriers as well as increased likelihood of occurrence and severity of the financial impact of generic investment risks. The paper offers an illustrative theory of change to facilitate a dialogue on the specific interventions needed to address these gender differentiated risks locally. It concludes that market transformation efforts for universal sustainable energy access must include targeted policy measures to ensure equal benefits to men and women entrepreneurs, and optimize the use of public resources to catalyze private investment and reduce poverty.

Numerical evaluation of energy barriers and magnetic relaxation in interacting nanostructured magnetic systems

International Nuclear Information System (INIS)

Chubykalo-Fesenko, Oksana A.; Chantrell, Roy W.

2004-01-01

We discuss a model to quantify long-time thermally induced magnetization reversal in magnetic systems with distributed properties. Two algorithms, based on kinetic and Metropolis Monte Carlo are introduced. While the former requires the constant recalculation of all energy barriers and is useful when the interactions are weak, the latter uses the Metropolis Monte Carlo to estimate the magnetization trajectory and, consequently, only the most probable transition rates are evaluated. The ridge optimization method is used to evaluate the energy barriers in a multidimensional energy landscape. The algorithms are applied to a granular system modeled by means of Voronoi polyhedra and having random in-plane anisotropy

High tension generator for corona barrier discharge

International Nuclear Information System (INIS)

Baltag, O.; Costandache, D.; Gheorghiu, M.; Paraschivescu, A.; Popa, G.

2001-01-01

Different types of high-voltage generators are in use for the study of low pressure (or atmospheric) discharges. Mostly used are the Tesla coils generators or the power generators working in linear or switching regime. The Tesla coils generators have the advantage of a simple bloc diagram. In exchange, they have a number of short-comings, such as: the difficulty in modifying the frequency of the high voltage pulses, generation of a high voltage and frequency pulse train, the amplitude is not constant.This paper presents a high-voltage generator meant to be used in the study of the dielectric barrier discharges (DBD). The bloc diagram is presented. Performances obtained are as follows: - Generated frequency: 10 Hz - 100 Hz, 100 Hz - 1 KHz, 1 KHz - 10 KHz; - High voltage pulses control: a single pulse from an internal or external generator; - Synchronization with the oscilloscope, variable delay: 5 μs - 0.1 s; - Output voltage: variable both smoothly and in steps: 1 kV -15 kV; - High voltage polarity: mono and bipolar; - Output power during the continuous duty: 300 VA (maximum 600 VA for a short time); - Pulse energy: 0.23 J; - Pulse duration: 4 μs - 50 μs

Potential and barrier study. Energy efficiency of Norwegian homes; Potensial- og barrierestudie. Energieffektivisering av norske boliger

Energy Technology Data Exchange (ETDEWEB)

Mjoenes, Christian; Pettersen, Folke Vogn Haug; Kristoffersen, Bjoerge Sandberg; Birkeland, Bjoern Mangor; Essen, Jan von; Haarberg; Karl Johan

2012-01-15

On behalf of Enova SF, Prognosesenteret AS and Entelligens AS carried out a potential and barrier study of energy efficiency of the Norwegian housing stock. The study made use of newer and known studies of the Norwegian housing stock, known and documented barriers to energy efficiency, and new and extensive studies of several topics which have only been partially or never explored before. Through unique analysis and a case-based approach, it revealed a real energy efficiency potential in Norwegian homes with known technology and revealed representativeness, relevance, strength and extent of the barriers that prevent that one can realize most of the technical energy efficiency potential in the Norwegian housing stock. (eb)

Energy efficiency in social housing: Opportunities and barriers from a case study in Brazil

International Nuclear Information System (INIS)

Bodach, Susanne; Hamhaber, J.

2010-01-01

This paper investigates the energy efficiency in a segment of the building sector in emerging countries by analyzing and evaluating the energy efficiency of a social housing project in Brazil. Energy efficiency measures and bioclimatic design strategies are developed in order to improve thermal comfort in this social housing project and to reduce the energy consumption and expenses of their residents. The institutional barriers and constraints toward higher efficiency are described. The results of this study show that there is a high potential to increase energy efficiency in social housing in emerging countries like Brazil. The implementation and consideration of the energy efficiency measures and policy recommendations would contribute substantially to the goal to dampen the fast growth of energy demand in these countries. Moreover the improvement of energy efficiency in the social housing sector could be a driver for market transformation towards more sustainability in the whole building sector. - Research highlights: →There is a high potential to increase energy efficiency in social housing in Brazil. →Energy-efficient social housing would contribute substantially to dampen the fast growth of energy consumption in emerging countries like Brazil. →Implementation of energy efficiency would improve the income situation of the poorest strata of the population.

Overcoming barriers to increased bio-energy use. Suggestions for a high impact policy

International Nuclear Information System (INIS)

Chanakya, H.N.; Ravindranath, N.H.

1997-01-01

A few options that are likely to result in a high impact policy towards ensuring increased use of bio-energy in the developing world are discussed. Such options are: Moving towards greater energy security /guarantee, bio-energy technology transfer platforms, documentation in bio-energy businesses, removing risk perceptions in financing, increasing private entrepreneur stakes, etc. (K.A.)

Driving forces and barriers to improved energy performance of buildings: an analysis of energy performance of Swedish buildings, 2000-2006

Energy Technology Data Exchange (ETDEWEB)

Fuglseth, Bente Beckstroem

2008-06-15

The building sector is responsible for a substantial part of energy use and green house gas emissions in Europe. This report explores driving forces and barriers to improved energy performance of buildings, using the Swedish building sector as a case. The development of energy performance of buildings in Sweden from 2000 until 2006 is explored by applying a threefold understanding of energy performance of buildings: substitution from fossil fuels to renewable energy, conversion from electrical heating to thermal energy and reduction in energy demand. Three explanatory approaches are used to analyse driving forces and barriers to improved energy performance: the techno-economic approach stresses the physical aspects of infrastructure and technologies, the institutional approach emphasizes the role of institutional factors, while the regulative approach focuses on formal rules and laws. The study concludes that all factors have promoted substitution of fossil fuels with renewable energy, while they have prevented conversion from electrical heating to thermal energy and reduction in energy demand. (author). 95 refs

Transport Barriers in Bootstrap Driven Tokamaks

Science.gov (United States)

Staebler, Gary

2017-10-01

Maximizing the bootstrap current in a tokamak, so that it drives a high fraction of the total current, reduces the external power required to drive current by other means. Improved energy confinement, relative to empirical scaling laws, enables a reactor to more fully take advantage of the bootstrap driven tokamak. Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is due to the suppression of turbulence primarily due to the large Shafranov shift. ExB velocity shear does not play a significant role in the transport barrier due to the high safety factor. It will be shown, that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift driven barrier formation. The ion energy transport is reduced to neoclassical and electron energy and particle transport is reduced, but still turbulent, within the barrier. Deeper into the plasma, very large levels of electron transport are observed. The observed electron temperature profile is shown to be close to the threshold for the electron temperature gradient (ETG) mode. A large ETG driven energy transport is qualitatively consistent with recent multi-scale gyrokinetic simulations showing that reducing the ion scale turbulence can lead to large increase in the electron scale transport. A new saturation model for the quasilinear TGLF transport code, that fits these multi-scale gyrokinetic simulations, can match the data if the impact of zonal flow mixing on the ETG modes is reduced at high safety factor. This work was supported by the U.S. Department of Energy under DE-FG02-95ER54309 and DE-FC02

Modeling and Characteristic Analysis of Wireless Ultrasonic Vibration Energy Transmission Channels through Planar and Curved Metal Barriers

Directory of Open Access Journals (Sweden)

DingXin Yang

2018-01-01

Full Text Available Wireless ultrasonic vibration energy transmission systems through metal barriers based on piezoelectric transducers have drawn a lot of focus due to the advantage of nonpenetration of the barriers, thus maintaining the integrity of sealed structures. It is meaningful to investigate appropriate modeling methods and to characterize such wireless ultrasonic energy transmission channels with different geometric shapes. In this paper, equivalent circuit modeling and finite element modeling methods are applied to the planar metal barrier channel, and a 3-dimensional finite element modeling method is applied to the cylindrical metallic barrier channel. Meanwhile, the experimental setup is established and measurements are carried out to validate the effectiveness of the corresponding modeling methods. The results show that Leach’s equivalent circuit modeling method and finite element modeling method are nearly similarly effective in characterizing the planar metal barrier channel. But for a cylindrical metal barrier, only the three-dimensional finite element modeling method is effective. Furthermore, we found that, for the planar barrier, the effect of standing waves on the efficiency of wireless energy transmission is dominated. But for the curved barrier, only the resonant phenomenon of the piezoelectric transducer exists.

Renewable energy in South Africa: Potentials, barriers and options for support

International Nuclear Information System (INIS)

Pegels, Anna

2010-01-01

The challenge of transforming entire economies is enormous; even more so if a country is as fossil fuel based and emission intensive as South Africa. However, in an increasingly carbon constrained world and already now facing climate change impacts South Africa has to reduce greenhouse gas emissions intensity soon and decidedly. The South African electricity sector is a vital part of the economy and at the same time contributes most to the emissions problem. First steps have been taken by the South African government to enhance energy efficiency and promote renewable energy, however, they fail to show large-scale effects. This paper seeks to identify the relevant barriers to renewable energy investments and, based on experience from other countries, provide policy recommendations. The major barrier identified in the paper is based on the economics of renewable energy technologies, i.e. their cost and risk structures, two main factors in investment planning. As a solution, the South African government introduced several renewable energy support measures, such as a feed-in tariff. The paper discusses the potential and possible shortcomings of this and other existing support schemes and identifies complementing measures on a national scale.

Modeling barriers of solid waste to energy practices: An Indian perspective

International Nuclear Information System (INIS)

Bag, S.; Mondal, N.; Dubey, R.

2016-01-01

In recent years managing solid wastes has been one of the burning problems in front of state and local municipal authorities. This is mainly due to scarcity of lands for landfill sites. In this context experts suggest that conversion of solid waste to energy and useful component is the best approach to reduce space and public health related problems. The entire process has to be managed by technologies that prevent pollution and protect the environment and at the same time minimize the cost through recovery of energy. Energy recovery in the form of electricity, heat and fuel from the waste using different technologies is possible through a variety of processes, including incineration, gasification, pyrolysis and anaerobic digestion. These processes are often grouped under “Waste to Energy technologies”. The objective of the study is twofold. First authors assessed the current status of solid waste management practices in India. Secondly the leading barriers are identified and Interpretive structural modeling technique and MICMAC analysis is performed to identify the contextual interrelationships between leading barriers influencing the solid waste to energy programs in the country. Finally the conclusions are drawn which will assist policy makers in designing sustainable waste management programs.

Renewable energy in South Africa. Potentials, barriers and options for support

Energy Technology Data Exchange (ETDEWEB)

Pegels, Anna [German Development Institute/Deutsches Institut fuer Entwicklungspolitik, Tulpenfeld 6, 53113 Bonn (Germany)

2010-09-15

The challenge of transforming entire economies is enormous; even more so if a country is as fossil fuel based and emission intensive as South Africa. However, in an increasingly carbon constrained world and already now facing climate change impacts South Africa has to reduce greenhouse gas emissions intensity soon and decidedly. The South African electricity sector is a vital part of the economy and at the same time contributes most to the emissions problem. First steps have been taken by the South African government to enhance energy efficiency and promote renewable energy, however, they fail to show large-scale effects. This paper seeks to identify the relevant barriers to renewable energy investments and, based on experience from other countries, provide policy recommendations. The major barrier identified in the paper is based on the economics of renewable energy technologies, i.e. their cost and risk structures, two main factors in investment planning. As a solution, the South African government introduced several renewable energy support measures, such as a feed-in tariff. The paper discusses the potential and possible shortcomings of this and other existing support schemes and identifies complementing measures on a national scale. (author)

Renewable energy in South Africa: Potentials, barriers and options for support

Energy Technology Data Exchange (ETDEWEB)

Pegels, Anna, E-mail: anna.pegels@die-gdi.d [German Development Institute/Deutsches Institut fuer Entwicklungspolitik, Tulpenfeld 6, 53113 Bonn (Germany)

2010-09-15

The challenge of transforming entire economies is enormous; even more so if a country is as fossil fuel based and emission intensive as South Africa. However, in an increasingly carbon constrained world and already now facing climate change impacts South Africa has to reduce greenhouse gas emissions intensity soon and decidedly. The South African electricity sector is a vital part of the economy and at the same time contributes most to the emissions problem. First steps have been taken by the South African government to enhance energy efficiency and promote renewable energy, however, they fail to show large-scale effects. This paper seeks to identify the relevant barriers to renewable energy investments and, based on experience from other countries, provide policy recommendations. The major barrier identified in the paper is based on the economics of renewable energy technologies, i.e. their cost and risk structures, two main factors in investment planning. As a solution, the South African government introduced several renewable energy support measures, such as a feed-in tariff. The paper discusses the potential and possible shortcomings of this and other existing support schemes and identifies complementing measures on a national scale.

Simultaneous realization of high density edge transport barrier and improved L-mode on CHS

International Nuclear Information System (INIS)

Minami, Takashi; Okamura, Shoichi; Suzuki, Chihiro

2008-10-01

An edge transport barrier (ETB) formation and an improved L-mode (IL mode) have been simultaneously realized in high density region (n-bar e - 1.2x10 20 m -3 ) on Compact Helical System (CHS). When the ETB is formed during the IL mode, the density reduction in the edge region is suppressed by the barrier formation. As a result of the continuous increasing of the temperature by the IL mode, the stored energy during the combined mode increased up to the maximum stored energy (W p - 9.4 kJ) recorded in CHS experiments. The plasma pressure in the peripheral region increases up to three times larger than that of the L-mode, and the large edge plasma pressure gradient is formed accompanying the pedestal structure. That is caused by the anomalous transport reduction that is confirmed from the sharp drop of the density fluctuation in the edge region. The neutral particle reduction in the peripheral region and the metallic impurity accumulation in the core plasma are simultaneously observed during the high density ETB formation. (author)

Barriers and Potential Solutions for Energy Renovation of Buildings in Denmark

DEFF Research Database (Denmark)

Meyer, Niels I; Mathiesen, Brian vad; Hvelplund, Frede

2014-01-01

the supply and demand side for heat, electricity and transport. Implementing such Smart Energy Systems requires integrated strategic energy planning on the national and local level. With the fundamental changes in the energy supply technologies expected during the coming years, it is important to synchronize...... investments in energy conservation measures with investments in the supply side, in order to avoid overinvestment in supply systems and thus to minimize the total costs of the transformation to Smart Energy Systems. This paper highlights some of the most important barriers for renovation of existing buildings...

Transport barriers in bootstrap-driven tokamaks

Science.gov (United States)

Staebler, G. M.; Garofalo, A. M.; Pan, C.; McClenaghan, J.; Van Zeeland, M. A.; Lao, L. L.

2018-05-01

Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is caused by the suppression of turbulence primarily from the large Shafranov shift. It is shown that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift-driven barrier formation. Two self-organized states of the internal and edge transport barrier are observed. It is shown that these two states are controlled by the interaction of the bootstrap current with magnetic shear, and the kinetic ballooning mode instability boundary. Election scale energy transport is predicted to be dominant in the inner 60% of the profile. Evidence is presented that energetic particle-driven instabilities could be playing a role in the thermal energy transport in this region.

Simulations of skin barrier function: free energies of hydrophobic and hydrophilic transmembrane pores in ceramide bilayers.

Science.gov (United States)

Notman, Rebecca; Anwar, Jamshed; Briels, W J; Noro, Massimo G; den Otter, Wouter K

2008-11-15

Transmembrane pore formation is central to many biological processes such as ion transport, cell fusion, and viral infection. Furthermore, pore formation in the ceramide bilayers of the stratum corneum may be an important mechanism by which penetration enhancers such as dimethylsulfoxide (DMSO) weaken the barrier function of the skin. We have used the potential of mean constraint force (PMCF) method to calculate the free energy of pore formation in ceramide bilayers in both the innate gel phase and in the DMSO-induced fluidized state. Our simulations show that the fluid phase bilayers form archetypal water-filled hydrophilic pores similar to those observed in phospholipid bilayers. In contrast, the rigid gel-phase bilayers develop hydrophobic pores. At the relatively small pore diameters studied here, the hydrophobic pores are empty rather than filled with bulk water, suggesting that they do not compromise the barrier function of ceramide membranes. A phenomenological analysis suggests that these vapor pores are stable, below a critical radius, because the penalty of creating water-vapor and tail-vapor interfaces is lower than that of directly exposing the strongly hydrophobic tails to water. The PMCF free energy profile of the vapor pore supports this analysis. The simulations indicate that high DMSO concentrations drastically impair the barrier function of the skin by strongly reducing the free energy required for pore opening.

Pair transfer processes probed at deep sub barrier energies

International Nuclear Information System (INIS)

Corradi, L.; Mason, P.; Fioretto, E.; Michelagnoli, C.; Stefanini, A.M.; Valiente-Dobon, J.J.; Szinler, S.; Jelavic-Malenica, D.; Soic, N.; Pollarolo, G.; Farnea, E.; Montagnoli, G.; Montanari, D.; Scarlassara, F.; Ur, C.A.; Gadea, A.; Haas, F.; Marginean, N.

2011-01-01

Multinucleon transfer cross sections in the system 40 Ca+ 96 Zr have been measured at bombarding energies ranging from the Coulomb barrier to ∼ 25% below. Target-like (lighter) recoils in inverse kinematics have been completely identified in A,Z and Q-value with the large solid angle magnetic spectrometer PRISMA. The experimental slopes of the neutron transfer probabilities at large internuclear separation are consistent with the values derived from the binding energies. A phenomenological interpretation of the transfer probabilities indicates the presence of enhanced values for the even number of neutron transfers. (authors)

Response of wave-dominated and mixed-energy barriers to storms

NARCIS (Netherlands)

Masselink, G.; Heteren, S. van

2014-01-01

Wave-dominated and mixed-energy barriers are extremely dynamic landforms, responding to processes operating over a spectrum of time scales, ranging from daily-to-monthly fluctuations related to storm and post-storm conditions, to century-to-millennium-scale evolution driven by relative sea-level

Socio-cultural barriers to the development of a sustainable energy system - the case of hydrogen

DEFF Research Database (Denmark)

Petersen, Lars Kjerulf; Andersen, Anne Holst

Any transition to a more sustainable energy system, radically reducing greenhouse gas emissions, is bound to run in to a host of different barriers - technological and economic, but also socio-cultural. This will also be the case for any large-scale application of hydrogen as energy carrier......, especially if the system is going to be based on renewable energy sources. The aim of these research notes is to review and discuss major socio-cultural barriers to new forms of energy supply in general and to hydrogen specifically. Reaching sufficient reductions in greenhouse gas emissions may require more...

Organizational human factors as barriers to energy efficiency in electrical motors systems in industry

International Nuclear Information System (INIS)

Sola, Antonio Vanderley Herrero; Augusto de Paula, Xavier Antonio

2007-01-01

This paper presents a study accomplished in the State of Parana in Southern Brazil, aiming at verifying the correlation between organizational human factors (OHF) and the level of energy losses in organizations. The purpose is to subsidize the formularization of institutional policies in organizations to improve the energy efficiency in the productive sector. The research was carried out in ten industries of the following sectors: pulp and paper; food; wood and chemical products. The losses of electric energy were determined in motor systems with the aid of a mathematical model and the evaluation of 27 OHF identified in the literature review was made with the supervisors in the industries by means of a structurized questionnaire. Seven OHF had presented significant correlation with energy losses and six of them are inversely proportional to the losses, in accordance with linear regression analysis. The inversely proportional factors to the losses also with significant correlation are considered determinative OHF and constitute barriers for energy efficiency in organizations. These barriers are linked with the following organizational areas: management system; education of employees; strategical vision. The study recommends the implementation of the determinative OHF in organizations as a way to transpose the human barriers for energy efficiency

The congruence energy: a contribution to nuclear masses, deformation energies and fission barriers

International Nuclear Information System (INIS)

Myers, W.D.; Swiatecki, W.J.

1997-01-01

The difference between measured binding energies and those calculated using a shell- and pairing-corrected Thomas-Fermi model can be described approximately by C(I)=-10 exp(-4.2 vertical stroke I vertical stroke) MeV, where I=(N-Z)/A. Our interpretation of this extra binding is in terms of the granularity of quantal nucleonic density distributions, which leads to a stronger interaction for a neutron and proton with congruent nodal structures of their wave functions. The predicted doubling of this congruence energy in fission is supported by an analysis of measured fission barriers and by a study of wave functions in a dividing Hill-Wheeler box potential. A semi-empirical formula for the shape-dependent congruence energy is described. (orig.)

Organizational, interface, and financial barriers to the commercial development of community energy systems

Energy Technology Data Exchange (ETDEWEB)

Schladale, R.; Ritschard, R.

1979-12-01

The scope of this analysis was limited to systems producing electricity - the output of a community energy system typically falling in the range 10 kW to 150 MW. The purpose of this study was to identify the barriers that groups and individuals will face when attempting to commercialize community energy systems. Three particular classes of barriers were investigated: those within the organization attempting the commercialization, those that arise from attempts to link the community system with an electric utility, and those that impede the flow of investment capital into community energy systems. In summary, three general observations regarding community energy systems may be distilled from this study. First, although many barriers exist to the commercialization of the systems, few if any appear unresolvable. Perhaps most challenginng will be the problem of expanding the use of cogeneration and municipal sold waste while at the same time maintaining or improving ambient air quality. Second, the financial subsidies required to make community systems competitive are not extraordinary. Indeed, with the exception of photovoltaics they should not amount to more than about 10% of capital cost of the new systems, and mass production may eliminate the need for subsidies altogether at some point in the future. Third, the administrative and regulatory procedures required to make community energy systems viable appear to be taking shape in a positive and timely fashion.

Negotiating EU CO2/energy taxation. Political economic driving forces and barriers

International Nuclear Information System (INIS)

Klok, Jacob

2001-11-01

The primary objective of this project is to identify the main political economic driving forces behind and barriers against the creation of an EU agreement on CO 2 /energy taxation. The analysis is based on a theoretical framework for understanding European integration and on detailed historical investigations into a process of EU negotiations concerning CO 2 /energy taxation that took place from the 1980s to 1994. Following the historical analysis of political economic driving forces and barriers, some overall perspectives on possible future developments within the field of EU CO 2 /energy taxation are finally advanced. The secondary objective of the project is to consider the possible effects on the EU negotiation process of Danish efforts to push the CO 2 /energy tax proposal from the late 1980s to 994. This analysis is based on the preceding historical analysis of the EU negotiation process, as well as further investigations into the national Danish development within the field of CO 2 /energy taxation, including accounts of Denmark's particular relations with the EU during the period in question. Finally, based on the likely future developments in the field EU CO 2 /energy taxation. Denmark's strategic opportunities are outlined. (BA)

Energy barriers between metastable states in first-order quantum phase transitions

Science.gov (United States)

Wald, Sascha; Timpanaro, André M.; Cormick, Cecilia; Landi, Gabriel T.

2018-02-01

A system of neutral atoms trapped in an optical lattice and dispersively coupled to the field of an optical cavity can realize a variation of the Bose-Hubbard model with infinite-range interactions. This model exhibits a first-order quantum phase transition between a Mott insulator and a charge density wave, with spontaneous symmetry breaking between even and odd sites, as was recently observed experimentally [Landig et al., Nature (London) 532, 476 (2016), 10.1038/nature17409]. In the present paper, we approach the analysis of this transition using a variational model which allows us to establish the notion of an energy barrier separating the two phases. Using a discrete WKB method, we then show that the local tunneling of atoms between adjacent sites lowers this energy barrier and hence facilitates the transition. Within our simplified description, we are thus able to augment the phase diagram of the model with information concerning the height of the barrier separating the metastable minima from the global minimum in each phase, which is an essential aspect for the understanding of the reconfiguration dynamics induced by a quench across a quantum critical point.

Current-induced changes of migration energy barriers in graphene and carbon nanotubes

Science.gov (United States)

Obodo, J. T.; Rungger, I.; Sanvito, S.; Schwingenschlögl, U.

2016-05-01

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative.An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative. Electronic supplementary information (ESI) available. See DOI: 10.1039/C6NR00534A

Barriers to Energy Efficiency and the Uptake of Green Revolving Funds in Canadian Universities

Science.gov (United States)

Maiorano, John; Savan, Beth

2015-01-01

Purpose: The purpose of this paper is to investigate the barriers to the implementation of energy efficiency projects in Canadian universities, including access to capital, bounded rationality, hidden costs, imperfect information, risk and split incentives. Methods to address these barriers are investigated, including evaluating the efficacy of…

Study of the dynamical potential barriers in heavy ion collisions

International Nuclear Information System (INIS)

Zhu, Long; Su, Jun; Xie, Wen-Jie; Zhang, Feng-Shou

2013-01-01

The nucleus–nucleus interaction potentials for the fusion reactions 16 O + 208 Pb, 64 Ni + 64 Ni, 58 Ni + 58 Ni and 16 O + 154 Sm are extracted from the improved isospin-dependent quantum molecular dynamics model. The shell correction effects are discussed. The negative shell correction energies lower potential barriers of a certain reaction. The incident energy dependence of the potential barrier is investigated for each system. A complex phenomenon of energy dependence is observed. It is also found that incident energy dependence of the barrier radius and barrier height shows opposite behaviors. The Coulomb potential shows weak energy dependence when distance of two colliding nuclei is lower than the touching distance. The isospin effects of the potential barrier are investigated. The orientation effects of the potential barrier is also discussed for the system 16 O + 154 Sm. The fusion cross sections that correspond to the equatorial orientation of 154 Sm are very low in sub-barrier region because of the high fusion barriers and the shallow potential pockets

Renewable energy market conditions and barriers in Turkey

International Nuclear Information System (INIS)

Nalan, Cicek Bezir; Murat, Oeztuerk; Nuri, Oezek

2009-01-01

Decentralized wind, hydropower, biogas and biomass, geothermal, solar thermal and solar electricity energy systems are the most commonly found renewable energy technologies promoted for rural energy supply within sustainable developments programs. They are, therefore, seen to have a central place in the practice of sustainable development and in allowing less development countries to bypass the environmentally damaging fossil fuel intensive paths made by industrialized countries. On the political front, many less development countries are critical of pressure on them to adopt environmental energy technologies. Turkey is situated the meeting point of three continents (Asia, Europe and Africa) and stands as a bridge between Asia and Europe. The country is located in southeastern Europe and southwestern Asia. As Turkey's economy has expanded in recent years, the consumption of primary energy has increased. Presently in order to increase the energy production from domestic energy resources, decrease the use of fossil fuels as well as reduce of green house gas emissions different renewable energy sources are used for energy production in Turkey. The share of energy production from renewable energy sources has increased during the last 10 years. Turkey must import most of the energy to meet her needs. Turkey also has a large potential for renewable energies. The lack of knowledge about renewable energy technologies by most policy-makers, potential consumers, and energy firm managers has played against renewable energy developments. The paper presents renewable energy used in Turkey and Europe Union and evaluation of the market conditions and barriers of renewable energy use in Turkey. (author)

Reactions with weakly bound nuclei at near barrier energies

International Nuclear Information System (INIS)

Nanal, Vandana

2014-01-01

In reactions with weakly bound nuclei, the effect of breakup on fusion process has attracted much attention in recent years. The experimental study shows that breakup channel leads to suppression of complete fusion at above barrier energies due to loss of flux. The fusion barrier distribution can provide a further insight into understanding the influence of coupling to the breakup channels. Similar information could be obtained from the elastic and quasielastic (QEL) scattering because of the conservation of the reaction flux (i.e. R+T= 1), where R is the reflection probability and T is the transmission probability. Thus, quasi-elastic scattering at backward angles is the counterpart of the fusion process and it is expected that the barrier distributions extracted from two processes, namely, QEL and fusion should be similar. While this is true for tightly bound reaction systems, in reactions involving weakly bound projectiles significant differences have been observed for QEL barrier distributions with and without inclusion of breakup processes. This talk will present the recent results for fusion and quasi-elastic scattering in "6","7Li + "1"9"7Au system. Developmental efforts towards a momentum achromatic separator, MARIE, to extract projectile-like secondary ion beams following the reactions of heavy-ion beams from superconducting LINAC booster at Mumbai will also be presented. (author)

Assessment of non-cost barriers to renewable energy growth in EU Member States - AEON

Energy Technology Data Exchange (ETDEWEB)

NONE

2010-05-15

The accelerated deployment of renewable energy technologies has become a major priority for public policy makers across the globe. In the last two decades, most of the debate concerning the promotion of renewables was focused on the financial support schemes and on improving grid access conditions for renewable electricity. Of course, these are crucial issues which will continue to deserve serious attention in the future. However, during the last few years, the importance of tackling non-financial and non-technical barriers to renewable electricity, heat and transport has gained the attention of many policy analysts. In June 2009, Directive 2009/28/EC on the promotion of the use of energy from renewable sources, entered into force. The articles 13, 14 and 16 of the Directive contain a number of requirements for Member States to address or remove non-cost barriers to the increased deployment of renewable energy sources. This study presents among others an overview of these barriers in all EU Member States; their history, their impact on renewable energy deployment and suggestions for policy solutions, where feasible. Separate studies were carried out for 27 EU-countries and made available in a zip-file.

Free-Energy Barrier of Filling a Spherical Cavity in the Presence of Line Tension: Implication to the Energy Barrier between the Cassie and Wenzel States on a Superhydrophobic Surface with Spherical Cavities.

Science.gov (United States)

Iwamatsu, Masao

2016-09-20

The free-energy barrier of filling a spherical cavity having an inner wall of various wettabilities is studied. The morphology and free energy of a lens-shaped droplet are determined from the minimum of the free energy. The effect of line tension on the free energy is also studied. Then, the equilibrium contact angle of the droplet is determined from the generalized Young's equation. By increasing the droplet volume within the spherical cavity, the droplet morphology changes from spherical with an equilibrium contact angle of 180° to a lens with a convex meniscus, where the morphological complete drying transition occurs. By further increasing the droplet volume, the meniscus changes from convex to concave. Then, the lens-shaped droplet with concave meniscus spreads over the whole inner wall, resulting in an equilibrium contact angle of 0° to leave a spherical bubble, where the morphological complete wetting transition occurs. Finally, the whole cavity is filled with liquid. The free energy shows a barrier from complete drying to complete wetting as a function of droplet volume, which corresponds to the energy barrier between the Cassie and Wenzel states of the superhydrophobic surface with spherical cavities. The free-energy maximum occurs when the meniscus of the droplet becomes flat, and it is given by an analytic formula. The effect of line tension is expressed by the scaled line tension, and this effect is largest at the free-energy maximum. The positive line tension increases the free-energy maximum, which thus increases the stability of the Cassie superhydrophobic state, whereas the negative line tension destabilizes the superhydrophobic state.

Unraveling the interplay between hydrogen bonding and rotational energy barrier to fine-tune the properties of triazine molecular glasses.

Science.gov (United States)

Laventure, Audrey; De Grandpré, Guillaume; Soldera, Armand; Lebel, Olivier; Pellerin, Christian

2016-01-21

Mexylaminotriazine derivatives form molecular glasses with outstanding glass-forming ability (GFA), high resistance to crystallization (glass kinetic stability, GS), and a glass transition temperature (Tg) above room temperature that can be conveniently modulated by selection of the headgroup and ancillary groups. A common feature of all these compounds is their secondary amino linkers, suggesting that they play a critical role in their GFA and GS for reasons that remain unclear because they can simultaneously form hydrogen (H) bonds and lead to a high interconversion energy barrier between different rotamers. To investigate independently and better control the influence of H bonding capability and rotational energy barrier on Tg, GFA and GS, a library of twelve analogous molecules was synthesized with different combinations of NH, NMe and O linkers. Differential scanning calorimetry (DSC) revealed that these compounds form, with a single exception, kinetically stable glasses with Tg values spanning a very broad range from -25 to 94 °C. While variable temperature infrared spectroscopy combined to chemometrics reveals that, on average, around 60% of the NH groups are still H-bonded as high as 40 °C above Tg, critical cooling rates obtained by DSC clearly show that molecules without H-bond donating linkers also present an outstanding GFA, meaning that H bonding plays a dominant role in controlling Tg but is not required to prevent crystallization. It is a high interconversion energy barrier, provoking a distribution of rotamers, that most efficiently promotes both GFA and resistance to crystallization. These new insights pave the way to more efficient glass engineering by extending the possible range of accessible Tg, allowing in particular the preparation of homologous glass-formers with high GS at ambient temperature in either the viscous or vitreous state.

Breakup mechanisms for 7Li + 197Au, 204Pb systems at sub-barrier energies

Directory of Open Access Journals (Sweden)

Luong D.H.

2013-12-01

Full Text Available Coincidence measurements of breakup fragments were carried out for the 7Li + 197Au and 204Pb systems at sub-barrier energies. The mechanisms triggering breakup, and time-scales of each process, were identified through the reaction Q-values and the relative energy of the breakup fragments. Binary breakup of 7Li were found to be predominantly triggered by nucleon transfer, with p-pickup leading to 8Be → α + α decay being the preferred breakup mode. From the time-scales of each process, the coincidence yields were separated into prompt and delayed components, allowing the identification of breakup process important in the suppression of complete fusion of 7Li at above-barrier energies.

Socio-cultural barriers to the development of a sustainable energy system - the case of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Kjerulf Petersen, L.; Holst Andersen, A.

2009-02-15

Any transition to a more sustainable energy system, radically reducing greenhouse gas emissions, is bound to run in to a host of different barriers - technological and economic, but also socio-cultural. This will also be the case for any large-scale application of hydrogen as energy carrier, especially if the system is going to be based on renewable energy sources. The aim of these research notes is to review and discuss major socio-cultural barriers to new forms of energy supply in general and to hydrogen specifically. Reaching sufficient reductions in greenhouse gas emissions may require more than large-scale dissemination of renewable energy sources. Also reductions or moderations in energy demand may be necessary. Hence, a central point in the research note is to consider not only socio-cultural obstacles for changing technologies in energy production, distribution and consumption but also obstacles for changing the scale of energy consumption, i.e. moderating the growth in how much energy is consumed or even reducing consumption volumes. (au)

Stabilising high energy orbit oscillations by the utilisation of centrifugal effects for rotating-tyre-induced energy harvesting

Science.gov (United States)

Zhang, Yunshun; Zheng, Rencheng; Nakano, Kimihiko; Cartmell, Matthew P.

2018-04-01

Nonlinear energy harvesters are frequently considered in preference to linear devices because they can potentially overcome the narrow frequency bandwidth limitations inherent to linear variants; however, the possibility of variable harvesting efficiency is raised for the nonlinear case. This paper proposes a rotational energy harvester which may be fitted into an automobile tyre, with the advantage that it may broaden the rotating frequency bandwidth and simultaneously stabilise high-energy orbit oscillations. By consideration of the centrifugal effects due to rotation, the overall restoring force will potentially be increased for a cantilever implemented within the harvester, and this manifests as an increase in its equivalent elastic stiffness. In addition, this study reveals that the initial potential well barriers become as shallow as those for a bistable system. When the rotational frequency increases beyond an identifiable boundary frequency, the system transforms into one with a potential barrier of a typical monostable system. On this basis, the inter-well motion of the bistable system can provide sufficient kinetic energy so that the cantilever maintains its high-energy orbit oscillation for monostable hardening behaviour. Furthermore, in a vehicle drive experiment, it has been shown that the effective rotating frequency bandwidth can be widened from 15 km/h-25 km/h to 10 km/h-40 km/h. In addition, it is confirmed that the centrifugal effects can improve the harvester performance, producing a mean power of 61 μW at a driving speed of 40 km/h, and this is achieved by stabilising the high-energy orbit oscillations of the rotational harvester.

Barriers to installing innovative energy systems in existing housing stock identified

NARCIS (Netherlands)

Hoppe, Thomas

2013-01-01

Several barriers to upgrading existing social housing with innovative energy systems (IES) have been identified by a study of eight large-scale renovation projects in the Netherlands. These include a lack of trust between stakeholders, opposition from tenants on grounds of increased costs or delays,

Barriers and possibilities for low-carbon-energy consuming technologies

DEFF Research Database (Denmark)

Bjarklev, Araceli

consensus that one of the solutions to the current environmental challenge will be based on low-carbon-technologies, there are many issues that set a barrier for its adequate development and still many actors in these sectors are sceptical about the possibilities. Illumination is a very interesting sector...... to target, since it uses 19% of the total electricity produced in the world. Consequently, this paper takes the Danish office lighting sector as a study object and discusses the question: What are the main barriers and possibilities for the energy saving illumination technologies to efficiently reduce...... their ecological footprint. The discussion is supported by using relevant elements of the cradle-to-grave, eco-design and environmental-innovation theories. It is based on active participation in interdisciplinary projects and face-to-face in-depth interviews with relevant actors along the entire Danish...

Analyzing Barriers to Energy Conservation in Residences and Offices: The Rewire Program at the University of Toronto

Science.gov (United States)

Stokes, Leah C.; Mildenberger, Matto; Savan, Beth; Kolenda, Brian

2012-01-01

Conducting a barriers analysis is an important first step when designing proenvironmental behavior change interventions. Yet, detailed information on common barriers to energy conservation campaigns remains unavailable. Using a pair of original surveys, we leverage the theory of planned behavior to report on the most important barriers for…

Barriers to the use of renewable energy in Western Australia

International Nuclear Information System (INIS)

Harman, F.; Stocker, L.; Walker, I.; Stirling, M.

1991-08-01

Public attitudes towards renewable energy sources, in particular solar energy is examined through a survey of water heating in the metropolitan area, energy supply and use on pastoral leases in Western Australia. The private costs of water heating systems was assessed in a way which may give guidance to manufacturers on improving the economics of solar water heating systems, and to policy makers for facilitating the use of solar water heating systems. The policies currently in place in Western Australia which act as barriers to the greater use of renewable energy were also outlined. The cost data, together with the attitudes of consumers as revealed in the surveys, indicate that manufacturers and suppliers of renewable energy equipment need to reduce costs and improve the actual and perceived capability, performance and reliability of their equipment. 96 refs., 30 tabs., 38 figs

Current-induced changes of migration energy barriers in graphene and carbon nanotubes.

Science.gov (United States)

Obodo, J T; Rungger, I; Sanvito, S; Schwingenschlögl, U

2016-05-21

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative.

NOVEL TSUNAMI BARRIERS AND THEIR APPLICATIONS FOR HYDROELECTRIC ENERGY STORAGE, FISH FARMING, AND FOR LAND RECLAMATION

Directory of Open Access Journals (Sweden)

Hans J. Scheel

2014-10-01

Full Text Available The tsunami hazard can be mitigated if the destructive waves generated from earthquakes and landslides can be reflected by a stable submerged vertical barrier before striking coastal communities or important structures. Building such deep walls by conventional submarine technology is difficult. The present study describes the principle and the erection of such submarine defensive walls by a relatively simple efficient and economic technology. This technology is based on lowering high- strength steel fences with horizontal anchors, or two parallel steel fences with distance holders, into the sea and fixing them with rocks deposited from top. Dredged material like gravel or sand can be used for additional filling. This Tsunami-Flooding Barrier (TFB extends a few meters above sea level and carries on top a concrete supply and service road protected on both sides against storm waves by concrete walls. Replaceable surge stoppers (parapets, wave return walls prevent overtopping and erosion of the seaward barrier face. The TFBs protect the coastline against tsunami and the highest storm waves from hurricanes, but also can provide protection from oil spills or other contaminations from the ocean and thus protect flora, fauna, coral reefs and beaches. Channels and gates allow navigation and can be closed quickly upon a tsunami or storm warning. The construction costs can be eventually compensated by using the reservoirs between coast and barriers for hydroelectric energy storage (using pump-turbines in the barriers or for fish-farming, or alternatively the reservoir can be filled with rocks, rubble, gravel, sand and covered with soil in order to reclaim new land. Tidal energy can be generated by installing turbines within these barriers. Also, this submarine architecture may be applied to protect pillars of bridges and offshore platforms, and for erecting “roads” into the sea to connect near-shore platforms and wind-parks with the coast and

Low energy pion detection by a silicon surface barrier telescope

International Nuclear Information System (INIS)

Sealock, R.M.; Caplan, H.S.; Leung, M.K.

1978-01-01

Four telescopes of three (2-ΔE, 1-E) silicon surface barrier detectors each, mounted in the focal plane of a magnetic spectrometer, have been used to detect positive pions in the energy range from 4.7-17.9 MeV and negative pions from 14.1-17.9 MeV. Positive pions from 4.7-12.7 MeV were stopped in the third detector while positive and negative pions from 14.1-17.9 MeV were detected in transmission. For energies greater than 7.4 MeV aluminum moderators were placed in front of the first detector to degrade the pion energy. Energy spectra show well resolved pion peaks with extremely low background. Double differential cross sections for the 12 C(e,π + ) 12 B,e' reaction have been measured. (Auth.)

The Barriers to High-Quality Inpatient Pain Management: A Qualitative Study.

Science.gov (United States)

Lin, Richard J; Reid, M Carrington; Liu, Lydia L; Chused, Amy E; Evans, Arthur T

2015-09-01

The current literature suggests deficiencies in the quality of acute pain management among general medical inpatients. The aim of this qualitative study is to identify potential barriers to high-quality acute pain management among general medical inpatients at an urban academic medical center during a 2-year period. Data are collected using retrospective chart reviews, survey questionnaires, and semistructured, open-ended interviews of 40 general medical inpatients who have experienced pain during their hospitalization. Our results confirm high prevalence and disabling impacts of pain and significant patient- and provider-related barriers to high-quality acute pain management. We also identify unique system-related barriers such as time delay and pain management culture. Efforts to improve the pain management experience of general medical inpatients will need to address all these barriers. © The Author(s) 2014.

Financing renewable energy in developing countries. Drivers and barriers for private finance in sub-Saharan Africa

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-02-15

The focus of this report is to identify and portray current barriers to the scaling up of private investment and finance for electricity generation from renewable energy sources in the sub-Saharan region. Best practice in tackling these barriers is identified, partly from a literature review but especially from the results of a survey conducted among 36 financial institutions that are UNEP Finance Initiative members and two non-member banks (all survey respondents have experience in the field of energy infrastructure finance). Promising avenues in the areas of local policy reform, incentive mechanisms and international de-risking instruments are highlighted. In particular, this report addresses the following questions: (a) Why are sub-Saharan Africa and developing countries elsewhere failing to expand electricity generation from renewable sources? What are the barriers to such expansion? What is keeping the risk-return profile of renewable energy investments in sub-Saharan Africa unattractive and projects commercially unviable?; (b) What have been the experiences of private sector lenders and investors in the area of renewable energy projects in developing countries? What barriers and drivers have they encountered, and how can these experiences be of use in sub-Saharan Africa?; (c) What can be learned from the modest but encouraging successes of a few sub-Saharan African countries? Can these results be replicated? What was done in these countries to improve the risk-return profile of renewable energy and unlock private finance?.

BARRIERS TO ENERGY ACCESS IN THE URBAN POOR AREAS OF DHAKA, BANGLADESH: ANALYSIS OF PRESENT SITUATION AND RECOMMENDATIONS

Directory of Open Access Journals (Sweden)

Molla Shahadat Hossain Lipu

2013-10-01

Full Text Available Energy is a crucial input to promote socioeconomic development. In Bangladesh, about 96 million people (59% do not have access to electricity and 143 million people (88% still depend on biomass for cooking. The urban poor living in slum areas with lack of access to clean and modern sources of energy have not been addressed comprehensively. The main objective of this study is to identify the barriers faced by the urban poor in the slum areas of Dhaka in accessing different fuels and provide specific recommendations to overcome the barriers to enable energy access. The study is mainly based on field survey covering 185 households of the four major slum areas of Dhaka, literature review, and stakeholder interviews. Many barriers have been identified through this research where urban poor face problems in accessing legal energy services due to illegal settlement, lack of explicit policy on energy and housing, lack of dedicated institution, the pervasive role of Mastaans, poor infrastructure and lack of monitoring and evaluating system. Barriers specific recommendations are also suggested based on the experiences from the field visit and the best practices outside Bangladesh are also identified.

Socio-technical barriers to the use of energy-efficient timber drying technology in New Zealand

International Nuclear Information System (INIS)

Bell, Martha; Carrington, Gerry; Lawson, Rob; Stephenson, Janet

2014-01-01

This study of industrial energy behaviours identifies barriers to the use of energy-efficient drying technology in the New Zealand timber industry, and explores these barriers through the “energy cultures” lens. Vented kiln dryers were preferred by larger firms and heat pump kiln dryers were used by smaller firms. Although few firms could specify all their costs, we found no significant differences in the average operating costs, drying costs or commercial success of the larger and smaller firms. We found that socio-technical barriers create “energy cultures” at the level of both the firm and the sector, supporting the dominance of vented kiln dryers. The prevailing technologies, practices and norms at the sector level strongly support vented kilns, the status quo being embedded in the socio-technical context, hindering technological learning, improved energy efficiency and innovation. Influential stakeholders in the industry were thus part of, and locked into, the industry-wide energy culture, and were not in a position to effect change. We conclude that actors external to the prevailing industry energy culture need to leverage change in the industry norms, practices and/or technologies in order to reap the advantages of energy-efficient drying technology, assist its continued evolution and avoid the risks of path-dependency. - Highlights: • Firms processing timber in New Zealand use two main drying technologies. • Relatively inefficient vented dryers dominate over energy-efficient heat pumps. • Operating costs are similar but the socio-technical regime supports vented dryers. • Stasis is created by fixed energy cultures both within firms and across the sector. • Stasis hampers technical development in heat pump drying and business innovation

Observation of the one- to six-neutron transfer reactions at sub-barrier energies

Energy Technology Data Exchange (ETDEWEB)

Jiang, C.L.; Rehm, K.E.; Gehring, J. [and others

1995-08-01

It was suggested many years ago that when two heavy nuclei are in contact during a grazing collision, the transfer of several correlated neutron-pairs could occur. Despite considerable experimental effort, however, so far only cross sections for up to four-neutron transfers have been uniquely identified. The main difficulties in the study of multi-neutron transfer reactions are the small cross sections encountered at incident energies close to the barrier, and various experimental uncertainties which can complicate the analysis of these reactions. We have for the first time found evidence for multi-neutron transfer reactions covering the full sequence from one- to six-neutron transfer reactions at sub-barrier energies in the system {sup 58}Ni + {sup 100}Mo.

Current-induced changes of migration energy barriers in graphene and carbon nanotubes

KAUST Repository

Obodo, Tobechukwu Joshua

2016-04-29

An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative. © 2016 The Royal Society of Chemistry.

Understanding the free energy barrier and multiple timescale dynamics of charge separation in organic photovoltaic cells.

Science.gov (United States)

Yan, Yaming; Song, Linze; Shi, Qiang

2018-02-28

By employing several lattice model systems, we investigate the free energy barrier and real-time dynamics of charge separation in organic photovoltaic (OPV) cells. It is found that the combined effects of the external electric field, entropy, and charge delocalization reduce the free energy barrier significantly. The dynamic disorder reduces charge carrier delocalization and results in the increased charge separation barrier, while the effect of static disorder is more complicated. Simulation of the real-time dynamics indicates that the free charge generation process involves multiple time scales, including an ultrafast component within hundreds of femtoseconds, an intermediate component related to the relaxation of the hot charge transfer (CT) state, and a slow component on the time scale of tens of picoseconds from the thermally equilibrated CT state. Effects of hot exciton dissociation as well as its dependence on the energy offset between the Frenkel exciton and the CT state are also analyzed. The current results indicate that only a small energy offset between the band gap and the lowest energy CT state is needed to achieve efficient free charge generation in OPV devices, which agrees with recent experimental findings.

Understanding the free energy barrier and multiple timescale dynamics of charge separation in organic photovoltaic cells

Science.gov (United States)

Yan, Yaming; Song, Linze; Shi, Qiang

2018-02-01

By employing several lattice model systems, we investigate the free energy barrier and real-time dynamics of charge separation in organic photovoltaic (OPV) cells. It is found that the combined effects of the external electric field, entropy, and charge delocalization reduce the free energy barrier significantly. The dynamic disorder reduces charge carrier delocalization and results in the increased charge separation barrier, while the effect of static disorder is more complicated. Simulation of the real-time dynamics indicates that the free charge generation process involves multiple time scales, including an ultrafast component within hundreds of femtoseconds, an intermediate component related to the relaxation of the hot charge transfer (CT) state, and a slow component on the time scale of tens of picoseconds from the thermally equilibrated CT state. Effects of hot exciton dissociation as well as its dependence on the energy offset between the Frenkel exciton and the CT state are also analyzed. The current results indicate that only a small energy offset between the band gap and the lowest energy CT state is needed to achieve efficient free charge generation in OPV devices, which agrees with recent experimental findings.

Market and behavioral barriers to energy efficiency: A preliminary evaluation of the case for tariff financing in California

Energy Technology Data Exchange (ETDEWEB)

Fujita, K. Sydny

2011-06-23

Consumers regularly forgo purchases of high efficiency appliances that appear to be cost effective at a reasonable rate of return. While some argue that this is a true revelation of preferences for appliance features, this 'efficiency gap' can be largely explained by a combination of market and behavioral failures that reduce consumers ability to evaluate the relative value of appliances and skew preferences toward initial cost savings, undervaluing future reductions in operating costs. These failures and barriers include externalities of energy use, imperfect competition between manufacturers, asymmetric information, bounded rationality, split incentives, and transaction costs (Golove 1996). Recognizing the social benefit of energy conservation, several major methods are used by policymakers to ensure that efficient appliances are purchased: minimum efficiency standards, Energy Star labeling, and rebates and tax credits. There is no single market for energy services; there are hundreds of uses, thousands of intermediaries, and millions of users, and likewise, no single appropriate government intervention (Golove 1996). Complementary approaches must be implemented, considering policy and institutional limitations. In this paper, I first lay out the rationale for government intervention by addressing the market and behavioral failures and barriers that arise in the context of residential energy efficiency. I then consider the ways in which some of these failures and barriers are addressed through major federal programs and state and utility level programs that leverage them, as well as identifying barriers that are not addressed by currently implemented programs. Heterogeneity of consumers, lack of financing options, and split incentives of landlords and tenants contribute significantly to the under-adoption of efficient appliances. To quantify the size of the market most affected by these barriers, I estimate the number of appliances, and in particular

Overcoming barriers to high performance seismic design using lessons learned from the green building industry

Science.gov (United States)

Glezil, Dorothy

NEHRP's Provisions today currently governing conventional seismic resistant design. These provisions, though they ensure the life-safety of building occupants, extensive damage and economic losses may still occur in the structures. This minimum performance can be enhanced using the Performance-Based Earthquake Engineering methodology and passive control systems like base isolation and energy dissipation systems. Even though these technologies and the PBEE methodology are effective reducing economic losses and fatalities during earthquakes, getting them implemented into seismic resistant design has been challenging. One of the many barriers to their implementation has been their upfront costs. The green building community has faced some of the same challenges that the high performance seismic design community currently faces. The goal of this thesis is to draw on the success of the green building industry to provide recommendations that may be used overcome the barriers that high performance seismic design (HPSD) is currently facing.

Disentangling complete and incomplete fusion for 9Be+187Re system at near barrier energies

International Nuclear Information System (INIS)

Kharab, Rajesh; Chahal, Rajiv; Rajiv Kumar

2015-01-01

The breakup of projectile before fusion leads to some unusual fusion mechanisms like incomplete fusion (ICF) and sequential complete fusion (SCF). Experimentally, it is not possible to separate SCF events from direct complete fusion (DCF). However, the complete fusion and incomplete fusion can be measured separately. Theoretically it is very difficult to calculate the complete and incomplete fusion cross section separately using different models. Very recently A. Diaz-Torres has developed a computer code platypus based on classical dynamical model wherein the complete and incomplete fusion cross sections are calculated separately. But this model is found to work very well at energies above the barrier energy. Here we have attempted to extrapolate the results of the code platypus by using simple Wong's formula in conjunction with the energy dependent Woods-Saxon potential (EDWSP) in the below barrier energy region

New light on an old problem: Reflections on barriers and enablers of distributed energy

International Nuclear Information System (INIS)

Szatow, Anthony; Quezada, George; Lilley, Bill

2012-01-01

This viewpoint article, New light on an Old Problem, aims to stimulate thought and discussion on pathways to rapid emission reduction trajectories. It considers briefly the history of the Australian energy system and recent attempts to support emerging, distributed energy supply systems, before exploring the importance of new energy supply models and how they may emerge organically, ahead of further policy and regulatory shifts in Australia. The article is shaped by extensive primary research, literature review and engagement with policy makers, industry and community organisations, energy market institutions, colleagues and others over a period of four years. It outlines how new business models may reduce emissions ahead of policy and regulation, and the importance of keeping an open mind when considering ‘barriers’ to distributed energy. We hope this article will spark interest and dialogue with colleagues who may be experiencing and grappling with similar challenges. - Research highlights: ► We discuss documented barriers to distributed energy. ► We draw on socio-technical system literature and our research experience to outline a possible solution to distributed energy barriers. ► We describe a hypothetical energy service business model, led by the property sector, as a catalyst for energy market change. ► We outline reasons for our confidence in this property sector led energy services model.

Potential and barrier study. Passive house and near-zero energy buildings; Potensial- og barrierestudie. Passivhus og naer nullenergibygninger

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

The main conclusion from the analysis is that the barriers to realize both passive and near zero-energy buildings are significant. In addition to being a mere economic assessment indicates that 30-70% of the technical potential is not profitable depending on energy price levels, the barriers is reducing the economic potential with approximately another half as a realistic market potential.(eb)

Electrical and optical characteristics of dielectric-barrier discharge driven by high voltage nanosecond generator

International Nuclear Information System (INIS)

Ahmadeev, V.V.; Kost'yuchenko, S.V.; Kudryavtsev, N.N.; Kurkin, G.A.; Vasilyak, L.M.

1998-01-01

Electrical and optical characteristics of the dielectric-barrier discharge in the pressure range of 10-400 Torr were investigated experimentally, particular attention being paid to the discharge homogeneity and to the energy dissipation in the discharge volume. The discharge was driven by a high-voltage pulse generator producing nanosecond high-voltage pulses with an amplitude of 20-30 kV. Air, nitrogen, and helium were used as working gases. The discharge was found to be homogeneous within a wide range of gas pressure. A power density of up to 250 mW/cm 3 has been achieved. (J.U.)

Deformation energy of a toroidal nucleus and plane fragmentation barriers

International Nuclear Information System (INIS)

Fauchard, C.; Royer, G.

1996-01-01

The path leading to pumpkin-like configurations and toroidal shapes is investigated using a one-parameter shape sequence. The deformation energy is determined within the analytical expressions obtained for the various shape-dependent functions and the generalized rotating liquid drop model taking into account the proximity energy and the temperature. With increasing mass and angular momentum, a potential well appears in the toroidal shape path. For the heaviest systems, the pocket is large and locally favourable with respect to the plane fragmentation barriers which might allow the formation of evanescent toroidal systems which would rapidly decay in several fragments to minimize the surface tension. (orig.)

Mapping of barley alpha-amylases and outer subsite mutants reveals dynamic high-affinity subsites and barriers in the long substrate binding cleft

DEFF Research Database (Denmark)

Kandra, L.; Abou Hachem, Maher; Gyemant, G.

2006-01-01

Subsite affinity maps of long substrate binding clefts in barley alpha-amylases, obtained using a series of maltooligosaccharides of degree of polymerization of 3-12, revealed unfavorable binding energies at the internal subsites -3 and -5 and at subsites -8 and +3/+4 defining these subsites...... as binding barriers. Barley a-amylase I mutants Y105A and T212Y at subsite -6 and +4 resulted in release or anchoring of bound substrate, thus modifying the affinities of other high-affinity subsites (-2 and +2) and barriers. The double mutant Y105A-T212Y displayed a hybrid subsite affinity profile......, converting barriers to binding areas. These findings highlight the dynamic binding energy distribution and the versatility of long maltooligosaccharide derivatives in mapping extended binding clefts in a-amylases....

Complex energy eigenvalues of a linear potential with a parabolical barrier

International Nuclear Information System (INIS)

Malherbe, J.B.

1978-01-01

The physical meaning and restrictions of complex energy eigenvalues are briefly discussed. It is indicated that a quasi-stationary phase describes an idealised disintegration system. Approximate resonance-eigenvalues of the one dimensional Schrodinger equation with a linear potential and parabolic barrier are calculated by means of Connor's semiclassical method. This method is based on the generalized WKB-method of Miller and Good. The results obtained confirm the correctness of a model representation which explains the unusual distribution of eigenvalues by certain other linear potentials in a complex energy level [af

The Schottky energy barrier dependence of charge injection in organic light-emitting diodes

Science.gov (United States)

Campbell, I. H.; Davids, P. S.; Smith, D. L.; Barashkov, N. N.; Ferraris, J. P.

1998-04-01

We present device model calculations of the current-voltage (I-V) characteristics of organic diodes and compare them with measurements of structures fabricated using MEH-PPV. The structures are designed so that all of the current is injected from one contact. The I-V characteristics are considered as a function of the Schottky energy barrier to charge injection from the contact. Experimentally, the Schottky barrier is varied from essentially zero to more than 1 eV by using different metal contacts. A consistent description of the device I-V characteristics is obtained as the Schottky barrier is varied from small values, less than about 0.4 eV, where the current flow is space-charge limited to larger values where it is contact limited.

Implementation of renewable energy technology - Opportunities and barriers. Summary of country studies

Energy Technology Data Exchange (ETDEWEB)

Painuly, J.P.; Fenhann, J.V.

2002-07-01

The project was launched to identify barriers to the implementation of renewable energy technologies (RETs) and explore measures to overcome the identified barriers. National institutions in Egypt, Ghana and Zimbabwe carried out the country studies based on the basic methodological framework provided by the UNEP Centre. The objectives of the project included strengthening institutional capacity for analysis and implementation of RET projects in the participating countries and bring out experiences on RETs barriers and removal measures for dissemination so that others can benefit from the knowledge so gained. An important highlight of the studies was involvement of stake holders in the process of identification of barriers and measures to remove them. A preliminary identification of relevant RETs for their countries was done by the country teams in the initial stage of the project. After that, national workshops involving various stake holders were held between July and September 1999 to discuss the RETs and barriers to their implementation. Based on the discussions, a few important RETs were identified for more detailed study. PV systems for rural electrification, solar water heating systems and large-scale biogas system were identified and analysed for barriers in the Egypt country study. Economic, information and policy barriers were identified as major barriers for these technologies. Solar water pumps, biogas and small hydro were the focus of study in Ghana. In this case also, economic, information and policy barriers were found to be the important barriers for the selected technologies. In the case of Zimbabwe, focus was on identification of primary and secondary barriers to RETs dissemination. The primary barriers included lack of capacity to develop proposals, lack of information for policy making and framework for information dissemination. The study concluded that the secondary barriers as seen and experienced by the stake holders are due to primary

Transportation Energy Futures Series. Non-Cost Barriers to Consumer Adoption of New Light-Duty Vehicle Technologies

Energy Technology Data Exchange (ETDEWEB)

Stephens, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States)

2013-03-01

Consumer preferences are key to the adoption of new vehicle technologies. Barriers to consumer adoption include price and other obstacles, such as limited driving range and charging infrastructure; unfamiliarity with the technology and uncertainty about direct benefits; limited makes and models with the technology; reputation or perception of the technology; standardization issues; and regulations. For each of these non-cost barriers, this report estimates an effective cost and summarizes underlying influences on consumer preferences, approximate magnitude and relative severity, and assesses potential actions, based on a comprehensive literature review. While the report concludes that non-cost barriers are significant, effective cost and potential market share are very uncertain. Policies and programs including opportunities for drivers to test drive advanced vehicles, general public outreach and information programs, incentives for providing charging and fueling infrastructure, and development of technology standards were examined for their ability to address barriers, but little quantitative data exists on the effectiveness of these measures. This is one in a series of reports produced as a result of the Transportation Energy Futures project, a Department of Energy-sponsored multi-agency effort to pinpoint underexplored strategies for reducing GHGs and petroleum dependence related to transportation. View all reports on the TEF Web page, http://www.eere.energy.gov/analysis/transportationenergyfutures/index.html.

Recent results from TMX-U thermal barrier experiments

International Nuclear Information System (INIS)

Molvik, A.W.; Allen, S.; Barter, J.

1984-01-01

The Tandem Mirror Experiment-Upgrade (TMX-U) device was designed to study plasma confinement in a tandem mirror with thermal barriers. Previously the author reported improved axial confinement with high end-plug potentials, consistent with thermal barrier operation. Now, the existence of thermal barriers in TMX-U confirmed by measuring the axial potential profile. Specifically, measured the change in energy of a 5-keV deuterium neutral beam that is injected nearly parallel to the axis and is ionized between the barrier and the central cell. The authors found that the barrier potential is lower than the central cell potential, as required for a thermal barrier. The peak potential is at least 2.4 keV, as determined from the minimum energy of end loss ions. In addition, radial transport is reduced by the use of floating and electrodes that map to concentric cylinders in the central cell. Sloshing ions continue to be microstable

Deuteron interaction with 124Sn nuclei at sub-barrier energies

Directory of Open Access Journals (Sweden)

Yu.N. Pavlenko

2015-04-01

Full Text Available The measurements of cross sections for deuteron elastic scattering and (d,p reaction on 124Sn nuclei have been performed with aim to study the features of sub-barrier deuteron interaction with heavy nuclei. Experimental data were obtained on the electrostatic Tandem accelerator EGP-10K of the Institute for Nuclear Research (Kyiv at the deuteron beam energies Ed = 4.0; 5.0 and 5.5 MeV. Cross sections of deuteron elastic scattering were calculated in approach where the deuteron interaction potential with heavy nuclei at sub-barrier energies has been constructed in the framework of single folding model using the complex dynamic polarization potential. It is shown that the account of finite deuteron size leads to the increasing the nuclear potential in outer region of interaction and significantly improves the description of the experimental data. The calculations of elastic scattering cross sections were performed without any variations of the nuclear potential parameters. The analysis of measured integral cross sections of the 124Sn(d,p reaction and calculated cross sections of deuteron breakup reaction 124Sn(d,pn124Sn shows the dominant contribution of the neutron transfer reaction in the processes of the formation of protons and elastic scattering cross sections.

Energy Transition and Barriers on the Path to its Introduction

Directory of Open Access Journals (Sweden)

Tomislav Tkalec

2015-12-01

Full Text Available Energy transition is a concept originating from the necessity of solving environmental problems and conflicts in the energy sector. It originates from environmental tradition and advocates transition from environmentally and socially controversial sources of energy to renewables. That also means a shift from large centralized production units (mainly based on fossil and nuclear energy to smaller, dispersed ones. This decentralization process inherently leads to a democratization of the electricity sector, as large energy companies are losing their power and position in the energy policy arena, as more and more smaller actors emerge. However, when trying to change the electricity system, many obstacles arise – from the economics, old energy paradigm, path dependence, inertia of electricity system, power relations between actors, institutional lock-in, to perceptions and values of the dominant players. All barriers are reflected in the energy policy arena, dominated mainly by large energy companies, reluctant to accept changes. Demands for a change come from non-dominant actors, mainly from civil society actors and others, who are pushed to the margins of the political arena. Therefore, decision-makers should recognize their role, change institutional structure of the energy policy arena, and open it to various actors that can add new qualities to decision-making processes and outputs.

Multiple Interfacial Fe3O4@BaTiO3/P(VDF-HFP) Core-Shell-Matrix Films with Internal Barrier Layer Capacitor (IBLC) Effects and High Energy Storage Density.

Science.gov (United States)

Zhou, Ling; Fu, Qiuyun; Xue, Fei; Tang, Xiahui; Zhou, Dongxiang; Tian, Yahui; Wang, Geng; Wang, Chaohong; Gou, Haibo; Xu, Lei

2017-11-22

Flexible nanocomposites composed of high dielectric constant fillers and polymer matrix have shown great potential for electrostatic capacitors and energy storage applications. To obtain the composited material with high dielectric constant and high breakdown strength, multi-interfacial composited particles, which composed of conductive cores and insulating shells and possessed the internal barrier layer capacitor (IBLC) effect, were adopted as fillers. Thus, Fe 3 O 4 @BaTiO 3 core-shell particles were prepared and loaded into the poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) polymer matrix. As the mass fraction of core-shell fillers increased from 2.5 wt % to 30 wt %, the dielectric constant of the films increased, while the loss tangent remained at a low level (capacitor model was also adopted to interpret the efficiency of IBLC effects on the suppressed loss tangent and the superior breakdown strength. This work explored an effective approach to prepare dielectric nanocomposites for energy storage applications experimentally and theoretically.

Energy consumption and CO2 emissions of industrial process technologies. Saving potentials, barriers and instruments

International Nuclear Information System (INIS)

Fleiter, Tobias; Schlomann, Barbara; Eichhammer, Wolfgang

2013-01-01

Which contribution can the increase of energy efficiency achieve in the industry energy for the energy transition in Germany? To answer this question a model-based analysis of existing energy efficiency potentials of the energy-intensive industries is performed, which account for about 70% of the total energy demand of the industry. Based on this industry for each sector are instruments proposed for the implementation of the calculated potential and to overcome the existing barriers. [de

Fusion barriers in heavy ion collisions

International Nuclear Information System (INIS)

Zhu Long; Su Jun; Xie Wenjie; Guo Chenchen; Zhang Donghong; Zhang Fengshou

2014-01-01

Study of fusion barrier is very important for people to better understand fusion reactions. In this paper the Improved Isospin-dependent Quantum Molecular Dynamics (ImIQMD) model is introduced firstly. Then the shell correction effects, energy dependence, isospin effects and orientation effects of fusion barrier are studied. The fusion barriers for the fusion reactions "4"0Ca + "4"0Ca, "4"8Ca + "2"0"8Pb, "4"8Ca + "2"0"4Pb and "1"6O + "1"5"4Sm are extracted. The negative shell correction energies lower potential barriers of a certain reaction. A complex phenomenon of energy dependence is observed. It is also found that incident energy dependence of the barrier radius and barrier height shows opposite behaviors. The Coulomb potential shows weak energy dependence when distance of two colliding nuclei is lower than the touching distance. The isospin effects of the potential barrier are investigated. The orientation effects of the potential barrier are also discussed for the system "1"6O + "1"5"4Sm. (authors)

Driven diffusion against electrostatic or effective energy barrier across α-hemolysin

Energy Technology Data Exchange (ETDEWEB)

Ansalone, Patrizio [Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, Torino, IT-10135 (Italy); Chinappi, Mauro [Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Via Regina Elena 291, 00161 Roma (Italy); Rondoni, Lamberto [Scienze Matematiche, Politecnico di Torino Corso Duca degli Abruzzi 24, Torino, IT-10129, Italy and INFN, Sez. di Torino, Via P. Giuria 1, Torino IT-10125 (Italy); Cecconi, Fabio, E-mail: fabio.cecconi@roma1.infn.it [CNR-Istituto dei Sistemi Complessi UoS “Sapienza,” Via dei Taurini 19, 00185 Roma (Italy)

2015-10-21

We analyze the translocation of a charged particle across an α-Hemolysin (αHL) pore in the framework of a driven diffusion over an extended energy barrier generated by the electrical charges of the αHL. A one-dimensional electrostatic potential is extracted from the full 3D solution of the Poisson’s equation. We characterize the particle transport under the action of a constant forcing by studying the statistics of the translocation time. We derive an analytical expression of translocation time average that compares well with the results from Brownian dynamic simulations of driven particles over the electrostatic potential. Moreover, we show that the translocation time distributions can be perfectly described by a simple theory which replaces the true barrier by an equivalent structureless square barrier. Remarkably, our approach maintains its accuracy also for low-applied voltage regimes where the usual inverse-Gaussian approximation fails. Finally, we discuss how the comparison between the simulated time distributions and their theoretical prediction results to be greatly simplified when using the notion of the empirical Laplace transform technique.

9Be+120Sn scattering at near-barrier energies within a four-body model

Science.gov (United States)

Arazi, A.; Casal, J.; Rodríguez-Gallardo, M.; Arias, J. M.; Lichtenthäler Filho, R.; Abriola, D.; Capurro, O. A.; Cardona, M. A.; Carnelli, P. F. F.; de Barbará, E.; Fernández Niello, J.; Figueira, J. M.; Fimiani, L.; Hojman, D.; Martí, G. V.; Martínez Heimman, D.; Pacheco, A. J.

2018-04-01

Cross sections for elastic and inelastic scattering of the weakly bound 9Be nucleus on a 120Sn target have been measured at seven bombarding energies around and above the Coulomb barrier. The elastic angular distributions are analyzed with a four-body continuum-discretized coupled-channels (CDCC) calculation, which considers 9Be as a three-body projectile (α +α +n ). An optical model analysis using the São Paulo potential is also shown for comparison. The CDCC analysis shows that the coupling to the continuum part of the spectrum is important for the agreement with experimental data even at energies around the Coulomb barrier, suggesting that breakup is an important process at low energies. At the highest incident energies, two inelastic peaks are observed at 1.19(5) and 2.41(5) MeV. Coupled-channels (CC) calculations using a rotational model confirm that the first inelastic peak corresponds to the excitation of the 21+ state in 120Sn, while the second one likely corresponds to the excitation of the 31- state.

Energy barrier of bcc-fcc phase transition via the Bain path in Yukawa system

Science.gov (United States)

Kiyokawa, Shuji

2018-05-01

In the Yukawa system with the dimensionless screening parameter κ>1.5 , when bcc-fcc transition occurs via Bain path, we show that spontaneous transitions do not occur even if the system temperature reaches the transition point of bcc-fcc because it is necessary to increase once the free energy in the process of transition from bcc to fcc through Bain deformation. Here, we refer the temporary increment of the free energy during Bain deformation as Bain barrier. Since there are the Bain barriers at the transitions between bcc and fcc phases, these phases may coexist as metastable state in the wide region (not a coexistence line) of κ and the coupling constant Γ. We study the excess energy of the system and the free energy difference between bcc and fcc phases by the Monte Carlo method, where the simulation box is divided into a large number of elements with small volume and a particle in the box is restricted be placed in one of these elements. By this method, we can tabulate the values of the interparticle potential and can calculate the internal energy fast and precisely.

Reaction channels of 6,7Li+28Si at near-barrier energies

International Nuclear Information System (INIS)

Pakou, A; Rusek, K; Nicolis, N G; Alamanos, N; Doukelis, G; Gillibert, A; Kalyva, G; Kokkoris, M; Lagoyannis, A; Musumarra, A; Papachristodoulou, C; Perdikakis, G; Pierroutsakou, D; Pollacco, E C; Spyrou, A; Zarkadas, Ch

2005-01-01

The production of α-particles in the reactions 6,7 Li+ 28 Si was studied as a means to disentangle the various reaction channels at near-barrier energies. The competition between compound and direct reactions was determined by using the shape of angular distributions and statistical model calculations. DWBA calculations were also performed to probe the various direct channels. It was found that, approaching barrier, transfer channels are the most dominant for both reactions. For 7 Li+ 28 Si d-transfer is one of the contributing channels without excluding t-transfer, while for 6 Li+ 28 Si, n-transfer and p-transfer have substantial contribution but without excluding d-transfer

Energy transfer of excitons between quantum wells separated by a wide barrier

International Nuclear Information System (INIS)

Lyo, S. K.

2000-01-01

We present a microscopic theory of the excitonic Stokes and anti-Stokes energy-transfer mechanisms between two widely separated unequal quantum wells with a large energy mismatch (Δ) at low temperatures (T). Several important intrinsic energy-transfer mechanisms have been examined, including dipolar coupling, real and virtual photon-exchange coupling, and over-barrier ionization of the excitons via exciton-exciton Auger processes. The transfer rate is calculated as a function of T and the center-to-center distance d between the wells. The rates depend sensitively on T for plane-wave excitons. For localized excitons, the rates depend on T only through the T dependence of the exciton localization radius. For Stokes energy transfer, the dominant energy transfer occurs through a photon-exchange interaction, which enables the excitons from the higher-energy wells to decay into free electrons and holes in the lower-energy wells. The rate has a slow dependence on d, yielding reasonable agreement with recent data from GaAs/Al x Ga 1-x As quantum wells. The dipolar rate is about an order of magnitude smaller for large d (e.g., d=175Aa) with a stronger range dependence proportional to d -4 . However, the latter can be comparable to the radiative rate for small d (e.g., d≤80Aa). For anti-Stokes transfer through exchange-type (e.g., dipolar and photon-exchange) interactions, we show that thermal activation proportional to exp(-Δ/k B T) is essential for the transfer, contradicting a recent nonactivated result based on the Fo''rster-Dexter's spectral-overlap theory. Phonon-assisted transfer yields a negligibly small rate. On the other hand, energy transfer through over-barrier ionization of excitons via Auger processes yields a significantly larger nonactivated rate which is independent of d. The result is compared with recent data

High-energy intermediates in protein unfolding characterized by thiol labeling under nativelike conditions.

Science.gov (United States)

Malhotra, Pooja; Udgaonkar, Jayant B

2014-06-10

A protein unfolding reaction usually appears to be so dominated by a large free energy barrier that identifying and characterizing high-energy intermediates and, hence, dissecting the unfolding reaction into multiple structural transitions have proven to be a challenge. In particular, it has been difficult to identify any detected high-energy intermediate with the dry (DMG) and wet (WMG) molten globules that have been implicated in the unfolding reactions of at least some proteins. In this study, a native-state thiol labeling methodology was used to identify high-energy intermediates, as well as to delineate the barriers to the disruption of side chain packing interactions and to site-specific solvent exposure in different regions of the small protein, single-chain monellin (MNEI). Labeling studies of four single-cysteine-containing variants of MNEI have identified three high-energy intermediates, populated to very low extents under nativelike conditions. A significant dispersion in the opening rates of the cysteine side chains has allowed multiple steps, leading to the loss of side chain packing, to be resolved temporally. A detailed structural analysis of the positions of the four cysteine residue positions, which are buried to different depths within the protein, has suggested a direct correlation with the structure of a DMG, detected in previous studies. It is observed that side chain packing within the core of the protein is maintained, while that at the surface is disrupted, in the DMG. The core of the protein becomes solvent-exposed only in a WMG populated after the rate-limiting step of unfolding at high denaturant concentrations.

The Schottky energy barrier dependence of charge injection in organic light-emitting diodes

Energy Technology Data Exchange (ETDEWEB)

Campbell, I.H.; Davids, P.S.; Smith, D.L. [Los Alamos National Laboratory, Los Alamos, New Mexico87545 (United States); Barashkov, N.N.; Ferraris, J.P. [The University of Texas at Dallas, Richardson, Texas75083 (United States)

1998-04-01

We present device model calculations of the current{endash}voltage (I{endash}V) characteristics of organic diodes and compare them with measurements of structures fabricated using MEH-PPV. The structures are designed so that all of the current is injected from one contact. The I{endash}V characteristics are considered as a function of the Schottky energy barrier to charge injection from the contact. Experimentally, the Schottky barrier is varied from essentially zero to more than 1 eV by using different metal contacts. A consistent description of the device I{endash}V characteristics is obtained as the Schottky barrier is varied from small values, less than about 0.4 eV, where the current flow is space-charge limited to larger values where it is contact limited. {copyright} {ital 1998 American Institute of Physics.}

High speed PVD thermal barrier coatings

Energy Technology Data Exchange (ETDEWEB)

Beele, W. [Sulzer Metco Coatings BV (Netherlands); Eschendorff, G. [Sulzer Metco Coatings BV (Netherlands); Eldim BV (Netherlands)

2006-07-15

The high speed PVD process (HS-PVD) combines gas phase coating synthesis with high deposition rates. The process has been demonstrated for high purity YSZ deposited as a chemically bonded top thermal barrier with columnar structure of EB-PVD features. The process can manufacture EB-PVD like coatings that match in regards to their TGO-formation and columnar structure. Coatings with a columnar structure formed by individual columns of 1/4 of the diameter of a classical EB-PVD type TBC have been deposited. These coatings have the potential to prove a significant reduction in thermal conductivity and in erosion performance. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

High speed PVD thermal barrier coatings

International Nuclear Information System (INIS)

Beele, W.; Eschendorff, G.

2006-01-01

The high speed PVD process (HS-PVD) combines gas phase coating synthesis with high deposition rates. The process has been demonstrated for high purity YSZ deposited as a chemically bonded top thermal barrier with columnar structure of EB-PVD features. The process can manufacture EB-PVD like coatings that match in regards to their TGO-formation and columnar structure. Coatings with a columnar structure formed by individual columns of 1/4 of the diameter of a classical EB-PVD type TBC have been deposited. These coatings have the potential to prove a significant reduction in thermal conductivity and in erosion performance. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Investigation of Ozone Yield of Air Fed Ozonizer by High Pressure Homogeneous Dielectric Barrier Discharge

Science.gov (United States)

2013-07-01

around 2 ms and 12 ms in this figure, and during the discharge period, the current was continuous without any pulse . Once a discharge generated in...electron avalanches [10]. Fig. 1. High pressure ozone generator. (a) Top view (b) Side view Fig. 2. Barrier discharge device. Table 1... discharge N. Osawa P1 P, UY. Yoshioka UP2 P, R. Hanaoka P1 P 1 Center for Electric, Optic and Energy applications, Department of Electric and

Barriers to and drivers of the adpotion of energy crops by Swedish farmers: An empirical approach

Energy Technology Data Exchange (ETDEWEB)

Jonsson, Anna C.; Ostwald, Madelene; Asplund, Therese; Wibeck, Victoria (Linkoeping Univ., Linkoeping (Sweden). The Tema Inst., Centre for Climate Science and Policy Research)

2011-06-15

Since the Swedish government and the EU intend to encourage farmers to expand energy crop production, knowledge of the factors motivating adoption decisions is vital to policy success. Earlier studies have demonstrated that important barriers to farmer adoption of energy crops include converting from annual to perennial crops and from traditional crops or production systems to new ones. Economic motivations for changing production systems are strong, but factors such as values (e.g., aesthetics), knowledge (e.g., habits and knowledge of production methods), and legal conditions (e.g., cultivation licenses) are crucial for the change to energy crops. This paper helps fill gaps in the literature regarding why farmers decide to keep or change a production system. Based on a series of focus group interviews with Swedish farmers, the paper explores how farmers frame crop change decisions and what factors they consider most important. The main drivers of and barriers to growing energy crops, according to interviewees, are grouped and discussed in relation to four broad groups of motivational factors identified in the literature, i.e., values, legal conditions, knowledge, and economic factors. The paper ends by discussing whether some barriers could be overcome by policy changes at the national and European levels

Polymer in a pore: Effect of confinement on the free energy barrier

Science.gov (United States)

Kumar, Sanjiv; Kumar, Sanjay

2018-06-01

We investigate the transfer of a polymer chain from cis- side to trans- side through two types of pores: cone-shaped channel and flat-channel. Using the exact enumeration technique, we obtain the free energy landscapes of a polymer chain for such systems. We have also calculated the free-energy barrier of a polymer chain attached to the edge of the pore. The model system allows us to calculate the force required to pull polymer from the pore and stall-force to confine polymer within the pore.

Transmission electron microscopy study for investigating high-temperature reliability of Ti10W90-based and Ta-based diffusion barriers up to 600 C

International Nuclear Information System (INIS)

Budhiman, Nando; Schuermann, Ulrich; Kienle, Lorenz; Jensen, Bjoern; Chemnitz, Steffen; Wagner, Bernhard

2016-01-01

Abstractauthoren Transmission electron microscopy (TEM) analysis, including energy dispersive X-ray (EDX) (elemental mapping, line, and point measurements) and energy filtered TEM (EFTEM) methods, is applied to investigate the high temperature reliability, especially material diffusion, of two types of diffusion barriers: titanium-tungsten-based (Ti 10 W 90 -based) and tantalum-based (Ta-based), with nickel (Ni) layer on top. Both barriers were deposited as a form of stacked layers on sili-con (Si) wafers using the physical vapor deposition (PVD) technique. TEM analysis is performed on both barriers before and after annealing (at 600 C for 24 h inside a vacuum chamber). No diffusion of material into the Si substrate as observed. Additionally, only diffusion between the Ni and adjoining Ti 10 W 90 layers, and between Ni and adjoining Ta layers in the Ti 10 W 90 -based and Ta-based barriers, respectively, are observed due to annealing. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Reduction of the energy of secondary beams down to the Coulomb barrier

International Nuclear Information System (INIS)

Yang Yong Feng; Mittig, W.; Roussel-Chomaz, P.; Lewitowicz, M.; Sida, J.L.; Alamanos, N.; Auger, F.; Gillibert, A.; Volant, C.; Cabot, C.; Borcea, C.

1993-01-01

With the doubly achromatic spectrometer LISE at GANIL, the energy of a secondary 11 Be beam produced by the reaction of 63 MeV/nucleon 18 O with a 9 Be target has been reduced to Coulomb barrier energies using various thick targets and a thinner target plus a thick degrader. The experimental results were compared with calculations performed with the program INTENSITY and with simple analytical expressions. It was found that in the present device, the thick target method is more convenient and efficient than the achromatic degrader

Role of structural barriers for carotenoid bioaccessibility upon high pressure homogenization.

Science.gov (United States)

Palmero, Paola; Panozzo, Agnese; Colle, Ines; Chigwedere, Claire; Hendrickx, Marc; Van Loey, Ann

2016-05-15

A specific approach to investigate the effect of high pressure homogenization on the carotenoid bioaccessibility in tomato-based products was developed. Six different tomato-based model systems were reconstituted in order to target the specific role of the natural structural barriers (chromoplast substructure/cell wall) and of the phases (soluble/insoluble) in determining the carotenoid bioaccessibility and viscosity changes upon high pressure homogenization. Results indicated that in the absence of natural structural barriers (carotenoid enriched oil), the soluble and insoluble phases determined the carotenoid bioaccessibility upon processing whereas, in their presence, these barriers governed the bioaccessibility. Furthermore, it was shown that the increment of the viscosity upon high pressure homogenization is determined by the presence of insoluble phase, however, this result was related to the initial ratio of the soluble:insoluble phases in the system. In addition, no relationship between the changes in viscosity and carotenoid bioaccessibility upon high pressure homogenization was found. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transportation Energy Futures Series: Non-Cost Barriers to Consumer Adoption of New Light-Duty Vehicle Technologies

Energy Technology Data Exchange (ETDEWEB)

Stephens, T.

2013-03-01

Consumer preferences are key to the adoption of new vehicle technologies. Barriers to consumer adoption include price and other obstacles, such as limited driving range and charging infrastructure; unfamiliarity with the technology and uncertainty about direct benefits; limited makes and models with the technology; reputation or perception of the technology; standardization issues; and regulations. For each of these non-cost barriers, this report estimates an effective cost and summarizes underlying influences on consumer preferences, approximate magnitude and relative severity, and assesses potential actions, based on a comprehensive literature review. While the report concludes that non-cost barriers are significant, effective cost and potential market share are very uncertain. Policies and programs including opportunities for drivers to test drive advanced vehicles, general public outreach and information programs, incentives for providing charging and fueling infrastructure, and development of technology standards were examined for their ability to address barriers, but little quantitative data exists on the effectiveness of these measures. This is one in a series of reports produced as a result of the Transportation Energy Futures project, a Department of Energy-sponsored multi-agency effort to pinpoint underexplored strategies for reducing GHGs and petroleum dependence related to transportation.

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

Science.gov (United States)

Li, Jianlin; Du, Zhijia; Ruther, Rose E.; AN, Seong Jin; David, Lamuel Abraham; Hays, Kevin; Wood, Marissa; Phillip, Nathan D.; Sheng, Yangping; Mao, Chengyu; Kalnaus, Sergiy; Daniel, Claus; Wood, David L.

2017-09-01

Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by 70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.

Fusion enhancement at near and sub-barrier energies in {sup 19}O + {sup 12}C

Energy Technology Data Exchange (ETDEWEB)

Singh, Varinderjit; Vadas, J.; Steinbach, T.K.; Wiggins, B.B.; Hudan, S. [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Souza, R.T. de, E-mail: deSouza@indiana.edu [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Lin, Zidu; Horowitz, C.J. [Department of Physics and Center for Exploration of Energy and Matter, Indiana University, 2401 Milo B. Sampson Lane, Bloomington, IN 47408 (United States); Baby, L.T.; Kuvin, S.A.; Tripathi, Vandana; Wiedenhöver, I. [Department of Physics, Florida State University, Tallahassee, FL 32306 (United States); Umar, A.S. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States)

2017-02-10

Measuring the fusion excitation function for an isotopic chain of projectile nuclei provides a stringent test of a microscopic description of fusion. We report the first measurement of the fusion excitation function at near-barrier energies for the {sup 19}O + {sup 12}C system. The measured excitation function is compared with the fusion excitation function of {sup 18}O + {sup 12}C. A significant enhancement in the fusion probability of {sup 19}O ions with a {sup 12}C target as compared to {sup 18}O ions is observed. The experimental cross-sections observed at near-barrier energies are compared with a state-of-the-art microscopic model.

Single event upset and charge collection measurements using high energy protons and neutrons

International Nuclear Information System (INIS)

Normand, E.; Oberg, D.L.; Wert, J.L.; Ness, J.D.; Majewski, P.P.; Wender, S.; Gavron, A.

1994-01-01

RAMs, microcontrollers and surface barrier detectors were exposed to beams of high energy protons and neutrons to measure the induced number of upsets as well as energy deposition. The WNR facility at Los Alamos provided a neutron spectrum similar to that of the atmospheric neutrons. Its effect on devices was compared to that of protons with energies of 200, 400, 500, and 800 MeV. Measurements indicate that SEU cross sections for 400 MeV protons are similar to those induced by the atmospheric neutron spectrum

Partitioning of methyl internal rotational barrier energy of ...

Indian Academy of Sciences (India)

The nature of methyl internal rotational barrier in thioacetaldehyde has been investigated by relaxation effect, natural bond orbital (NBO) analysis and Pauling exchange interactions. The true experimental barrier can be obtained by considering fully relaxed rotation. Nuclear-electron attraction term is a barrier forming term in ...

ANALYSIS OF BARRIERS IN LISTENING COMPREHENSION AMONG JUNIOR HIGH SCHOOL STUDENTS

Directory of Open Access Journals (Sweden)

Setia Muljanto

2012-12-01

Full Text Available This research paper identifies barriers and difficulties in listening comprehension faced by junior high school students. The research questions were what barriers did students encounter and how did they used strategies to overcome those barriers. This study used a qualitative method and was a case study involving 40 students and one English teacher. The data were obtained by ways of conducting a test of listening taken from TOEIC test. The tests indicated that the results scores were not quite satisfactory. This is primarily caused by speech delivery of the native speaker which was too fast. This means that students faced listening barriers especially in processing information. The data also indicated that students were also nervous when doing the test as habitual barrier. Strategies used to overcome these barriers are by making students get used to listen and use English and making them familiar with certain contexts in real life.

SOLPLAN Report: An Assessment of Barriers and Incentives to Conservation and Alternative-Energy Use in the Residential Sector in Wisconsin

Energy Technology Data Exchange (ETDEWEB)

Fulenwider, Claire K.; Weiss, Lonnie S.; Pfefferkorn, Carol; Wiener, Don E.; Feldman, Stephen L.

1981-03-01

The Alternative Energy Policy Project of the Wisconsin Center for Public Policy focused upon two principle objectives: (1) gathering and analyzing new and previously unavailable data on barriers and incentives to greater energy conservation and alternative energy commercialization in the state of Wisconsin; and (2) building consensus around alternative energy policy to develop guidelines for alternative energy policy for the state. Particular attention was paid to public involvement in the policy process and to assessing barriers and incentives from as many key sectors of the energy field as possible. Thus, data were gathered from the general public, alternative energy users, the heating industry generally, the alternative-energy industry specifically, and key decision makers. The report is divided into four principal sections. The first looks at findings and analyses dealing with barriers to greater conservation and alternative energy use. Incentives for accelerating the extent of residential conservation and alternative energy use are discussed in the second section. The decision-making process itself in energy policy has been little analyzed and seldom documented. The role of consensus-building in the alternative-energy field and analysis of the decision-making process are discussed in Section III. Appendices in Section IV provide survey instruments and descriptions, a compendium of energy-related legislation developed within the project, and various reports. The total report reflects the interactive decision-making model as it was applied in SOLPLAN. (MCW)

Computing the Free Energy Barriers for Less by Sampling with a Coarse Reference Potential while Retaining Accuracy of the Target Fine Model.

Science.gov (United States)

Plotnikov, Nikolay V

2014-08-12

Proposed in this contribution is a protocol for calculating fine-physics (e.g., ab initio QM/MM) free-energy surfaces at a high level of accuracy locally (e.g., only at reactants and at the transition state for computing the activation barrier) from targeted fine-physics sampling and extensive exploratory coarse-physics sampling. The full free-energy surface is still computed but at a lower level of accuracy from coarse-physics sampling. The method is analytically derived in terms of the umbrella sampling and the free-energy perturbation methods which are combined with the thermodynamic cycle and the targeted sampling strategy of the paradynamics approach. The algorithm starts by computing low-accuracy fine-physics free-energy surfaces from the coarse-physics sampling in order to identify the reaction path and to select regions for targeted sampling. Thus, the algorithm does not rely on the coarse-physics minimum free-energy reaction path. Next, segments of high-accuracy free-energy surface are computed locally at selected regions from the targeted fine-physics sampling and are positioned relative to the coarse-physics free-energy shifts. The positioning is done by averaging the free-energy perturbations computed with multistep linear response approximation method. This method is analytically shown to provide results of the thermodynamic integration and the free-energy interpolation methods, while being extremely simple in implementation. Incorporating the metadynamics sampling to the algorithm is also briefly outlined. The application is demonstrated by calculating the B3LYP//6-31G*/MM free-energy barrier for an enzymatic reaction using a semiempirical PM6/MM reference potential. These modifications allow computing the activation free energies at a significantly reduced computational cost but at the same level of accuracy compared to computing full potential of mean force.

Thermal barrier coatings (TBC's) for high heat flux thrust chambers

Science.gov (United States)

Bradley, Christopher M.

The last 30 years materials engineers have been under continual pressure to develop materials with a greater temperature potential or to produce configurations that can be effectively cooled or otherwise protected at elevated temperature conditions. Turbines and thrust chambers produce some of the harshest service conditions for materials which lead to the challenges engineers face in order to increase the efficiencies of current technologies due to the energy crisis that the world is facing. The key tasks for the future of gas turbines are to increase overall efficiencies to meet energy demands of a growing world population and reduce the harmful emissions to protect the environment. Airfoils or blades tend to be the limiting factor when it comes to the performance of the turbine because of their complex design making them difficult to cool as well as limitations of their thermal properties. Key tasks for space transportation it to lower costs while increasing operational efficiency and reliability of our space launchers. The important factor to take into consideration is the rocket nozzle design. The design of the rocket nozzle or thrust chamber has to take into account many constraints including external loads, heat transfer, transients, and the fluid dynamics of expanded hot gases. Turbine engines can have increased efficiencies if the inlet temperature for combustion is higher, increased compressor capacity and lighter weight materials. In order to push for higher temperatures, engineers need to come up with a way to compensate for increased temperatures because material systems that are being used are either at or near their useful properties limit. Before thermal barrier coatings were applied to hot-section components, material alloy systems were able to withstand the service conditions necessary. But, with the increased demand for performance, higher temperatures and pressures have become too much for those alloy systems. Controlled chemistry of hot

Investigation of significantly high barrier height in Cu/GaN Schottky diode

Directory of Open Access Journals (Sweden)

Manjari Garg

2016-01-01

Full Text Available Current-voltage (I-V measurements combined with analytical calculations have been used to explain mechanisms for forward-bias current flow in Copper (Cu Schottky diodes fabricated on Gallium Nitride (GaN epitaxial films. An ideality factor of 1.7 was found at room temperature (RT, which indicated deviation from thermionic emission (TE mechanism for current flow in the Schottky diode. Instead the current transport was better explained using the thermionic field-emission (TFE mechanism. A high barrier height of 1.19 eV was obtained at room temperature. X-ray photoelectron spectroscopy (XPS was used to investigate the plausible reason for observing Schottky barrier height (SBH that is significantly higher than as predicted by the Schottky-Mott model for Cu/GaN diodes. XPS measurements revealed the presence of an ultrathin cuprous oxide (Cu2O layer at the interface between Cu and GaN. With Cu2O acting as a degenerate p-type semiconductor with high work function of 5.36 eV, a high barrier height of 1.19 eV is obtained for the Cu/Cu2O/GaN Schottky diode. Moreover, the ideality factor and barrier height were found to be temperature dependent, implying spatial inhomogeneity of barrier height at the metal semiconductor interface.

Physical activity barriers and motivators among high-risk employees.

Science.gov (United States)

Paguntalan, John C; Gregoski, Mathew

2016-11-22

Worksite wellness programs offer an ideal setting to target high-risk sedentary workers to improve health status. Lack of physical activity is associated with increased risk for coronary heart disease and mortality. Despite the risks, the number of sedentary workers is increasing. This study examined the perceived barriers and motivators for physical activity among employees at high-risk for coronary heart disease. A purposive sample of 24 high-risk workers participating in a wellness program in rural South Carolina were enrolled in the study. Qualitative data was obtained through semi-structured face-to-face interviews. Grounded theory was used to analyze qualitative data, and identify overarching themes. Physical limitations due to pain and weakness, lack of motivation, and lack of time emerged as the main barriers to physical activity. Family relationships were reported as the strongest motivator along with social support and potential health benefits. Findings highlight the unique experience of high-risk workers with physical activity. The findingsunderscore the need to design and implement effective interventions specifically designed to meet the needs of high-risk employees.

Liquid-drop model description of heavy ion fusion at sub-barrier energies

Energy Technology Data Exchange (ETDEWEB)

Aguiar, C E; Barbosa, V C; Canto, L F; Donangelo, R

1987-10-05

The enhancement of the heavy ion fusion cross section at sub-barrier energies is studied in the liquid-drop model approach. The shape of the system is described by two spheres smoothly connected by a neck, and the kinetic and potential energies are calculated within this parametrization. Underbarrier fusion cross sections for symmetric projectile-target combinations are calculated in the WKB approximation and a comparison with the available data is made. The agreement is quite satisfactory, except for those systems in which the reaction is strongly affected by the details of the nuclear structure of the collision partners.

Potential and barrier study. Energy efficiency of Norwegian homes; Potensial- og barrierestudie. Energieffektivisering av norske boliger

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-01

Enova has identified potentials and barriers for energy efficiency in Norwegian buildings. This report summarizes the results of this work. Efficient energy in buildings is important to ensure that future economic activity and growth can occur in a way that reduces the possibilities for an environmentally and economically sound development. (eb)

Fusion barrier distributions - What have we learned?

International Nuclear Information System (INIS)

Hinde, D. J.; Dasgupta, M.

1998-01-01

The study of nuclear fusion received a strong impetus from the realisation that an experimental fusion barrier distribution could be determined from precisely measured fusion cross-sections. Experimental data for different reactions have shown in the fusion barrier distributions clear signatures of a range of nuclear excitations, for example the effects of static quadrupole and hexadecapole deformations, single- and double-phonon states, transfer of nucleons, and high-lying excited states. The improved understanding of fusion barrier distributions allows more reliable prediction of fusion angular momentum distributions, which aids interpretation of fission probabilities and fission anisotropies, and understanding of the population of super-deformed bands for nuclear structure studies. Studies of the relationship between the fusion barrier distribution and the extra-push energy should improve our understanding of the mechanism of the extra-push effect, and may help to predict new ways of forming very heavy or super-heavy nuclei

Measurement of Fission Fragment Angular Distributions for 14 N+ 232 Th and 11 B+ 235 U at Near-Barrier Energies

International Nuclear Information System (INIS)

Behera, B.R.; Jena, S.; Satapathy, M.; Ison, V.V.; Kailas, S.; Chatterjee, A.; Shrivastava, A.; Mahata, K.; Satpathy, L.; Basu, P.; Roy, S.; Sharan, M.; Chatterjee, M.L; Datta, S.K.

2000-01-01

Fission fragment angular distributions of heavy-ion induced fission in actinide nuclei at near-barrier energies show anomalous fragment anisotropies. At above barrier energies entrance channel dependence is a probable cause and explanation in terms of pre-equilibrium fission and the critical mass asymmetry parameter (Businaro-Gallone) has been tried. Target deformation and ground state spin also seem to influence the measured anisotropy. To understand the extent of importance of some or all of these features, we performed a set of experiments where (i) entrance channel dependence (ii) mass asymmetry on the two sides of Businaro-Gallone and (iii) different ground state spins are present. The channels chosen are 14 N+ 232 Th and 11 B+ 235 U. Experiments were done using the Pelletron accelerators at NSC, New Delhi and BARC-TIFR, Bombay. Compound nucleus populated in both cases is 246 Bk. 232 Th has ground state spin zero and 235 U has spin 7/2. Fragment anisotropies have been measured from 10-15 % above barrier to 10 % below barrier at similar excitation energy (around 40 MeV to 58 MeV). The mean square angular momentum is matched at least at one energy. Results indicate that when both excitation energy and angular momentum are matched, there are differences in the measured values of fission anisotropies. This implies entrance channel dependence consistent with the expectation of pre-equilibrium fission model. (authors)

Factors Affecting Energy Barriers for Pyramidal Inversion in Amines and Phosphines: A Computational Chemistry Lab Exercise

Science.gov (United States)

Montgomery, Craig D.

2013-01-01

An undergraduate exercise in computational chemistry that investigates the energy barrier for pyramidal inversion of amines and phosphines is presented. Semiempirical calculations (PM3) of the ground-state and transition-state energies for NR[superscript 1]R[superscript 2]R[superscript 3] and PR[superscript 1]R[superscript 2]R[superscript 3] allow…

Origins and implications of temperature-dependent activation energy barriers for dislocation nucleation in face-centered cubic metals

International Nuclear Information System (INIS)

Warner, D.H.; Curtin, W.A.

2009-01-01

The linking of atomistic simulations of stress-driven processes to experimentally observed mechanical behavior via the computation of activation energy barriers is a topic of intense current research. Using dislocation nucleation from a crack tip as the reaction process, long-time multiscale molecular dynamics simulations show that the activation barrier can exhibit significant temperature dependence. Using an analytic model for the nucleation process and computing the relevant material properties (elastic constants and stacking fault energies), the temperature dependence is shown to arise primarily from the temperature dependence of the material parameters for both Al and Ni. After thermally activated emission of the first partial dislocation, there is then a competition between two other thermally activated processes: twinning and full dislocation emission. Because the activation barriers depend on temperature, this transition is more complex than usually envisioned. Simulations in Al reveal that a transition from twinning to full dislocation emission back to twinning occurs with increasing temperature, which is counter to traditional metallurgical wisdom. Temperature-dependent activation energies are thus essential to accurate understanding and prediction of those phenomena that control fracture and deformation in metals at realistic loading rates.

Temperature dependence of the distribution of the thermally activated energy barriers in Tl2Ba2CaCu2O8 film

International Nuclear Information System (INIS)

Ren, C.; Lin, F.Y.; Ding, S.Y.; Li, Z.M.; Aruna, S.A.; Qiu, L.; Yao, X.X.; Yan, S.L.; Si, M.S.

1999-01-01

The effects of frequency and ac amplitude on ac susceptibility have been measured for a thin Tl 2 Ba 2 CaCu 2 O 8 film in the range 100 Hz-100 kHz in magnetic field 0.52 T. A phenomenological equation with an asymmetrical distribution of thermally activated energy barriers has been used to analyse these frequency and amplitude dependences of the ac susceptibility χ(ω,h ac ) in the vicinity of the peak temperature of χ''. We obtain the effective energy barrier U against amplitude h ac (current density j): U h ac -0.38 . This U(j) relationship shows that the flux lines are in the 3D collective creep regime. Therefore, we conclude that the effective energy barrier is in fact an average of the barrier's distribution, and the distribution function is a distinguished asymmetrical one in this 3D collective creep regime. (author)

US-China Clean Energy Research Center on Building Energy Efficiency: Materials that Improve the Cost-Effectiveness of Air Barrier Systems

Energy Technology Data Exchange (ETDEWEB)

Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-12-01

The US–China Clean Energy Research Center (CERC) was launched in 2009 by US Energy Secretary Steven Chu, Chinese Minister of Science and Technology Wan Gang, and Chinese National Energy Agency Administrator Zhang Guobao. This 5-year collaboration emerged from the fact that the United States and China are the world’s largest energy producers, energy consumers, and greenhouse gas emitters, and that their joint effort could have significant positive repercussions worldwide. CERC’s main goal is to develop and deploy clean energy technologies that will help both countries meet energy and climate challenges. Three consortia were established to address the most pressing energy-related research areas: Advanced Coal Technology, Clean Vehicles, and Building Energy Efficiency (BEE). The project discussed in this report was part of the CERC-BEE consortia; its objective was to lower energy use in buildings by developing and evaluating technologies that improve the cost-effectiveness of air barrier systems for building envelopes.

Coastal barrier stratigraphy for Holocene high-resolution sea-level reconstruction.

Science.gov (United States)

Costas, Susana; Ferreira, Óscar; Plomaritis, Theocharis A; Leorri, Eduardo

2016-12-08

The uncertainties surrounding present and future sea-level rise have revived the debate around sea-level changes through the deglaciation and mid- to late Holocene, from which arises a need for high-quality reconstructions of regional sea level. Here, we explore the stratigraphy of a sandy barrier to identify the best sea-level indicators and provide a new sea-level reconstruction for the central Portuguese coast over the past 6.5 ka. The selected indicators represent morphological features extracted from coastal barrier stratigraphy, beach berm and dune-beach contact. These features were mapped from high-resolution ground penetrating radar images of the subsurface and transformed into sea-level indicators through comparison with modern analogs and a chronology based on optically stimulated luminescence ages. Our reconstructions document a continuous but slow sea-level rise after 6.5 ka with an accumulated change in elevation of about 2 m. In the context of SW Europe, our results show good agreement with previous studies, including the Tagus isostatic model, with minor discrepancies that demand further improvement of regional models. This work reinforces the potential of barrier indicators to accurately reconstruct high-resolution mid- to late Holocene sea-level changes through simple approaches.

Barriers and drivers for energy efficiency : Different perspectives from an exploratory study in the Netherlands

NARCIS (Netherlands)

Cagno, Enrico; Trianni, Andrea; Worrell, Ernst; Miggiano, Federica

2014-01-01

Increased energy efficiency represents a crucial opportunity for European industrial sustainability, but several barriers still need to be tackled, as recent policies have not often succeeded as expected. Thus, it is crucial to understand the existing mismatches between the perception of

High-performance blue phosphorescent OLEDs using energy transfer from exciplex.

Science.gov (United States)

Seino, Yuki; Sasabe, Hisahiro; Pu, Yong-Jin; Kido, Junji

2014-03-12

An efficient energy transfer from an exciplex between a sulfone and an arylamine derivatives to a blue phosphorescent emitter enables OLED performances among the best, of over 50 lm W(-1) at 100 cd m(-2) . The formation of the exciplex realizes a barrier-free hole-electron recombination pathway, thereby leading to high OLED performances with an extremely low driving voltage of 2.9 V at 100 cd m(-2) . © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Barriers on the propagation of renewable energy sources and sustainable solid waste management practices in Greece.

Science.gov (United States)

Boemi, Sn; Papadopoulos, Am; Karagiannidis, A; Kontogianni, S

2010-11-01

Renewable energy sources (RES), excluding large hydroelectric plants, currently produce 4.21% of total electricity production in Greece. Even when considering the additional production from large hydroelectric plants, which accounts for some 7.8%, the distance to be covered towards the objective of 20% electricity produced from RES by 2010 and respectively towards 20% of total energy production by 2020 is discouraging. The potential, however, does exist; unfortunately so do serious barriers. On the other hand, solid waste management (SWM) is an issue that generates continuously increasing interest due to the extra amounts of solid waste generated; the lack of existing disposal facilities with adequate infrastructure and integrated management plans, also often accompanied by legislative and institutional gaps. However, socio-economic and public awareness problems are still met in the planning and implementation of RES and SWM projects, together with the lack of a complete national cadastre and a spatial development master plan, specifying areas eligible for RES and SWM development. Specific barriers occur for individual RES and the on-going inclusion of waste-derived renewable energy in the examined palette further increases the complexity of the entire issue. The consolidated study of this broad set of barriers was a main task of the present study which was carried out within the frame of a Hellenic-Canadian research project; the main results will be discussed herein.

Barriers to electric energy efficiency in Ghana

Science.gov (United States)

Berko, Joseph Kofi, Jr.

Development advocates argue that sustainable development strategies are the best means to permanently improve living standards in developing countries. Advocates' arguments are based on the technical, financial, and environmental advantages of sustainable development. However, they have not addressed the organizational and administrative decision-making issues which are key to successful implementation of sustainable development in developing countries. Using the Ghanaian electricity industry as a case study, this dissertation identifies and analyzes organizational structures, administrative mechanisms, and decision-maker viewpoints that critically affect the success of adoption and implementation of energy efficiency within a sustainable development framework. Utilizing semi-structured interviews in field research, decision-makers' perceptions of the pattern of the industry's development, causes of the electricity supply shortfall, and barriers to electricity-use efficiency were identified. Based on the initial findings, the study formulated a set of policy initiatives to establish support for energy use efficiency. In a second set of interviews, these policy suggestions were presented to some of the top decision-makers to elicit their reactions. According to the decision-makers, the electricity supply shortfall is due to rapid urbanization and increased industrial consumption as a result of the structural adjustment program, rural electrification, and the sudden release of suppressed loads. The study found a lack of initiative and collaboration among industry decision-makers, and a related divergence in decision-makers' concerns and viewpoints. Also, lacking are institutional support systems and knowledge of proven energy efficiency strategies and technologies. As a result, planning, and even the range of perceived solutions to choose from are supply-side oriented. The final chapter of the study presents implications of its findings and proposes that any

Application of a Barrier Filter at a High Purity Synthetic Graphite Plant, CRADA 99-F035, Final Report

Energy Technology Data Exchange (ETDEWEB)

National Energy Technology Laboratory

2000-08-31

Superior Graphite Company and the US Department of Energy have entered into a Cooperative Research and Development Agreement (CRADA) to study the application of ceramic barrier filters at its Hopkinsville, Kentucky graphite plant. Superior Graphite Company is a worldwide leader in the application of advanced thermal processing technology to produce high purity graphite and carbons. The objective of the CRADA is to determine the technical and economic feasibility of incorporating the use of high-temperature filters to improve the performance of the offgas treatment system. A conceptual design was developed incorporating the ceramic filters into the offgas treatment system to be used for the development of a capital cost estimate and economic feasibility assessment of this technology for improving particulate removal. This CRADA is a joint effort of Superior Graphite Company, Parsons Infrastructure and Technology Group, and the National Energy Technology Laboratory (NETL) of the US Department of Energy (DOE).

High density internal transport barriers for burning plasma operation

International Nuclear Information System (INIS)

Pericoli Ridolfini, V.

2005-01-01

One of the proposed ITER scenarios foresees the creation and sustainment of an internal transport barrier (ITB) in order to improve the confinement properties of the hot core plasma. The more stringent requests are: the ITB must be sustained with electron heating only with no or very small external momentum source, the strong collisional coupling at the envisaged density (line average >1.0 1020 m-3) must not prevent the barrier existence, the bootstrap current created by the large induced gradients must have a radial profile consistent with that requested by the barrier creation and sustainment. To all these items the studies carried out in FTU in the same density range (ne0 ?1.5 1020 m-3) provide encouraging prospects. With pure electron heating and current drive (LH+ECH) steady electron barrier are generated and maintained with central e- temperature >5.0 keV. Almost full CD conditions are established with a bootstrap current close to 25% of the total and well aligned with that driven by the LH waves and responsible for the barrier building. The clear change in the density fluctuations close to the ITB radius, observed by reflectometry, indicates stabilization of turbulence that is consistent with the drop of the thermal electron diffusivity inside the ITB to very low values, ?e<0.5 m2/s estimated by the transport analysis. The 10 fold neutron rate increase testifies a significant collisional ion heating, even though usually ?Ti0/Ti0 does not exceed 40%, because the e--i + equipartition time, always 4-5 times longer than the energy confinement time, does not allow thermal equilibrium with electrons to be attained. The ion thermal diffusivity inside the barrier must be lowered to the neoclassical level to account for the observed Ti(r) profiles, clearly indicating at least a non-degraded ion transport. The global confinement in turn improves by 1.6 times above the FTU L-scaling. The ITB radius can be controlled by varying the LH power deposition profile that is

Barriers, drivers and decision-making process for industrial energy efficiency: A broad study among manufacturing small and medium-sized enterprises

International Nuclear Information System (INIS)

Trianni, Andrea; Cagno, Enrico; Farné, Stefano

2016-01-01

Highlights: • Barriers and drivers vary along the decision-making process of EEM adoption. • Economic barriers, awareness and behavioural are most critical. • Beside economic drivers, major relevance of regulatory and vocational training. • Importance of stakeholders providing technical support. • Barriers and drivers are different according to several firm characteristics. - Abstract: Energy efficiency has been recognized as a primary means to increase the competitiveness of the industrial sector, and in particular for small and medium-sized enterprises (SMEs), in which energy efficiency measures (EEMs) are scarcely implemented. For this reason, future policies should carefully address such issue. Hence, it is really crucial to have a precise and punctual knowledge of the barriers to be tackled in the decision-making process of adopting an EEM and the drivers to be promoted. This study discussed the findings from a broad investigation within 222 manufacturing SMEs located in a Northern Italy region. Beside economic issues particularly affecting SMEs, awareness and behavioural issues emerge as critical, affecting the very first steps of the decision-making process, related to the punctual identification and evaluation of plausible EEMs. The support from manufacturers, technology suppliers, installers and ESCOs supporting SMEs through vocational training drivers (e.g. technical support) is really important to tackle such issues. More generally, beside financial institutions, the supply chain of technologies is recognized as particularly useful for supporting enterprises in the adoption of EEMs. Additionally, having previously conducted energy audit and implemented EEMs are critical factors able to highlight non-economic barriers and drivers. Therefore, the promotion of EEMs will necessarily imply a further effort in pointing out the so-called non-energy benefits (NEBs) from the implementation of EEMs. Finally, our study reveals that smaller and non-energy

Alpha-production channels in 6Li+159Tb at energies around the Coulomb barrier

International Nuclear Information System (INIS)

Pradhan, M.K.; Mukherjee, A.; Roy, S.; Basu, P.; Goswami, A.; Saha Sarkar, M.; Kshetri, R.; Roy Chowdhury, R.; Ray, M.; Santra, S.; Kailas, S.; Parkar, V.V.; Palit, R.

2010-01-01

In order to investigate what are the dominant processes that might contribute to the inclusive α-particle channels, very recently measurements have been performed by the characteristic γ-ray method for the system 6 Li+ 159 Tb at energies below and above the Coulomb barrier (V B = 26.9 MeV)

Calculation of multidimensional potential energy surfaces for even-even transuranium nuclei: systematic investigation of the triaxiality effect on the fission barrier

Science.gov (United States)

Chai, Qing-Zhen; Zhao, Wei-Juan; Liu, Min-Liang; Wang, Hua-Lei

2018-05-01

Static fission barriers for 95 even-even transuranium nuclei with charge number Z = 94–118 have been systematically investigated by means of pairing self-consistent Woods-Saxon-Strutinsky calculations using the potential energy surface approach in multidimensional (β 2, γ, β 4) deformation space. Taking the heavier 252Cf nucleus (with the available fission barrier from experiment) as an example, the formation of the fission barrier and the influence of macroscopic, shell and pairing correction energies on it are analyzed. The results of the present calculated β 2 values and barrier heights are compared with previous calculations and available experiments. The role of triaxiality in the region of the first saddle is discussed. It is found that the second fission barrier is also considerably affected by the triaxial deformation degree of freedom in some nuclei (e.g., the Z=112–118 isotopes). Based on the potential energy curves, general trends of the evolution of the fission barrier heights and widths as a function of the nucleon numbers are investigated. In addition, the effects of Woods-Saxon potential parameter modifications (e.g., the strength of the spin-orbit coupling and the nuclear surface diffuseness) on the fission barrier are briefly discussed. Supported by National Natural Science Foundation of China (11675148, 11505157), the Project of Youth Backbone Teachers of Colleges and Universities of Henan Province (2017GGJS008), the Foundation and Advanced Technology Research Program of Henan Province (162300410222), the Outstanding Young Talent Research Fund of Zhengzhou University (1521317002) and the Physics Research and Development Program of Zhengzhou University (32410017)

Measurements of internal stresses in bond coating using high energy x-rays from synchrotron radiation source

CERN Document Server

Suzuki, K; Akiniwa, Y; Nishio, K; Kawamura, M; Okado, H

2002-01-01

Thermal barrier coating (TBC) techniques enable high temperature combustion of turbines made of Ni-base alloy. TBC is made of zirconia top coating on NiCoCrAlY bond coating. The internal stresses in the bond coating play essential role in the delamination or fracture of TBC in service. With the X-rays from laboratory equipments, it is impossible to measure nondestructively the internal stress in the bond coating under the top coating. synchrotron radiations with a high energy and high brightness have a large penetration depth as compared with laboratory X-rays. Using the high energy X-rays from the synchrotron radiation, it is possible to measure the internal stress in the bond coating through the top coating. In this study, the furnace, which can heat a specimen to 1473 K, was developed for the stress measurement of the thermal barrier coatings. The internal stresses in the bond coating were measured at the room temperature, 773 K, 1073 K and 1373 K by using the 311 diffraction from Ni sub 3 Al with about 73...

Future energy efficiency improvements within the US department of defense: Incentives and barriers

International Nuclear Information System (INIS)

Umstattd, Ryan J.

2009-01-01

The present work describes the military impact of improved efficiency and then highlights existing technological, political, and financial barriers for improving overall energy efficiency. As the largest user of energy within the US government, the Department of Defense (DOD) is rightly concerned that any disruption to the nation's energy supply may have an extremely adverse impact on its military capabilities. The total solution to providing energy security will be multi-faceted with progress required on many fronts. Increasing the use of renewable energy sources and improving energy storage capabilities are gradually creating a positive impact, but investing in improving the overall efficiency of the military effort provides both immediate and long-lasting payback. One might suppose that a decrease in the energy used by the DOD should lead to a decrease in military capability, but historical data proves otherwise. It is shown that the military has additional impetus, compared to civilian consumers, to pursue energy-efficiency improvements. Many tools are available to help the DOD along this path, yet there remain obstacles which must first be identified and analyzed as discussed herein.

Stochastic transport of particles across single barriers

International Nuclear Information System (INIS)

Kreuter, Christian; Siems, Ullrich; Henseler, Peter; Nielaba, Peter; Leiderer, Paul; Erbe, Artur

2012-01-01

Transport phenomena of interacting particles are of high interest for many applications in biology and mesoscopic systems. Here we present measurements on colloidal particles, which are confined in narrow channels on a substrate and interact with a barrier, which impedes the motion along the channel. The substrate of the particle is tilted in order for the particles to be driven towards the barrier and, if the energy gained by the tilt is large enough, surpass the barrier by thermal activation. We therefore study the influence of this barrier as well as the influence of particle interaction on the particle transport through such systems. All experiments are supported with Brownian dynamics simulations in order to complement the experiments with tests of a large range of parameter space which cannot be accessed in experiments.

Initiatives for the energy renovation of single-family houses inDenmark evaluated on the basis of barriers and motivators

DEFF Research Database (Denmark)

Grøn Bjørneboe, Matilde; Svendsen, Svend; Heller, Alfred

2018-01-01

The renovation of single-family houses in Denmark is progressing only slowly. Changes in current pol-icy are needed if the political goal of a fossil-free building sector as part of a fossil-free society is to beachieved. Known barriers and motivators for energy renovation are identified, and arr......The renovation of single-family houses in Denmark is progressing only slowly. Changes in current pol-icy are needed if the political goal of a fossil-free building sector as part of a fossil-free society is to beachieved. Known barriers and motivators for energy renovation are identified......, suggestions are madefor improvement in four areas: (1) focus on non-energy benefits rather than investment, (2) enhance-ment of subsidy system, (3) including relevant renovation plans in the energy performance certificate(EPC), and (4) long-term regulation on the maximum allowed energy consumption of houses....

Shielding Design and Leaking Measurement for the High Energy Radiation Room

International Nuclear Information System (INIS)

Chu, Sung Sil

1979-01-01

An optimum shielding design and the computation of protective barriers for high energy radiation therapy room, Toshiba 13 MeV , are presented. We obtained following results by comparison between the p recalculating values and actual survey after complete installation of radio generating units. 1. The precalculating values of protective barrier are 5 times more protective than that of actual measurement. 2. The dose rate during exposure are 2-10 mR /hr at out of the door and the control room. 3. The exposure doses for occupationally persons are relatively low levels, the average values of exposure dose is 10-50 mR per month. 4. The foul smelling and ozone gas production from long exposure of cancer patients cannot be eliminated when the room is ill ventilated

Identifying Barriers and Pathways to Success for Renewable Energy Development on American Indian Lands

Energy Technology Data Exchange (ETDEWEB)

Necefer, Len Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. of Arizona, Tucson, AZ (United States); Jones, Thomas Elisha [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States)

2016-11-01

American Indian tribes possess lands rich with renewable energy (RE) resources. Tribes have great potential and need to develop these resources, yet face a host of barriers that continue to impede development. Understanding these challenges as well as the pathways that can be taken to overcome them may facilitate more economic development to meet community needs and better position tribes to play a role in securing a low-carbon energy future for the United States. This paper presents the results of an expert elicitation of 24 tribal energy experts from federal, tribal, academic, and private industry backgrounds to identify barriers and opportunities for federally recognized tribes in the lower 48 states. Experts identified a number of unique challenges facing tribes including financing and funding, infrastructure, tribal leadership and staff, state-level influence, and partnerships. Cultural factors were seen only to be of concern with large-scale development. Tribal sovereignty is a significant motivation for RE development and has yet to be fully realized. Cultural considerations are critical to the success of future projects; smaller residential and community-scale projects may be a better fit. Improving partnerships between tribes and the private sector can increase RE deployment and overcome historical distrust. States can have a double-ended influence on projects within tribal lands through taxation.

Survey of the Relationship Between Activity Energy Expenditure Metabolic Equivalents and Barrier Factors of Physical Activity in the Elderly in Kashan

OpenAIRE

Sadrollahi, Ali; Khalili, Zahra; Pour Nazari, Robab; Mohammadi, Majid; Ahmadi Khatir, Maryam; Mossadegh, Najima

2016-01-01

Background Physical activity in the elderly is influenced by aspects of aging that cause personal, mental, environmental, and social changes. Increases in factors that are barriers to activity cause physical energy expenditure to decrease. Objectives The aim of the present study was to survey the relationship between energy expenditure in metabolic equivalent units (MET) and factors that are barriers to physical activity in elderly people in Kashan, Iran Methods This is a descriptive analysis...

Barriers to clean development mechanism renewable energy projects in Mexico

International Nuclear Information System (INIS)

Lokey, Elizabeth

2009-01-01

Mexico is not reaching its full potential to capture benefits from clean development mechanism (CDM) projects because of its limited market for independent power producers (IPPs) and the barriers imposed on these entities by the state-run electric utility that controls most of the country's generation and transmission. This state-run entity has pursued CDM revenues only in isolated cases where international financial assistance was given because it is bound by law to pursue the least-cost generation option for its customers. Recent changes in Mexican legislation that provide incentives for renewable energy development could open the marketplace for these types of projects. (author)

The energy highways. The three safety barriers at nuclear power plants. Where does coal fit into the energy mix?. Sustainable urban development in Hanover. Energy in sub-Saharan Africa

International Nuclear Information System (INIS)

Anon.

2005-01-01

This issue of Alternatives newsletter contains a main press-kit about the economics of interconnected power distribution systems and 4 articles dealing with reactors safety, the advantages and drawbacks of coal in the energy mix, the environmental policy of Hanover city, and the energy situation in sub-Saharan Africa: 1 - 'The energy highways': Spotlight on the electrical power grids. From the much needed modernization of existing installations to the extension of networks in developing countries, Alternatives takes a look at these infrastructures that shape our environment, which can be considered as veritable 'energy highways' ensuring the coverage of our planet. 2 - 'The three safety barriers at nuclear power plants': Review of the three protective barriers deployed in the nuclear industry to ensure reactor safety. 3 - 'Where does coal fit into the energy mix?': Two experts put into perspective the challenges related to the use of coal, its efficiency and its environmental impact, on the basis of the Chinese and Polish examples. 4 - 'Sustainable urban development in Hanover': Bringing together quality of living and energy savings, this is the challenge taken up by Hanover in the Kronsberg area. Alternatives has examined this original model, which could serve as an example for other European cities. 5 - 'Energy in sub-Saharan Africa': Relatively abundant resources but which are poorly utilized and distributed characterize the energy situation in sub-Saharan Africa. Analysis of the situation and explanation of this paradox

Prediction of point-defect migration energy barriers in alloys using artificial intelligence for atomistic kinetic Monte Carlo applications

Energy Technology Data Exchange (ETDEWEB)

Castin, N. [Structural Materials Group, Nuclear Materials Science Institute, Studiecentrum voor Kerneenergie Centre d' etude de l' energie nucleaire (SCK CEN), Boeretang 200, B-2400 Mol (Belgium); Universite Libre de Bruxelles (ULB), Physique des Solides Irradies et Nanostructures (PSIN), CP234 Boulevard du triomphe, Brussels (Belgium); Malerba, L. [Structural Materials Group, Nuclear Materials Science Institute, Studiecentrum voor Kerneenergie Centre d' etude de l' energie nucleaire (SCK CEN), Boeretang 200, B-2400 Mol (Belgium)], E-mail: lmalerba@sckcen.be

2009-09-15

We significantly improved a previously proposed method to take into account chemical and also relaxation effects on point-defect migration energy barriers, as predicted by an interatomic potential, in a rigid lattice atomistic kinetic Monte Carlo simulation. Examples of energy barriers are rigorously calculated, including chemical and relaxation effects, as functions of the local atomic configuration, using a nudged elastic bands technique. These examples are then used to train an artificial neural network that provides the barriers on-demand during the simulation for each configuration encountered by the migrating defect. Thanks to a newly developed training method, the configuration can include a large number of neighbour shells, thereby properly including also strain effects. Satisfactory results have been obtained when the configuration includes different chemical species only. The problems encountered in the extension of the method to configurations including any number of point-defects are stated and solutions to tackle them are sketched.

NATURAL BARRIERS TARGETED THRUST FY 2004 PROJECTS

International Nuclear Information System (INIS)

NA

2005-01-01

This booklet contains project descriptions of work performed by the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology and International's (OSTandI) Natural Barriers Targeted Thrust during Fiscal Year (FY) 2004. The Natural Barriers Targeted Thrust is part of OSTandI's Science and Technology Program which supports the OCRWM mission to manage and dispose of high-level radioactive waste and spent nuclear fuel in a manner that protects health, safety, and the environment; enhances national and energy security; and merits public confidence. In general, the projects described will continue beyond FY 2004 assuming that the technical work remains relevant to the proposed Yucca Mountain Repository and sufficient funding is made available to the Science and Technology Program

Enhancing the effective energy barrier of a Dy(III) SMM using a bridged diamagnetic Zn(II) ion.

Science.gov (United States)

Upadhyay, Apoorva; Singh, Saurabh Kumar; Das, Chinmoy; Mondol, Ranajit; Langley, Stuart K; Murray, Keith S; Rajaraman, Gopalan; Shanmugam, Maheswaran

2014-08-18

Field induced single-molecule-magnet behaviour is observed for both a heterodinuclear [ZnDy(L(-))2](3+) complex (1) and a mononuclear [Dy(HL)2](3+) complex (2), with effective energy barriers of 83 cm(-1) and 16 cm(-1), respectively. Insights into the relaxation mechanism(s) and barrier heights are provided via ab initio and DFT calculations. Our findings reveal an interesting observation that the U(eff) of SMMs can be enhanced by incorporating diamagnetic metal ions.

Overview Of The U.S. Department Of Energy And Nuclear Regulatory Commission Performance Assessment Approaches: Cementitious Barriers Partnership

International Nuclear Information System (INIS)

Langton, C.; Burns, H.

2009-01-01

Engineered barriers including cementitious barriers are used at sites disposing or contaminated with low-level radioactive waste to enhance performance of the natural environment with respect to controlling the potential spread of contaminants. Drivers for using cementitious barriers include: high radionuclide inventory, radionuclide characteristics (e.g., long half-live, high mobility due to chemical form/speciation, waste matrix properties, shallow water table, and humid climate that provides water for leaching the waste). This document comprises the first in a series of reports being prepared for the Cementitious Barriers Partnership. The document is divided into two parts which provide a summary of: (1) existing experience in the assessment of performance of cementitious materials used for radioactive waste management and disposal and (2) sensitivity and uncertainty analysis approaches that have been applied for assessments. Each chapter is organized into five parts: Introduction, Regulatory Considerations, Specific Examples, Summary of Modeling Approaches and Conclusions and Needs. The objective of the report is to provide perspective on the state of the practice for conducting assessments for facilities involving cementitious barriers and to identify opportunities for improvements to the existing approaches. Examples are provided in two contexts: (1) performance assessments conducted for waste disposal facilities and (2) performance assessment-like analyses (e.g., risk assessments) conducted under other regulatory regimes. The introductory sections of each section provide a perspective on the purpose of performance assessments and different roles of cementitious materials for radioactive waste management. Significant experience with assessments of cementitious materials associated with radioactive waste disposal concepts exists in the US Department of Energy Complex and the commercial nuclear sector. Recently, the desire to close legacy facilities has created

OVERVIEW OF THE U.S. DEPARTMENT OF ENERGY AND NUCLEAR REGULATORY COMMISSION PERFORMANCE ASSESSMENT APPROACHES: CEMENTITIOUS BARRIERS PARTNERSHIP

Energy Technology Data Exchange (ETDEWEB)

Langton, C.; Burns, H.

2009-05-29

Engineered barriers including cementitious barriers are used at sites disposing or contaminated with low-level radioactive waste to enhance performance of the natural environment with respect to controlling the potential spread of contaminants. Drivers for using cementitious barriers include: high radionuclide inventory, radionuclide characteristics (e.g., long half-live, high mobility due to chemical form/speciation, waste matrix properties, shallow water table, and humid climate that provides water for leaching the waste). This document comprises the first in a series of reports being prepared for the Cementitious Barriers Partnership. The document is divided into two parts which provide a summary of: (1) existing experience in the assessment of performance of cementitious materials used for radioactive waste management and disposal and (2) sensitivity and uncertainty analysis approaches that have been applied for assessments. Each chapter is organized into five parts: Introduction, Regulatory Considerations, Specific Examples, Summary of Modeling Approaches and Conclusions and Needs. The objective of the report is to provide perspective on the state of the practice for conducting assessments for facilities involving cementitious barriers and to identify opportunities for improvements to the existing approaches. Examples are provided in two contexts: (1) performance assessments conducted for waste disposal facilities and (2) performance assessment-like analyses (e.g., risk assessments) conducted under other regulatory regimes. The introductory sections of each section provide a perspective on the purpose of performance assessments and different roles of cementitious materials for radioactive waste management. Significant experience with assessments of cementitious materials associated with radioactive waste disposal concepts exists in the US Department of Energy Complex and the commercial nuclear sector. Recently, the desire to close legacy facilities has created

High-Risk Smoking Behaviors and Barriers to Smoking Cessation Among Homeless Individuals.

Science.gov (United States)

Chen, Joseph S; Nguyen, Austin Huy; Malesker, Mark A; Morrow, Lee E

2016-05-01

Although tobacco practices and the effects of tobacco use among the general American population are well described, minimal data exist regarding tobacco use and barriers to smoking cessation among homeless individuals. Anonymous, voluntary surveys based on a previously implemented instrument were completed by 100 smoking individuals residing at a homeless shelter. These surveys assessed high-risk smoking behaviors and respondents' perceived barriers to long-term smoking cessation. Ninety percent of study participants reported engaging in at least one of the high-risk tobacco practices. Nicotine replacement therapy was perceived by respondents to be the most desired form of smoking cessation aid. Excessive stress with use of tobacco smoking to alleviate stress and anxiety was the most significant self-perceived barrier to smoking cessation. High-risk tobacco practices are remarkably common among smoking homeless individuals. Despite literature consistently showing that non-nicotine tobacco cessation pharmacotherapies (varenicline, buproprion) have higher smoking cessation rates, nicotine replacement monotherapy was perceived as more valuable by survey respondents. Although lack of financial resources was expected to be the biggest barrier to successful cessation, social stressors and the use of smoking to cope with homelessness were perceived as a greater obstacle in this cohort. Given the paucity of data on the long-term effects of the high-risk tobacco behaviors reported by these homeless smokers, this study highlights the need for further investigations regarding tobacco use and tobacco cessation in this vulnerable population. Copyright © 2016 by Daedalus Enterprises.

Tunneling of an energy eigenstate through a parabolic barrier viewed from Wigner phase space

DEFF Research Database (Denmark)

Heim, D.M.; Schleich, W.P.; Alsing, P.M.

2013-01-01

We analyze the tunneling of a particle through a repulsive potential resulting from an inverted harmonic oscillator in the quantum mechanical phase space described by the Wigner function. In particular, we solve the partial differential equations in phase space determining the Wigner function...... of an energy eigenstate of the inverted oscillator. The reflection or transmission coefficients R or T are then given by the total weight of all classical phase-space trajectories corresponding to energies below, or above the top of the barrier given by the Wigner function....

A barrier analysis for the development of distributed energy in China: A case study in Fujian province

International Nuclear Information System (INIS)

Liu, Jian; Wang, Run; Sun, Yanwei; Lin, Yanjie; Xiao, Lishan

2013-01-01

Distributed energy (DE) is receiving lots of attention from the Chinese government. A number of DE projects have been constructed in China. However, there are still numerous problems with DE projects. What hinders the development of DE in China? The Huadian Jimei distributed energy project (HJDE) is a typical DE building project that was not completed successfully. This paper focuses on this DE project to explore the barriers to DE development. The research group conducted 13 semi-structured interviews with representatives of institutions and corporations involved in the HJDE project to collect information. Based on the information, three types of problems were determined, and the results indicate that these conflicts between the core stakeholders make DE projects unsuccessful. These problems result from institutional barriers to DE, rooting in the development policy and the current energy market. Moreover, several key stakeholders are not able to play an active role in the design or management of DE projects. The Chinese government will put a much greater effort into the development of future DE projects. Many national support policies and rules will be announced, which are easy to practical use. Under these conditions, 1000 DE projects will be successfully completed until 2015. - Highlights: • Using stakeholder analysis, this paper focuses on one typical building DE project. • Conflicts between core stakeholders make the DE project cannot be completed. • The barriers are related to the role of electricity consumers in DE projects. • The barriers are also related to current Chinese natural gas and LNG market. • Drivers such as regulation, incentives and so on should be built and modified

High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems

Energy Technology Data Exchange (ETDEWEB)

Kepler, Keith [Farasis Energy Inc; Slater, Michael [Farasis Energy Inc

2018-03-14

This Li-ion cell technology development project had three objectives: to develop advanced electrode materials and cell components to enable stable high-voltage operation; to design and demonstrate a Li-ion cell using these materials that meets the PHEV40 performance targets; and to design and demonstrate a Li-ion cell using these materials that meets the EV performance targets. The major challenge to creating stable high energy cells with long cycle life is system integration. Although materials that can give high energy cells are known, stabilizing them towards long-term cycling in the presence of other novel cell components is a major challenge. The major technical barriers addressed by this work include low cathode specific energy, poor electrolyte stability during high voltage operation, and insufficient capacity retention during deep discharge for Si-containing anodes. Through the course of this project, Farasis was able to improve capacity retention of NCM materials for 4.4+ V operation, through both surface treatment and bulk-doping approaches. Other material advances include increased rate capability and of HE-NCM materials through novel synthesis approach, doubling the relative capacity at 1C over materials synthesized using standard methods. Silicon active materials proved challenging throughout the project and ultimately were the limiting factor in the energy density vs. cycle life trade off. By avoiding silicon anodes for the lower energy PHEV design, we manufactured cells with intermediate energy density and long cycle life under high voltage operation for PHEV applications. Cells with high energy density for EV applications were manufactured targeting a 300 Wh/kg design and were able to achieve > 200 cycles.

High energy lithium-oxygen batteries - Transport barriers and thermodynamics

KAUST Repository

Das, Shyamal K.

2012-01-01

We show that it is possible to achieve higher energy density lithium-oxygen batteries by simultaneously lowering the discharge overpotential and increasing the discharge capacity via thermodynamic variables alone. By assessing the relative effects of temperature and pressure on the cell discharge profiles, we characterize and diagnose the critical roles played by multiple dynamic processes that have hindered implementation of the lithium-oxygen battery. © 2012 The Royal Society of Chemistry.

What we have learned so far on reactions and scattering with weakly bound nuclei at near barrier energies

International Nuclear Information System (INIS)

Gomes, P.R.S.

2011-01-01

Reactions involving weakly bound nuclei, especially halo nuclei, at near barrier energies, are an important subject not yet fully understood. Due to the low threshold energy for breakup, this process is particularly important and may affect significantly the fusion process and elastic scattering. In this talk I will show the systematic of results so far available in this field, concerning static and dynamical effects of halo and breakup on fusion and total reaction cross sections, the energy dependence of the optical potential on the elastic scattering and coupling effects on quasi-elastic scattering barrier distributions involving weakly bound nuclei, both stable and radioactive. The data to be discussed are new data from our group and from the literature, together with some older data. I will also present some experimental challenges for the development of this field. (author)

Application of a Barrier Filter at a High Purity Synthetic Graphite Plant, CRADA 99-F035, Final Report; FINAL

International Nuclear Information System (INIS)

National Energy Technology Laboratory

2000-01-01

Superior Graphite Company and the US Department of Energy have entered into a Cooperative Research and Development Agreement (CRADA) to study the application of ceramic barrier filters at its Hopkinsville, Kentucky graphite plant. Superior Graphite Company is a worldwide leader in the application of advanced thermal processing technology to produce high purity graphite and carbons. The objective of the CRADA is to determine the technical and economic feasibility of incorporating the use of high-temperature filters to improve the performance of the offgas treatment system. A conceptual design was developed incorporating the ceramic filters into the offgas treatment system to be used for the development of a capital cost estimate and economic feasibility assessment of this technology for improving particulate removal. This CRADA is a joint effort of Superior Graphite Company, Parsons Infrastructure and Technology Group, and the National Energy Technology Laboratory (NETL) of the US Department of Energy (DOE)

Mind the gap! Barriers and implementation deficiencies of energy policies at the local scale in urban China

International Nuclear Information System (INIS)

Wu, Jing; Zuidema, Christian; Gugerell, Katharina; Roo, Gert de

2017-01-01

Environmental concerns and potential social-economic impacts associated with fossil fuels have turned cities into indispensable entities for supporting energy transitions in China. Pursuing a transition towards a sustainable energy system has become a major policy concern for the Chinese central government. In response, and on the basis of a top-down and conformance-oriented system of policy implementation and evaluation, the Chinese central government has launched various policies and targets on energy efficiency and production that lower levels of government have to follow. However, the translation of top-down targets and the measurement of conformance-based targets have both proved to be problematic. This paper investigates Chinese state policy on energy efficiency through four empirical case studies. It identifies how policy design of target setting and evaluation is both impacting and driving the implementation of energy efficiency at the local urban scale. We demonstrate how local authorities are faced with constraining barriers that can inhibit the implementation of centrally issued targets and policies. These barriers may even undermine local performance in the pursuit of ambitious energy efficiency goals, resulting in potentially harmful consequences. - Highlights: • Energy efficiency policies are ill-adapted to the diversity of local circumstances. • Predominant focus on conformance in energy policies overlooks local performance. • Pursuing ambitions runs the risk of being undermined by strict measuring systems. • Chinese energy transition needs more flexibility in target setting and evaluation.

Barriers for Energy Renovation of Danish Single-Family Houses and Suggested Solutions to Overcome These

DEFF Research Database (Denmark)

Mortensen, Andrea; Heiselberg, Per; Knudstrup, Mary-Ann

2011-01-01

As much as 40% of the total energy consumption in Denmark is utilized by the building sector and most of this energy is used for heating. Political initiatives have been taken to reduce this amount considerably but for this to happen, the energy consumption of the existing residential housing stock...... must be reduced dramatically. The greatest saving potential is found among the approximately 440.000 standardised single-family houses which were constructed in the 1960’s and 1970’s. It is found that barriers preventing the implementation of this great potential are present in various forms among all...

Fusion of light ion systems at energies near and below the Coulomb barrier

International Nuclear Information System (INIS)

Arnould, M.; Howard, W.M.; Cusson, R.Y.

1978-01-01

Experimental fusion cross sections for light ion systems at energies below the Coulomb barrier become available in greater and greater number, and provide a stringent test of the macroscopic and microscopic physics involved in models of heavy-ion reactions. Measurements and predictions of the fusion cross sections for 12 C + 12 C, 12 C + 16 O and 16 O + 16 O are also of major importance in astrophysics. (orig.) [de

Non-monotonic probability of thermal reversal in thin-film biaxial nanomagnets with small energy barriers

Directory of Open Access Journals (Sweden)

N. Kani

2017-05-01

Full Text Available The goal of this paper is to investigate the short time-scale, thermally-induced probability of magnetization reversal for an biaxial nanomagnet that is characterized with a biaxial magnetic anisotropy. For the first time, we clearly show that for a given energy barrier of the nanomagnet, the magnetization reversal probability of an biaxial nanomagnet exhibits a non-monotonic dependence on its saturation magnetization. Specifically, there are two reasons for this non-monotonic behavior in rectangular thin-film nanomagnets that have a large perpendicular magnetic anisotropy. First, a large perpendicular anisotropy lowers the precessional period of the magnetization making it more likely to precess across the x^=0 plane if the magnetization energy exceeds the energy barrier. Second, the thermal-field torque at a particular energy increases as the magnitude of the perpendicular anisotropy increases during the magnetization precession. This non-monotonic behavior is most noticeable when analyzing the magnetization reversals on time-scales up to several tens of ns. In light of the several proposals of spintronic devices that require data retention on time-scales up to 10’s of ns, understanding the probability of magnetization reversal on the short time-scales is important. As such, the results presented in this paper will be helpful in quantifying the reliability and noise sensitivity of spintronic devices in which thermal noise is inevitably present.

Sub-barrier capture with quantum diffusion approach

Directory of Open Access Journals (Sweden)

Scheid W.

2011-10-01

Full Text Available With the quantum diffusion approach the behavior of capture cross sections and mean-square angular momenta of captured systems are revealed in the reactions with deformed and spherical nuclei at sub-barrier energies. With decreasing bombarding energy under the barrier the external turning point of the nucleus-nucleus potential leaves the region of short-range nuclear interaction and action of friction. Because of this change of the regime of interaction, an unexpected enhancement of the capture cross section is found at bombarding energies far below the Coulomb barrier. This effect is shown its worth in the dependence of mean-square angular momentum on the bombarding energy. From the comparison of calculated capture cross sections and experimental capture or fusion cross sections the importance of quasifission near the entrance channel is demonstrated for the actinidebased reactions and reactions with medium-heavy nuclei at extreme sub-barrier energies.

Better Policies Accelerate Clean Energy Transition. Policy brief - Focus on energy system flexibility

DEFF Research Database (Denmark)

Karimi, Farid; Lund, Peter; Skytte, Klaus

2018-01-01

The use of variable renewable energy sources will increase in the Nordic and Baltic countries in the future. This will call for increased flexibility in the electricity market to ensure both high energy security and efficient use of renewable power in all circumstances. The barriers and hence also...... policies to energy system flexibility are numerous. In this brief, we focus on policy recommendations for two important barriers to flexibility in the Nordic electricity market, namely insufficient market signals to some stakeholders, and uneven market frameworks for different renewable energy resources...

Barriers and opportunities for improving energy efficiency in the social housing sector: Case study of E4C's Division of Housing and Mental Health

Science.gov (United States)

Marchand-Smith, Patrick

Energy efficiency improvements in the social housing sector have the potential to produce a range of environmental and social benefits. These improvements can be produced through retrofits that deliver energy savings or new construction built to a high standard of energetic efficiency. However, implementation of these approaches is hindered by economic and organizational constraints affecting the agencies that provide society with social housing and the governments that support the provision of these services. This thesis builds on the work of other researchers studying these constraints by supplying an in-depth case study from Alberta and a discussion based on its findings. The case study focuses on E4C, a social service agency with several housing projects. Overall, findings matched important themes identified in the academic literature. The in-depth nature of the case study added additional insight to many of these themes. Most barriers are economic in nature and related to a lack of sufficient funding or the up-front costs of energy-saving retrofits. The recommendations presented are based on consideration of the multiple barriers and opportunities faced. Most of these require a considerable investment of time on the part of agencies and would be followed up by capital investments to implement energy-saving changes. Therefore it is important to note that the most significant barrier is commitment, which is one of E4C's central values. This thesis showed that commitment cannot exceed capacity to act. Greater commitment on the part of governments, agencies or society at large could have significant impacts in improving the energy efficiency of buildings in the Albertan, and Canadian, social housing sector.

The Influence of High-Energy Electrons Irradiation on Surface of n-GaP and on Au/n-GaP/Al Schottky Barrier Diode

Science.gov (United States)

Demir, K. Çinar; Kurudirek, S. V.; Oz, S.; Biber, M.; Aydoğan, Ş.; Şahin, Y.; Coşkun, C.

We fabricated 25 Au/n-GaP/Al Schottky devices and investigated the influence of high electron irradiation, which has 12MeV on the devices, at room temperature. The X-ray diffraction patterns, scanning electron microscopic images and Raman spectra of a gallium phosphide (GaP) semiconductor before and after electron irradiation have been analyzed. Furthermore, some electrical measurements of the devices were carried out through the current-voltage (I-V) and capacitance-voltage (C-V) measurements. From the I-V characteristics, experimental ideality factor n and barrier height Φ values of these Schottky diodes have been determined before and after irradiation, respectively. The results have also been analyzed statically, and a gauss distribution has been obtained. The built-in potential Vbi, barrier height Φ, Fermi level EF and donor concentration Nd values have been determined from the reverse bias C-V and C-2-V curves of Au/n-GaP/Al Schottky barrier diodes at 100kHz before and after 12MeV electron irradiation. Furthermore, we obtained the series resistance values of Au/n-GaP/Al Schottky barrier diodes with the help of different methods. Experimental results confirmed that the electrical characterization of the device changed with the electron irradiation.

Nested barriers to low-carbon infrastructure investment

Science.gov (United States)

Granoff, Ilmi; Hogarth, J. Ryan; Miller, Alan

2016-12-01

Low-carbon, 'green' economic growth is necessary to simultaneously improve human welfare and avoid the worst impacts of climate change and environmental degradation. Infrastructure choices underpin both the growth and the carbon intensity of the economy. This Perspective explores the barriers to investing in low-carbon infrastructure and some of the policy levers available to overcome them. The barriers to decarbonizing infrastructure 'nest' within a set of barriers to infrastructure development more generally that cause spending on infrastructure--low-carbon or not--to fall more than 70% short of optimal levels. Developing countries face additional barriers such as currency and political risks that increase the investment gap. Low-carbon alternatives face further barriers, such as commercialization risk and financial and public institutions designed for different investment needs. While the broader barriers to infrastructure investment are discussed in other streams of literature, they are often disregarded in literature on renewable energy diffusion or climate finance, which tends to focus narrowly on the project costs of low- versus high-carbon options. We discuss how to overcome the barriers specific to low-carbon infrastructure within the context of the broader infrastructure gap.

Containment barrier metals for high-level waste packages in a Tuff repository

Energy Technology Data Exchange (ETDEWEB)

Russell, E.W.; McCright, R.D.; O`Neal, W.C.

1983-10-12

The Nevada Nuclear Waste Storage Investigations (NNWSI) Waste Package project is part of the US Department of Energy`s Civilian Radioactive Waste Management (CRWM) Program. The NNWSI project is working towards the development of multibarriered packages for the disposal of spent fuel and high-level waste in tuff in the unsaturated zone at Yucca Mountain at the Nevada Test Site (NTS). The final engineered barrier system design may be composed of a waste form, canister, overpack, borehole liner, packing, and the near field host rock, or some combination thereof. Lawrence Livermore National Laboratory`s (LLNL) role is to design, model, and test the waste package subsystem for the tuff repository. At the present stage of development of the nuclear waste management program at LLNL, the detailed requirements for the waste package design are not yet firmly established. In spite of these uncertainties as to the detailed package requirements, we have begun the conceptual design stage. By conceptual design, we mean design based on our best assessment of present and future regulatory requirements. We anticipate that changes will occur as the detailed requirements for waste package design are finalized. 17 references, 4 figures, 10 tables.

Hurdling barriers through market uncertainty: Case studies ininnovative technology adoption

Energy Technology Data Exchange (ETDEWEB)

Payne, Christopher T.; Radspieler Jr., Anthony; Payne, Jack

2002-08-18

The crisis atmosphere surrounding electricity availability in California during the summer of 2001 produced two distinct phenomena in commercial energy consumption decision-making: desires to guarantee energy availability while blackouts were still widely anticipated, and desires to avoid or mitigate significant price increases when higher commercial electricity tariffs took effect. The climate of increased consideration of these factors seems to have led, in some cases, to greater willingness on the part of business decision-makers to consider highly innovative technologies. This paper examines three case studies of innovative technology adoption: retrofit of time-and-temperature signs on an office building; installation of fuel cells to supply power, heating, and cooling to the same building; and installation of a gas-fired heat pump at a microbrewery. We examine the decision process that led to adoption of these technologies. In each case, specific constraints had made more conventional energy-efficient technologies inapplicable. We examine how these barriers to technology adoption developed over time, how the California energy decision-making climate combined with the characteristics of these innovative technologies to overcome the barriers, and what the implications of hurdling these barriers are for future energy decisions within the firms.

NATURAL BARRIERS TARGETED THRUST FY 2004 PROJECTS

Energy Technology Data Exchange (ETDEWEB)

NA

2005-07-27

This booklet contains project descriptions of work performed by the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM), Office of Science and Technology and International's (OST&I) Natural Barriers Targeted Thrust during Fiscal Year (FY) 2004. The Natural Barriers Targeted Thrust is part of OST&I's Science and Technology Program which supports the OCRWM mission to manage and dispose of high-level radioactive waste and spent nuclear fuel in a manner that protects health, safety, and the environment; enhances national and energy security; and merits public confidence. In general, the projects described will continue beyond FY 2004 assuming that the technical work remains relevant to the proposed Yucca Mountain Repository and sufficient funding is made available to the Science and Technology Program.

SOUND FIELD DIFFUSIVITY AT THE TOP SURFACE OF SCHROEDER DIFFUSER BARRIERS

Directory of Open Access Journals (Sweden)

M. R. Monazzam

2006-10-01

Full Text Available Reactive barriers are one of the most promising and novel environmental noise barriers. In this case using Schroeder diffusers (e.g. quadratic residue diffusers on the top surface of the T-shape barrier was shown to significantly improve the performance of absorbent T-shape barriers. The reasons behind the high performance of diffuser barriers are considered in this investigation. A question about the diffusivity behavior of Schroeder diffusers when they are utilized on the top of barrier was raised. Diffusion coefficients of a diffuser in different conditions at some receiver locations were predicted by using a 2D boundary element method. It was found that the diffusion coefficient of diffuser at the top of barrier is so small that the diffusivity of the structure is almost the same as rigid T-shape barrier. To find the barrier’s cap behavior, the total field above the top surface of profile barriers was also predicted. It was found that the lowest total energy is at the receiver side of the cap very close to the top surface,which could demonstrate the effect of top surface on absorbing the energy as wave transfers from source edge toward the receiver side of the cap. In this case the amount of minimum total energy depends on the frequency and the configuration of the top surface. A comparison between the reductions of total field at the source side of the cap with the improvements of barrier’s performance was also done. It was shown that the amount of decrease in total field compared to that of an absorbent barrier “Ref” is directly associated to the amount of improvement in the insertion loss made by the diffuser barrier compared to the “Ref” barrier in the wide area on the ground at the shadow zone. Finally it was concluded that the diffuser on the top of barrier does not act as a diffuser and a kind of similarity between the contribution of diffuser and absorbent material on the top of T-profile barrier is seen.

Project Guarantee 1985. Final repository for high-level radioactive wastes: The system of safety barriers

International Nuclear Information System (INIS)

Anon.

1985-01-01

Final disposal of radioactive waste involves preventing the waste from returning from the repository location into the biosphere by means of successively arranged containment measures known as safety barriers. In the present volume NGB 85-04 of the series of reports for Project 'Guarantee' 1985, the safety barrier system for the type C repository for high-level waste is described. The barrier parameters which are relevant for safety analysis are quantified and associated error limits and data scatter are given. The aim of the report is to give a summary documentation of the safety analysis input data and their scientific background. For secure containment of radioactive waste safety barriers are used which effectively limit the release of radioactive material from the repository (release barriers) and effectively retard the entry of the original radioactive material into the biosphere (time barriers). Safety barriers take the form of both technically constructed containment measures and the siting of the repository in suitable geological formations. The technical safety barrier system in the case of high-level waste comprises: the waste solidification matrix (borosilicate glass), massive steel canisters, encasement of the waste canisters, encasement of the waste canisters in highly compacted bentonite, sealing of vacant storage space and access routes on repository closure. The natural geological safety barriers - the host rock and overlying formations provide sufficiently long deep groundwater flow times from the repository location to the earth's surface and for additional lengthening of radionuclide migration times by means of various chemical and physical retardation mechanisms. The stability of the geological formations is so great that hydrogeological system is protected for a sufficient length of time from deterioration caused, in particular, by erosion. Observations in the final section of the report indicate that input data for the type C repository safety

High density high performance plasma with internal diffusion barrier in Large Helical Device

International Nuclear Information System (INIS)

Sakamoto, R.; Kobayashi, M.; Miyazawa, J.

2008-10-01

A attractive high density plasma operational regime, namely an internal diffusion barrier (IDB), has been discovered in the intrinsic helical divertor configuration on the Large Helical Device (LHD). The IDB which enables core plasma to access a high density/high pressure regime has been developed. It is revealed that the IDB is reproducibly formed by pellet fueling in the magnetic configurations shifted outward in major radius. Attainable central plasma density exceeds 1x10 21 m -3 . Central pressure reaches 1.5 times atmospheric pressure and the central β value becomes fairly high even at high magnetic field, i.e. β(0)=5.5% at B t =2.57 T. (author)

Micro-fabricated Liquid Encapsulated Energy Harvester with Polymer Barrier Layer as Liquid Electret Interface

International Nuclear Information System (INIS)

Bu, L; Xu, H Y; Xu, B J; Song, L

2014-01-01

This paper addresses the electret discharge issue for liquid based electret energy harvesters. An interface structure of PDMS/PTFE polymer barrier layer between liquid and electrets is introduced, achieving 75% charge retain rate over 100h, compared with 0% without the proposed layer over 100h. Further, the PDMS/PTFE layer is introduced into liquid encapsulated energy harvester (LEEH) and is compatible with micro-fabrication process. The retain rate of device voltage is about 47%∼65% over 100h. At 100h after corona charging, the device generates maximally 3.7V, 0.55μW @1Hz rotation

Barriers for the introduction of bioenergy in the Netherlands

International Nuclear Information System (INIS)

Gerlagh, T.; Groenendaal, B.; Van Ree, R.; Dinkelbach, L.; Van Doorn, J.; Hemmes, K.

2000-01-01

The use of biomass for energy in the Netherlands is still limited despite the political incentives to make bio-energy a major source of renewable energy. The hesitation of many stake-holders is due to the limited insight into the potential of biomass in the Netherlands and the presence of numerous other barriers. Availability of biomass, emission regulation and waste treatment regulations are considered important barriers. Analyses of their current state show that these barriers are broadly recognised and possibilities to decrease their impact are present. Some barriers with a minor influence so far will be of increasing importance and could be a threat to the development of bio-energy in future. These are the fast liberalising of the energy market and sustainable energy market, the competition with other renewables and the unclear status of the current technology available. Future research should focus on the possibilities to overcome these new barriers. 5 refs

How to perform Energy Trace & BarrierAnalysis (ETBA in industries? Acase study in Isomax Unit of Tehran refinery

Directory of Open Access Journals (Sweden)

J Adl

2006-04-01

Full Text Available Background and Aims: People, equipments and properties are continuously exposed tonumerous hazards while technology develops. The global increasing rate of accidents and workrelatedinjuries, especially in Iran, is an evidence for these hazards. There are numerous methodsfor hazard analysis such as the Energy Trace & Barrier Analysis (ETBA, which is a process ofanalysis based on system safety for detecting and definition of hazards and also risks that maycause system damage.Method: This is a case study in the Isomax unit of Tehran refinery and allied section. Datecollection and completion of the ETBAsheets were conducted through observation and interviewmethod with experts, walking - talking through method, investigation of technical and operativedocuments.Results: Twelve different kinds of energy and 28 subgroups were investigated. The types ofenergies, existence barriers, vulnerable targets, risk assessment code, and adequacy of barriers aswell as recommendations for decreasing risk level through tolerable risk were identified.Conclusion: The results of this study show potential application of ETBA in different industries,especially chemical industry, which is a method for identification hazards and prevention ofwork-related injuries.

Condensation on superhydrophobic surfaces: the role of local energy barriers and structure length scale.

Science.gov (United States)

Enright, Ryan; Miljkovic, Nenad; Al-Obeidi, Ahmed; Thompson, Carl V; Wang, Evelyn N

2012-10-09

Water condensation on surfaces is a ubiquitous phase-change process that plays a crucial role in nature and across a range of industrial applications, including energy production, desalination, and environmental control. Nanotechnology has created opportunities to manipulate this process through the precise control of surface structure and chemistry, thus enabling the biomimicry of natural surfaces, such as the leaves of certain plant species, to realize superhydrophobic condensation. However, this "bottom-up" wetting process is inadequately described using typical global thermodynamic analyses and remains poorly understood. In this work, we elucidate, through imaging experiments on surfaces with structure length scales ranging from 100 nm to 10 μm and wetting physics, how local energy barriers are essential to understand non-equilibrium condensed droplet morphologies and demonstrate that overcoming these barriers via nucleation-mediated droplet-droplet interactions leads to the emergence of wetting states not predicted by scale-invariant global thermodynamic analysis. This mechanistic understanding offers insight into the role of surface-structure length scale, provides a quantitative basis for designing surfaces optimized for condensation in engineered systems, and promises insight into ice formation on surfaces that initiates with the condensation of subcooled water.

Adoption of energy-efficiency measures in SMEs—An empirical analysis based on energy audit data from Germany

International Nuclear Information System (INIS)

Fleiter, Tobias; Schleich, Joachim; Ravivanpong, Ployplearn

2012-01-01

This paper empirically investigates factors driving the adoption of energy-efficiency measures by small and medium-sized enterprises (SMEs). Our analyses are based on cross-sectional data from SMEs which participated in a German energy audit program between 2008 and 2010. In general, our findings appear robust to alternative model specifications and are consistent with the theoretical and still scarce empirical literature on barriers to energy-efficiency in SMEs. More specifically, high investment costs, which are captured by subjective and objective proxies, appear to impede the adoption of energy-efficiency measures, even if these measures are deemed profitable. Similarly, we find that lack of capital slows the adoption of energy-efficiency measures, primarily for larger investments. Hence, investment subsidies or soft loans (for larger investments) may help accelerating the diffusion of energy-efficiency measures in SMEs. Other barriers were not found to be statistically significant. Finally, our findings provide evidence that the quality of energy audits affects the adoption of energy-efficiency measures. Hence, effective regulation should involve quality standards for energy audits, templates for audit reports or mandatory monitoring of energy audits. - Highlights: ► We empirically analyze barriers to the adoption of energy-efficiency measures in SMEs. ► We focus on firms participating in the German energy audit program for SMEs. ► The program overcomes information related barriers. ► High investment costs still impede the adoption even for profitable measures. ► Low audit quality also impedes the adoption of profitable measures.

Electron transmission through a periodically driven graphene magnetic barrier

Energy Technology Data Exchange (ETDEWEB)

Biswas, R., E-mail: rbiswas.pkc@gmail.com [Department of Physics, P. K. College, Contai, Purba Medinipur, West Bengal – 721401 (India); Maiti, S. [Ajodhya Hills G.S.A.T High School, Ajodhya, Purulia, West Bengal – 723152 (India); Mukhopadhyay, S. [Purulia Zilla School, Dulmi Nadiha, Purulia, West Bengal – 723102 (India); Sinha, C. [Department of Physics, P. K. College, Contai, Purba Medinipur, West Bengal – 721401 (India); Department of Theoretical Physics, Indian Association for the Cultivation of Science, Jadavpur – 700032 (India)

2017-05-10

Electronic transport through graphene magnetic barriers is studied theoretically in presence of an external time harmonic scalar potential in the framework of non-perturbative Landau–Floquet Formalism. The oscillating field mostly suppresses the transmission for rectangular magnetic barrier structure and exhibits the Fano resonance for multiphoton processes due to the presence of bound state inside the barrier. While, for a pair of delta function barriers of larger separation, the oscillating potential suppresses the usual Fabry–Perot oscillations in the transmission and a new type of asymmetric Fano resonance is noted for smaller separation, occurring due to extended states between the barriers. - Highlights: • Tunnelling of the Dirac Fermions through oscillating pure magnetic barriers is reported for the first time. • The high energy transmission through a graphene magnetic barrier is suppressed by the application of time periodic modulation. • Suppression of the Fabry Perot transmission is noted due to the application of an external time harmonic potential. • Two kinds of the Fano resonances are noted in transmission through a pair of modulated δ-function magnetic barriers.

High-resolution reconstruction of a coastal barrier system

DEFF Research Database (Denmark)

Fruergaard, Mikkel; Andersen, Thorbjørn Joest; Nielsen, Lars Henrik

2015-01-01

This study presents a detailed reconstruction of the sedimentary effects of Holocene sea-level rise on a modern coastal barrier system (CBS). Increasing concern over the evolution of CBSs due to future accelerated rates of sea-level rise calls for a better understanding of coastal barriers response...... from retreat of the barrier island and probably also due to formation of a tidal inlet close to the study area. Continued transgression and shoreface retreat created a distinct hiatus and wave ravinement surface in the seaward part of the CBS before the barrier shoreline stabilised between 5.0 and 4...

Some peculiarities of interactions of weakly bound lithium nuclei at near-barrier energies

Science.gov (United States)

Kabyshev, A. M.; Kuterbekov, K. A.; Sobolev, Yu G.; Penionzhkevich, Yu E.; Kubenova, M. M.; Azhibekov, A. K.; Mukhambetzhan, A. M.; Lukyanov, S. M.; Maslov, V. A.; Kabdrakhimova, G. D.

2018-02-01

This paper presents new experimental data on the total cross sections of 9Li + 28Si reactions at low energies as well as the analysis of previously obtained data for 6,7Li. Based on a large collection of data (authors’ and literature data) we carried out a comparative analysis of the two main experimental interaction cross sections (angular distributions of the differential cross sections and total reaction cross sections) for weakly bound lithium (6-9Li, 11Li) nuclei in the framework of Kox parameterization and the macroscopic optical model. We identified specific features of these interactions and predicted the experimental trend in the total reaction cross sections for Li isotopes at energies close to the Coulomb barrier.

Hindrance of O16+Pb208 fusion at extreme sub-barrier energies

Science.gov (United States)

Esbensen, Henning; Mişicu, Şerban

2007-11-01

We analyze the fusion data for O16+Pb208 using coupled-channels calculations. We include couplings to the low-lying surface excitations of the projectile and target and study the effect of the (O16,O17) one-neutron pickup. The hindrance of the fusion data that is observed at energies far below the Coulomb barrier cannot be explained by a conventional ion-ion potential and defining the fusion in terms of ingoing-wave boundary conditions (IWBC). We show that the hindrance can be explained fairly well by applying the M3Y double-folding potential which has been corrected with a calibrated, repulsive term that simulates the effect of nuclear incompressibility. We show that the coupling to one-neutron transfer channels plays a crucial role in improving the fit to the data. The best fit is achieved by increasing the transfer strength by 25% relative to the strength that is required to reproduce the one-neutron transfer data. The larger strength is not unrealistic because the calculated inelastic plus transfer cross section is in good agreement with the measured quasielastic cross section. We finally discuss the problem of reproducing the fusion data at energies far above the Coulomb barrier. Here we do not account for the data when we apply the IWBC but the discrepancy is essentially eliminated by applying the M3Y+repulsion potential and a weak, short-ranged imaginary potential.

One Component Encapsulating Material Matrix as High Barrier Coating, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — To address the NASA need for new flexible food packaging materials with effective high barrier against oxygen and moisture to protect food, minimize weight and...

Barrier island facies models and recognition criteria

Science.gov (United States)

Mulhern, J.; Johnson, C. L.

2017-12-01

Barrier island outcrops record transgressive shoreline motion at geologic timescales, providing integral clues to understanding how coastlines respond to rising sea levels. However, barrier island deposits are difficult to recognize. While significant progress has been made in understanding the modern coastal morphodynamics, this insight is not fully leveraged in existing barrier island facies models. Excellent outcrop exposures of the paralic Upper Cretaceous Straight Cliffs Formation of southern Utah provide an opportunity to revise facies models and recognition criteria for barrier island deposits. Preserved barrier islands are composed of three main architectural elements (shorefaces, tidal inlets, and tidal channels) which occur independently or in combination to create larger-scale barrier island deposits. Barrier island shorefaces record progradation, while barrier island tidal inlets record lateral migration, and barrier island tidal channels record aggradation within the tidal inlet. Four facies associations are used to describe and characterize these barrier island architectural elements. Barrier islands occur in association with backarrier fill and internally contain lower and upper shoreface, high-energy upper shoreface, and tidal channel facies. Barrier islands bound lagoons or estuaries, and are distinguished from other shoreface deposits by their internal facies and geometry, association with backbarrier facies, and position within transgressive successions. Tidal processes, in particular tidal inlet migration and reworking of the upper shoreface, also distinguish barrier island deposits. Existing barrier island models highlight the short term heterogeneous and dynamic nature of barrier island systems, yet overlook processes tied to geologic time scales, such as multi-directional motion, erosion, and reworking, and their expressions in preserved barrier island strata. This study uses characteristic outcrop expressions of barrier island successions to

Study on characteristics of high frequency dielectric barrier discharge for the removal of organic pollutant adsorbed on activated carbon

Energy Technology Data Exchange (ETDEWEB)

Qu, G.Z.; Li, G.F. [Dalian Univ. of Technology, Dalian (China). Inst. of Electrostatics and Special Power; Li, J.; Lu, N.; Wu, Y.; Li, D. [Dalian Univ. of Technology, Dalian (China). Inst. of Electrostatics and Special Power; Key Lab of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian (China)

2010-07-01

Advanced oxidation technologies such as photocatalysis, electrochemical degradation, Fenton oxidation, hydrogen peroxide oxidation, and plasma oxidation are increasingly being used to degrade refractory biodegradable organic contaminants. The plasma oxidation method has the advantage of direct in situ production of multiple types of high-reactive chemical species, including molecules and radicals that facilitate the degradation reaction. In addition, plasma oxidation does not produce any secondary pollution. Compared to other plasma technologies, the dielectric barrier discharge (DBD) plasma has been considered as a promising technology for removing toxic compounds because of its stability and its treatability property of biologically recalcitrant compounds in wastewater. However, the energy efficiency of DBD requires improvement for economic reasons. This paper reported on an experimental study that investigated the electrical characteristics of a parallel plate DBD reactor using a high frequency power supply for the removal of pentachlorophenol (PCP) adsorbed on activated carbon (AC). This study examined the effects of AC with different mass on discharge characteristics and compared the voltage and current waveforms, and discharge images of DBD reactors with different dielectric configurations. When the DBD reactor filled with AC, the applied voltage of discharge decreased regardless of the DBD reactor configuration in terms of having a single barrier or two barriers. The discharge characteristics had no significant change with AC mass increasing. The discharge images and current waveforms showed that DBD reactor configuration consisting of two dielectrics is more homogeneous and stable than the one consisting of a single dielectric. Under the same electric field condition, the degradation efficiency of PCP in two barriers reactor is higher than that in single barrier reactor. It was concluded that the findings from this study may be instrumental in treating

Analysis of administrative barriers in the industry of the high-rise construction in Russian Federation

Science.gov (United States)

Zaychenko, Irina; Borremans, Alexandra; Gutman, Svetlana

2018-03-01

The article describes the concept and types of administrative barriers encountered in various areas of the enterprise. The particularities of the Russian high-rise construction industry are described and a comparative analysis of administrative barriers in this sector is performed. The main stages and administrative procedures when the developers implement investment and construction projects in the field of high-rise construction are determined. The regulatory and legal framework for the implementation of investment and project activities in the high-rise construction industry has been studied and conclusions have been drawn on its low level of precision in the issue of the formation of competitive and efficient high-rise construction markets. The average number of administrative procedures for the implementation of the investment and construction project in the field of high-rise construction is determined. The factors preventing the reduction of administrative barriers in the high-rise construction industry are revealed.

Viscosity-Induced Crossing of the Phantom Barrier

Directory of Open Access Journals (Sweden)

Iver Brevik

2015-09-01

Full Text Available We show explicitly, by using astrophysical data plus reasonable assumptions for the bulk viscosity in the cosmic fluid, how the magnitude of this viscosity may be high enough to drive the fluid from its position in the quintessence region at present time t = 0 across the barrier w = −1 into the phantom region in the late universe. The phantom barrier is accordingly not a sharp mathematical divide, but rather a fuzzy concept. We also calculate the limiting forms of various thermodynamical quantities, including the rate of entropy production, for a dark energy fluid near the future Big Rip singularity.

Renewable energy clusters recurring barriers to cluster development in eleven countries

CERN Document Server

Jaegersberg, Gudrun

2017-01-01

Taking eleven countries in Europe, Canada, South Africa, America, Latin America and Australia, this book discusses recurring barriers to cluster development in the renewable energy sector. The authors look at the real-world dynamics and tensions between stakeholders on the ground, with a particular focus on the relationships between SMEs and other actors. This trans-regional study is unique in its scale and scope, drawing on a decade of field research to show how by learning from the successes and failures of other clusters, costs and risk can be reduced. The book fills a significant gap in the literature for policymakers, managers and economic developers in a key market.

Deep inelastic scattering near the Coulomb barrier

International Nuclear Information System (INIS)

Gehring, J.; Back, B.; Chan, K.

1995-01-01

Deep inelastic scattering was recently observed in heavy ion reactions at incident energies near and below the Coulomb barrier. Traditional models of this process are based on frictional forces and are designed to predict the features of deep inelastic processes at energies above the barrier. They cannot be applied at energies below the barrier where the nuclear overlap is small and friction is negligible. The presence of deep inelastic scattering at these energies requires a different explanation. The first observation of deep inelastic scattering near the barrier was in the systems 124,112 Sn + 58,64 Ni by Wolfs et al. We previously extended these measurements to the system 136 Xe + 64 Ni and currently measured the system 124 Xe + 58 Ni. We obtained better statistics, better mass and energy resolution, and more complete angular coverage in the Xe + Ni measurements. The cross sections and angular distributions are similar in all of the Sn + Ni and Xe + Ni systems. The data are currently being analyzed and compared with new theoretical calculations. They will be part of the thesis of J. Gehring

Fission excitation function for 19F + 194,196,198Pt at near and above barrier energies

Directory of Open Access Journals (Sweden)

Singh Varinderjit

2015-01-01

Full Text Available Fission excitation functions for 19F + 194,196,198Pt reactions populating 213,215,217Fr compound nuclei are reported. Out of these three compound nuclei, 213Fr is a shell closed (N=126 compound nucleus and the other two are away from the shell closure. From a comparison of the experimental fission cross-sections with the statistical model predictions, it is observed that the fission cross-sections are underestimated by the statistical model predictions using shell corrected finite range rotating liquid drop model (FRLDM fission barriers. Further the FRLDM fission barriers are reduced to fit the fission cross-sections over the entire measured energy range.

A novel approach for barriers to industrial energy efficiency

NARCIS (Netherlands)

Cagno, E.; Worrell, E.; Trianni, A.; Pugliese, G.

2013-01-01

A critical review of the literature highlighted the need for a new taxonomy encompassing the most relevant barriers stemmed from previous studies, and accounting for interactions and independences of the barriers to avoid overlaps and implicit interactions. Based on an extensive literature review

Fusion hindrance at deep sub-barrier energies for the 11B+197Au system

Science.gov (United States)

Shrivastava, A.; Mahata, K.; Nanal, V.; Pandit, S. K.; Parkar, V. V.; Rout, P. C.; Dokania, N.; Ramachandran, K.; Kumar, A.; Chatterjee, A.; Kailas, S.

2017-09-01

Fusion cross sections for the 11B+197Au system have been measured at energies around and deep below the Coulomb barrier, to probe the occurrence of fusion hindrance in case of asymmetric systems. A deviation with respect to the standard coupled channels calculations has been observed at the lowest energy. The results have been compared with an adiabatic model calculation that considers a damping of the coupling strength for a gradual transition from sudden to adiabatic regime at very low energies. The data could be explained without inclusion of the damping factor. This implies that the influence of fusion hindrance is not significant within the measured energy range for this system. The present result is consistent with the observed trend between the degree of fusion hindrance and the charge product that reveals a weaker influence of hindrance on fusion involving lighter projectiles on heavy targets.

High energy storage capacitor by embedding tunneling nano-structures

Science.gov (United States)

Holme, Timothy P; Prinz, Friedrich B; Van Stockum, Philip B

2014-11-04

In an All-Electron Battery (AEB), inclusions embedded in an active region between two electrodes of a capacitor provide enhanced energy storage. Electrons can tunnel to/from and/or between the inclusions, thereby increasing the charge storage density relative to a conventional capacitor. One or more barrier layers is present in an AEB to block DC current flow through the device. The AEB effect can be enhanced by using multi-layer active regions having inclusion layers with the inclusions separated by spacer layers that don't have the inclusions. The use of cylindrical geometry or wrap around electrodes and/or barrier layers in a planar geometry can enhance the basic AEB effect. Other physical effects that can be employed in connection with the AEB effect are excited state energy storage, and formation of a Bose-Einstein condensate (BEC).

Passive House and Low Energy Buildings: Barriers and Opportunities for Future Development within UK Practice

Directory of Open Access Journals (Sweden)

Adrian Pitts

2017-02-01

Full Text Available This paper describes research carried out to understand better the current and future emphases emerging from practice for the design and development of “Passive House” and low energy buildings. The paper initially discusses the extant position, particularly with regards to the UK and considers how regulation and assessment systems have changed in recent years, as well as projecting ideas forward taking account of contemporary political situations. Relevant previous research into Passive House and low energy design and construction is then reviewed. The need for greater understanding of professionals and their communication/collaboration with clients were identified as important factors impacting development. Those involved in the design and construction practice therefore have key roles in the process of enhancing energy efficiency. Five industry/practice based professional organizations were interviewed in-depth to gain insights into their experience of current low energy design, and to extrapolate the outcomes to future scenarios. The method employed used a structured interview technique with key question areas to lead the discussion. The anonymized responses discussed are grouped around key themes. Evidence suggests there has been a move towards the adoption of voluntary high level standards because of potential limitations with mandatory regulations and because of perceived additional benefits of higher quality design. This change is now more than previously, being driven by informed clients, design professionals, and the industry, with regulation taking a secondary role. New opportunities and barriers are becoming evident and these require further consideration.

Quantitative performance allocation of multi-barrier system for high-level radioactive waste disposal

International Nuclear Information System (INIS)

Ahn, Joon-Hong; Ikeda, Takao; Ohe, Toshiaki

1995-01-01

Performance assessment of each barrier consisting of geologic disposal system for high-level radioactive wastes is carried out quantitatively, and key radionuclides and parameters are pointed out. Chemical compositions and solubilities of radionuclides under repository conditions are determined by PHREEQE code staring from compositions of granitic groundwater observed in Japan. Glass dissolution analysis based on mass transfer theory and precipitation analysis have been done in order to determine the inner boundary condition for radionuclide diffusion through a bentonite-filled buffer region, where multi-member decay chain and isotopic sharing of solubility at the inner boundary are considered. Natural barrier is treated as homogeneous porous rock, or porous rock with infinite planar fractures. Performance of each barrier is evaluated in terms of non-dimensionalized hazard defined as the ratio of annual radioactivity release from each barrier to the annual limit on intake. At the outer edge of the engineered barriers, 239 Pu is the key unclide to the performance, whereas at the exit of the natural barrier, weakly-sorbing fission product nuclides such as 135 Cs, 129 I and 99 Tc dominate the hazard. (author) 50 refs

Nuclear reorganization barriers to electron transfer

International Nuclear Information System (INIS)

Sutin, N.; Brunschwig, B.S.; Creutz, C.; Winkler, J.R.

1988-01-01

The nuclear barrier to electron transfer arises from the need for reorganization of intramolecular and solvent internuclear distances prior to electron transfer. For reactions with relatively small driving force (''normal'' free-energy region) the nuclear factors and rates increase as intrinsic inner-shell and outer-shell barriers decrease; this is illustrated by data for transition metal complexes in their ground electronic states. By contrast, in the inverted free-energy region, rates and nuclear factors decrease with decreasing ''intrinsic'' barriers; this is illustrated by data for the decay of charge-transfer excited states. Several approaches to the evaluation of the outer-shell barrier are explored in an investigation of the distance dependence of the nuclear factor in intramolecular electron-transfer processes. 39 refs., 14 figs., 3 tabs

Dissociative chemisorption of N2 on Rhenium: Dynamics at high impact energies

DEFF Research Database (Denmark)

Henriksen, Niels Engholm; Billing, Gert D.; Hansen, Flemming Yssing

1990-01-01

forcing model. It is found that the energy transfer from the molecule to the phonons of the crystal is very significant. The smaller than unity dissociative sticking probability found experimentally even at the highest impact energies well above the barrier energy can be accounted for by the Landau...

A high rotational barrier for physisorbed hydrogen in an fcu-metal-organic framework

KAUST Repository

Pham, Tony T.; Forrest, Katherine A.; Georgiev, Peter A L; Lohstroh, Wiebke; Xue, Dongxu; Hogan, Adam; Eddaoudi, Mohamed; Space, Brian; Eckert, Juergen

2014-01-01

A combined inelastic neutron scattering (INS) and theoretical study of H2 sorption in Y-FTZB, a recently reported metal-organic framework (MOF) with fcu topology, reveals that the strongest binding site in the MOF causes a high barrier to rotation on the sorbed H2. This rotational barrier for H2 is the highest yet of reported MOF materials based on physisorption. This journal is

Performance of high level waste forms and engineered barriers under repository conditions

International Nuclear Information System (INIS)

1991-02-01

The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

Why high energy physics

International Nuclear Information System (INIS)

Diddens, A.N.; Van de Walle, R.T.

1981-01-01

An argument is presented for high energy physics from the point of view of the practitioners. Three different angles are presented: The cultural consequence and scientific significance of practising high energy physics, the potential application of the results and the discovery of high energy physics, and the technical spin-offs from the techniques and methods used in high energy physics. (C.F.)

Saudi high school students' attitudes and barriers toward the use of computer technologies in learning English.

Science.gov (United States)

Sabti, Ahmed Abdulateef; Chaichan, Rasha Sami

2014-01-01

This study examines the attitudes of Saudi Arabian high school students toward the use of computer technologies in learning English. The study also discusses the possible barriers that affect and limit the actual usage of computers. Quantitative approach is applied in this research, which involved 30 Saudi Arabia students of a high school in Kuala Lumpur, Malaysia. The respondents comprised 15 males and 15 females with ages between 16 years and 18 years. Two instruments, namely, Scale of Attitude toward Computer Technologies (SACT) and Barriers affecting Students' Attitudes and Use (BSAU) were used to collect data. The Technology Acceptance Model (TAM) of Davis (1989) was utilized. The analysis of the study revealed gender differences in attitudes toward the use of computer technologies in learning English. Female students showed high and positive attitudes towards the use of computer technologies in learning English than males. Both male and female participants demonstrated high and positive perception of Usefulness and perceived Ease of Use of computer technologies in learning English. Three barriers that affected and limited the use of computer technologies in learning English were identified by the participants. These barriers are skill, equipment, and motivation. Among these barriers, skill had the highest effect, whereas motivation showed the least effect.

Transport spectroscopy and modeling of a clean MOS point contact tunnel barrier

Science.gov (United States)

Shirkhorshidian, Amir; Bishop, Nathaniel; Dominguez, Jason; Grubbs, Robert; Wendt, Joel; Lilly, Michael; Carroll, Malcolm

2014-03-01

We present transport spectroscopy of non-implanted and antimony-implanted tunnel barriers formed in MOS split-gate structures at 4K. The non-implanted barrier shows no signs of resonant behavior while the Sb-implanted barrier shows resonances superimposed on the clean transport. We simulate the transmission through the clean barrier over the entire gate and bias range of the experiment using a phenomenological 1D-tunneling model that includes Fowler-Nordheim tunneling and Schottky barrier lowering to capture effects at high bias. The model is qualitatively similar to experiment when the barrier height has a quadratic dependence in contrast to a linear one, which can be a sign of 2D effects such as confinement perpendicular to the transport direction. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. This work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

High mobility two-dimensional electron gases in nitride heterostructures with high Al composition AlGaN alloy barriers

International Nuclear Information System (INIS)

Li Guowang; Cao Yu; Xing Huili Grace; Jena, Debdeep

2010-01-01

We report high-electron mobility nitride heterostructures with >70% Al composition AlGaN alloy barriers grown by molecular beam epitaxy. Direct growth of such AlGaN layers on GaN resulted in hexagonal trenches and a low mobility polarization-induced charge. By applying growth interruption at the heterojunction, the surface morphology improved dramatically and the room temperature two-dimensional electron gas (2DEG) mobility increased by an order of magnitude, exceeding 1300 cm 2 /V s. The 2DEG density was tunable at 0.4-3.7x10 13 /cm 2 by varying the total barrier thickness (t). Surface barrier heights of the heterostructures were extracted and exhibited dependence on t.

Alternative future energy pathways: Assessment of the potential of innovative decentralised energy systems in the UK

International Nuclear Information System (INIS)

Chmutina, Ksenia; Goodier, Chris I.

2014-01-01

In order to meet its 2050 target of 80% carbon emissions reduction, the UK is facing a challenge of restructuring its energy system, possibly by introducing more decentralised energy (DE) systems. Following semi-structured interviews, four exemplar international cases have been critiqued in order to investigate the variety and interrelationship of the drivers and barriers involved during their implementation, and then compared with the barriers and drivers that can potentially affect the implementation of similar projects in the UK context. The impacts of the barriers on the outcomes of these projects were evaluated, and recommendations were presented on overcoming these barriers if replicating similar projects in the UK context. Governance drivers play the most significant role, whereas financial drivers (commonly believed to be crucial), are deemed to play a lesser role. Social, governance and financial barriers rather than technological barriers constitute the central problem areas for the increased adoption of DE. The drivers and barriers experienced in the international cases were similar to those anticipated in the UK. The case studies present a high potential for replication and scaling up in the UK context and demonstrate that the increased implementation of DE systems could also enhance social and governance benefits. - Highlights: • This paper examines four international urban decentralised energy initiatives. • Drivers and barriers are found to be highly diverse but similar to the ones in the UK. • Governance drivers play the most significant role. • Increased implementation of DE systems can enhance social and governance benefits

Deep inelastic scattering near the Coulomb barrier

Energy Technology Data Exchange (ETDEWEB)

Gehring, J.; Back, B.; Chan, K. [and others

1995-08-01

Deep inelastic scattering was recently observed in heavy ion reactions at incident energies near and below the Coulomb barrier. Traditional models of this process are based on frictional forces and are designed to predict the features of deep inelastic processes at energies above the barrier. They cannot be applied at energies below the barrier where the nuclear overlap is small and friction is negligible. The presence of deep inelastic scattering at these energies requires a different explanation. The first observation of deep inelastic scattering near the barrier was in the systems {sup 124,112}Sn + {sup 58,64}Ni by Wolfs et al. We previously extended these measurements to the system {sup 136}Xe + {sup 64}Ni and currently measured the system {sup 124}Xe + {sup 58}Ni. We obtained better statistics, better mass and energy resolution, and more complete angular coverage in the Xe + Ni measurements. The cross sections and angular distributions are similar in all of the Sn + Ni and Xe + Ni systems. The data are currently being analyzed and compared with new theoretical calculations. They will be part of the thesis of J. Gehring.

Collisions between heavy nuclei near the barrier

International Nuclear Information System (INIS)

Henning, W.

1988-05-01

Detailed information has recently become available on the reaction behavior in very heavy nuclear systems close to the Coulomb barrier. Starting from an experimental study of the distribution of the reaction strength above and below the barrier, the dominant reaction channels of quasi-elastic and strongly-damped processes are examined. With decreasing incident energy, the sub-barrier collisions are increasingly dominated by quasi-elastic processes. From the division of internal excitation energy, new information is obtained on the nature of the dissipative processes. (orig.)

Influence of average ion energy and atomic oxygen flux per Si atom on the formation of silicon oxide permeation barrier coatings on PET

Science.gov (United States)

Mitschker, F.; Wißing, J.; Hoppe, Ch; de los Arcos, T.; Grundmeier, G.; Awakowicz, P.

2018-04-01

The respective effect of average incorporated ion energy and impinging atomic oxygen flux on the deposition of silicon oxide (SiO x ) barrier coatings for polymers is studied in a microwave driven low pressure discharge with additional variable RF bias. Under consideration of plasma parameters, bias voltage, film density, chemical composition and particle fluxes, both are determined relative to the effective flux of Si atoms contributing to film growth. Subsequently, a correlation with barrier performance and chemical structure is achieved by measuring the oxygen transmission rate (OTR) and by performing x-ray photoelectron spectroscopy. It is observed that an increase in incorporated energy to 160 eV per deposited Si atom result in an enhanced cross-linking of the SiO x network and, therefore, an improved barrier performance by almost two orders of magnitude. Furthermore, independently increasing the number of oxygen atoms to 10 500 per deposited Si atom also lead to a comparable barrier improvement by an enhanced cross-linking.

Investigation of 17F+p elastic scattering at near-barrier energies

International Nuclear Information System (INIS)

El-Azab Farid, M.; Ibraheem, Awad A.; Al-Hajjaji, Arwa S.

2015-01-01

The 17 F +p elastic scattering at two near-barrier energies of 3.5 and 4.3 MeV/nucleon, have been analyzed in the framework of the single folding approach. The folded potentials are constructed by folding the density-dependent (DDM3Y) effective nucleon-nucleon interaction over the nuclear density of the one-proton halo nucleus 17 F. Two versions of the density are considered. In addition, two versions of the one-nucleon knock-on exchange potentials are introduced to construct the real microscopic potentials. The derived potentials supplemented by phenomenological Woods-Saxon imaginary and spin-orbit potentials produced excellent description of the differential elastic scattering cross sections at the higher energy without need to introduce any renormalization. At the lower energy, however, in order to successfully reproduce the data, it is necessary to reduce the strength of the constructed real DDM3Y potential by about 25% of its original value. Furthermore, good agreement with data is obtained using the extracted microscopic DDM3Y potentials for both real and imaginary parts. Moreover, the interesting notch test is applied to investigate the sensitivity of the elastic scattering cross section to the radial distribution of the constructed microscopic potentials. The extracted reaction (absorption) cross sections are, also, investigated. (orig.)

Natural and Synthetic Barriers to Immobilize Radionuclides

International Nuclear Information System (INIS)

Um, W.

2011-01-01

The experiments of weathering of glass waste form and the reacted sediments with simulated glass leachates show that radionuclide sequestration can be significantly enhanced by promoting the formation of secondary precipitates. In addition, synthetic phosphate-bearing nanoporous material exhibits high stability at temperature and has a very high K d value for U(VI) removal. Both natural and synthetic barrier materials can be used as additional efficient adsorbents for retarding transport of radionuclides for various contaminated waste streams and waste forms present at U. S. Department of Energy clean-up sites and the proposed geologic radioactive waste disposal facility. In the radioactive waste repository facility, natural or synthetic materials are planned to be used as a barrier material to immobilize and retard radionuclide release. The getter material can be used to selectively scavenge the radionuclide of interest from a liquid waste stream and subsequently incorporate the loaded getters in a cementitious or various monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides from monolithic waste forms. Also, the getter material is to reduce the release of radionuclides form monolithic waste forms by being emplaced as a backfill barrier material around the wastes or waste form to minimize the potential around the wastes or waste form to minimize the potential hazard of leached radioactive wastes. The barrier material should be highly efficient to sequester radionuclides and possess physical and chemical stability for long-term exposure to severe weathering conditions. Because potential leaching of radionuclides depends on various environmental and weathering conditions of the near-field repository, the barrier materials must be durable and not disintegrate under a range of moisture, temperature, pressure, radiation, Eh, ph. and

Alpha-induced instabilities in tandem thermal barriers

Energy Technology Data Exchange (ETDEWEB)

Kammash, T.; Galbraith, D.L.

1987-01-01

A major premise in the operation of Tandem Mirror reactors is that the fusion reactions take place in the central cell only. The alpha particles generated by the Deuterium-Tritium (DT) fusions, along with other ions, will however pass from the central cell to the thermal barriers and return to the central cell as a result of reflection by the potential hills that exist by the plugs' side of these barriers. This streaming motion gives rise to electrostatic and electomagnetic instabilities which could detract from the barrier's function as a thermal insulator. The number density and streaming velocity of these passing particles are dictated by the electrostatic potential variation and the magnetic field structure in these regions. It is shown that, in the absence of alphas, barriers with deep potential depression are less susceptible to electrostatic instabilities while particularly vulnerable to unstable electromagnetic modes. In the presence of alphas, especially the fast alphas whose mean energy is significantly larger than the barrier potentials they see, (which is twice as high as that seen by the ions) both types of modes become unstable.

Monte-Carlo calculation of irradiation dose content beyond shielding of high-energy accelerators

International Nuclear Information System (INIS)

Mokhov, N.V.; Frolov, V.V.

1975-01-01

The MARS programme, designed for calculating the three-dimensional internuclear cascade in defence of the accelerators by the Monte Carlo method, is described. The methods used to reduce the dispersion and the system of semi-empirical formulas made it possible to exceed the parameters of the existing programmes. By means of a synthesis of the results, registered by MARS and HAMLET programmes, the dosage fields for homogeneous and heterogeneous defence were evaluated. The results of the calculated absorbed and equivalent dose behind the barrier, irradiated by a proton beam, having the energy of Esub(o)=1/1000 GeV are exposed. The dependence of the high- and low-energy neutron, proton, pion, kaon, muonium and γ-quantum dosage on the initial energy and thickness, on the material and the composition of the defence is investigated

Suppression of surface barriers in superconductors by columnar defects

International Nuclear Information System (INIS)

Koshelev, A. E.; Vinokur, V. M.

2001-01-01

We investigate the influence of columnar defects in layered superconductors on the thermally activated penetration of pancake vortices through the surface barrier. Columnar defects, located near the surface, facilitate penetration of vortices through the surface barrier, by creating ''weak spots,'' through which pancakes can penetrate into the superconductor. Penetration of a pancake mediated by an isolated column, located near the surface, is a two-stage process involving hopping from the surface to the column and the detachment from the column into the bulk; each stage is controlled by its own activation barrier. The resulting effective energy is equal to the maximum of those two barriers. For a given external field there exists an optimum location of the column for which the barriers for the both processes are equal and the reduction of the effective penetration barrier is maximal. At high fields the effective penetration field is approximately 2 times smaller than in unirradiated samples. We also estimate the suppression of the effective penetration field by column clusters. This mechanism provides further reduction of the penetration field at low temperatures

Control of internal transport barriers on Alcator C-Mod

International Nuclear Information System (INIS)

Fiore, C.L.; Bonoli, P.T.; Ernst, D.R.; Hubbard, A.E.; Greenwald, M.J.; Lynn, A.; Marmar, E.S.; Phillips, P.; Redi, M.H.; Rice, J.E.; Wolfe, S.M.; Wukitch, S.J.; Zhurovich, K.

2004-01-01

Recent studies of internal transport and double transport barrier regimes in the Alcator C-Mod [I. H. Hutchinson et al., Phys. Plasmas 1, 1511 (1994)] have explored the limits for forming, maintaining, and controlling these plasmas. The C-Mod provides a unique platform for studying such discharges: the ions and electrons are tightly coupled by collisions and the plasma has no internal particle or momentum sources. The double-barrier mode comprised of an edge barrier with an internal transport barrier (ITB) can be induced at will using off-axis ion cyclotron range of frequency (ICRF) injection on either the low or high field side of the plasma with either of the available ICRF frequencies (70 or 80 MHz). When an enhanced D α high confinement mode (EDA H-mode) is accessed in Ohmic plasmas, the double barrier ITB forms spontaneously if the H-mode is sustained for ∼2 energy confinement times. The ITBs formed in both Ohmic and ICRF heated plasmas are quite similar regardless of the trigger method. They are characterized by strong central peaking of the electron density, and a reduction of the core particle and energy transport. The control of impurity influx and heating of the core plasma in the presence of the ITB have been achieved with the addition of central ICRF power in both the Ohmic H-mode and ICRF induced ITBs. The radial location of the particle transport barrier is dependent on the toroidal magnetic field but not on the location of the ICRF resonance. A narrow region of decreased electron thermal transport, as determined by sawtooth heat pulse analysis, is found in these plasmas as well. Transport analysis indicates that a reduction of the particle diffusivity in the barrier region allows the neoclassical pinch to drive the density and impurity accumulation in the plasma center. An examination of the gyrokinetic stability at the trigger time for the ITB suggests that the density and temperature profiles are inherently stable to ion temperature gradient and

The GEOFAR Project - Geothermal Finance and Awareness in Europeans Regions - Development of new schemes to overcome non-technical barriers, focusing particularly on financial barriers

Science.gov (United States)

Poux, Adeline; Wendel, Marco; Jaudin, Florence; Hiegl, Mathias

2010-05-01

planners, developers and politicians when developing a new geothermal project. Each of the analyzed countries is facing a distinct bundle of non-technical barriers. Globally, deep geothermal projects are characterized by high up-front costs and are facing the geological risk of the non discovery of the resources in adequacy to the initial expectations. Moreover, investors are facing directly the competitiveness of fossils energy. The very long pay back period makes it also difficult for them to face the geological risk. GEOFAR will propose new targeting financing and funding schemes, in order to remove the financial barriers hindering the initial stages of geothermal energy projects. GEOFAR also considers a lack of awareness as important barrier hindering the future development of geothermal energy projects. Public opinion is globally positive to geothermal energy, but deep geothermal projects are often suffering from a lack of information leading sometimes to non public acceptance. By underlining the range of possibilities offered by the geothermal energy and the potential and emerging technologies, GEOFAR tends to increase the awareness of geothermal energy in order to boost the development and the investment in new geothermal energy projects. Geothermal energy is expected to contribute significantly to the future European energy sources and the GEOFAR project aims to facilitate it.

Barriers to the diffusion of renewable energy technologies - A case study of the state of Maharashtra, India

Energy Technology Data Exchange (ETDEWEB)

Reddy, B.S. [Indira Gandhi Inst. of Development Research, Mumbai (India)

2001-07-01

India's expanding economy and the strong growth expected in the next few decades (at around 10% per annum), will require additional energy. The use of fossil fuels is likely to dominate the strategy for meeting these needs in the near and medium term. However, India's own reserves are finite and will only be available for a limited period and the use of fossil fuels is not sustainable and is directly linked to environmental problems, particularly CO{sub 2} emissions and climate change. The importance of the increasing use of renewable energy sources was recognized in India in the early 1970s. During the past quarter century, a significant effort has gone into the development, trial and induction of a variety of technologies for use in different sectors. Today, India has one of the world's largest programs for renewable energy. The activities cower all the major renewable energy sources, including biogas, biomass, solar, wind and small-hydro power and other emerging technologies. By the end of 20th century nearly three million family-sized biogas plants (second in number in the world and next only to China's) and 30 million improved wood stoves have been established. These technologies could save about 15 million tons of fuel wood every year. Several other renewable energy technologies and products are now commercially available, and are economically viable in comparison to fossil fuels for some applications. However, there are many barriers to achieve the full potential of the renewable energy technologies. In order to study the potential and evaluate different RETs, we carried out a study of barriers to RETs in the state of Maharashtra, which accounts for about 16% of the Gross Domestic Product and 17% of the electricity supply in India. The study has been carried out in two parts. In the first part analysis was done on two technologies, viz., solar and wind. For doing this, information was collected from various secondary sources such as

High Performance Multi Barrier Thermionic Devices

National Research Council Canada - National Science Library

Vashaee, Daryoosh; Shakouri, Ali

2003-01-01

Thermoelectric transport perpendicular to layers in multiple barrier superlattice structures is investigated theoretically in two limiting cases of no lateral momentum scattering and strong scattering...

Stakeholder Perceptions of Barriers and Solutions to Significant Expansion of Postsecondary Enrollment Options for High School Students

Directory of Open Access Journals (Sweden)

Carl Wozniak

2013-02-01

Full Text Available Post-secondary experiences for students still in high school have been promoted as a means to increase academic rigor and create a better-trained workforce. Yet little is known regarding supports needed to significantly increase such options. This study obtained input from 411 stakeholders in one Midwestern state, including 201 district superintendents, 181 high school principals, and 23 college dual enrollment officers regarding their use of these options, their perceptions of barriers to program expansion, and their ranking of possible solutions to overcome the barriers. Findings demonstrate that all parties find postsecondary options of value, with traditional dual enrollment the most used option. Although all groups identified funding as a primary barrier, other systemic barriers were of great concern. Participants suggest that expansion of Advanced Placement and early and middle college programs, financial assistance for dually enrolled students, and increased program availability for career and technical options would be beneficial.Wozniak, Carl, (2012. Stakeholder Perceptions of Barriers and Solutions to Significant Expansion of Postsecondary Enrollment Options for High School Students. 8(2. Retrieved from www.ijepl.org .

Powerful highly efficient KrF lamps excited by surface and barrier discharges

International Nuclear Information System (INIS)

Borisov, V M; Vodchits, V A; El'tsov, A V; Khristoforov, O B

1998-01-01

An investigation was made of the characteristics of KrF lamps with different types of excitation by surface and barrier discharges in which the dielectric material was sapphire. The conditions were determined for the attainment of an extremely high yield of the KrF* fluorescence with the internal efficiency η in ∼30 % and 22% for pulsed surface and barrier discharges, respectively. A homogeneous surface discharge was maintained without gas circulation when the pulse repetition rate was 5 x 10 4 Hz. Quasicontinuous excitation of a surface discharge at near-atmospheric pressure made it possible to reach a KrF* fluorescence power density of about 80 W cm -3 , which was close to the limit set by the kinetics of the gaseous medium. Under prolonged excitation conditions the intensity of the UV output radiation was limited by the permissible heating of the gas to a temperature above which the operating life of the gaseous mixture containing fluorine fell steeply. This was the reason for the advantage of surface over barrier discharges: the former were characterised by a high thermal conductivity of a thin (∼0.2 mm) plasma layer on the surface of the cooled dielectric, which made it possible to construct powerful highly efficient KrF and ArF lamps emitting UV radiation of up to 1 W cm -2 intensity. (laser system components)

Radiant Barriers Save Energy in Buildings

Science.gov (United States)

2014-01-01

Langley Research Center needed to coat the Echo 1 satellite with a fine mist of vaporized metal, and collaborated with industry to create "radiant barrier technology." In 2010, Ryan Garrett learned about a new version of the technology resistant to oxidation and founded RadiaSource in Ogden, Utah, to provide the NASA-derived technology for applications in homes, warehouses, gymnasiums, and agricultural settings.

Barrier for cold-fusion production of superheavy elements

International Nuclear Information System (INIS)

Ichikawa, Takatoshi; Iwamoto, Akira; Moeller, Peter; Sierk, Arnold J.

2005-01-01

We estimate the fusion-barrier height B fu (two-body) for approaching ions in cold-fusion reactions in a model where the projectile deformation and quadrupole zero-point vibrational energy are taken into account. This barrier height is defined as the barrier energy at the target and projectile separation distance where an original oblate deformation of projectile and/or target caused by a repulsive Coulomb force turns into a large prolate deformation caused by the attractive nuclear force as the target and projectile come closer. The instability develops before touching because the attractive short-range nuclear force overcomes the repulsive Coulomb force and the shape-stabilizing effect of shell structure. The shell structure of the doubly magic 208 Pb target is sufficiently strong that its shape remains very close to spherical in all cases studied here. The fusion potential for approaching ions in the two-body channel is calculated in the macroscopic-microscopic model with the quadrupole vibrational zero-point energy obtained in the WKB approximation. We compare our results with data from 10 experimental cold-fusion reactions and with the Bass barriers. Differences and similarities between the Yukawa-plus-exponential model and the Bass model are discussed. We also calculate five-dimensional potential-energy surfaces for the single compound system and show that well-established fission and fusion valleys are both present. For heavy systems, B fu (two-body) becomes lower than the fission barrier just beyond the ground state of the compound system. In the vicinity of this transition, the optimum collision energy for formation of evaporation residues can be expected to depend in a delicate fashion on the interplay among B fu (two-body) , the fusion valley, the fission barrier of the compound system, and the one- and two-neutron separation energies S 1n and S 2n . We discuss these issues in detail and calculate fission-barrier heights. Except for reactions in which

Analysis of complete fusion excitation functions for 7Li+152Sm, 197Au and 209Bi reactions at around barrier energies

International Nuclear Information System (INIS)

Kharab, Rajesh; Chahal, Rajiv; Kumar, Rajiv

2017-01-01

In the present work we have analyzed the fusion excitation function for CF process using the simple Wong’s formula in conjunction with the energy dependent Woods-Saxon potential (EDWSP) in near barrier energy region for 7 Li+ 152 Sm, 197 Au and 209 Bi reactions

Hindered rotational energy barriers of BH4- tetrahedra in β-Mg(BH4)2 from quasielastic neutron scattering and DFT calculations

DEFF Research Database (Denmark)

Blanchard, Didier; Maronsson, Jon Bergmann; Riktor, M.D.

2012-01-01

, around the 2-fold (C2) and 3-fold (C3) axes were observed at temperatures from 120 to 440 K. The experimentally obtained activation energies (EaC2 = 39 and 76 meV and EaC3 = 214 meV) and mean residence times between reorientational jumps are comparable with the energy barriers obtained from DFT......In this work, hindered rotations of the BH4- tetrahedra in Mg(BH4)2 were studied by quasielastic neutron scattering, using two instruments with different energy resolution, in combination with density functional theory (DFT) calculations. Two thermally activated reorientations of the BH4- units...... calculations. A linear dependency of the energy barriers for rotations around the C2 axis parallel to the Mg-Mg axis with the distance between these two axes was revealed by the DFT calculations. At the lowest temperature (120 K) only 15% of the BH4- units undergo rotational motion and from comparison with DFT...

Structural stability of diffusion barriers in thermoelectric SbTe: From first-principles calculations to experimental results

International Nuclear Information System (INIS)

Hsu, Hsiao-Hsuan; Cheng, Chun-Hu; Chiou, Shan-Haw; Huang, Chiung-Hui; Liu, Chia-Mei; Lin, Yu-Li; Chao, Wen-Hsuan; Yang, Ping-Hsing; Chang, Chun-Yen; Cheng, Chin-Pao

2014-01-01

Highlights: • The diffusion behavior was originated from high-vapor-pressure Te atom. • Te out-diffusion is main driving force to cause inter-diffusion effect. • Mid-band Ta and TaN with favored ohmic-like contact showed small diffusion tail. • Strong Ta-N bonding and high total energy suppressed interfacial layer formation. -- Abstract: This study involved developing robust diffusion barrier for n-type antimony telluride (SbTe) thermoelectric devices. Compared to conventional Ni barrier, the mid-band metals of Ta and TaN with favored ohmic-like contact exhibited smaller diffusion tail because of structurally stable interface on SbTe, which have been supported by first-principles calculations and demonstrated by experimental results. Furthermore, the TaN barrier has strong ionic Ta–N bonding and a high total energy of −4.7 eV/atom that could effectively suppress the formation of SbTe-compounds interfacial layer

What are the barriers and incentives for community-owned means of energy production and use?

International Nuclear Information System (INIS)

Walker, Gordon

2008-01-01

This paper on community-owned means of renewable energy production and use, reviews experience to date in the UK and the incentives for and barriers limiting current and future growth. A broad view is taken of what the meaning of 'community-owned production and use' might constitute, as there are different models of community ownership, different notions of community and different degrees of connection or disconnection between production and use

High rates of hybridisation reveal fragile reproductive barriers between endangered Australian sea snakes

DEFF Research Database (Denmark)

Sanders, Kate L; Redsted Rasmussen, Arne; Guinea, Michael L.

2014-01-01

designations, but revealed high frequencies of hybrids on all four reefs and individuals of pure A. fuscus ancestry only at Scott and (historically) Ashmore. Most unexpectedly, 95% of snakes sampled at Hibernia were hybrids that resembled A. laevis in phenotype, revealing a collapse of reproductive barriers...... (‘reverse speciation’) at this reef. These results have dire implications for the conservation status of A. fuscus, and highlight the fragility of reproductive barriers in a recent marine radiation....

Application of CFRP with High Hydrogen Gas Barrier Characteristics to Fuel Tanks of Space Transportation System

Science.gov (United States)

Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo

In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.

Magnetized retarding field energy analyzer measuring the particle flux and ion energy distribution of both positive and negative ions

International Nuclear Information System (INIS)

Rafalskyi, Dmytro; Aanesland, Ane; Dudin, Stanislav

2015-01-01

This paper presents the development of a magnetized retarding field energy analyzer (MRFEA) used for positive and negative ion analysis. The two-stage analyzer combines a magnetic electron barrier and an electrostatic ion energy barrier allowing both positive and negative ions to be analyzed without the influence of electrons (co-extracted or created downstream). An optimal design of the MRFEA for ion-ion beams has been achieved by a comparative study of three different MRFEA configurations, and from this, scaling laws of an optimal magnetic field strength and topology have been deduced. The optimal design consists of a uniform magnetic field barrier created in a rectangular channel and an electrostatic barrier consisting of a single grid and a collector placed behind the magnetic field. The magnetic barrier alone provides an electron suppression ratio inside the analyzer of up to 6000, while keeping the ion energy resolution below 5 eV. The effective ion transparency combining the magnetic and electrostatic sections of the MRFEA is measured as a function of the ion energy. It is found that the ion transparency of the magnetic barrier increases almost linearly with increasing ion energy in the low-energy range (below 200 eV) and saturates at high ion energies. The ion transparency of the electrostatic section is almost constant and close to the optical transparency of the entrance grid. We show here that the MRFEA can provide both accurate ion flux and ion energy distribution measurements in various experimental setups with ion beams or plasmas run at low pressure and with ion energies above 10 eV

Imbalance of gut microbiome and intestinal epithelial barrier dysfunction in patients with high blood pressure.

Science.gov (United States)

Kim, Seungbum; Goel, Ruby; Kumar, Ashok; Qi, Yanfei; Lobaton, Gil; Hosaka, Koji; Mohammed, Mohammed; Handberg, Eileen M; Richards, Elaine M; Pepine, Carl J; Raizada, Mohan K

2018-03-30

Recent evidence indicates a link between gut pathology and microbiome with hypertension (HTN) in animal models. However, whether this association exists in humans is unknown. Thus, our objectives in the present study were to test the hypotheses that high blood pressure (BP) patients have distinct gut microbiomes and that gut-epithelial barrier function markers and microbiome composition could predict systolic BP (SBP). Fecal samples, analyzed by shotgun metagenomics, displayed taxonomic and functional changes, including altered butyrate production between patients with high BP and reference subjects. Significant increases in plasma of intestinal fatty acid binding protein (I-FABP), lipopolysaccharide (LPS), and augmented gut-targetting proinflammatory T helper 17 (Th17) cells in high BP patients demonstrated increased intestinal inflammation and permeability. Zonulin, a gut epithelial tight junction protein regulator, was markedly elevated, further supporting gut barrier dysfunction in high BP. Zonulin strongly correlated with SBP (R 2 = 0.5301, P <0.0001). Two models predicting SBP were built using stepwise linear regression analysis of microbiome data and circulating markers of gut health, and validated in a separate cohort by prediction of SBP from zonulin in plasma (R 2 = 0.4608, P <0.0001). The mouse model of HTN, chronic angiotensin II (Ang II) infusion, was used to confirm the effects of butyrate and gut barrier function on the cardiovascular system and BP. These results support our conclusion that intestinal barrier dysfunction and microbiome function are linked to HTN in humans. They suggest that manipulation of gut microbiome and its barrier functions could be the new therapeutic and diagnostic avenues for HTN. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Sub-barrier fusion and near-barrier quasi-elastic scattering

International Nuclear Information System (INIS)

Kolata, J.J.; Tighe, R.J.

1990-01-01

Elastic scattering of 32 S on 58,64 Ni and fusion of 32 S+ 58,64 Ni and 34 S+ 64 Ni have been measured at energies near the Coulomb barrier. Our results differ in several important respects from previous measurements on these systems. Coupled-channels calculations which explicitly allow for inelastic excitation and single-nucleon transfer reproduce the main features of the new data. Near-barrier elastic scattering of 48 Ca on 40 Ca has also been measured. These data provide evidence for the effect of strong coupling to positive Q-value channels other than single-nucleon transfer. 18 refs., 3 figs

Perceived barriers to physical activity among Polish adolescents.

Science.gov (United States)

Jodkowska, Maria; Mazur, Joanna; Oblacińska, Anna

2015-01-01

To identify barriers to physical activity (PA) for adolescents according to the gender and age and examine the association between these barriers and youths' physical activity. 3346 students aged 10-16 years (1759 girls) took part in the cross-sectional, nationally representative study. For this paper the dataset was created from adolescents who reported perceived barriers to PA, N = 2300, (1259 girls), range 13-16 years. Barriers and physical activity (MVPA) were analysed for all participants, as well as by gender, age group and place of residence. Multiple regression analysis was used to examine the relationships between perceived barriers and physical inactivity for all and than separately for boys and girls. Lack of energy, lack of time and lack of support were three of the five barriers reported by more than 40% of adolescents, statistically more likely by girls than boys and older youth than younger. For boys - lack of time (OR = 2.56; CI = 1.66-3.96), lack of skills (OR = 2.35; CI = 1.94-3.95), lack of willpower (OR = 1.71, CI = 1.05-2.80) and lack of support (OR = 1.64, CI = 1.11-2.41) were the predictors contributing to low level of PA. For girls lack of skills (OR = 3.16, CI = 1.62-6.18), lack of energy (OR = 1.84, CI = 1.14-2.96), lack of support (OR = 1.64, CI = 1.07-2.54) and lack of time (OR = 1.61,CI = 1.00-2.60) were positively and statistically significant associated with physical inactivity. 1. Perceived barriers to physical activity among adolescents have strong negative impact on recommended PA level. For girls lack of skills is the strongest predictor of low PA, for boys - lack of time. 2. Identification more precisely barriers to physical activity among adolescents will enable to developed more effective interventions in high-risk populations.

Polymers for subterranean containment barriers for underground storage tanks (USTs)

International Nuclear Information System (INIS)

Heiser, J.H.; Colombo, P.; Clinton, J.

1992-12-01

The US Department of Energy (DOE) set up the Underground Storage Tank Integrated Demonstration Program (USTID) to demonstrate technologies for the retrieval and treatment of tank waste, and closure of underground storage tanks (USTs). There are more than 250 underground storage tanks throughout the DOE complex. These tanks contain a wide variety of wastes including high level, low level, transuranic, mixed and hazardous wastes. Many of the tanks have performed beyond the designed lifetime resulting in leakage and contamination of the local geologic media and groundwater. To mitigate this problem it has been proposed that an interim subterranean containment barrier be placed around the tanks. This would minimize or prevent future contamination of soil and groundwater in the event that further tank leakages occur before or during remediation. Use of interim subterranean barriers can also provide sufficient time to evaluate and select appropriate remediation alternatives. The DOE Hanford site was chosen as the demonstration site for containment barrier technologies. A panel of experts for the USTID was convened in February, 1992, to identify technologies for placement of subterranean barriers. The selection was based on the ability of candidate grouts to withstand high radiation doses, high temperatures and aggressive tank waste leachates. The group identified and ranked nine grouting technologies that have potential to place vertical barriers and five for horizontal barriers around the tank. The panel also endorsed placement technologies that require minimal excavation of soil surrounding the tanks

High energy neutron radiography

International Nuclear Information System (INIS)

Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

1996-01-01

High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

Thames barrier (flood protection barriers on the Thames)

International Nuclear Information System (INIS)

Ilkovic, J.

2005-01-01

In this paper the flood protection barriers on the Thames are presented. The flood protection system on the Thames in 1984 was commissioned. During two decades this barrier was used 54 times against to the high water and 34 times against storm-sewage. There is installed buttress type hydroelectric power plant

Memory-induced acceleration and slowdown of barrier crossing

Science.gov (United States)

Kappler, Julian; Daldrop, Jan O.; Brünig, Florian N.; Boehle, Moritz D.; Netz, Roland R.

2018-01-01

We study the mean first-passage time τMFP for the barrier crossing of a single massive particle with non-Markovian memory by Langevin simulations in one dimension. In the Markovian limit of short memory time τΓ, the expected Kramers turnover between the overdamped (high-friction) and the inertial (low-friction) limits is recovered. Compared to the Markovian case, we find barrier crossing to be accelerated for intermediate memory time, while for long memory time, barrier crossing is slowed down and τMFP increases with τΓ as a power law τM F P˜τΓ2. Both effects are derived from an asymptotic propagator analysis: while barrier crossing acceleration at intermediate memory can be understood as an effective particle mass reduction, slowing down for long memory is caused by the slow kinetics of energy diffusion. A simple and globally accurate heuristic formula for τMFP in terms of all relevant time scales of the system is presented and used to establish a scaling diagram featuring the Markovian overdamped and the Markovian inertial regimes, as well as the non-Markovian intermediate memory time regime where barrier crossing is accelerated and the non-Markovian long memory time regime where barrier crossing is slowed down.

Comparison of Moderate and High Energy of a Nano-Fractional Radiofrequency Treatment on a Photoaging Hairless Mice Model.

Science.gov (United States)

Sun, Wenjia; Zhang, Chengfeng; Zhao, Juemin; Wu, Jiaqiang; Xiang, Leihong

2018-04-01

Fractional radiofrequency (FRF) has been widely used in skin rejuvenation. To explore optimal settings, it is important to compare different treatment parameters. This study was designed to compare the effect of moderate-energy and high-energy FRF treatment on a hairless mice model. Fifteen photoaged hairless mice were assigned to 3 groups: control, moderate energy, and high energy. Two treatment sessions (T × 1 and T × 2) were performed at 1-month interval. Transepidermal water loss was measured at baseline, immediately, 1, 2, and 4 weeks after T × 1. Skin samples were harvested before each treatment, 1 and 2 months after T × 2. Neocollagenesis was evaluated by hematoxylin and eosin staining, Masson staining, and immunohistochemistry analysis. Transepidermal water loss of high-energy group was significantly higher than the moderate-energy group (p = .008) immediately after T × 1. Remarkable fibroblast proliferation was observed at 1 month after T × 1, followed by significant dermal thickening, and increase of Type I collagen and Type III collagen. There was no significant difference between 2 energy groups in fibroblast proliferation, dermal thickness, and collagen density. The effect of moderate-energy treatment was comparable with that of high energy in neocollagenesis, whereas moderate energy yielded less damage to skin barrier function.

Conductance of graphene-based double-barrier nanostructures

Energy Technology Data Exchange (ETDEWEB)

Setare, M R [Department of Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Jahani, D, E-mail: Rezakord@ipm.co, E-mail: Dariush110@gmail.co [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of)

2010-12-22

The effect of a mass gap on the conductance of graphene double-barrier heterojunctions is studied. By obtaining the 2D expression for the electronic transport of the low energy excitations of pure graphene through double-barrier systems, it is found that the conductivity of these structures does not depend on the type of charge carriers in the zones of the electric field. However, a finite induced gap in the graphene spectrum makes conductivity dependent on the energy band index. We also discuss a few controversies concerning double-barrier systems stemming from an improper choice of the scattering angle. Then it is observed that, for some special values of the incident energy and potential's height, graphene junctions behave like left-handed materials, resulting in a maximum value for the conductivity.

Conductance of graphene-based double-barrier nanostructures

International Nuclear Information System (INIS)

Setare, M R; Jahani, D

2010-01-01

The effect of a mass gap on the conductance of graphene double-barrier heterojunctions is studied. By obtaining the 2D expression for the electronic transport of the low energy excitations of pure graphene through double-barrier systems, it is found that the conductivity of these structures does not depend on the type of charge carriers in the zones of the electric field. However, a finite induced gap in the graphene spectrum makes conductivity dependent on the energy band index. We also discuss a few controversies concerning double-barrier systems stemming from an improper choice of the scattering angle. Then it is observed that, for some special values of the incident energy and potential's height, graphene junctions behave like left-handed materials, resulting in a maximum value for the conductivity.

Conductance of graphene-based double-barrier nanostructures.

Science.gov (United States)

Setare, M R; Jahani, D

2010-12-22

The effect of a mass gap on the conductance of graphene double-barrier heterojunctions is studied. By obtaining the 2D expression for the electronic transport of the low energy excitations of pure graphene through double-barrier systems, it is found that the conductivity of these structures does not depend on the type of charge carriers in the zones of the electric field. However, a finite induced gap in the graphene spectrum makes conductivity dependent on the energy band index. We also discuss a few controversies concerning double-barrier systems stemming from an improper choice of the scattering angle. Then it is observed that, for some special values of the incident energy and potential's height, graphene junctions behave like left-handed materials, resulting in a maximum value for the conductivity.

Simultaneous escaping of explicit and hidden free energy barriers: application of the orthogonal space random walk strategy in generalized ensemble based conformational sampling.

Science.gov (United States)

Zheng, Lianqing; Chen, Mengen; Yang, Wei

2009-06-21

To overcome the pseudoergodicity problem, conformational sampling can be accelerated via generalized ensemble methods, e.g., through the realization of random walks along prechosen collective variables, such as spatial order parameters, energy scaling parameters, or even system temperatures or pressures, etc. As usually observed, in generalized ensemble simulations, hidden barriers are likely to exist in the space perpendicular to the collective variable direction and these residual free energy barriers could greatly abolish the sampling efficiency. This sampling issue is particularly severe when the collective variable is defined in a low-dimension subset of the target system; then the "Hamiltonian lagging" problem, which reveals the fact that necessary structural relaxation falls behind the move of the collective variable, may be likely to occur. To overcome this problem in equilibrium conformational sampling, we adopted the orthogonal space random walk (OSRW) strategy, which was originally developed in the context of free energy simulation [L. Zheng, M. Chen, and W. Yang, Proc. Natl. Acad. Sci. U.S.A. 105, 20227 (2008)]. Thereby, generalized ensemble simulations can simultaneously escape both the explicit barriers along the collective variable direction and the hidden barriers that are strongly coupled with the collective variable move. As demonstrated in our model studies, the present OSRW based generalized ensemble treatments show improved sampling capability over the corresponding classical generalized ensemble treatments.

Energy barriers for interlayer diffusion in Pt/Pt(111) and Rh/Rh(111) homoepitaxy: small islands

Czech Academy of Sciences Publication Activity Database

Máca, František; Kotrla, Miroslav; Trushin, O. S.

1999-01-01

Roč. 49, č. 11 (1999), s. 1591-1596 ISSN 0011-4626. [Symposium on Surface Physics /8./. Třešť, 28.06.1999-02.07.1999] R&D Projects: GA MŠk OC P3.80 Institutional research plan: CEZ:AV0Z1010914 Keywords : molecular statics * energy barriers * Pt and Rh Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.328, year: 1999

Air Leakage Rates in Typical Air Barrier Assemblies

Energy Technology Data Exchange (ETDEWEB)

Hun, Diana E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Atchley, Jerald Allen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Phillip W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-11-01

Estimates for 2010 indicate that infiltration in residential buildings was responsible for 2.85 quads of energy (DOE 2014), which is about 3% of the total energy consumed in the US. One of the mechanisms being implemented to reduce this energy penalty is the use of air barriers as part of the building envelope. These technologies decrease airflow through major leakage sites such as oriented strand board (OSB) joints, and gaps around penetrations (e.g., windows, doors, pipes, electrical outlets) as indicated by Hun et al. (2014). However, most air barrier materials do not properly address leakage spots such as wall-to-roof joints and wall-to-foundation joints because these are difficult to seal, and because air barrier manufacturers usually do not provide adequate instructions for these locations. The present study focuses on characterizing typical air leakage sites in wall assemblies with air barrier materials.

Design of high efficiency and energy saving aeration device for aquaculture

Science.gov (United States)

Liu, Sibo

2017-03-01

Energy efficient aeration device for aquaculture, in line with "by more than a generation, dynamic aeration" train of thought for technical design and improvement. Removable aeration terminal as the core, multi-level water to improve the method, the mobile fading pore aeration, intelligent mobile and open and close as the main function, aimed at solving the existing pond aeration efficiency, low energy consumption is high, the function of a single problem. From energy saving, efficiency, biological bacteria on the three directions, the aquaculture industry of energy conservation and emissions reduction. Device of the main advantages are: 1, original mobile fading aerator on the one hand, to expand the scope of work, playing a micro porous aeration of dissolved oxygen with high efficiency and to achieve "by more than a generation", on the other hand, through the sports equipment, stir the mixture of water, the water surface of photosynthesis of plants rich in dissolved oxygen input parts of the tank, compared to the stillness of the aerator can be more fully dissolved oxygen.2, through the opening of the pressure sensor indirect control device, can make the equipment timely and stop operation, convenient in use at the same time avoid the waste of energy.3, the biofilm suspension in aeration terminal, can be accomplished by nitration of microbial multi-level water improvement, still can make biofilm increase rate of netting in the movement process, the biological and mechanical aerobic promote each other, improve the efficiency of both. In addition, the device has small power consumption, low cost of characteristics. And have a certain degree of technical barriers, have their own intellectual property rights, and high degree of product market demand, easily accepted by customers, has a very high popularization value.

Silicon surface barrier detector and study of energy spectrum of alpha particles from radioactive source

International Nuclear Information System (INIS)

Verma, S.D.; Sinha, Vijaya

1986-01-01

The principles of working of three commonly used radiation detectors, namely ionization chambers, scintillation counters with photomultiplier tube (PMT) systems and semiconductor detectors are briefly discussed. Out of the semiconductor detectors, the silicon surface barrier (SSB) detector has distinct advantages for detection of radiations, alpha particles in particular. The experimental setup to obtain the energy spectrum of alpha particles from 241 Am source using SSB fabricated in the Physics Department of Gujarat University, Ahmedabad is described. Its performance is compared with scintillation counter using PMT. SSB detector shows a sharp peak of #approx # 3 per cent energy resolution. The factors affecting the peak, namely, electronic noise, source dependent factors and detector-dependent factors are discussed. A method of calibrating SSB detectors based on energy loss mechanism of alpha particles in thin absorbers is described. Applications of such detectors are indicated. (M.G.B.)

Pseudocapacitive Oxides and Sulfides for High-Performance Electrochemical Energy Storage

KAUST Repository

Xia, Chuan

2018-03-22

atypically layered systems can greatly lower the interaction energy and Li+ diffusion barrier, and it can completely suppress the crystal transformation during the charge-discharge process. As a result, we have successfully enabled the kinetically sluggish step to proceed at room temperature. We show that even at charge-discharge rates as fast as 100C (36 s), these 2D electrodes still offer a high capacity of 140 mAh g-1 due to the rapid Li+ ion diffusion in these 2D sheets. These results discussed in this part conclusively show that the ultrathin 2D geometry of atypically layered or non-layered materials could lead to significantly enhanced pseudocapacitive performance.

Experimental fusion excitation functions and derived barrier distributions for heavy ion systems involving prolate and oblate target nuclei

International Nuclear Information System (INIS)

Bierman, J.D.; Chan, P.; Liang, J.F.; Kelly, M.P.; Sonzogni, A.A.; Vandenbosch, R.

1996-01-01

Fusion excitation functions spanning the entire barrier region in 1 MeV energy steps for the two systems 40 Ca + 192 Os, 194 Pt are presented. The results of fission fragment angular distribution measurements for fusion-fission of 40 Ca + 197 Au at several projectile energies within the barrier region are also presented. The fusion data is of high enough precision to allow for extraction of the distribution of fusion barriers from the second differential of the product of E and σ. Basic coupled channels calculations which are in quite good agreement with the data are shown and discussed

Comparison of three dielectric barrier discharges regarding their physical characteristics and influence on the adhesion properties on maple, high density fiberboards and wood plastic composite

International Nuclear Information System (INIS)

Peters, F; Wieneke, S; Ohms, G; Viöl, W; Hünnekens, B; Militz, H

2017-01-01

In this study, three different dielectric barrier discharges, based on the same setup and run with the same power supply, are characterized by emission spectroscopy with regards to the reduced electrical field strength, and the rotational, vibrational and electron temperature. To compare discharges common for the treatment on wood, a coplanar surface barrier discharge, a direct dielectric barrier discharge and a jet system/remote plasma are chosen. To minimize influences due to the setups or power, the discharges are realized with the same electrodes and power supply and normalized to the same power. To evaluate the efficiency of the different discharges and the influence on treated materials, the surface free energy is determined on a maple wood, high density fiberboard and wood plastic composite. The influence is measured depending on the treatment time, with the highest impact in the time of 5 s. (paper)

Comparison of three dielectric barrier discharges regarding their physical characteristics and influence on the adhesion properties on maple, high density fiberboards and wood plastic composite

Science.gov (United States)

Peters, F.; Hünnekens, B.; Wieneke, S.; Militz, H.; Ohms, G.; Viöl, W.

2017-11-01

In this study, three different dielectric barrier discharges, based on the same setup and run with the same power supply, are characterized by emission spectroscopy with regards to the reduced electrical field strength, and the rotational, vibrational and electron temperature. To compare discharges common for the treatment on wood, a coplanar surface barrier discharge, a direct dielectric barrier discharge and a jet system/remote plasma are chosen. To minimize influences due to the setups or power, the discharges are realized with the same electrodes and power supply and normalized to the same power. To evaluate the efficiency of the different discharges and the influence on treated materials, the surface free energy is determined on a maple wood, high density fiberboard and wood plastic composite. The influence is measured depending on the treatment time, with the highest impact in the time of 5 s.

High to ultra-high power electrical energy storage.

Science.gov (United States)

Sherrill, Stefanie A; Banerjee, Parag; Rubloff, Gary W; Lee, Sang Bok

2011-12-14

High power electrical energy storage systems are becoming critical devices for advanced energy storage technology. This is true in part due to their high rate capabilities and moderate energy densities which allow them to capture power efficiently from evanescent, renewable energy sources. High power systems include both electrochemical capacitors and electrostatic capacitors. These devices have fast charging and discharging rates, supplying energy within seconds or less. Recent research has focused on increasing power and energy density of the devices using advanced materials and novel architectural design. An increase in understanding of structure-property relationships in nanomaterials and interfaces and the ability to control nanostructures precisely has led to an immense improvement in the performance characteristics of these devices. In this review, we discuss the recent advances for both electrochemical and electrostatic capacitors as high power electrical energy storage systems, and propose directions and challenges for the future. We asses the opportunities in nanostructure-based high power electrical energy storage devices and include electrochemical and electrostatic capacitors for their potential to open the door to a new regime of power energy.

Microscopic study on dynamic barrier in fusion reactions

International Nuclear Information System (INIS)

Wu Xizhen; Tian Junlong; Zhao Kai; Li Zhuxia; Wang Ning

2004-01-01

The authors briefly review the fusion process of very heavy nuclear systems and some theoretical models. The authors propose a microscopic transport dynamic model, i.e. the Improved Quantum Molecular Dynamic model, for describing fusion reactions of heavy systems, in which the dynamical behavior of the fusion barrier in heavy fusion systems has been studied firstly. The authors find that with the incident energy decreasing the lowest dynamic barrier is obtained which approaches to the adiabatic static barrier and with increase of the incident energy the dynamic barrier goes up to the diabatic static barrier. The authors also indicate that how the dynamical fusion barrier is correlated with the development of the configuration of fusion partners along the fusion path. Associating the single-particle potentials obtained at different stages of fusion with the Two Center Shell Model, authors can study the time evolution of the single particle states of fusion system in configuration space of single particle orbits along the fusion path. (author)

Photochemical approach to high-barrier films for the encapsulation of flexible laminary electronic devices

Energy Technology Data Exchange (ETDEWEB)

Prager, L., E-mail: lutz.prager@iom-leipzig.de [Leibniz-Institut für Oberflächenmodifizierung e.V., Permoserstr. 15, 04318 Leipzig (Germany); Helmstedt, U. [Leibniz-Institut für Oberflächenmodifizierung e.V., Permoserstr. 15, 04318 Leipzig (Germany); Herrnberger, H. [Solarion AG, Pereser Höhe 1, Breitscheidstraße 45, 04442 Zwenkau (Germany); Kahle, O. [Fraunhofer-Einrichtung für Polymermaterialien und Composite PYCO, Kantstraße 55, 14513 Teltow (Germany); Kita, F. [AZ Electronic Materials Germany GmbH, Rheingaustraße 190-196, 65203 Wiesbaden (Germany); Münch, M. [Solarion AG, Pereser Höhe 1, Breitscheidstraße 45, 04442 Zwenkau (Germany); Pender, A.; Prager, A.; Gerlach, J.W. [Leibniz-Institut für Oberflächenmodifizierung e.V., Permoserstr. 15, 04318 Leipzig (Germany); Stasiak, M. [Fraunhofer-Einrichtung für Polymermaterialien und Composite PYCO, Kantstraße 55, 14513 Teltow (Germany)

2014-11-03

Based on results of preceding research and development, thin gas barriers were made by wet application of perhydropolysilazane solution onto polymer films and its subsequent photo-initiated conversion to dense silica layers applying vacuum ultraviolet irradiation. Compared to the state of the art, these layers were sufficiently improved and characterized by spectroscopic methods, by scanning electron microscopy and by gas permeation measurements. Water vapor transmission rates (WVTR) below 10{sup −2} g m{sup −2} d{sup −1} were achieved. In this way, single barrier films were developed and produced on a pilot plant from roll to roll, 250 mm wide, at speeds up to 10 m min{sup −1}. Two films were laminated using adhesives curable with ultraviolet (UV) light and evaluated by peel tests, gas permeation measurement and climate testing. It could be shown that the described high-barrier laminates which exhibit WVTR ≈ 5 × 10{sup −4} g m{sup −2} d{sup −1}, determined by the calcium mirror method, are suitable for encapsulation of flexible thin-film photovoltaic modules. Durability of the encapsulated modules could be verified in several climate tests including damp-heat, thermo-cycle (heating, freezing, wetting) and UV exposures which are equivalent to more than 20 years of endurance at outdoor conditions in temperate climate. In the frame of further research and technical development it seems to be possible to design a cost efficient industrial scale process for the production of encapsulation films for photovoltaic applications. - Highlights: • Dense silica barrier layers were developed by a photochemical approach. • Polymer based barrier films were laminated yielding flexible high-barrier films. • Using these laminates photovoltaic test modules were encapsulated and tested. • A durability of more than 20 years at outdoor conditions could be proved.

High-energy detector

Science.gov (United States)

Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

2011-11-22

The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

Nucleus fragmentation induced by a high-energy hadron

International Nuclear Information System (INIS)

Zielinski, P.

1982-10-01

The author presents a review about the spallation in hadron reactions. Especially he considers proton-proton correlations at low relative momentum, angular distributions of 30-100 MeV protons, emission of fast deuterons, the vanishing of the Coulomb barrier, fission-like processes, the rise of the heavy fragment yield with energy transfer, proton-deuteron breakup reactions, and the backward emission of fast protons. (HSI)

Energy Systems High-Pressure Test Laboratory | Energy Systems Integration

Science.gov (United States)

Facility | NREL Energy Systems High-Pressure Test Laboratory Energy Systems High-Pressure Test Laboratory In the Energy Systems Integration Facility's High-Pressure Test Laboratory, researchers can safely test high-pressure hydrogen components. Photo of researchers running an experiment with a hydrogen fuel

Group-III nitride based high electron mobility transistor (HEMT) with barrier/spacer layer

Science.gov (United States)

Chavarkar, Prashant; Smorchkova, Ioulia P.; Keller, Stacia; Mishra, Umesh; Walukiewicz, Wladyslaw; Wu, Yifeng

2005-02-01

A Group III nitride based high electron mobility transistors (HEMT) is disclosed that provides improved high frequency performance. One embodiment of the HEMT comprises a GaN buffer layer, with an Al.sub.y Ga.sub.1-y N (y=1 or y 1) layer on the GaN buffer layer. An Al.sub.x Ga.sub.1-x N (0.ltoreq.x.ltoreq.0.5) barrier layer on to the Al.sub.y Ga.sub.1-y N layer, opposite the GaN buffer layer, Al.sub.y Ga.sub.1-y N layer having a higher Al concentration than that of the Al.sub.x Ga.sub.1-x N barrier layer. A preferred Al.sub.y Ga.sub.1-y N layer has y=1 or y.about.1 and a preferred Al.sub.x Ga.sub.1-x N barrier layer has 0.ltoreq.x.ltoreq.0.5. A 2DEG forms at the interface between the GaN buffer layer and the Al.sub.y Ga.sub.1-y N layer. Respective source, drain and gate contacts are formed on the Al.sub.x Ga.sub.1-x N barrier layer. The HEMT can also comprising a substrate adjacent to the buffer layer, opposite the Al.sub.y Ga.sub.1-y N layer and a nucleation layer between the Al.sub.x Ga.sub.1-x N buffer layer and the substrate.

Nucleus fragmentation induced by a high-energy hadron. Pt. 2

International Nuclear Information System (INIS)

Zielinski, P.

1981-09-01

The author compares some experimental results concerning the emission of 8 Li nuclei in hadron induced reactions from nuclear emulsions. Especially he considers the vanishing of the Coulomb barrier, fission-like processes, and the rise of the heavy fragment yield with energy-transfer. (HSI) [de

Fusion cross sections for 6,7Li + 24Mg reactions at energies below and above the barrier

International Nuclear Information System (INIS)

Ray, M.; Mukherjee, A.; Pradhan, M. K.; Kshetri, Ritesh; Sarkar, M. Saha; Dasmahapatra, B.; Palit, R.; Majumdar, I.; Joshi, P. K.; Jain, H. C.

2008-01-01

Measurement of fusion cross sections for the 6,7 Li + 24 Mg reactions by the characteristic γ-ray method has been done at energies from below to well above the respective Coulomb barriers. The fusion cross sections obtained from these γ-ray cross sections for the two systems are found to agree well with the total reaction cross sections at low energies. The relatively large difference between total cross sections and measured fusion cross sections at higher energies is consistent with the fact that other channels, in particular breakup, open up with an increase of bombarding energy. The breakup channel, however, appears not to have any influence on fusion cross sections. The critical angular momenta (l cr ) deduced from the fusion cross sections are found to have an energy dependence similar to other Li-induced reactions

Investigation of {sup 17}F+p elastic scattering at near-barrier energies

Energy Technology Data Exchange (ETDEWEB)

El-Azab Farid, M. [Assiut University, Physics Department, Assiut (Egypt); Ibraheem, Awad A. [Al-Azhar University, Physics Department, Assiut (Egypt); King Khalid University, Physics Department, Abha (Saudi Arabia); Al-Hajjaji, Arwa S. [Taiz University, Physics Department, Taiz (Yemen)

2015-10-15

The {sup 17}F +p elastic scattering at two near-barrier energies of 3.5 and 4.3 MeV/nucleon, have been analyzed in the framework of the single folding approach. The folded potentials are constructed by folding the density-dependent (DDM3Y) effective nucleon-nucleon interaction over the nuclear density of the one-proton halo nucleus {sup 17}F. Two versions of the density are considered. In addition, two versions of the one-nucleon knock-on exchange potentials are introduced to construct the real microscopic potentials. The derived potentials supplemented by phenomenological Woods-Saxon imaginary and spin-orbit potentials produced excellent description of the differential elastic scattering cross sections at the higher energy without need to introduce any renormalization. At the lower energy, however, in order to successfully reproduce the data, it is necessary to reduce the strength of the constructed real DDM3Y potential by about 25% of its original value. Furthermore, good agreement with data is obtained using the extracted microscopic DDM3Y potentials for both real and imaginary parts. Moreover, the interesting notch test is applied to investigate the sensitivity of the elastic scattering cross section to the radial distribution of the constructed microscopic potentials. The extracted reaction (absorption) cross sections are, also, investigated. (orig.)

Fission barriers in the quasi-molecular shape path

International Nuclear Information System (INIS)

Royer, G.; Bonilla, C.; Zbiri, K.; Gherghescu, R.A.