Science.gov

Sample records for making energy transition

  1. Flexible Scheduling: Making the Transition

    ERIC Educational Resources Information Center

    Creighton, Peggy Milam

    2008-01-01

    Citing literature that supports the benefits of flexible scheduling on student achievement, the author exhorts readers to campaign for flexible scheduling in their library media centers. She suggests tips drawn from the work of Graziano (2002), McGregor (2006) and Stripling (1997) for making a smooth transition from fixed to flexible scheduling:…

  2. Making the transition to automation

    SciTech Connect

    Christenson, D.J. )

    1992-10-01

    By 1995, the Bureau of Reclamation's hydropower plant near Hungry Horse, Montana, will be remotely operated from Grand Coulee dam (about 300 miles away) in Washington State. Automation at Hungry Horse will eliminate the need for four full-time power plant operators. Between now and then, a transition plan that offers employees choices for retraining, transferring, or taking early retirement will smooth the transition in reducing from five operators to one. The transition plan also includes the use of temporary employees to offset risks of reducing staff too soon. When completed in 1953, the Hungry Horse structure was the world's fourth largest and fourth highest concrete dam. The arch-gravity structure has a crest length of 2,115 feet; it is 3,565 feet above sea level. The four turbine-generator units in the powerhouse total 284 MW, and supply approximately 1 billion kilowatt-hours of electricity annually to the federal power grid managed by the Bonneville Power Administration. In 1988, Reclamation began to automate operations at many of its hydro plants, and to establish centralized control points. The control center concept will increase efficiency. It also will coordinate water movements and power supply throughout the West. In the Pacific Northwest, the Grand Coulee and Black Canyon plants are automated control centers. Several Reclamation-owned facilities in the Columbia River Basin, including Hungry Horse, will be connected to these centers via microwave and telephone lines. When automation is complete, constant monitoring by computer will replace hourly manual readings and equipment checks. Computers also are expected to increase water use efficiency by 1 to 2 percent by ensuring operation for maximum turbine efficiency. Unit efficiency curves for various heads will be programmed into the system.

  3. Making Sense of Energy

    ERIC Educational Resources Information Center

    Boohan, Richard

    2014-01-01

    This article describes an approach to teaching about the energy concept that aims to be accessible to students starting in early secondary school, while being scientifically rigorous and forming the foundation for later work. It discusses how exploring thermal processes is a good starting point for a more general consideration of the ways that…

  4. School to Work: Making the Transition.

    ERIC Educational Resources Information Center

    Academy for Educational Development, Washington, DC. National Inst. for Work and Learning.

    This publication describes the Academy for Educational Development's (AED's) vision and work in school-to-work transition and related areas. School-to-work transition is defined, and components of a successful school-to-work transition system are listed. The National Institute for Work and Learning (NIWL) is currently conducting an extensive study…

  5. Process for making transition metal nitride whiskers

    DOEpatents

    Bamberger, C.E.

    1988-04-12

    A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites. 1 fig., 1 tab.

  6. Process for making transition metal nitride whiskers

    SciTech Connect

    Bamberger, Carlos E.

    1989-01-01

    A process for making metal nitrides, particularly titanium nitride whiskers, using a cyanide salt as a reducing agent for a metal compound in the presence of an alkali metal oxide. Sodium cyanide, various titanates and titanium oxide mixed with sodium oxide react to provide titanium nitride whiskers that can be used as reinforcement to ceramic composites.

  7. Making the transition from health professional to manager.

    PubMed

    Prideaux, G

    1993-01-01

    Health professionals who make a career change into a managerial role frequently find that the adjustment is a difficult one. Often they are not well prepared for the new role. They find that the world of the manager is different in a number of ways from the professional world they have known, and the skills required for effective performance are also different. This preliminary study, which involved interviews with a number of professionals who have made the transition, highlighted the adjustments they had to make and the transition difficulties they experienced. Attention is drawn to a number of ways in which health professionals can be assisted to develop into effective managers. PMID:10127672

  8. Making use of renewable energy

    SciTech Connect

    Johnston, J.C.

    1984-01-01

    This book describes renewable energy projects proposed for the rural areas of developing countries. Topics considered include biogas generation in Zimbabwe, biogas technology for water pumping in Botswana, soil fertility and energy problems in rural development in the Zaire rain forest, international scientific collaboration on biogas technologies for rural development, alcohol from biomass, an ethanol project in Zimbabwe, biomass alcohol and the fuel-food issue, solar water heating in Zimbabwe, absorbent box solar cookers, solar crop drying in Zimbabwe, the use of passive solar energy in Botswana buildings, the potential of mini hydro systems, woodfuel as a potential renewable energy source, small-scale afforestation for domestic needs in the communal lands of Zimbabwe, muscle power, the use of human energy in construction, hand-operated water pumps, animal power for water pumping in Botswana, the production of charcoal in Zambia, improving the efficiency of a traditional charcoal-burning Burmese cooking stove, social impacts, non-engineering constraints affecting energy use in a rural area, women and energy, and non-technical factors influencing the establishment of fuels-from-crops industries in developing countries.

  9. Making `Internal Thermal Energy' Visible

    NASA Astrophysics Data System (ADS)

    Zou, Xueli

    2004-09-01

    In a 1992 paper published in this journal, Uri Ganiel described a pair of model carts used to demonstrate elastic and inelastic collisions. The wooden carts had low-friction wheels and a steel-strip bumper on one end. On one of the carts, a number of brass washers were rigidly mounted in vertical stacks to a wooden framework. The other cart was similar except that the washers were tied to rubber bands that were stretched horizontally and diagonally across the framework. When the first cart was rolled into a wall it bounced off with only a small reduction in speed ("elastic" collision). The second cart, on the other hand, was found to come nearly to a complete stop upon colliding with the wall ("inelastic" collision). Following the instructions given in Ganiel's paper, I built a pair of carts and demonstrated them to introductory-level physics students at a large public university. It was interesting to find that many students were distracted by the different-looking structures of the two model carts.2 They thought the different distributions of washers between the carts resulted in the rubber-band cart bouncing back a significantly shorter distance than the rigid-rod one after they both collided with a wall at the same initial speed. Apparently, the students had difficulties in understanding the collisions and used surface features to reason about them. To avoid this superficial distraction and to help students visualize easily "where the kinetic energy goes in an inelastic collision," I modified the rigid-rod cart to have washers fixed on hollow aluminum rods mounted at four different levels horizontally and diagonally (see Fig. 1). The new pair of the model carts look very similar to each other: They have the same bumpers, same wheels, same distributions of washers, and same masses.

  10. Energy Transition Initiative: Islands Playbook (Book)

    SciTech Connect

    Not Available

    2015-01-01

    The Island Energy Playbook (the Playbook) provides an action-oriented guide to successfully initiating, planning, and completing a transition to an energy system that primarily relies on local resources to eliminate a dependence on one or two imported fuels. It is intended to serve as a readily available framework that any community can adapt to organize its own energy transition effort.

  11. Healthcare transition managers make market exits easier for insurers.

    PubMed

    Resnick, L R

    1999-10-01

    Insurers have been struggling to meet and maintain their profit margins on the health insurance business they underwrite. As a result, many have exited or are contemplating exiting from the health insurance market. At the same time, managed care organizations are seeking ways to augment their enrollment base and satisfy investor expectations. Insurers that wish to transfer their health insurance business to other carriers and managed care organizations that are interested in accepting this business have turned to a new type of healthcare financing company--the healthcare transition manager--to facilitate the transaction. Part broker, part matchmaker, and part administrative coordinator, these companies make it possible for commercial insurers to exit the health insurance market without undue hardship to enrollees or the managed care plans that assume risk for their care. PMID:11066665

  12. An Institutional Approach to Understanding Energy Transitions

    NASA Astrophysics Data System (ADS)

    Koster, Auriane Magdalena

    Energy is a central concern of sustainability because how we produce and consume energy affects society, economy, and the environment. Sustainability scientists are interested in energy transitions away from fossil fuels because they are nonrenewable, increasingly expensive, have adverse health effects, and may be the main driver of climate change. They see an opportunity for developing countries to avoid the negative consequences fossil-fuel-based energy systems, and also to increase resilience, by leap-frogging-over the centralized energy grid systems that dominate the developed world. Energy transitions pose both challenges and opportunities. Obstacles to transitions include 1) an existing, centralized, complex energy-grid system, whose function is invisible to most users, 2) coordination and collective-action problems that are path dependent, and 3) difficulty in scaling up RE technologies. Because energy transitions rely on technological and social innovations, I am interested in how institutional factors can be leveraged to surmount these obstacles. The overarching question that underlies my research is: What constellation of institutional, biophysical, and social factors are essential for an energy transition? My objective is to derive a set of "design principles," that I term institutional drivers, for energy transitions analogous to Ostrom's institutional design principles. My dissertation research will analyze energy transitions using two approaches: applying the Institutional Analysis and Development Framework and a comparative case study analysis comprised of both primary and secondary sources. This dissertation includes: 1) an analysis of the world's energy portfolio; 2) a case study analysis of five countries; 3) a description of the institutional factors likely to promote a transition to renewable-energy use; and 4) an in-depth case study of Thailand's progress in replacing nonrenewable energy sources with renewable energy sources. My research will

  13. Energy transition in developing countries

    SciTech Connect

    Not Available

    1984-01-01

    Contents cover: The energy outlook; Energy demand management; Energy supply prospects and issues; Management of the energy sector; Financing energy investments; The role of the World Bank; Assumptions used for natural gas netback studies; and World energy indicators.

  14. X-Ray Transition Energies Database

    National Institute of Standards and Technology Data Gateway

    SRD 128 X-Ray Transition Energies Database (Web, free access)   This X-ray transition table provides the energies and wavelengths for the K and L transitions connecting energy levels having principal quantum numbers n = 1, 2, 3, and 4. The elements covered include Z = 10, neon to Z = 100, fermium. There are two unique features of this data base: (1) a serious attempt to have all experimental values on a scale consistent with the International System of measurement (the SI) and (2) inclusion of accurate theoretical estimates for all transitions.

  15. Making the Transition from Geoscience Geek to Policy Wonk

    NASA Astrophysics Data System (ADS)

    Rowan, L.

    2013-12-01

    Geoscientists are often drawn into policymaking, willingly or otherwise, because mapping a course of action for a specific outcome benefits from geoscientific expertise. Policy development, such as legislation or regulation regarding energy, water, minerals, soils, hazards, land use, and other Earth-based processes, is informed by the geosciences. Some geoscientists have moved fully into policymaking as full time policymakers for congressional offices, government agencies, think tanks, non-profits, foundations, industry, and other places. Geoscientists turned policymakers need good communication skills, patience, persistence, strategic forethought, agility, timing, an understanding of competing interests, and the courage to advance geoscientifically sound policy with the right people at the right time. Transitioning from the geeky world of geoscience to the wonky world of policy for a brief time or full time is possible, can be fulfilling as well as frustrating, and ultimately can have a profound impact on how society adapts to living with a dynamic Earth.

  16. Parallel Transitions in IT Outsourcing: Making It Happen

    NASA Astrophysics Data System (ADS)

    Beulen, Erik; Tiwari, Vinay

    Global sourcing of IT services is growing consistently over the last decades. Along with this rapid growth, instances of failures, sore relationships or unsatisfactory performances during IT outsourcing engagements are prevalent and require management attention. Over two-thirds of the problems in these unsuccessful engagements arise due to failed or poor transition. Transition is immediately followed by contract signing and precedes service delivery phase. It sets the tone for the entire relationship and involves handover of outsourced services from either the client's internal IT department or the incumbent service provider. Recently second and third generation outsourcing engagements are coming into existence, with offshoring and multi-sourcing as an integral component of these engagements. Multi-sourcing deals, involving several service providers are emerging and require transition to be implemented in parallel. These developments exacerbate the complexity of transitions due to the presence of multiple service providers and several distributed or offshore locations, thereby further enhancing its bearing on the success of an engagement. What are the Critical Success Factors for parallel transitions? We conducted an initial Delphi study to explore success factors for parallel transitions. The findings highlight the importance of understanding the contractual agreement including transition exit criteria. Also the implementation of a joint steering committee contributes to transition success. All the stakeholders, including representatives of the incumbent service provider(s), should be represented in the steering committee to act responsive. Finally, the findings emphasis the need to manage dependencies between the transitions not limited to time lines and availability of critical resources for knowledge transfer and balancing between business continuity and timely and effective knowledge transfer.

  17. Making a Meaningful Connection--Freshman Transition and Service-Learning

    ERIC Educational Resources Information Center

    Dedmond, Rebecca M.; Kestler, Erin T.

    2010-01-01

    Student engagement is an essential part of the many transitions adolescents must make on their way to self-sufficient adulthood. Motivating students to learn at pivotal points in their school careers, especially as they transition into high school, is sometimes difficult. The Freshman Transition Initiative (FTI) at The George Washington University…

  18. Household energy management strategies in Bulgaria's transitioning energy sector

    NASA Astrophysics Data System (ADS)

    Carper, Mark Daniel Lynn

    Recent transition literature of post-socialist states has addressed the shortcomings of a rapid blanket implementation of neo-liberal policies and practices placed upon a landscape barren of the needed institutions and experiences. Included in these observations are the policy-making oversight of spatial socioeconomic variations and their individual and diverse methods of coping with their individual challenges. Of such literature addressing the case of Bulgaria, a good portion deals with the spatial consequences of restructuring as well as with embedded disputes over access to and control of resources. With few exceptions, studies of Bulgaria's changing energy sector have largely been at the state level and have not been placed within the context of spatial disparities of socioeconomic response. By exploring the variations of household energy management strategies across space, my dissertation places this resource within such a theoretical context and offers analysis based on respective levels of economic and human development, inherited material infrastructures, the organization and activities of institutions, and fuel and technological availability. A closed survey was distributed to explore six investigational themes across four geographic realms. The investigational themes include materials of housing construction, methods of household heating, use of electrical appliances, energy conservation strategies, awareness and use of energy conservation technologies, and attitudes toward the transitioning energy sector. The geographic realms include countrywide results, the urban-rural divide, regional variations, and urban divisions of the capital city, Sofia. Results conclude that, indeed, energy management strategies at the household level have been shaped by multiple variables, many of which differ across space. These variables include price sensitivity, degree of dependence on remnant technologies, fuel and substitute availability, and level of human and

  19. Making the Transition from Preschool to Infant/Toddler Teacher.

    ERIC Educational Resources Information Center

    Keenan, Marjory

    1998-01-01

    Draws on discussions with child care workers to discuss important changes involved in moving from teaching preschoolers to teaching infants and toddlers. Describes differences in (1) relating to children; (2) parent/teacher relationships; (3) group dynamics; (4) curriculum; (5) routines and transitions; (6) coworker relationships; (7) director…

  20. Learning in Global Settings: Developing Transitions for Meaning-Making

    ERIC Educational Resources Information Center

    Norden, Birgitta; Avery, Helen; Anderberg, Elsie

    2012-01-01

    Global teaching and learning for sustainable development reaches from the classroom to the world outside, and is therefore a particularly interesting setting for practising transition skills. The article suggests a number of features perceived as crucial in developing young people's capability to act in a changing world and under circumstances…

  1. Making the Transition from Classical to Quantum Physics

    ERIC Educational Resources Information Center

    Dutt, Amit

    2011-01-01

    This paper reports on the nature of the conceptual understandings developed by Year 12 Victorian Certificate of Education (VCE) physics students as they made the transition from the essentially deterministic notions of classical physics, to interpretations characteristic of quantum theory. The research findings revealed the fact that the…

  2. Making the Transition to Hospice: Exploring Hospice Professionals' Perspectives

    ERIC Educational Resources Information Center

    Waldrop, Deborah P.; Rinfrette, Elaine S.

    2009-01-01

    Hospice care is available for 6 months before death but the length of use varies widely, suggesting that there are different perspectives on the appropriate timing for this transition. This qualitative study explored hospice professionals' views on the appropriate timing for and communication about hospice. Ethnography of team meetings informed…

  3. Help Us Make the 9th Grade Transition

    ERIC Educational Resources Information Center

    Cushman, Kathleen

    2006-01-01

    New 9th graders reflect on the worries they had as middle school students about moving into high school. They also suggest ways of easing the transition and providing support in 9th grade. Teens want teachers to connect middle school students regularly with high school students, give them more responsibility in middle school, and focus on…

  4. Making the Transition to Middle Level Schools. Practitioner's Monograph #10.

    ERIC Educational Resources Information Center

    Lake, Sara

    A middle-grade restructuring effort implemented by the Monterey Peninsula Unified School District is described in this report. A literature review and interviews with four educators experienced in restructuring explore issues in middle-school transition at the school and district levels. Topics related to the implementation process include needs…

  5. Making the Transition to Primary School: An Evaluation of a Transition Program for Parents

    ERIC Educational Resources Information Center

    Giallo, Rebecca; Treyvaud, Karli; Matthews, Jan; Kienhuis, Mandy

    2010-01-01

    The transition to primary school is an important time for both children and parents. The aim of this randomized controlled study was to assess the effectiveness of a Transition to Primary School Parent Program in strengthening parent knowledge and confidence to manage the transition process, increasing parent involvement in their children's…

  6. Stellar activity effects on high energy exoplanet transits

    NASA Astrophysics Data System (ADS)

    Llama, Joe; Shkolnik, Evgenya

    2016-01-01

    High energy (X-ray / UV) observations of transiting exoplanets have revealed the presence of extended atmospheres around a number of systems. At such high energies, stellar radiation is absorbed high up in the planetary atmosphere, making X-ray and UV observations a potential tool for investigating the upper atmospheres of exoplanets. At these high energies, stellar activity can dramatically impact the observations. At short wavelengths the stellar disk appears limb-brightened, and active regions appear as extended bright features that evolve on a much shorter timescale than in the optical making it difficult . These features impact both the transit depth and shape, affecting our ability to measure the true planet-to-star radius ratio.I will show results of simulated exoplanet transit light curves using Solar data obtained in the soft X-ray and UV by NASA's Solar Dynamics Observatory to investigate the impact of stellar activity at these wavelengths. By using a limb-brightened transit model coupled with disk resolved Solar images in the X-ray, extreme- and far-UV I will show how both occulted and unocculted active regions can mimic an inflated planetary atmosphere by changing the depth and shape of the transit profile. I will also show how the disk integrated Lyman-alpha Solar irradiance varies on both short and long timescales and how this variability can impact our ability to recover the true radius ratio of a transiting exoplanet.Finally, I will present techniques on how to overcome these effects to determine the true planet-to-star radius in X-ray and UV observations.

  7. Transitions from Temporary to Permanent Work in Canada: Who Makes the Transition and Why?

    ERIC Educational Resources Information Center

    Fang, Tony; MacPhail, Fiona

    2008-01-01

    The focus of this paper is on a microeconomic analysis of the annual transition rate from temporary to permanent work of individual workers in Canada for the period 1999-2004. Given that a large proportion of temporary employment is involuntary, an understanding of the factors associated with the transition to permanent work may inform public…

  8. Transitions.

    ERIC Educational Resources Information Center

    Field, David; And Others

    1992-01-01

    Includes four articles: "Career Aspirations" (Field); "Making the Transition to a New Curriculum" (Baker, Householder); "How about a 'Work to School' Transition?" (Glasberg); and "Technological Improvisation: Bringing CNC to Woodworking" (Charles, McDuffie). (SK)

  9. Aspects of energy transitions: History and determinants

    NASA Astrophysics Data System (ADS)

    O'Connor, Peter A.

    Energy intensity in the U.S. from 1780 to 2010 shows a declining trend when traditional energy is included, in contrast to the "inverted U-curve" seen when only commercial energy is considered. The analysis quantifies use of human and animal muscle power, wind and water power, biomass, harvested ice, fossil fuels, and nuclear power. Historical prices are provided for many energy resources. The analysis reaffirms the importance of innovation in conversion technologies in energy transitions. An increase in energy intensity in the early 20th century is explained by diminishing returns to pre-electric manufacturing systems, which produced a transformation in manufacturing. In comparison to similar studies for other countries, the U.S. has generally higher energy intensity. A population-weighted series of heating degree days and cooling degree days partially explains differences in energy intensity. Series are developed for 231 countries and territories with multiple reference temperatures, with a "wet-bulb" series accounting for the effects of humidity. Other variables considered include energy prices, income per capita, and governance indices. A panel regression of thirty-two countries from 1995 to 2010 establishes GDP per capita and share of primary energy as determinants of energy intensity, but fails to establish statistical significance of the climate variables. A group mean regression finds average heating and cooling degree days to be significant predictors of average energy intensity over the study period, increasing energy intensity by roughly 1.5 kJ per 2005 international dollar for each annual degree day. Group mean regression results explain differences in countries' average energy intensity, but not changes within a country over time. Energy Return on Investment (EROI) influences the economic competitiveness and environmental impacts of an energy resource and is one driver of energy transitions. The EROI of U.S. petroleum production has declined since 1972

  10. Helping Prepare Community College Students to Make the Transition from College to Work

    ERIC Educational Resources Information Center

    Bradley, Lagena Arlette

    2010-01-01

    The purpose of the study was to investigate students' perceptions about the need for more student training on making the transition from community college enrollment to employment. The hypothesis was that community college students would perceive that additional career counseling services would help them transition successfully into the world of…

  11. Making an Energy Conservation Program Work.

    ERIC Educational Resources Information Center

    Rump, Erwin E.; Hunter, James L.

    The first step of an energy conservation program is to monitor energy consumption. A system is explained that, in order to determine which buildings are energy efficient (considering all types of energy that a building might use), monitors total energy consumption. All such consumptions can be reduced to a common denominator: Barrels of Energy…

  12. A transitioning universe with anisotropic dark energy

    NASA Astrophysics Data System (ADS)

    Yadav, Anil Kumar

    2016-08-01

    In this paper, we present a model of transitioning universe with minimal interaction between perfect fluid and anisotropic dark energy in Bianchi I space-time. The two sources are assumed to minimally interacted and therefore their energy momentum tensors are conserved separately. The explicit expression for average scale factor are considered in hybrid form that gives time varying deceleration parameter which describes both the early and late time physical features of universe. We also discuss the physical and geometrical properties of the model derived in this paper. The solution is interesting physically as it explain accelerating universe as well as singularity free universe.

  13. From Scripted Instruction to Teacher Empowerment: Supporting Literacy Teachers to Make Pedagogical Transitions

    ERIC Educational Resources Information Center

    Fang, Zhihui; Fu, Danling; Lamme, Linda Leonard

    2004-01-01

    The article describes a longitudinal professional development project in rural Florida (USA) schools that supports the efforts of inservice teachers to make pedagogical transitions from total reliance on prepackaged commercial programmes to making informed decisions about curriculum and pedagogy autonomously. It demonstrates that in order to…

  14. Activation energy of water structural transitions

    NASA Astrophysics Data System (ADS)

    Kholmanskiy, Alexander

    2015-06-01

    In this work, the nature of molecular motions that dominate in the thermodynamics of anomalies of liquid water properties in the range of 0-100 °C has been studied. Temperature dependencies of water properties have been approximated by exponential functions and the activation energies for water structure transitions have been evaluated. The activation energy values were compared with the energy spectra of characteristic vibrations and with those of cooperative molecular motion in the lattice-type structure of hydrogen bonds. It has been found that it is the reaction of hydrogen bond breaking that mainly limits the abnormal dynamics of water viscosity, self-diffusion, dielectric relaxation time and electric conductivity. It has been assumed that the thermodynamics of cooperative motion and resonance phenomena in water clusters form a basis for the differentiation mechanism of extrema points in temperature dependencies of water density, isobaric heat capacity, sound velocity, surface tension coefficient and compressibility.

  15. Energy bands in some transition metals

    NASA Astrophysics Data System (ADS)

    Laurent, D. G.

    1981-08-01

    Self consistent linear combination of Gaussian orbitals energy band calculations were performed for the two paramagnetic 3d transition metals, chromium and vanadium. The energy bands densities of states and Fermi surfaces were obtained using the two most popular local exchange correlation potentials (Kohn-Sham-Gaspar and von Barth-Hedin) for chromium and the Kohn-Sham-Gaspar potential alone for vanadium. A comparison was made with the available experimental data. New interpretations for some of the neutron scattering data are made in the chromium case. Results are also presented for the Compton profiles and optical conductivities. These correlate well with the experiments if appropriate angular averages (for the Compton profile) and lifetime effcts (for the optical conductivity) are included. The electron energy loss spectrum, computed over the range 0-6.5 eV agreed well with experiment.

  16. Get Started: Energy Efficiency Makes More Sense Than Ever.

    ERIC Educational Resources Information Center

    Alban, Josh; Drabick, J. R.

    2003-01-01

    Describes the benefits of making school building more energy efficient. Provides examples of physical retrofits and behavioral changes to save energy costs. Describes four-step process to create an energy efficiency plan. Includes resources and information such as U.S. Department of Energy's Energy STAR program (www.energystar.gov). (PKP)

  17. Method of making fully dense anisotropic high energy magnets

    SciTech Connect

    Chatterjee, D.K.

    1990-01-09

    This patent describes a method of making anisotropic permanent magnets. It comprises extruding a rare earth, transition metal, magnetic alloy together with an oxygen-getter material at a temperature of from about 600{degrees} C to about 1000{degrees} C at an extrusion ratio of from about 10:1 to about 26:1 the rare earth, transition metal, magnetic alloy and the oxygen-getter material being disposed within an extrusion zone in Separate and discrete locations.

  18. Making More Light with Less Energy

    SciTech Connect

    Kuritzky, Leah; Jewell, Jason

    2013-07-18

    Representing the Center for Energy Efficient Materials (CEEM), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE: energy. The mission of the CEEM is to discover and develop materials that control the interactions among light, electricity, and heat at the nanoscale for improved solar energy conversion, solid-state lighting, and conversion of heat into electricity.

  19. Making the Most of Waste Energy

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The Thermo-Mechanical Systems Branch at NASA s Glenn Research Center is responsible for planning and conducting research efforts to advance thermal systems for space, aerospace, and non-aerospace applications. Technological areas pertain to solar and thermal energy conversion. For example, thermo-mechanical systems researchers work with gas (Stirling) and liquid/vapor (Rankine) systems that convert thermal energy to electrical power, as well as solar dynamic power systems that concentrate sunlight to electrical power. The branch s development of new solar and thermal energy technologies is propelling NASA s missions deep into unfamiliar territories of space. Solar dynamic power systems are actively improving the health of orbiting satellites, giving them longer life and a stronger radiation tolerance, thus, creating less need for on-orbit maintenance. For future missions, NASA may probe even deeper into the mysterious cosmos, with the adoption of highly efficient thermal energy converters that have the potential to serve as the source of onboard electrical power for satellites and spacecraft. Research indicates that these thermal converters can deliver up to 5 times as much power as radioisotope thermoelectric generators in use today, for the same amount of radioisotope. On Earth, energy-converting technologies associated with NASA s Thermo-Mechanical Systems Branch are being used to recover and transform low-temperature waste heat into usable electric power, with a helping hand from NASA.

  20. Using Left Overs to Make Energy

    SciTech Connect

    Steuterman, Sally; Czarnecki, Alicia; Hurley, Paul; Peruski, Kathryn; Cartagena-Sierra, Alejandra; Evans, Isaac; Guzman, Alexis

    2013-07-18

    Representing the Material Science Antinides (MSA), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of MSA is to conduct transformative research in the actinide sciences with full integration of experimental and computational approaches, and an emphasis on research questions that are important to the energy future of the nation.

  1. A Career in Professional Athletics: A Guide for Making the Transition.

    ERIC Educational Resources Information Center

    Bolig, Laura E., Ed.

    This booklet provides guidance to student-athletes on making the transition to a career in professional athletics. It contains a list of do's and don'ts for students in regard to their collegiate eligibility, along with suggestions on obtaining disability insurance coverage for protection from loss of future earnings. The booklet provides…

  2. From Incarceration to Productive Lifestyle. Making the Transition: An Instructional Guide for Incarcerated Youth Education.

    ERIC Educational Resources Information Center

    Hudson River Center for Program Development, Glenmont, NY.

    This guide, which is intended for instructors of incarcerated youth, contains materials for use in helping incarcerated youth make the transition from incarceration to a productive life. Presented first are an overview of the project during which the guide was developed and a brief history of educational programming for incarcerated youth in New…

  3. Making the Transition to Teaching Online: Strategies and Methods for the First-Time, Online Instructor.

    ERIC Educational Resources Information Center

    VanSickle, Jennifer

    This paper discusses the changes in instruction needed to make the transition to teaching an online course. It discusses both traditional and alternative teaching methods a first-time online instructor might choose to use. The advantages and disadvantages of online courses are explored through a review of the literature, and ways in which online…

  4. Make Energy at the Bay Area Maker Faire

    ScienceCinema

    None

    2016-06-24

    Think. Make. Innovate. A festival of invention, creativity and resourcefulness that gathers makers of all kinds. Scientists are seeking to find innovative solutions to the energy challenges in the world.

  5. Optimal strategies for electric energy contract decision making

    NASA Astrophysics Data System (ADS)

    Song, Haili

    2000-10-01

    The power industry restructuring in various countries in recent years has created an environment where trading of electric energy is conducted in a market environment. In such an environment, electric power companies compete for the market share through spot and bilateral markets. Being profit driven, electric power companies need to make decisions on spot market bidding, contract evaluation, and risk management. New methods and software tools are required to meet these upcoming needs. In this research, bidding strategy and contract pricing are studied from a market participant's viewpoint; new methods are developed to guide a market participant in spot and bilateral market operation. A supplier's spot market bidding decision is studied. Stochastic optimization is formulated to calculate a supplier's optimal bids in a single time period. This decision making problem is also formulated as a Markov Decision Process. All the competitors are represented by their bidding parameters with corresponding probabilities. A systematic method is developed to calculate transition probabilities and rewards. The optimal strategy is calculated to maximize the expected reward over a planning horizon. Besides the spot market, a power producer can also trade in the bilateral markets. Bidding strategies in a bilateral market are studied with game theory techniques. Necessary and sufficient conditions of Nash Equilibrium (NE) bidding strategy are derived based on the generators' cost and the loads' willingness to pay. The study shows that in any NE, market efficiency is achieved. Furthermore, all Nash equilibria are revenue equivalent for the generators. The pricing of "Flexible" contracts, which allow delivery flexibility over a period of time with a fixed total amount of electricity to be delivered, is analyzed based on the no-arbitrage pricing principle. The proposed algorithm calculates the price based on the optimality condition of the stochastic optimization formulation

  6. Urban decision making for transportation investments: Portland's light-rail transit system. Final report

    SciTech Connect

    Edner, S.M.; Arrington, G.B.

    1985-03-01

    This report is a detailed case study of the various decisions which led to the investment in Portland, Oregon's light-rail transit system. The study reviews the alternatives that were considered, the factors that led to the choices made, and the impacts and secondary effects the choices triggered. Topics discussed include the withdrawal of the Mount Hood Freeway, the substitution of transit and the options considered, the changing political infrastructure that affected decision making, citizen participation in the process, financing of the system, involvement of the private sector downtown, and the actual building of the light-rail line. The report should be of special interest to staffs of local officials involved in making major transportation investment decisions.

  7. Hybrid radical energy storage device and method of making

    DOEpatents

    Gennett, Thomas; Ginley, David S.; Braunecker, Wade; Ban, Chunmei; Owczarczyk, Zbyslaw

    2016-04-26

    Hybrid radical energy storage devices, such as batteries or electrochemical devices, and methods of use and making are disclosed. Also described herein are electrodes and electrolytes useful in energy storage devices, for example, radical polymer cathode materials and electrolytes for use in organic radical batteries.

  8. Hybrid radical energy storage device and method of making

    DOEpatents

    Gennett, Thomas; Ginley, David S; Braunecker, Wade; Ban, Chunmei; Owczarczyk, Zbyslaw

    2015-01-27

    Hybrid radical energy storage devices, such as batteries or electrochemical devices, and methods of use and making are disclosed. Also described herein are electrodes and electrolytes useful in energy storage devices, for example, radical polymer cathode materials and electrolytes for use in organic radical batteries.

  9. Energy and Society: Investigations in Decision Making. [Student Manual].

    ERIC Educational Resources Information Center

    Biological Sciences Curriculum Study, Boulder, CO.

    This publication is the student handbook for a BSCS energy education module designed for high school, college, and adult students. It is designed to provide students with information about energy that will help them make decisions as citizens. Basically, this document is a text to supplement the activities and lesson plans in the teacher's guide.…

  10. Local energy governance in vermont: an analysis of energy system transition strategies and actor capacity

    NASA Astrophysics Data System (ADS)

    Rowse, Tarah

    While global, national, and regional efforts to address climate and energy challenges remain essential, local governments and community groups are playing an increasingly stronger and vital role. As an active state in energy system policy, planning and innovation, Vermont offers a testing ground for research into energy governance at the local level. A baseline understanding of the energy planning and energy organizing activities initiated at the local level can support efforts to foster a transition to a sustainable energy system in Vermont. Following an inductive, applied and participatory approach, and grounded in the fields of sustainability transitions, energy planning, and community energy, this research project identifies conditions for change, including opportunities and challenges, within Vermont energy system decision-making and governance at the local level. The following questions are posed: What are the main opportunities and challenges for sustainable energy development at the town level? How are towns approaching energy planning? What are the triggers that will facilitate a faster transition to alternative energy systems, energy efficiency initiatives, and localized approaches? In an effort to answer these questions two studies were conducted: 1) an analysis of municipal energy plans, and 2) a survey of local energy actors. Study 1 examined Vermont energy planning at the state and local level through a review and comparison of 40 municipal plan energy chapters with the state 2011 Comprehensive Energy Plan. On average, municipal plans mentioned just over half of the 24 high-level strategies identified in the Comprehensive Energy Plan. Areas of strong and weak agreement were examined. Increased state and regional interaction with municipal energy planners would support more holistic and coordinated energy planning. The study concludes that while municipalities are keenly aware of the importance of education and partnerships, stronger policy mechanisms

  11. Photoinduced energy transfer in transition metal complex oligomers

    SciTech Connect

    1997-06-01

    The work done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. The authors have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed them to prepare a variety of other ligands which may have unique applications (vide infra). They have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived (> 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, the authors have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.

  12. Photoinduced energy transfer in transition metal complex oligomers

    SciTech Connect

    1997-04-01

    The work we have done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. We have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed us prepare a variety of other ligands which may have unique applications (vide infra). We have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived ( > 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, we have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.

  13. DOE-HUD Initiative: Making Housing Affordable Through Energy Efficiency

    SciTech Connect

    Not Available

    1991-10-01

    A new collaborative program of the U.S. Department of Energy (DOE) and the U.S. Department of Housing and Urban Development (HUD) is a significant step toward making HUD-aided housing more comfortable and affordable through greater energy efficiency. The initiative on Energy Efficiency in Housing combines DOE's technical capabilities and HUD's experience in housing assistance. Over the next decade, the energy savings potential of this initiative is estimated to be 150 trillion Btu (0.15 quad) per year, or nearly $1.5 billion in annual energy costs.

  14. Estimation of drought transition probabilities in Sicily making use of exogenous variables

    NASA Astrophysics Data System (ADS)

    Bonaccorso, Brunella; di Mauro, Giuseppe; Cancelliere, Antonino; Rossi, Giuseppe

    2010-05-01

    Drought monitoring and forecasting play a very important role for an effective drought management. A timely monitoring of drought features and/or forecasting of an incoming drought do make possible an effective mitigation of its impacts, more than in the case of other natural disasters (e.g. floods, earthquakes, hurricanes, etc.). An accurate selection of indices, able to monitor the main characteristics of droughts, is essential to help decision makers to implement appropriate preparedness and mitigation measures. Among the several proposed indices for drought monitoring, the Standardized Precipitation Index (SPI) has found widespread use to monitor dry and wet periods of precipitation aggregated at different time scales. Recently, some efforts have been made to analyze the role of SPI for drought forecasting, as well as to estimate transition probabilities between drought classes. In the present work, a model able to estimate transition probabilities from a current SPI drought class or from a current SPI value to future classes, corresponding to droughts of different severities, is presented and extended in order to include information provided by an exogenous variable, such as a large scale climatic index as the North Atlantic Oscillation Index (NAO). The model has been preliminarily applied and tested with reference to SPI series computed on average areal precipitation in Sicily island, Italy, making use of NAO as exogenous variable. Results seem to indicate that winter drought transition probabilities in Sicily are generally affected by NAO index. Furthermore, the statistical significance of such influence has been tested by means of a Montecarlo analysis, which indicates that the effect of NAO on drought transition in Sicily should be considered significant.

  15. Substituent effect on electronic transition energy of dichlorobenzyl radicals

    NASA Astrophysics Data System (ADS)

    Yoon, Young Wook; Chae, Sang Youl; Lee, Sang Kuk

    2016-01-01

    Ring-substituted benzyl radicals exhibit electronic energies of the D1 → D0 transition being shifted to red region with respect to the benzyl radical. The red-shifts of disubstituted benzyl radicals are highly dependent on the substitution positions irrespective of substituents. By analyzing the red-shifts of dichlorobenzyl radicals observed, we found that the substituent effect on electronic transition energy is attributed to the molecular plane shape of delocalized π electrons. We will discuss the influences of locations of Cl substituents on the D1 → D0 transition energies of dichlorobenzyl radicals using Hückel's molecular orbital theory.

  16. Trends in Ionization Energy of Transition-Metal Elements

    ERIC Educational Resources Information Center

    Matsumoto, Paul S.

    2005-01-01

    A rationale for the difference in the periodic trends in the ionization energy of the transition-metal elements versus the main-group elements is presented. The difference is that in the transition-metal elements, the electrons enter an inner-shell electron orbital, while in the main-group elements, the electrons enter an outer-shell electron…

  17. Energy Released During the H-L Back Transition

    NASA Astrophysics Data System (ADS)

    Eldon, D.; Kolemen, E.; Gohil, P.; McKee, G. R.; Yan, Z.; Schmitz, L.

    2015-11-01

    Prompt energy loss (ΔW) at the H-L transition, as a fraction of total stored energy before the transition, is about 30 % and is insensitive to density in ITER-similar DIII-D plasmas. Occasionally, some ELMs will appear before the transition and reduce total energy, thus reducing ΔW across the following transition. Other results (not in the ITER-similar shape) have shown that ELMs can be triggered in low powered H-modes, prior to H-L transitions, when the plasma is stable to ideal P-B modes (these are not typical type-I ELMs, despite superficial similarities) and E × B shear is strong. These are indeed ELMs occurring in H-mode and not part of a dithering transition. Finally, ELM ΔW is sensitive to edge toroidal rotation and becomes smaller than uncertainty (< 5 kJ) at low rotation (ωtor < 5 krad/s). These results point to a strategy where ΔW for the H-L transition may be reduced by the presence of (not type-I) ELMs before the transition, and ΔW for the ELMs may be reduced by controlling rotation. Work supported by the US Department of Energy under DE-AC02-09CH11466 and DE-FC02-04ER54698.

  18. [Relationships between settlement morphology transition and residents commuting energy consumption].

    PubMed

    Zhou, Jian; Xiao, Rong-Bo; Sun, Xiang

    2013-07-01

    Settlement morphology transition is triggered by rapid urbanization and urban expansion, but its relationships with residents commuting energy consumption remains ambiguous. It is of significance to understand the controlling mechanisms of sustainable public management policies on the energy consumption and greenhouse gases emission during the process of urban settlement morphology transition. Taking the Xiamen City of East China as a case, and by using the integrated land use and transportation modeling system TRANUS, a scenario analysis was made to study the effects of urban settlement morphology transition on the urban spatial distribution of population, jobs, and land use, and on the residents commuting energy consumption and greenhouse gasses emission under different scenarios. The results showed that under the Business As Usual (BAU) scenario, the energy consumption of the residents at the morning peak travel time was 54.35 tce, and the CO2 emission was 119.12 t. As compared with those under BAU scenario, both the energy consumption and the CO2 emission under the Transition of Settlement Morphology (TSM) scenario increased by 12%, and, with the implementation of the appropriate policies such as land use, transportation, and economy, the energy consumption and CO2 emission under the Transition of Settlement Morphology with Policies (TSMP) scenario reduced by 7%, indicating that urban public management policies could effectively control the growth of residents commuting energy consumption and greenhouse gases emission during the period of urban settlement morphology transition. PMID:24175530

  19. Reducing fatigue damage for ships in transit through structured decision making

    USGS Publications Warehouse

    Nichols, J.M.; Fackler, P.L.; Pacifici, K.; Murphy, K.D.; Nichols, J.D.

    2014-01-01

    Research in structural monitoring has focused primarily on drawing inference about the health of a structure from the structure’s response to ambient or applied excitation. Knowledge of the current state can then be used to predict structural integrity at a future time and, in principle, allows one to take action to improve safety, minimize ownership costs, and/or increase the operating envelope. While much time and effort has been devoted toward data collection and system identification, research to-date has largely avoided the question of how to choose an optimal maintenance plan. This work describes a structured decision making (SDM) process for taking available information (loading data, model output, etc.) and producing a plan of action for maintaining the structure. SDM allows the practitioner to specify his/her objectives and then solves for the decision that is optimal in the sense that it maximizes those objectives. To demonstrate, we consider the problem of a Naval vessel transiting a fixed distance in varying sea-state conditions. The physics of this problem are such that minimizing transit time increases the probability of fatigue failure in the structural supports. It is shown how SDM produces the optimal trip plan in the sense that it minimizes both transit time and probability of failure in the manner of our choosing (i.e., through a user-defined cost function). The example illustrates the benefit of SDM over heuristic approaches to maintaining the vessel.

  20. Energy level transitions of gas in a 2D nanopore

    SciTech Connect

    Grinyaev, Yurii V.; Chertova, Nadezhda V.; Psakhie, Sergei G.

    2015-10-27

    An analytical study of gas behavior in a 2D nanopore was performed. It is shown that the temperature dependence of gas energy can be stepwise due to transitions from one size-quantized subband to another. Taking into account quantum size effects results in energy level transitions governed by the nanopore size, temperature and gas density. This effect leads to an abrupt change of gas heat capacity in the nanopore at the above varying system parameters.

  1. Meaning-Making Dynamics of Emancipated Foster Care Youth Transitioning into Higher Education: A Constructivist-Grounded Theory

    ERIC Educational Resources Information Center

    Okumu, Jacob O.

    2014-01-01

    This study explored college transition meaning-making dynamics of emancipated foster care youth and the role campus environments play in that process. It adds to the college student development theoretical base by acknowledging the needs, goals, and values of disenfranchised college students transitioning into higher education. Emancipated foster…

  2. The Developmental Transition from Living with to Dying From Cancer: Hospice Decision-making

    PubMed Central

    Waldrop, Deborah; Meeker, Mary Ann; Kutner, Jean S.

    2016-01-01

    Despite increasing utilization of hospice care, older adults with cancer enroll in hospice for shorter periods of time than those with other life-limiting illnesses. How older adults with cancer and their family members consider hospice is unknown. The purpose of this study was to compare decision-making in late-stage cancer in people who enrolled in hospice with those who declined. Concepts from the Carroll and Johnson (1990) decision-making framework guided the development of a hospice decision-making model. The study design was exploratory-descriptive, cross-sectional and used a 2-group comparison. Qualitative and quantitative data were collected in the same interview. Open-ended questions were used to explore the illness trajectory and decision-making process. The interrelationships between functional ability, quality of life and social support with hospice decision-making were assessed using the Katz, QLQ-30 and Lubben Social Network Scales. Study participants included 42 older adults with cancer who had been offered hospice enrollment (24 non-hospice and 18 hospice) and 38 caregivers (15 non-hospice and 23 hospice); N=80. The decisional model illustrates that the Recognition of Advanced Cancer and Information and Communication Needs were experienced similarly by both groups. There was interaction between the decisional stages: Formulation of Awareness and Generation of Alternatives that informed the Evaluation of Hospice but these stages were different in the hospice and non-hospice groups. The hospice enrollment decision represents a critical developmental juncture which is accompanied by a transformed identity and substantive cognitive shift. Increased attention to the psychosocial and emotional issues that accompany this transition are important for quality end-of-life care. PMID:26176303

  3. The Developmental Transition From Living With to Dying From Cancer: Hospice Decision Making.

    PubMed

    Waldrop, Deborah; Meeker, Mary Ann; Kutner, Jean S

    2015-01-01

    Despite increasing utilization of hospice care, older adults with cancer enroll in hospice for shorter periods of time than those with other life-limiting illnesses. How older adults with cancer and their family members consider hospice is unknown. The purpose of this study was to compare decision making in late-stage cancer in people who enrolled in hospice with those who declined. Concepts from the Carroll and Johnson (1990) decision-making framework guided the development of a hospice decision-making model. The study design was exploratory-descriptive, cross-sectional, and used a two-group comparison. Qualitative and quantitative data were collected in the same interview. Open-ended questions were used to explore the illness trajectory and decision-making process. The interrelationships between functional ability, quality of life, and social support with hospice decision making were assessed using the Katz, QLQ-30, and Lubben Social Network Scales. Study participants included 42 older adults with cancer who had been offered hospice enrollment (24 non-hospice and 18 hospice) and 38 caregivers (15 non-hospice and 23 hospice); N = 80. The decisional model illustrates that the recognition of advanced cancer and information and communication needs were experienced similarly by both groups. There was interaction between the decisional stages: formulation of awareness and generation of alternatives that informed the evaluation of hospice but these stages were different in the hospice and non-hospice groups. The hospice enrollment decision represents a critical developmental juncture, which is accompanied by a transformed identity and substantive cognitive shift. Increased attention to the psychosocial and emotional issues that accompany this transition are important for quality end-of-life care. PMID:26176303

  4. Minimum energy paths of wetting transitions on grooved surfaces.

    PubMed

    Pashos, George; Kokkoris, George; Boudouvis, Andreas G

    2015-03-17

    A method that computes minimum energy paths (MEPs) of wetting transitions is developed. The method couples the Cahn-Hilliard formulation of a modified phase-field method with the simplified string method. Its main computational kernel is the fast Fourier transform that is efficiently performed on graphics processing units. The effectiveness of the proposed method is demonstrated on two types of transitions of droplets on grooved surfaces. The first is the transition from the Cassie-Baxter wetting state to the Wenzel state, where it is shown that it progresses in a sequential manner with the droplet wetting each groove successively. The second transition type is a lateral displacement of the droplet against the grooves, where the droplet successively detaches/attaches from/to the rear/front protrusion of the surface (a transition in the reverse order is also possible). The energy barriers of both the transitions are extracted from the MEP; they are useful for the evaluation of the robustness of superhydrophobic surfaces (resistance to the Cassie-Baxter to Wenzel transition) and the droplet mobility on those surfaces (high mobility/small resistance to lateral displacements). The relation of the MEP with the potential transition paths coming from the solution space mapping is discussed. PMID:25715270

  5. Universal energy transport law for dissipative and diffusive phase transitions

    NASA Astrophysics Data System (ADS)

    Nadkarni, Neel; Daraio, Chiara; Abeyaratne, Rohan; Kochmann, Dennis M.

    2016-03-01

    We present a scaling law for the energy and speed of transition waves in dissipative and diffusive media. By considering uniform discrete lattices and continuous solids, we show that—for arbitrary highly nonlinear many-body interactions and multistable on-site potentials—the kinetic energy per density transported by a planar transition wave front always exhibits linear scaling with wave speed and the ratio of energy difference to interface mobility between the two phases. We confirm that the resulting linear superposition applies to highly nonlinear examples from particle to continuum mechanics.

  6. Turbulent diffusion phase transition is due to singular energy spectrum.

    PubMed Central

    Wallstrom, T C

    1995-01-01

    The phase transition for turbulent diffusion, reported by Avellaneda and Majda [Avellaneda, M. & Majda, A. J. (1994) Philos. Trans. R. Soc. London A 346, 205-233, and several earlier papers], is traced to a modeling assumption in which the energy spectrum of the turbulent fluid is singularly dependent on the viscosity in the inertial range. Phenomenological models of turbulence and intermittency, by contrast, require that the energy spectrum be independent of the viscosity in the inertial range. When the energy spectrum is assumed to be consistent with the phenomenological models, there is no phase transition for turbulent diffusion. Images Fig. 2 PMID:11607590

  7. The carbon-consuming home: residential markets and energy transitions.

    PubMed

    Jones, Christopher

    2011-01-01

    Home heating and lighting markets have played crucial and underappreciated roles in driving energy transitions. When historians have studied the adoption of fossil fuels, they have often privileged industrial actors, markets, and technologies. My analysis of the factors that stimulated the adoption of anthracite coal and petroleum during the nineteenth century reveals that homes shaped how, when, and why Americans began to use fossil fuel energy. Moreover, a brief survey of other fossil fuel transitions shows that heating and lighting markets have been critical drivers in other times and places. Reassessing the historical patterns of energy transitions offers a revised understanding of the past for historians and suggests a new set of options for policymakers seeking to encourage the use of renewable energy in the future. PMID:22213886

  8. Understanding the human dimensions of a sustainable energy transition.

    PubMed

    Steg, Linda; Perlaviciute, Goda; van der Werff, Ellen

    2015-01-01

    Global climate change threatens the health, economic prospects, and basic food and water sources of people. A wide range of changes in household energy behavior is needed to realize a sustainable energy transition. We propose a general framework to understand and encourage sustainable energy behaviors, comprising four key issues. First, we need to identify which behaviors need to be changed. A sustainable energy transition involves changes in a wide range of energy behaviors, including the adoption of sustainable energy sources and energy-efficient technology, investments in energy efficiency measures in buildings, and changes in direct and indirect energy use behavior. Second, we need to understand which factors underlie these different types of sustainable energy behaviors. We discuss three main factors that influence sustainable energy behaviors: knowledge, motivations, and contextual factors. Third, we need to test the effects of interventions aimed to promote sustainable energy behaviors. Interventions can be aimed at changing the actual costs and benefits of behavior, or at changing people's perceptions and evaluations of different costs and benefits of behavioral options. Fourth, it is important to understand which factors affect the acceptability of energy policies and energy systems changes. We discuss important findings from psychological studies on these four topics, and propose a research agenda to further explore these topics. We emphasize the need of an integrated approach in studying the human dimensions of a sustainable energy transition that increases our understanding of which general factors affect a wide range of energy behaviors as well as the acceptability of different energy policies and energy system changes. PMID:26136705

  9. Understanding the human dimensions of a sustainable energy transition

    PubMed Central

    Steg, Linda; Perlaviciute, Goda; van der Werff, Ellen

    2015-01-01

    Global climate change threatens the health, economic prospects, and basic food and water sources of people. A wide range of changes in household energy behavior is needed to realize a sustainable energy transition. We propose a general framework to understand and encourage sustainable energy behaviors, comprising four key issues. First, we need to identify which behaviors need to be changed. A sustainable energy transition involves changes in a wide range of energy behaviors, including the adoption of sustainable energy sources and energy-efficient technology, investments in energy efficiency measures in buildings, and changes in direct and indirect energy use behavior. Second, we need to understand which factors underlie these different types of sustainable energy behaviors. We discuss three main factors that influence sustainable energy behaviors: knowledge, motivations, and contextual factors. Third, we need to test the effects of interventions aimed to promote sustainable energy behaviors. Interventions can be aimed at changing the actual costs and benefits of behavior, or at changing people’s perceptions and evaluations of different costs and benefits of behavioral options. Fourth, it is important to understand which factors affect the acceptability of energy policies and energy systems changes. We discuss important findings from psychological studies on these four topics, and propose a research agenda to further explore these topics. We emphasize the need of an integrated approach in studying the human dimensions of a sustainable energy transition that increases our understanding of which general factors affect a wide range of energy behaviors as well as the acceptability of different energy policies and energy system changes. PMID:26136705

  10. Exchange and relaxation effects in low-energy radiationless transitions

    NASA Technical Reports Server (NTRS)

    Chen, M. H.; Crasemann, B.; Aoyagi, M.; Mark, H.

    1978-01-01

    The effect on low-energy atomic inner-shell Coster-Kronig and super Coster-Kronig transitions that is produced by relaxation and by exchange between the continuum electron and bound electrons was examined and illustrated by specific calculations for transitions that deexcite the 3p vacancy state of Zn. Taking exchange and relaxation into account is found to reduce, but not to eliminate, the discrepancies between theoretical rates and measurements.

  11. Native proteins trap high-energy transit conformations

    PubMed Central

    Brereton, Andrew E.; Karplus, P. Andrew

    2015-01-01

    During protein folding and as part of some conformational changes that regulate protein function, the polypeptide chain must traverse high-energy barriers that separate the commonly adopted low-energy conformations. How distortions in peptide geometry allow these barrier-crossing transitions is a fundamental open question. One such important transition involves the movement of a non-glycine residue between the left side of the Ramachandran plot (that is, ϕ < 0°) and the right side (that is, ϕ > 0°). We report that high-energy conformations with ϕ ~ 0°, normally expected to occur only as fleeting transition states, are stably trapped in certain highly resolved native protein structures and that an analysis of these residues provides a detailed, experimentally derived map of the bond angle distortions taking place along the transition path. This unanticipated information lays to rest any uncertainty about whether such transitions are possible and how they occur, and in doing so lays a firm foundation for theoretical studies to better understand the transitions between basins that have been little studied but are integrally involved in protein folding and function. Also, the context of one such residue shows that even a designed highly stable protein can harbor substantial unfavorable interactions. PMID:26601321

  12. Smart Building: Decision Making Architecture for Thermal Energy Management

    PubMed Central

    Hernández Uribe, Oscar; San Martin, Juan Pablo; Garcia-Alegre, María C.; Santos, Matilde; Guinea, Domingo

    2015-01-01

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction. PMID:26528978

  13. Smart Building: Decision Making Architecture for Thermal Energy Management.

    PubMed

    Uribe, Oscar Hernández; Martin, Juan Pablo San; Garcia-Alegre, María C; Santos, Matilde; Guinea, Domingo

    2015-01-01

    Smart applications of the Internet of Things are improving the performance of buildings, reducing energy demand. Local and smart networks, soft computing methodologies, machine intelligence algorithms and pervasive sensors are some of the basics of energy optimization strategies developed for the benefit of environmental sustainability and user comfort. This work presents a distributed sensor-processor-communication decision-making architecture to improve the acquisition, storage and transfer of thermal energy in buildings. The developed system is implemented in a near Zero-Energy Building (nZEB) prototype equipped with a built-in thermal solar collector, where optical properties are analysed; a low enthalpy geothermal accumulation system, segmented in different temperature zones; and an envelope that includes a dynamic thermal barrier. An intelligent control of this dynamic thermal barrier is applied to reduce the thermal energy demand (heating and cooling) caused by daily and seasonal weather variations. Simulations and experimental results are presented to highlight the nZEB thermal energy reduction. PMID:26528978

  14. Scaling and Topological Phase Transitions: Energy vs. Entropy

    NASA Astrophysics Data System (ADS)

    Wang, Yuting; Gulden, Tobias; Janas, Michael; Kamenev, Alex

    The critical point of a topological phase transition is described by a conformal field theory. Finite-size corrections give rise to a scaling function away from criticality for both energy and entanglement entropy of the system. While in the past the scaling function for the usual von Neumann entropy was found to be equal for the trivial and the topological side of the transition, we find that the scaling functions for energy and Renyi entropy with α > 1 are different for the two sides. This provides an easy tool to distinguish between the trivial and topological phases near criticality.

  15. Breaking and Making of Carbon-Carbon Bonds by Lanthanides and Third-Row Transition Metals.

    PubMed

    Zhou, Shaodong; Li, Jilai; Schlangen, Maria; Schwarz, Helmut

    2016-02-24

    Carbon-atom extrusion from the ipso-position of a halobenzene ring (C6 H5 X; X=F, Cl, Br, I) and its coupling with a methylene ligand to produce acetylene is not confined to [LaCH2 ](+) ; also, the third-row transition-metal complexes [MCH2 ](+) , M=Hf, Ta, W, Re, and Os, bring about this unusual transformation. However, substrates with substituents X=CN, NO2 , OCH3 , and CF3 are either not reactive at all or give rise to different products when reacted with [LaCH2 ](+) . In the thermal gas-phase processes of atomic Ln(+) with C7 H7 Cl substrates, only those lanthanides with a promotion energy small enough to attain a 4f(n) 5d(1) 6s(1) configuration are reactive and form both [LnCl](+) and [LnC5 H5 Cl](+) . Branching ratios and the reaction efficiencies of the various processes seem to correlate with molecular properties, like the bond-dissociation energies of the C-X or M(+) -X bonds or the promotion energies of lanthanides. PMID:26875940

  16. Carbon budgets and energy transition pathways

    NASA Astrophysics Data System (ADS)

    van Vuuren, Detlef P.; van Soest, Heleen; Riahi, Keywan; Clarke, Leon; Krey, Volker; Kriegler, Elmar; Rogelj, Joeri; Schaeffer, Michiel; Tavoni, Massimo

    2016-07-01

    Scenarios from integrated assessment models can provide insights into how carbon budgets relate to other policy-relevant indicators by including information on how fast and by how much emissions can be reduced. Such indicators include the peak year of global emissions, the decarbonisation rate and the deployment of low-carbon technology. Here, we show typical values for these indicators for different carbon budgets, using the recently compiled IPCC scenario database, and discuss how these vary as a function of non-CO2 forcing, energy use and policy delay. For carbon budgets of 2000 GtCO2 and less over the 2010–2100 period, supply of low carbon technologies needs to be scaled up massively from today’s levels, unless energy use is relatively low. For the subgroup of scenarios with a budget below 1000 GtCO2 (consistent with >66% chance of limiting global warming to below 2 °C relative to preindustrial levels), the 2050 contribution of low-carbon technologies is generally around 50%–75%, compared to less than 20% today (range refers to the 10–90th interval of available data).

  17. Making Transitions Work: Short- and Long-Term Transition Strategies: A Planning Guide for Junior and Senior High School Teachers. Secondary Transition and Employment Project: STEP.

    ERIC Educational Resources Information Center

    Baumgart, Diane; And Others

    The guide, developed by the Secondary Transition and Employment Project (STEP) in Idaho, is for junior and senior high teachers of disabled students and provides strategies to aid in the transition of students from school to the community. Section I of the manual contains short-term transition strategies, for use with students graduating within a…

  18. Energy Efficienct Processes for Making Tackifier Dispersions used to make Pressure Sensitive Adhesives

    SciTech Connect

    Rakesh Gupta

    2006-07-26

    The primary objective of this project was to develop an energy efficient, environmentally friendly and low cost process (compared to the current process) for making tackifier dispersions that are used to make pressure-sensitive adhesives. These adhesives are employed in applications such as self-adhesive postage stamps and disposable diapers and are made by combining the tackifier dispersion with a natural or synthetic rubber latex. The current process for tackifier dispersion manufacture begins by melting a (plastic) resin and adding water to it in order to form a water-in-oil emulsion. This is then converted to an oil-in-water emulsion by phase inversion in the presence of continuous stirring. The resulting emulsion is the tackifier dispersion, but it is not concentrated and the remaining excess water has to be transported and removed. The main barrier that has to be overcome in the development of commercial quality tackifier dispersions is the inability to directly emulsify resin in water due to the very low viscosity of water as compared to the viscosity of the molten resin. In the present research, a number of solutions were proposed to overcome this barrier, and these included use of different mixer types to directly form the emulsion from the molten resin but without going through a phase inversion, the idea of forming a solid resin-in-water suspension having the correct size and size distribution but without melting of the resin, and the development of techniques of making a colloidal powder of the resin that could be dispersed in water just prior to use. Progress was made on each of these approaches, and each was found to be feasible. The most appealing solution, though, is the last one, since it does not require melting of the resin. Also, the powder can be shipped in dry form and then mixed with water in any proportion depending on the needs of the process. This research was conducted at Argonne National Laboratory, and it was determined the new process

  19. ENERGY AND CARBON BUDGETS IN TRANSITIONAL CROPPING SYSTEMS IN MINNESOTA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Energy and carbon budgets were constructed for a wide range of cropping systems during the transition from conventional cropping practices. Cropping system treatments included factorial combinations of: conventional and organic systems (CNV and ORG), conventional tillage and strip tillage (CT and ST...

  20. An earlier origin for stone tool making: implications for cognitive evolution and the transition to Homo.

    PubMed

    Lewis, Jason E; Harmand, Sonia

    2016-07-01

    The discovery of the earliest known stone tools at Lomekwi 3 (LOM3) from West Turkana, Kenya, dated to 3.3 Ma, raises new questions about the mode and tempo of key adaptations in the hominin lineage. The LOM3 tools date to before the earliest known fossils attributed to Homo at 2.8 Ma. They were made and deposited in a more C3 environment than were the earliest Oldowan tools at 2.6 Ma. Their discovery leads to renewed investigation on the timing of the emergence of human-like manipulative capabilities in early hominins and implications for reconstructing cognition. The LOM3 artefacts form part of an emerging paradigm shift in palaeoanthropology, in which: tool-use and tool-making behaviours are not limited to the genus Homo; cranial, post-cranial and behavioural diversity in early Homo is much wider than previously thought; and these evolutionary changes may not have been direct adaptations to living in savannah grassland environments.This article is part of the themed issue 'Major transitions in human evolution'. PMID:27298464

  1. The roles of users in shaping transitions to new energy systems

    NASA Astrophysics Data System (ADS)

    Schot, Johan; Kanger, Laur; Verbong, Geert

    2016-05-01

    Current government information policies and market-based instruments aimed at influencing the energy choices of consumers often ignore the fact that consumer behaviour is not fully reducible to individuals making rational conscious decisions all the time. The decisions of consumers are largely configured by shared routines embedded in socio-technical systems. To achieve a transition towards a decarbonized and energy-efficient system, an approach that goes beyond individual consumer choice and puts shared routines and system change at its centre is needed. Here, adopting a transitions perspective, we argue that consumers should be reconceptualized as users who are important stakeholders in the innovation process shaping new routines and enacting system change. We review the role of users in shifts to new decarbonized and energy-efficient systems and provide a typology of user roles.

  2. Transition Metal Nitrides for Electrocatalytic Energy Conversion: Opportunities and Challenges.

    PubMed

    Xie, Junfeng; Xie, Yi

    2016-03-01

    Electrocatalytic energy conversion has been considered as one of the most efficient and promising pathways for realizing energy storage and energy utilization in modern society. To improve electrocatalytic reactions, specific catalysts are needed to lower the overpotential. In the search for efficient alternatives to noble metal catalysts, transition metal nitrides have attracted considerable interest due to their high catalytic activity and unique electronic structure. Over the past few decades, numerous nitride-based catalysts have been explored with respect to their ability to drive various electrocatalytic reactions, such as the hydrogen evolution reaction and the oxygen evolution reaction to achieve water splitting and the oxygen reduction reaction coupled with the methanol oxidation reaction to construct fuel cells or rechargeable Li-O2 batteries. This Minireview provides a brief overview of recent progress on electrocatalysts based on transition metal nitrides, and outlines the current challenges and future opportunities. PMID:26494184

  3. Internal Conversion Coefficients for Low-Energy Nuclear Transitions

    NASA Astrophysics Data System (ADS)

    Band, I. M.; Trzhaskovskaya, M. B.

    1993-09-01

    Presented here are calculated internal conversion coefficients (ICCs) of gamma rays for 35 observed low-energy nuclear transitions having Eγ ≲ 3 keV. Additionally, the ICCs for 24 high-multipole-order transitions which have been measured extensively are also given. The ICC calculations have been performed using Dirac-Fock electron wave functions, the exchange terms of the Dirac-Fock equations being included wthout any approximations both for the interaction between bound electrons and the interaction between bound and free electrons. Our previous studies have shown that the Dirac-Fock method allows ICC values to be obtained in best agreement with experimental data.

  4. Public Discourse in Energy Policy Decision-Making: Final Report

    SciTech Connect

    Idaho Citizen; Eileen DeShazo; John Freemuth; Tina Giannini; Troy Hall; Ann Hunter; Jeffrey C. Joe; Michael Louis; Carole Nemnich; Jennie Newman; Steven J. Piet; Stephen Sorensen; Paulina Starkey; Kendelle Vogt; Patrick Wilson

    2010-08-01

    The ground is littered with projects that failed because of strong public opposition, including natural gas and coal power plants proposed in Idaho over the past several years. This joint project , of the Idaho National Laboratory, Boise State University, Idaho State University and University of Idaho has aimed to add to the tool box to reduce project risk through encouraging the public to engage in more critical thought and be more actively involved in public or social issues. Early in a project, project managers and decision-makers can talk with no one, pro and con stakeholder groups, or members of the public. Experience has shown that talking with no one outside of the project incurs high risk because opposition stakeholders have many means to stop most (if not all) energy projects. Talking with organized stakeholder groups provides some risk reduction from mutual learning, but organized groups tend not to change positions except under conditions of a negotiated settlement. Achieving a negotiated settlement may be impossible. Furthermore, opposition often arises outside pre-existing groups. Standard public polling provides some information but does not reveal underlying motivations, intensity of attitudes, etc. Improved methods are needed that probe deeper into stakeholder (organized groups and members of the public) values and beliefs/heuristics to increase the potential for change of opinions and/or out-of-box solutions. The term “heuristics” refers to the mental short-cuts, underlying beliefs, and paradigms that everyone uses to filter and interpret information, to interpret what is around us, and to guide our actions and decisions. This document is the final report of a 3-year effort to test different public discourse methods in the subject area of energy policy decision-making. We analyzed 504 mail-in surveys and 80 participants in groups on the Boise State University campus for their preference, financial support, and evaluations of eight attributes

  5. Summer Center for Climate, Energy, and Environmental Decision Making (SUCCEED)

    NASA Astrophysics Data System (ADS)

    Klima, K.; Hoss, F.; Welle, P.; Larkin, S.

    2013-12-01

    Science, Technology, and Math (STEM) fields are responsible for more than half of our sustained economic expansion, and over the past 25 years the science and engineering workforce has remained at over 5% of all U.S. jobs. However, America lags behind other nations when it comes to STEM education; globally, American students rank 23th in math and 31st in science. While our youngest students show an interest in STEM subjects, roughly 40% of college students planning to major in STEM switch to other subjects. Women and minorities, 50% and 43% of school-age children, are disproportionally underrepresented in STEM fields (25% and 15%, respectively). Studies show that improved teacher curriculum combined with annual student-centered learning summer programs can promote and sustain student interest in STEM fields. Many STEM fields appear superficially simple, and yet can be truly complex and controversial topics. Carnegie Mellon University's Center for Climate and Energy Decision Making focuses on two such STEM fields: climate and energy. In 2011, we created SUCCEED: the Summer Center for Climate, Energy, and Environmental Decision Making. SUCCEED consisted of two pilot programs: a 2-day workshop for K-12 teacher professional development and a free 5-day summer school targeted at an age gap in the university's outreach, students entering 10th grade. In addition to teaching lessons climate, energy, and environment, the program aimed to highlight different STEM careers so students could better understand the breadth of choices available. SUCCEED, repeated in 2012, was wildly successful. A pre/post test demonstrated a significant increase in understanding of STEM topics. Furthermore, SUCCEED raised excitement for STEM; teachers were enthusiastic about accurate student-centered learning plans and students wanted to know more. To grow these efforts, an additional component has been added to the SUCCEED 2013 effort: online publicly available curricula. Using the curricula form

  6. Making the Transition from Further to Higher Education: The Impact of a Preparatory Module on Retention, Progression and Performance

    ERIC Educational Resources Information Center

    Knox, Hazel

    2005-01-01

    Articulation across the further education/higher education (FE/HE) interface is of vital importance in addressing the government's widening participation agenda. Many institutions are grappling with how best to prepare students to make this transition particularly when they are direct entrants and join ongoing cohorts of students who are already…

  7. Energy Transition Initiative: Island Energy Snapshot - St. Lucia (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    This profile provides a snapshot of the electricity generation or reduction technologies, including solar hot water heating, available to Saint Lucia, one of six Caribbean countries that make up the Windward Islands - the southern arc of the Lesser Antilles chain - at the eastern end of the Caribbean Sea. Heating and transportation fuels are not addressed.

  8. Energy Transition Initiative, Island Energy Snapshot - Grenada (Fact Sheet)

    SciTech Connect

    Not Available

    2015-03-01

    This profile provides a snapshot of the energy landscape of Grenada - a small island nation consisting of the island of Grenada and six smaller islands in the southeastern Caribbean Sea - three of which are inhabited: Grenada, Carriacou, and Petite Martinique.

  9. From Initial Education to Working Life: Making Transitions Work. Education and Skills.

    ERIC Educational Resources Information Center

    Organisation for Economic Cooperation and Development, Paris (France).

    The Organisation for Economic Cooperation and Development (OECD) conducted a thematic review to identify changes in young people's transition to working life during the 1990s and to identify those policies and programs that are effective in delivering successful transition outcomes for young people. The review focused on 14 countries with widely…

  10. "Ready for Big School": Making the Transition to Primary School--A Jamaican Perspective

    ERIC Educational Resources Information Center

    Kinkead-Clark, Zoyah

    2015-01-01

    The aim of this small-scale, qualitative study is to understand the perspective of varying stakeholders responsible for student transitions from pre-primary to primary school in the Jamaican context. The questions that guided the research are: What factors affect student transitions to primary school? What skills do children need in order to…

  11. Making a Drama out of Transition: Challenges and Opportunities at Times of Change

    ERIC Educational Resources Information Center

    Hammond, Nick

    2016-01-01

    This case study explored how teachers and children perceive challenges and opportunities at transition. Using Forum Theatre (FT), an interactive drama approach, children were able to show aspects of transitions they perceived as challenging and how these barriers may be overcome. FT offered a tangible reference point for children to discuss their…

  12. National Renewable Energy Laboratory's Hydrogen Technologies and Systems Center is Helping to Facilitate the Transition to a New Energy Future

    SciTech Connect

    Not Available

    2011-01-01

    The Hydrogen Technologies and Systems Center (HTSC) at the U.S. Department of Energy's (DOE) National Renewable Energy Laboratory (NREL) uses a systems engineering and integration approach to hydrogen research and development to help the United States make the transition to a new energy future - a future built on diverse and abundant domestic renewable resources and integrated hydrogen systems. Research focuses on renewable hydrogen production, delivery, and storage; fuel cells and fuel cell manufacturing; technology validation; safety, codes, and standards; analysis; education; and market transformation. Hydrogen can be used in fuel cells to power vehicles and to provide electricity and heat for homes and offices. This flexibility, combined with our increasing demand for energy, opens the door for hydrogen power systems. HTSC collaborates with DOE, other government agencies, industry, communities, universities, national laboratories, and other stakeholders to promote a clean and secure energy future.

  13. Making scents of transition: smellscapes and the everyday in "old" and "new" urban Poland.

    PubMed

    Śliwa, Martyna; Riach, Kathleen

    2012-01-01

    In this article, the growing body of literature on transition within central and eastern Europe is developed by exploring how discussing the senses may illuminate the experience of change to post-socialism for urban dwellers. After situating the study within the rich ethnographic heritage on urban transition, the key tenets of ‘geographies of smell’ are outlined as a means of inquiry which emphasises the lived, sensually embodied experience of transition. The empirical study is focused upon the interrogation of the meanings created by, and attached to, olfactory experience in contemporary Poland, discussing three motifs that highlight the symbolic and transformative role of smell in relation to transition. In understanding smell as playing an active role in the creation of meaning, not only are current debates surrounding geographies of smell extended, but it is argued that addressing the relatively neglected sensual dimension of the social provides an avenue into more nuanced dimensions of urban transition. PMID:22319812

  14. Energy levels and radiative transition rates for Ba XLVIII

    NASA Astrophysics Data System (ADS)

    Khatri, Indu; Goyal, Arun; Aggarwal, Sunny; Singh, A. K.; Mohan, Man

    2016-01-01

    Energy levels and radiative rates are reported for transitions in F-like Ba XLVIII. Configuration interaction has been included among 27 configurations (generating 431 levels) over a wide energy range up to 618 Rydbergs, and the fully relativistic multi-configurational Dirac-Fock method adopted for the calculations. To assess the accuracy, calculations have also been performed with the flexible atomic code, FAC. Radiative rates, oscillator strengths and line strengths are reported for all electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions from the lowest 3 levels, although calculations have been performed for a much larger number of levels. We have made comparisons of our results with existing available results and a good agreement has been achieved. Additionally, lifetimes for all 431 levels are listed.

  15. Energy transitions in the early 21st Century

    SciTech Connect

    Paul Meakin

    2013-01-01

    We are in the early stages of a long and complex transition from a global economy based on fossil energy to an economy based on low carbon renewable energy. However, fossil fuel resources are abundant and widely distributed, and they will remain the dominant source of primary energy for at least the next quarter century. In the United States, displacement of coal by natural gas for electric power generation has done more to reduce CO2 emissions than all new renewables combined, and this may occur globally for the next decade or two, even if the European Union does not take advantage of its large unconventional natural gas resources. Greater energy efficiency (not including the efficiencies associated with displacement of coal by gas) will also be more important than new renewables. Cost/benefit ratios are important for sustainability of the transition, and some energy efficiency technologies and displacement of coal by natural gas have lower cost/benefit ratios than wind power, solar power or biofuels. Money spent on the large scale deployment of wind, solar and especially biofuels would be better spent on research, development and demonstration of a broader suite of technologies that would support the energy transition, with a focus on improving the cost benefit ratios of already deployed technologies and developing alternatives. Advanced nuclear reactors, engineered geothermal systems, fossil fuel recovery coupled with CO2 sequestration and pre-combustion or post-combustion decarbonation of fossil fuels with geological CO2 sequestration are among the technologies that might be more cost effective than wind, solar or biofuels, and biofuels have serious adverse societal and environment consequences.

  16. Biomolecular dynamics: order-disorder transitions and energy landscapes.

    PubMed

    Whitford, Paul C; Sanbonmatsu, Karissa Y; Onuchic, José N

    2012-07-01

    While the energy landscape theory of protein folding is now a widely accepted view for understanding how relatively weak molecular interactions lead to rapid and cooperative protein folding, such a framework must be extended to describe the large-scale functional motions observed in molecular machines. In this review, we discuss (1) the development of the energy landscape theory of biomolecular folding, (2) recent advances toward establishing a consistent understanding of folding and function and (3) emerging themes in the functional motions of enzymes, biomolecular motors and other biomolecular machines. Recent theoretical, computational and experimental lines of investigation have provided a very dynamic picture of biomolecular motion. In contrast to earlier ideas, where molecular machines were thought to function similarly to macroscopic machines, with rigid components that move along a few degrees of freedom in a deterministic fashion, biomolecular complexes are only marginally stable. Since the stabilizing contribution of each atomic interaction is on the order of the thermal fluctuations in solution, the rigid body description of molecular function must be revisited. An emerging theme is that functional motions encompass order-disorder transitions and structural flexibility provides significant contributions to the free energy. In this review, we describe the biological importance of order-disorder transitions and discuss the statistical-mechanical foundation of theoretical approaches that can characterize such transitions. PMID:22790780

  17. Biomolecular Dynamics: Order-Disorder Transitions and Energy Landscapes

    PubMed Central

    Whitford, Paul C.; Sanbonmatsu, Karissa Y.; Onuchic, José N.

    2013-01-01

    While the energy landscape theory of protein folding is now a widely accepted view for understanding how relatively-weak molecular interactions lead to rapid and cooperative protein folding, such a framework must be extended to describe the large-scale functional motions observed in molecular machines. In this review, we discuss 1) the development of the energy landscape theory of biomolecular folding, 2) recent advances towards establishing a consistent understanding of folding and function, and 3) emerging themes in the functional motions of enzymes, biomolecular motors, and other biomolecular machines. Recent theoretical, computational, and experimental lines of investigation are providing a very dynamic picture of biomolecular motion. In contrast to earlier ideas, where molecular machines were thought to function similarly to macroscopic machines, with rigid components that move along a few degrees of freedom in a deterministic fashion, biomolecular complexes are only marginally stable. Since the stabilizing contribution of each atomic interaction is on the order of the thermal fluctuations in solution, the rigid body description of molecular function must be revisited. An emerging theme is that functional motions encompass order-disorder transitions and structural flexibility provide significant contributions to the free-energy. In this review, we describe the biological importance of order-disorder transitions and discuss the statistical-mechanical foundation of theoretical approaches that can characterize such transitions. PMID:22790780

  18. Energy spectra and optical transitions in germanene quantum dots.

    PubMed

    Herath, Thakshila M; Apalkov, Vadym

    2016-04-27

    The band gap of buckled graphene-like materials, such as silicene and germanene, depends on external perpendicular electric field. Then a specially design profile of electric field can produce trapping potential for electrons. We study theoretically the energy spectrum and optical transitions for such designed quantum dots (QDs) in graphene-like materials. The energy spectra depend on the size of the QD and applied electric field in the region of the QD. The number of the states in the QD increases with increasing the size of the dot and the energies of the states have almost linear dependence on the applied electric field with the slope which increases with increasing the dot size. The optical properties of the QDs are characterized by two types of absorption spectra: interband (optical transitions between the states of the valence and conduction bands) and intraband (transitions between the states of conduction/valence band). The interband absorption spectra have triple-peak structure with peak separation around 10 meV, while intraband absorption spectra, which depend on the number of electrons in the dot, have double-peak structure. PMID:27008912

  19. Phase/Shape Transitions and the Two Neutron Separation Energies

    SciTech Connect

    Zamfir, N. V.; Anghel, Sabina; Cata-Danil, G.

    2008-11-11

    We investigated the evolution of experimental two-neutron separation energies (S{sub 2n}) along the isotopic chains for the even-even nuclei. In order to enhance the sensitivity of our search, differential variation of the S{sub 2n} has been investigated. The emphasis is on finding nonmonotonic behaviors which can be correlated with phase/shape transition. Correlations of the ground state S{sub 2n} values with the excited states energies R{sub 4/2} ratio are also discussed.

  20. Transitions into the negative-energy Dirac continuum

    SciTech Connect

    Krekora, P.; Su, Q.; Grobe, R.

    2004-11-01

    We compare the predictions of the single-particle Dirac equation with quantum field theory for an electron subjected to a space and time dependent field. We demonstrate analytically and numerically that a transition into the negative-energy subspace predicted by the single-particle Dirac equation is directly associated with the degree of suppression of pair-production as described by quantum field theory. We show that the portion of the mathematical wave function that populates the negative-energy states corresponds to the difference between the positron spatial density for systems with and without an electron initially present.

  1. Making the transition to middle schooling: A case study of experienced science teachers coping with change

    NASA Astrophysics Data System (ADS)

    Strong, Donna Dorough

    The increasing popularity of the middle school movement necessitates a need for more interpretive research in middle level education. The purpose of this qualitative case study was to explore science teachers' perceptions of the transition to a new middle school and the meanings they attached to this new experience. The participants were three eighth grade science teachers, each with 20 plus years of teaching experience. The primary data for analysis was a series of five interviews with each participant. Data collection also included weekly participant observation of team meetings. Findings revealed that the science teachers all had positive feelings attached to the ability to keep track of students' academic progress and behavior problems as a result of teaming. The changes associated with the first year were very stressful for all three, primarily the loss of the traditional junior high departmentalized structure. The two participants who transferred directly from the junior high school were very skeptical of any benefits from an interdisciplinary curriculum, the appropriateness of the middle school philosophy for eighth grade students, and the move to heterogeneously grouped science classes. In contrast, the former junior high teacher who had spent the past ten years teaching sixth grade at the elementary school had positive beliefs about the potential benefits of an interdisciplinary curriculum and heterogeneous grouping. Teacher stress associated with a change in the school setting and the science teachers' constraints to actualizing a meaningful middle schooling experience are illuminated. Teachers' lack of ownership in the reform decision making process, loss of time with their science teacher peers, diminished compliments from high school counterparts, and need for more empirical evidence supporting proposed changes all served as barriers to embracing the reform initiatives. The participants found taking a very slow approach to be their most useful means of

  2. Solar Electricity and Solar Fuels: Status and Perspectives in the Context of the Energy Transition.

    PubMed

    Armaroli, Nicola; Balzani, Vincenzo

    2016-01-01

    The energy transition from fossil fuels to renewables is already ongoing, but it will be a long and difficult process because the energy system is a gigantic and complex machine. Key renewable energy production data show the remarkable growth of solar electricity technologies and indicate that crystalline silicon photovoltaics (PV) and wind turbines are the workhorses of the first wave of renewable energy deployment on the TW scale around the globe. The other PV alternatives (e.g., copper/indium/gallium/selenide (CIGS) or CdTe), along with other less mature options, are critically analyzed. As far as fuels are concerned, the situation is significantly more complex because making chemicals with sunshine is far more complicated than generating electric current. The prime solar artificial fuel is molecular hydrogen, which is characterized by an excellent combination of chemical and physical properties. The routes to make it from solar energy (photoelectrochemical cells (PEC), dye-sensitized photoelectrochemical cells (DSPEC), PV electrolyzers) and then synthetic liquid fuels are presented, with discussion on economic aspects. The interconversion between electricity and hydrogen, two energy carriers directly produced by sunlight, will be a key tool to distribute renewable energies with the highest flexibility. The discussion takes into account two concepts that are often overlooked: the energy return on investment (EROI) and the limited availability of natural resources-particularly minerals-which are needed to manufacture energy converters and storage devices on a multi-TW scale. PMID:26584653

  3. Energy and population: transitional issues and eventual limits.

    PubMed

    Werbos, P J

    1990-08-01

    The implication of population size for US energy requirements is explored in this essay. The basic argument is that the present supply of fuels and energy technologies is not sustainable in the long run, that a wide range of choices is possible when a complete transition is made to sustainable technologies, and that the growth of population and the composition of this growth during the next 30 years are the most serious problems impacting on the achievement of sustainable technology. The importance and future of fuel oil is discussed as well as the transition to sustainable energy supplies: conservation, renewables, nuclear and coal. Dependency on oil can only be changed through time and the infusion of money, but even with these givens, the transition is also dependent on the political and budgetary climate. The race is between crisis and cure. It is argued that the soft energy systems (biomass, solar water heater, wind, hydro, and geothermal energy) along with conservation will increase easily and naturally, but the total potential from these sources amounts to only 10% of the present US energy supply. Conservation offers greater hope because 80% of end-use fossil fuel is used in transportation and industry. Further growth of the population in the US would create a demand to desalinate water, which would increase the demand for energy. A totally soft energy economy is probably not feasible without a drastic reduction in US population. The expected direction is in the increased use of coal, and then nuclear energy. Unfortunately, coal contributes to greenhouse warming, and the supply is limited to 60-100 years. Nuclear proliferation and terrorism is connected to the widespread use of nuclear energy. Some breakthrough technology with cold fusion may offer a safer alternative. High technology renewables such as solar cells can be competitive with nuclear energy, if prices can be kept down. on earth or in space, are being investigated. Exploring a variety of advanced

  4. Vertical transition energies vs. absorption maxima: illustration with the UV absorption spectrum of ethylene.

    PubMed

    Lasorne, Benjamin; Jornet-Somoza, Joaquim; Meyer, Hans-Dieter; Lauvergnat, David; Robb, Michael A; Gatti, Fabien

    2014-02-01

    We revisit the validity of making a direct comparison between measured absorption maxima and computed vertical transition energies within 0.1 eV to calibrate an excited-state level of theory. This is illustrated on the UV absorption spectrum of ethylene for which the usual experimental values of 7.66 eV (V←N) and 7.11 eV (R(3s)←N) cannot be compared directly to the results of electronic structure calculations for two very different reasons. After validation of our level of theory against experimental data, a new experimental reference of 7.28 eV is suggested for benchmarking the Rydberg state, and the often-cited average transition energy (7.80 eV) is confirmed as a safer estimate for the valence state. PMID:23711543

  5. Energy efficient engine: Turbine transition duct model technology report

    NASA Technical Reports Server (NTRS)

    Leach, K.; Thurlin, R.

    1982-01-01

    The Low-Pressure Turbine Transition Duct Model Technology Program was directed toward substantiating the aerodynamic definition of a turbine transition duct for the Energy Efficient Engine. This effort was successful in demonstrating an aerodynamically viable compact duct geometry and the performance benefits associated with a low camber low-pressure turbine inlet guide vane. The transition duct design for the flight propulsion system was tested and the pressure loss goal of 0.7 percent was verified. Also, strut fairing pressure distributions, as well as wall pressure coefficients, were in close agreement with analytical predictions. Duct modifications for the integrated core/low spool were also evaluated. The total pressure loss was 1.59 percent. Although the increase in exit area in this design produced higher wall loadings, reflecting a more aggressive aerodynamic design, pressure profiles showed no evidence of flow separation. Overall, the results acquired have provided pertinent design and diagnostic information for the design of a turbine transition duct for both the flight propulsion system and the integrated core/low spool.

  6. A Framework for Supporting Organizational Transition Processes Towards Sustainable Energy Systems

    NASA Astrophysics Data System (ADS)

    Buch, Rajesh

    Economic development over the last century has driven a tripling of the world's population, a twenty-fold increase in fossil fuel consumption, and a tripling of traditional biomass consumption. The associated broad income and wealth inequities are retaining over 2 billion people in poverty. Adding to this, fossil fuel combustion is impacting the environment across spatial and temporal scales and the cost of energy is outpacing all other variable costs for most industries. With 60% of world energy delivered in 2008 consumed by the commercial and industrial sector, the fragmented and disparate energy-related decision making within organizations are largely responsible for the inefficient and impacting use of energy resources. The global transition towards sustainable development will require the collective efforts of national, regional, and local governments, institutions, the private sector, and a well-informed public. The leadership role in this transition could be provided by private and public sector organizations, by way of sustainability-oriented organizations, cultures, and infrastructure. The diversity in literature exemplifies the developing nature of sustainability science, with most sustainability assessment approaches and frameworks lacking transformational characteristics, tending to focus on analytical methods. In general, some shortfalls in sustainability assessment processes include lack of: · thorough stakeholder participation in systems and stakeholder mapping, · participatory envisioning of future sustainable states, · normative aggregation of results to provide an overall measure of sustainability, and · influence within strategic decision-making processes. Specific to energy sustainability assessments, while some authors aggregate results to provide overall sustainability scores, assessments have focused solely on energy supply scenarios, while including the deficits discussed above. This paper presents a framework for supporting

  7. Many-body energy localization transition in periodically driven systems

    SciTech Connect

    D’Alessio, Luca; Polkovnikov, Anatoli

    2013-06-15

    According to the second law of thermodynamics the total entropy of a system is increased during almost any dynamical process. The positivity of the specific heat implies that the entropy increase is associated with heating. This is generally true both at the single particle level, like in the Fermi acceleration mechanism of charged particles reflected by magnetic mirrors, and for complex systems in everyday devices. Notable exceptions are known in noninteracting systems of particles moving in periodic potentials. Here the phenomenon of dynamical localization can prevent heating beyond certain threshold. The dynamical localization is known to occur both at classical (Fermi–Ulam model) and at quantum levels (kicked rotor). However, it was believed that driven ergodic systems will always heat without bound. Here, on the contrary, we report strong evidence of dynamical localization transition in both classical and quantum periodically driven ergodic systems in the thermodynamic limit. This phenomenon is reminiscent of many-body localization in energy space. -- Highlights: •A dynamical localization transition in periodically driven ergodic systems is found. •This phenomenon is reminiscent of many-body localization in energy space. •Our results are valid for classical and quantum systems in the thermodynamic limit. •At critical frequency, the short time expansion for the evolution operator breaks down. •The transition is associated to a divergent time scale.

  8. City-Level Energy Decision Making. Data Use in Energy Planning, Implementation, and Evaluation in U.S. Cities

    SciTech Connect

    Aznar, Alexandra; Day, Megan; Doris, Elizabeth; Mathur, Shivani; Donohoo-Vallett, Paul

    2015-07-08

    The Cities-LEAP technical report, City-Level Energy Decision Making: Data Use in Energy Planning, Implementation, and Evaluation in U.S. Cities, explores how a sample of cities incorporates data into making energy-related decisions. This report provides the foundation for forthcoming components of the Cities-LEAP project that will help cities improve energy decision making by mapping specific city energy or climate policies and actions to measurable impacts and results.

  9. A "Step-Back" Is Actually a "Step-Forward" When Attempting to Make the Transition from Administrator to Faculty within the Canadian College Environment

    ERIC Educational Resources Information Center

    Jacobs, Steven

    2015-01-01

    Many college faculty have sought and secured administrative positions. This type of transition is not uncommon. What is uncommon, however, is the transition back from an administrative position to a faculty position within Canadian colleges. There are many barriers and obstacles to this type of role transition which make it very difficult to do. I…

  10. The Transition to Middle Level Schools: Making It a Good Experience for All Students.

    ERIC Educational Resources Information Center

    Midgley, Carol; Urdan, Tim

    1992-01-01

    Describes approaches for solving the problem of students' declining motivation and performance when they move to middle-level schools. Urges educators to examine school policies, practices, and procedures, and to make changes that will make it very clear to students that effort, challenge, improvement, and mastery are the goals of schooling. (16…

  11. How We Make Energy Work: Grades 4, 5, 6 Science.

    ERIC Educational Resources Information Center

    National Science Teachers Association, Washington, DC.

    This packet of units is designed to focus on the technological aspects of energy. Four units are presented, with from 1-4 lessons included in each unit. Units include: (1) basic concepts and applications of energy; (2) steps and processes of energy production and transmission; (3) fuel acquisition; and (4) energy futures and application of…

  12. Practice Makes Perfect? University Students' Response to a First-Year Transition Course

    ERIC Educational Resources Information Center

    Browning, Catherine; Sheffield, Suzanne Le-May

    2008-01-01

    This paper shares new insights on the first-year university student transition experience. Our research focuses on students' practice of academic skills developed in a "Foundations for Learning" course, from their own perspective, after they completed the course. Once they had an opportunity to practice what they learned in subsequent…

  13. Building on Success: Helping Students Make Transitions from Year to Year

    ERIC Educational Resources Information Center

    Thompson, Carolyn

    2006-01-01

    Throughout a student's time in school, a variety of transitions will occur. From home to school, grade to grade, school to school, school to post-secondary training or employment, students experience changes in expectations, responsibilities and routines. This resource provides sample ideas and templates for creating a Learner Profile that…

  14. The Post-School Outcomes Transition Survey: A Tool for Effective Decision Making?

    ERIC Educational Resources Information Center

    Eaves, Ronald C.; Rabren, Karen; Hall, George

    2012-01-01

    This study investigated the validity of the "Post-School Outcomes Transition Survey" (PSOTS). The PSOTS was designed to ascertain whether individuals who received special education services in secondary school have obtained postschool employment or have enrolled in postsecondary education or training within 1 to 2 years of exiting high school. The…

  15. Students with Traumatic Brain Injury: Making the Transition from Hospital to School.

    ERIC Educational Resources Information Center

    Mira, Mary P.; Tyler, Janet Siantz

    1991-01-01

    This paper uses a case study of a 16-year-old girl with traumatic brain injury (TBI) to present information on the demographics of head injury, neuropathology, recovery patterns, acute rehabilitation, educationally significant effects, behavioral sequelae, the school as a vehicle for rehabilitation, a transition model, school reentry, and…

  16. Declining Motivation After the Transition to Middle School: Schools Can Make a Difference.

    ERIC Educational Resources Information Center

    Anderman, Eric M.; Maehr, Martin L.; Midgley, Carol

    1999-01-01

    Investigated the effects of transitioning from elementary to middle school on the motivational beliefs of students attending two very different types of middle schools. Surveys of students at the end of grades 5, 6, and 7 indicated that while few differences existed in elementary school, students' motivational beliefs changed differently,…

  17. Rocking & Rolling: Supporting Infants, Toddlers, and Their Families. Helping Babies Make Transitions

    ERIC Educational Resources Information Center

    Merrill, Sarah; Britt, Donna

    2008-01-01

    The authors discuss three steps to helping babies with transitions: observe, ask, and respond (OAR). They advise teachers about how to ask a family questions about their baby and how to give the family suggestions to alleviate the baby's stress, without offending family members. This column includes a list of recommended resources. (Contains 7…

  18. The Work Experiences of Transgender Individuals: Negotiating the Transition and Career Decision-Making Processes

    ERIC Educational Resources Information Center

    Budge, Stephanie L.; Tebbe, Esther N.; Howard, Kimberly A. S.

    2010-01-01

    This study explored the work experiences of individuals who have started transitioning from their biological sex to a different gender expression through 18 interviews of transgender-identified individuals. Thirteen of the participants identified as male-to-female transsexuals, 2 participants identified as female-to-male transsexuals, 2…

  19. Making the Transition: An Explanatory Model of Special Education Students' Participation in Postsecondary Education.

    ERIC Educational Resources Information Center

    Butler-Nalin, Paul; And Others

    The report of the National Longitudinal Transition Study presents initial findings on individual characteristics which relate to postsecondary education participation since 1985-86 among more than 8,000 youth (ages 13 to 23) with disabilities. A series of logistic regression models examines such factors as youth's background characteristics,…

  20. Making Community Connections: Educator Perspectives on Transition Planning for Students with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Schwartz, Karen; Mactavish, Jennifer; Lutfiyya, Zana Marie

    2006-01-01

    For students with intellectual disabilities and their families, planning for the transition from school to adult life can be a complicated process. Successful planning is sometimes made more challenging when post-school options and opportunities are not well known or understood. The purpose of this study is to seek out the perspectives of…

  1. Transitions.

    ERIC Educational Resources Information Center

    Nathanson, Jeanne H., Ed.

    1993-01-01

    This theme issue on transitions for individuals with disabilities contains nine papers discussing transition programs and issues. "Transition Issues for the 1990s," by Michael J. Ward and William D. Halloran, discusses self-determination, school responsibility for transition, continued educational engagement of at-risk students, and service…

  2. Global Warming and Energy Transition: A Public Policy Imperative

    NASA Astrophysics Data System (ADS)

    Stone, G. T.

    2006-12-01

    The historic transition from fossil fuels to alternative energy resources has begun. This development is commonly attributed to increasing energy costs and the need for energy security. Looming ever larger, however, is the issue that will soon drive the third energy revolution: global warming. A preponderance of evidence documents accelerating warming, enlarging impacts, and human causes -- principally combustion of fossil fuels. The carbon dioxide (C02) content of Earth's atmosphere has increased more than 35 percent since the beginning of the industrial revolution and is the highest in 650,000 years. This dramatic rise of C02 and attendant positive feedbacks are already forcing significant impacts worldwide. These include atmospheric warming with shifting climatic and habitat zones, spreading tropical disease, and more extreme weather events; rapid ice loss at high latitude and high altitude; ocean warming and acidification with coral reef bleaching and intensifying tropical storms; rising sea level; and accelerating extinction rates. The 2007 draft report of the Intergovernmental Panel on Climate Change (IPCC) predicts greater warming than in previous models. A tipping point to abrupt climate change may be imminent. It is incumbent upon geoscientists and geoscience educators to assume leadership in addressing this challenge through public outreach and general education. The following topics should be integrated into all appropriate courses: the evidence of global warming and its causes; observed present and predicted future impacts of global warming; mitigation and adaptation strategies; and implications for energy policies and economic opportunities. New entry-level science and general education courses -- such as Climate Change Fundamentals and Energy in Nature, Technology, and Society -- are proving to be effective should be widely developed In addition, by workshops and presentations to civic and business organizations and by demonstrated examples of

  3. Steering quantum transitions between three crossing energy levels

    SciTech Connect

    Ivanov, S. S.; Vitanov, N. V.

    2008-02-15

    We calculate the propagator and the transition probabilities for a coherently driven three-state quantum system. The energies of the three states change linearly in time, whereas the interactions between them are pulse shaped. We derive a highly accurate analytic approximation by assuming independent pairwise Landau-Zener transitions occurring instantly at the relevant avoided crossings, and adiabatic evolution elsewhere. Quantum interferences are identified, which occur due to different possible evolution paths in Hilbert space between an initial and a final state. A detailed comparison with numerical results for Gaussian-shaped pulses demonstrates a remarkable accuracy of the analytic approximation. We use the analytic results to derive estimates for the half-width of the excitation profile, and for the parameters required for creation of a maximally coherent superposition of the three states. These results are of potential interest in ladder climbing in alkali-metal atoms by chirped laser pulses, in quantum rotors, in transitions between Zeeman sublevels of a J=1 level in a magnetic field, and in control of entanglement of a pair of spin-1/2 particles. The results for the three-state system can be generalized, without essential difficulties, to higher dimensions.

  4. Process for making whiskers, fibers and flakes of transition metal compounds

    DOEpatents

    Bamberger, C.E.

    1992-06-02

    A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH[sub 3]. The products exhibit the same morphology as the starting material.

  5. Process for making whiskers, fibers and flakes of transition metal compounds

    DOEpatents

    Bamberger, Carlos E.

    1992-01-01

    A process for making titanium and chromium nitrides of known morphology by reacting potassium titanate and chromium oxide in the gas phase with NH.sub.3. The products exhibit the same morphology as the starting material.

  6. A Guide to making Energy-Smart Purchases

    SciTech Connect

    1999-04-01

    Being more energy efficient can be as simple and inexpensive as buying and installing caulk and weatherstripping or as complicated and expensive as building a state-of-the-art, energy-efficient house. However, whatever you do to reduce energy costs will usually require the purchase of goods or services.

  7. A Model for Education: Energy-Water Consumption Decision Making.

    ERIC Educational Resources Information Center

    Bontrager, Ralph L.; Hubbard, Charles W.

    Public schools are in a position to convince society-at-large of the national energy problem. There is a direct relationship between energy costs to the schools and the type of educational programs they can provide. While waiting for a national energy policy with a section devoted to schools, districts can calculate the amount and cost of energy…

  8. Making the transition to the third era of natural resources management

    USGS Publications Warehouse

    Stephenson, Nathan L.

    2015-01-01

    We are entering the third era of National Park Service (NPS) natural resources management— an era defined by rapid and unprecedented global changes. This third era promises to overturn not only some of our most fundamental assumptions about parks and protected areas, but also many of the ideals we currently hold dear. A common initial reaction to the diverse challenges of this transition is to feel overwhelmed and adrift; I have certainly had such feelings myself. But these feelings carry the risk of reducing our effectiveness as resource stewards right when we can least afford to be less effective: during a transition that is demanding us to be particularly clear-headed and far-seeing. Here I briefly examine some of the challenges of this new era, focusing on those that can most often elicit feelings of discouragement. When we examine the challenges individually, they begin to lose some of their ability to cast gloom—especially when we consider them in the light of lessons from an earlier fundamental transition in NPS natural resources management, beginning a half-century ago. My perspective is shaped by my 35 years as a place-based scientist stationed in a large national park (Sequoia and Kings Canyon), and by my passion for national parks in general. While the discussion that follows is most relevant to large national parks set aside primarily for their natural features, several of the ideas are also relevant to other park units.

  9. Many-body energy localization transition in periodically driven system

    NASA Astrophysics Data System (ADS)

    D'Alessio, Luca; Polkovnikov, Anatoli

    2013-03-01

    According to the second law of thermodynamics the total entropy and energy of a system is increased during almost any dynamical process. Notable exceptions are known in noninteracting systems of particles moving in periodic potentials. Here the phenomenon of dynamical localization can prevent heating beyond certain threshold. However, it was believed that driven ergodic systems will always heat without bound. Here, on the contrary, we report strong evidence of dynamical localization transition in periodically driven ergodic systems in the thermodynamic limit. This phenomenon is reminiscent of many-body localization in energy space. We report numerical evidence based on exact diagonalization of small spin chains and theoretical arguments based on the Magnus expansion. Our findings are valid for both classical and quantum systems.

  10. Phase transition in the Jarzynski estimator of free energy differences.

    PubMed

    Suárez, Alberto; Silbey, Robert; Oppenheim, Irwin

    2012-05-01

    The transition between a regime in which thermodynamic relations apply only to ensembles of small systems coupled to a large environment and a regime in which they can be used to characterize individual macroscopic systems is analyzed in terms of the change in behavior of the Jarzynski estimator of equilibrium free energy differences from nonequilibrium work measurements. Given a fixed number of measurements, the Jarzynski estimator is unbiased for sufficiently small systems. In these systems the directionality of time is poorly defined and the configurations that dominate the empirical average, but which are in fact typical of the reverse process, are sufficiently well sampled. As the system size increases the arrow of time becomes better defined. The dominant atypical fluctuations become rare and eventually cannot be sampled with the limited resources that are available. Asymptotically, only typical work values are measured. The Jarzynski estimator becomes maximally biased and approaches the exponential of minus the average work, which is the result that is expected from standard macroscopic thermodynamics. In the proper scaling limit, this regime change has been recently described in terms of a phase transition in variants of the random energy model. In this paper this correspondence is further demonstrated in two examples of physical interest: the sudden compression of an ideal gas and adiabatic quasistatic volume changes in a dilute real gas. PMID:23004704

  11. Phase transition in the Jarzynski estimator of free energy differences

    NASA Astrophysics Data System (ADS)

    Suárez, Alberto; Silbey, Robert; Oppenheim, Irwin

    2012-05-01

    The transition between a regime in which thermodynamic relations apply only to ensembles of small systems coupled to a large environment and a regime in which they can be used to characterize individual macroscopic systems is analyzed in terms of the change in behavior of the Jarzynski estimator of equilibrium free energy differences from nonequilibrium work measurements. Given a fixed number of measurements, the Jarzynski estimator is unbiased for sufficiently small systems. In these systems the directionality of time is poorly defined and the configurations that dominate the empirical average, but which are in fact typical of the reverse process, are sufficiently well sampled. As the system size increases the arrow of time becomes better defined. The dominant atypical fluctuations become rare and eventually cannot be sampled with the limited resources that are available. Asymptotically, only typical work values are measured. The Jarzynski estimator becomes maximally biased and approaches the exponential of minus the average work, which is the result that is expected from standard macroscopic thermodynamics. In the proper scaling limit, this regime change has been recently described in terms of a phase transition in variants of the random energy model. In this paper this correspondence is further demonstrated in two examples of physical interest: the sudden compression of an ideal gas and adiabatic quasistatic volume changes in a dilute real gas.

  12. Nudged-elastic band method with two climbing images: Finding transition states in complex energy landscapes

    SciTech Connect

    Zarkevich, Nikolai A.; Johnson, Duane D.

    2015-01-09

    The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. Improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP. In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB.

  13. Nudged-elastic band method with two climbing images: Finding transition states in complex energy landscapes

    DOE PAGESBeta

    Zarkevich, Nikolai A.; Johnson, Duane D.

    2015-01-09

    The nudged-elastic band (NEB) method is modified with concomitant two climbing images (C2-NEB) to find a transition state (TS) in complex energy landscapes, such as those with a serpentine minimal energy path (MEP). If a single climbing image (C1-NEB) successfully finds the TS, then C2-NEB finds it too. Improved stability of C2-NEB makes it suitable for more complex cases, where C1-NEB misses the TS because the MEP and NEB directions near the saddle point are different. Generally, C2-NEB not only finds the TS, but guarantees, by construction, that the climbing images approach it from the opposite sides along the MEP.more » In addition, C2-NEB provides an accuracy estimate from the three images: the highest-energy one and its climbing neighbors. C2-NEB is suitable for fixed-cell NEB and the generalized solid-state NEB.« less

  14. Toward the renewables - A natural gas/solar energy transition strategy

    NASA Technical Reports Server (NTRS)

    Hanson, J. A.; Escher, W. J. D.

    1979-01-01

    The inevitability of an energy transition from today's non-renewable fossil base toward a renewable energy base is considered from the viewpoint of the need for a national transition strategy. Then, one such strategy is offered. Its technological building blocks are described in terms of both energy use and energy supply. The strategy itself is then sketched at four points in its implementation; (1) initiation, (2) early transition, (3) late transition, and (4) completion. The transition is assumed to evolve from a heavily natural gas-dependent energy economy. It then proceeds through its transition toward a balanced, hybrid energy system consisting of both centralized and dispersed energy supply technologies supplying hydrogen and electricity from solar energy. Related institutional, environmental and economic factors are examined briefly.

  15. Nanotechnology makes biomass electrolysis more energy efficient than water electrolysis.

    PubMed

    Chen, Y X; Lavacchi, A; Miller, H A; Bevilacqua, M; Filippi, J; Innocenti, M; Marchionni, A; Oberhauser, W; Wang, L; Vizza, F

    2014-01-01

    The energetic convenience of electrolytic water splitting is limited by thermodynamics. Consequently, significant levels of hydrogen production can only be obtained with an electrical energy consumption exceeding 45 kWh kg(-1)H2. Electrochemical reforming allows the overcoming of such thermodynamic limitations by replacing oxygen evolution with the oxidation of biomass-derived alcohols. Here we show that the use of an original anode material consisting of palladium nanoparticles deposited on to a three-dimensional architecture of titania nanotubes allows electrical energy savings up to 26.5 kWh kg(-1)H2 as compared with proton electrolyte membrane water electrolysis. A net energy analysis shows that for bio-ethanol with energy return of the invested energy larger than 5.1 (for example, cellulose), the electrochemical reforming energy balance is advantageous over proton electrolyte membrane water electrolysis. PMID:24892771

  16. Nanotechnology makes biomass electrolysis more energy efficient than water electrolysis

    NASA Astrophysics Data System (ADS)

    Chen, Y. X.; Lavacchi, A.; Miller, H. A.; Bevilacqua, M.; Filippi, J.; Innocenti, M.; Marchionni, A.; Oberhauser, W.; Wang, L.; Vizza, F.

    2014-06-01

    The energetic convenience of electrolytic water splitting is limited by thermodynamics. Consequently, significant levels of hydrogen production can only be obtained with an electrical energy consumption exceeding 45 kWh kg-1H2. Electrochemical reforming allows the overcoming of such thermodynamic limitations by replacing oxygen evolution with the oxidation of biomass-derived alcohols. Here we show that the use of an original anode material consisting of palladium nanoparticles deposited on to a three-dimensional architecture of titania nanotubes allows electrical energy savings up to 26.5 kWh kg-1H2 as compared with proton electrolyte membrane water electrolysis. A net energy analysis shows that for bio-ethanol with energy return of the invested energy larger than 5.1 (for example, cellulose), the electrochemical reforming energy balance is advantageous over proton electrolyte membrane water electrolysis.

  17. With a Little Help from Their Friends: Making the Transition from Student to Teacher

    ERIC Educational Resources Information Center

    Spangler, Susan

    2013-01-01

    A university's seminar model suggests the design of a collaborative structure that promotes team sharing and problem solving. The mentoring that occurs in the seminar comes mainly from the student teachers sharing their experiences with each other and working together to make sense of their classrooms in the context of the theories they have…

  18. The Process of Occupational Decision Making: Patterns during the Transition to Adulthood.

    ERIC Educational Resources Information Center

    Mortimer, Jeylan T.; Zimmer-Gembeck, Melanie J.; Shanahan, Michael J.; Holmes, Mikki

    2002-01-01

    Interviews of 69 adults who had participated in the Youth Development Study as adolescents identified occupational decision-making themes: unfulfilled expectations, postponement of decisions, turning points, resources, and obstacles. Results suggest a need for changing and strengthening social policy especially related to career counseling.…

  19. On Their Own? Making the Transition from School to Work in the Information Age.

    ERIC Educational Resources Information Center

    Crysdale, Stewart; King, Alan J. C.; Mandell, Nancy

    This book examines the factors responsible for the difficulties being experienced by many young Canadians trying to find permanent jobs in a growing economy and explains how Canadian youths can make the best use of the opportunities offered by academic and other programs to find a satisfying life in the workforce. The following are among the…

  20. Who Makes It to Secondary School? Determinants of Transition to Secondary Schools in Rural India

    ERIC Educational Resources Information Center

    Siddhu, Gaurav

    2011-01-01

    Despite considerable progress made, a significant proportion of children continue to drop out before reaching secondary school in India. This study investigates factors influencing parental decision-making with regard to children's secondary schooling in the context of a rural area of Uttar Pradesh. The study finds that cost, distance to the…

  1. Energy Transition Initiative, Island Energy Snapshot - British Virgin Islands (Fact Sheet)

    SciTech Connect

    Not Available

    2015-03-01

    This profile provides a snapshot of the energy landscape of the British Virgin Islands (BVI), one of three sets of the Virgin Island territories in an archipelago making up the northern portion of the Lesser Antilles.

  2. Sustainable Schools: Making Energy Efficiency a Lifestyle Priority

    ERIC Educational Resources Information Center

    Purnell, Ken; Sinclair, Mark; Gralton, Anna

    2004-01-01

    Promoting efficient energy use in schools that consequently reduces greenhouse gas emissions is the purpose of a residential Energy Efficiency in Schools (EEIS) program reported on in this paper. Research on this program aligns with one of the "key "overarching" sustainability issues", set out in the "Learning for Sustainability: NSW Environmental…

  3. Transition.

    ERIC Educational Resources Information Center

    Thompson, Sandy, Ed.; And Others

    1990-01-01

    This "feature issue" focuses on transition from school to adult life for persons with disabilities. Included are "success stories," brief program descriptions, and a list of resources. Individual articles include the following titles and authors: "Transition: An Energizing Concept" (Paul Bates); "Transition Issues for the 1990s" (William Halloran…

  4. Interactions between negative energy balance, metabolic diseases, uterine health and immune response in transition dairy cows.

    PubMed

    Esposito, Giulia; Irons, Pete C; Webb, Edward C; Chapwanya, Aspinas

    2014-01-30

    The biological cycles of milk production and reproduction determine dairying profitability thus making management decisions dynamic and time-dependent. Diseases also negatively impact on net earnings of a dairy enterprise. Transition cows in particular face the challenge of negative energy balance (NEB) and/or disproportional energy metabolism (fatty liver, ketosis, subacute, acute ruminal acidosis); disturbed mineral utilization (milk fever, sub-clinical hypocalcemia); and perturbed immune function (retained placenta, metritis, mastitis). Consequently NEB and reduced dry matter intake are aggravated. The combined effects of all these challenges are reduced fertility and milk production resulting in diminishing profits. Risk factors such as NEB, inflammation and impairment of the immune response are highly cause-and-effect related. Thus, managing cows during the transition period should be geared toward reducing NEB or feeding specially formulated diets to improve immunity. Given that all cows experience a reduced feed intake and body condition, infection and inflammation of the uterus after calving, there is a need for further research on the immunology of transition dairy cows. Integrative approaches at the molecular, cellular and animal level may unravel the complex interactions between disturbed metabolism and immune function that predispose cows to periparturient diseases. PMID:24378117

  5. Hydrogen and Fuel Cell Transit Bus Evaluations: Joint Evaluation Plan for the U.S. Department of Energy and the Federal Transit Administration (Report and Appendix)

    SciTech Connect

    Eudy, L.; Chandler, K.

    2008-05-01

    This document describes the hydrogen transit bus evaluations performed by the National Renewable Energy Laboratory (NREL) and funded by the U.S. Department of Energy (DOE) and the U.S. Department of Transportation's Federal Transit Administration (FTA).

  6. Basic JCL for the CRAY-1 operating system (COS) with emphasis on making the transition from CDC 7600/SCOPE

    NASA Technical Reports Server (NTRS)

    Howe, G.; Saunders, D.

    1983-01-01

    Users of the CDC 7600 at Ames are assisted in making the transition to the CRAY-1. Similarities and differences in the basic JCL are summarized, and a dozen or so examples of typical batch jobs for the two systems are shown in parallel. Some changes to look for in FORTRAN programs and in the use of UPDATE are also indicated. No attempt is made to cover magnetic tape handling. The material here should not be considered a substitute for reading the more conventional manuals or the User's Guide for the Advanced Computational Facility, available from the Computer Information Center.

  7. Controlling Light to Make the Most Energy From the Sun

    SciTech Connect

    Callahan, Dennis; Corcoran, Chris; Eisler, Carissa; Flowers, Cris; Goodman, Matt; Hofmann, Carrie; Sadtler, Bryce

    2013-07-18

    Representing the Light-Material Interactions in Energy Conversion (LMI), this document is one of the entries in the Ten Hundred and One Word Challenge. As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE energy. The mission of LMI to tailor the morphology, complex dielectric structure, and electronic properties of matter so as to sculpt the flow of sunlight and heat, enabling light conversion to electrical and chemical energy with unprecedented efficiency.

  8. Energy Policy Decision-Making: The Need for Balanced Input

    ERIC Educational Resources Information Center

    DeVolpi, A.

    1974-01-01

    Indicates that the credibility of environmentalists and nuclear advocates has been damaged by misinformed alarmist positions. Advocates the public's right of equal standing on advisory councils in the areas of energy development, environmental protection, and public safety. (GS)

  9. Transition Metal Oxide Alloys as Potential Solar Energy Conversion Materials

    SciTech Connect

    Toroker, Maytal; Carter, Emily A.

    2013-02-21

    First-row transition metal oxides (TMOs) are inexpensive potentia alternative materials for solar energy conversion devices. However, some TMOs, such as manganese(II) oxide, have band gaps that are too large for efficiently absorbing solar energy. Other TMOs, such as iron(II) oxide, have conduction and valence band edges with the same orbital character that may lead to unfavorably high electron–hole recombination rates. Another limitation of iron(II) oxide is that the calculated valence band edge is not positioned well for oxidizing water. We predict that key properties, including band gaps, band edge positions, and possibly electron–hole recombination rates, may be improved by alloying TMOs that have different band alignments. A new metric, the band gap center offset, is introduced for simple screening of potential parent materials. The concept is illustrated by calculating the electronic structure of binary oxide alloys that contain manganese, nickel, iron, zinc, and/or magnesium, within density functional theory (DFT)+U and hybrid DFT theories. We conclude that alloys of iron(II) oxide are worth evaluating further as solar energy conversion materials.

  10. Household Energy Consumption: Community Context and the Fuelwood Transition*

    PubMed Central

    Link, Cynthia F.; Axinn, William G.; Ghimire, Dirgha J.

    2012-01-01

    We examine the influence of community context on change over time in households’ use of non-wood fuels. Our theoretical framework builds on sociological concepts in order to study energy consumption at the micro-level. The framework emphasizes the importance of nonfamily organizations and services in the local community as determinants of the transition from use of fuelwood to use of alternative fuels. We use multilevel longitudinal data on household fuel choice and community context from rural Nepal to provide empirical tests of our theoretical model. Results reveal that increased exposure to nonfamily organizations in the local community increases the use of alternative fuels. The findings illustrate key features of human impacts on the local environment and motivate greater incorporation of social organization into research on environmental change. PMID:23017795

  11. Transition metal oxide hierarchical nanotubes for energy applications.

    PubMed

    Wei, Wei; Wang, Yongcheng; Wu, Hao; Al-Enizi, Abdullah M; Zhang, Lijuan; Zheng, Gengfeng

    2016-01-15

    We report a general synthetic method for transition metal oxide (TMO) hierarchical nanotube (HNT) structures by a solution-phase cation exchange method from Cu2O nanowire templates. This method leads to the formation of hollow, tubular backbones with secondary, thin nanostructures on the tube surface, which substantially increases the surface reactive sites for electrolyte contacts and electrochemical reactions. As proofs-of-concept, several representative first-row TMO HNTs have been synthesized, including CoOx, NiOx, MnOx, ZnOx and FeOx, with specific surface areas much larger than nanotubes or nanoparticles of corresponding materials. An example of the potential energy storage applications of CoOx HNTs as supercapacitors is also demonstrated. PMID:26629880

  12. Energy levels and radiative rates for transitions in Ti VI

    NASA Astrophysics Data System (ADS)

    Aggarwal, Kanti; Keenan, Francis; Msezane, Alfred Z.

    2012-06-01

    Energies for 568 levels among the n=3+3p^64l+3s3p^54l configurations of Ti VI are calculated using the GRASP (General-purpose Relativistic Atomic Structure Program) code, which is based on the multi-configuration Dirac-Fock (MCDF) method. Additionally, radiative rates are calculated for all types of transitions, namely electric dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2). Lifetimes are also calculated for all the levels and extensive comparisons are made with the earlier available data as well as with other parallel calculations from the FAC (Flexible Atomic Code). Discrepancies for several levels with the earlier calculations of Mohan et al, (ADNDT 93 105 (2007)) are highlighted.

  13. Can decoherence make quantum theories unfalsifiable? Understanding the quantum-to-classical transition without it

    NASA Astrophysics Data System (ADS)

    Oriols, X.

    2016-03-01

    Exact predictions for most quantum systems are computationally inaccessible. This is the so-called many body problem, which is present in most common interpretations of quantum mechanics. Therefore, predictions of natural quantum phenomena have to rely on some approximations (assumptions or simplifications). In the literature, there are different types of approximations, ranging from those whose justification is basically based on theoretical developments to those whose justification lies on the agreement with experiments. This last type of approximations can convert a quantum theory into an “unfalsifiable” quantum theory, true by construction. On the practical side, converting some part of a quantum theory into an “unfalsifiable” one ensures a successful modeling (i.e. compatible with experiments) for quantum engineering applications. An example of including irreversibility and dissipation in the Bohmian modeling of open systems is presented. On the ontological level, however, the present-day foundational problems related to controversial quantum phenomena have to avoid (if possible) being contaminated by the unfalsifiability originated from the many body problem. An original attempt to show how the Bohmian theory itself (minimizing the role of many body approximations) explains the transitions from a microscopic quantum system towards a macroscopic classical one is presented.

  14. Energy boost in laser wakefield accelerators using sharp density transitions

    NASA Astrophysics Data System (ADS)

    Döpp, A.; Guillaume, E.; Thaury, C.; Lifschitz, A.; Ta Phuoc, K.; Malka, V.

    2016-05-01

    The energy gain in laser wakefield accelerators is limited by dephasing between the driving laser pulse and the highly relativistic electrons in its wake. Since this phase depends on both the driver and the cavity length, the effects of dephasing can be mitigated with appropriate tailoring of the plasma density along propagation. Preceding studies have discussed the prospects of continuous phase-locking in the linear wakefield regime. However, most experiments are performed in the highly non-linear regime and rely on self-guiding of the laser pulse. Due to the complexity of the driver evolution in this regime, it is much more difficult to achieve phase locking. As an alternative, we study the scenario of rapid rephasing in sharp density transitions, as was recently demonstrated experimentally. Starting from a phenomenological model, we deduce expressions for the electron energy gain in such density profiles. The results are in accordance with particle-in-cell simulations, and we present gain estimations for single and multiple stages of rephasing.

  15. Coal exports may make Australia's energy sector among least sustainable

    SciTech Connect

    2009-11-15

    Plentiful coal and cheap energy prices have resulted in an unusually heavy carbon footprint. Clearly, Australia has to rethink how much coal it will use to feed its own growing economy while becoming more conscious of its significant carbon export problem. For a country long used to digging the coal out of the ground and shipping it overseas, climate change will be a game changer.

  16. Spin symmetry transitions make DNA strands separate. New insight into the mechanism of transcription.

    PubMed

    Tulub, Alexander A; Stefanov, Vassily E

    2015-01-01

    The DFT:B3LYP (6-31G** basis set) method, including the hyperfine and spin-orbit couplings (HFC and SOC, respectively), is used to study the separation of two complementary trinucleotide sequences, (dC-dG-dA)-(dG-dC-dT), upon the action of two Mg(2+) cofactors (a simplified model). The computations reveal a crossing of the singlet (S) potential energy surface by the triplet (T) surface at two distinct points. Within the crossing region the T curve lies below the S curve. Adhering to the concept of the minimal energy path, one can assume that the T path is more favorable compared to that of the S path. The T path is not simple; it consists of two, T+ and T-, curves initially separated by the HFC and SOC. On reaching the second crossing point, both curves merge into the T0 state, which facilitates the T → S transfer. Totally, the process of the two trinucleotide separation (the first step of transcription) appears as the S → T → S symmetry conversion. PMID:26656910

  17. Energy at the Frontier: Low Carbon Energy System Transitions and Innovation in Four Prime Mover Countries

    NASA Astrophysics Data System (ADS)

    Araujo, Kathleen M.

    All too often, discussion about the imperative to change national energy pathways revolves around long timescales and least cost economics of near-term energy alternatives. While both elements certainly matter, they don't fully reflect what can drive such development trajectories. This study explores national energy transitions by examining ways in which four prime mover countries of low carbon energy technology shifted away from fossil fuels, following the first global oil crisis of 1973. The research analyzes the role of readiness, sectoral contributions and adaptive policy in the scale-up and innovations of advanced, alternative energy technologies. Cases of Brazilian biofuels, Danish wind power, French nuclear power and Icelandic geothermal energy are analyzed for a period of four decades. Fundamentally, the research finds that significant change can occur in under 15 years; that technology complexity need not necessarily impede change; and that countries of different governance approaches and consumption levels can effectuate such transitions. This research also underscores that low carbon energy technologies may be adopted before they are competitive and then become competitive in the process. (Copies available exclusively from MIT Libraries, libraries.mit.edu/docs - docs mit.edu)

  18. Hanford Site cleanup and transition: Risk data needs for decision making (Hanford risk data gap analysis decision guide)

    SciTech Connect

    Gajewski, S.; Glantz, C.; Harper, B.; Bilyard, G.; Miller, P.

    1995-10-01

    Given the broad array of environmental problems, technical alternatives, and outcomes desired by different stakeholders at Hanford, DOE will have to make difficult resource allocations over the next few decades. Although some of these allocations will be driven purely by legal requirements, almost all of the major objectives of the cleanup and economic transition missions involve choices among alternative pathways. This study examined the following questions: what risk information is needed to make good decisions at Hanford; how do those data needs compare to the set(s) of risk data that will be generated by regulatory compliance activities and various non-compliance studies that are also concerned with risk? This analysis examined the Hanford Site missions, the Hanford Strategic Plan, known stakeholder values, and the most important decisions that have to be made at Hanford to determine a minimum domain of risk information required to make good decisions that will withstand legal, political, and technical scrutiny. The primary risk categories include (1) public health, (2) occupational health and safety, (3) ecological integrity, (4) cultural-religious welfare, and (5) socio-economic welfare.

  19. Development and application of a battery energy storage system simulation program for rail transit systems. Volume 3. Final report

    SciTech Connect

    Ball, C.E.; Uher, R.A.

    1995-03-01

    Under the Rail Transit Energy Management Program, a computer model was developed to assess the economic feasibility of applying battery energy storage to rail transit systems. This model was applied to the Port Authority of Allegheny County (PAT) (Pittsburgh) light rail system and the Washington Metropolitan Area Transit Authority`s (WMATA) MetroRail. The results indicate that the payback periods for investment into battery energy storage and relatively long; 14 years for WMATA and 10 years for PAT. These payback periods are marginal and with the risk associated with implementing battery storage, it is doubtful whether transit management would be inclined to make such an investment. The capital cost of battery storage can be reduced by eliminating the power conditioning equipment and allowing the battery to be connected directly to the third rail catenary or trolley system. The model can easily be modified to assess the economic feasibility of other alternative energy sources such as cogeneration and other storage media, such as superconducting magnetic energy storage.

  20. Exploring Agricultural Livelihood Transitions with an Agent-Based Virtual Laboratory: Global Forces to Local Decision-Making

    PubMed Central

    Magliocca, Nicholas R.; Brown, Daniel G.; Ellis, Erle C.

    2013-01-01

    Rural populations are undergoing rapid changes in both their livelihoods and land uses, with associated impacts on ecosystems, global biogeochemistry, and climate change. A primary challenge is, thus, to explain these shifts in terms of the actors and processes operating within a variety of land systems in order to understand how land users might respond locally to future changes in broader-scale environmental and economic conditions. Using ‘induced intensification’ theory as a benchmark, we develop a generalized agent-based model to investigate mechanistic explanations of relationships between agricultural intensity and population density, environmental suitability, and market influence. Land-use and livelihood decisions modeled from basic micro-economic theories generated spatial and temporal patterns of agricultural intensification consistent with predictions of induced intensification theory. Further, agent actions in response to conditions beyond those described by induced intensification theory were explored, revealing that interactions among environmental constraints, population pressure, and market influence may produce transitions to multiple livelihood regimes of varying market integration. The result is new hypotheses that could modify and enrich understanding of the classic relationship between agricultural intensity and population density. The strength of this agent-based model and the experimental results is the generalized form of the decision-making processes underlying land-use and livelihood transitions, creating the prospect of a virtual laboratory for systematically generating hypotheses of how agent decisions and interactions relate to observed land-use and livelihood patterns across diverse land systems. PMID:24039892

  1. Examining Longitudinal Relationships between Dysfunctional Career Thoughts and Career Decision-Making Self-Efficacy in School-to-Work Transition

    ERIC Educational Resources Information Center

    Kim, Boyoung; Lee, Bo Hyun; Ha, Gyuyoung; Lee, Hong Kwon; Lee, Sang Min

    2015-01-01

    This study examines the role of dysfunctional career thoughts between two-wave longitudinal data (Time 1 and Time 2) in career decision-making self-efficacy during school-to-work transition periods. Career decision-making self-efficacy was measured before (Time 1) and after college graduation (Time 2). The results indicated that the growth of…

  2. Surviving, and Maybe Thriving, on Vouchers: A Guide for Organizations Making the Transition to Individual Training Accounts under the Workforce Investment Act. Working Ventures.

    ERIC Educational Resources Information Center

    Maguire, Sheila

    This booklet, which is intended for organizations making the transition to individual training accounts (ITAs) under the Workforce Investment Act (WIA), explains how educational and training institutions can make vouchers work for them. After a brief overview of the WIA's main provisions regarding ITAs and the future of voucher programs, the…

  3. Transition from supercapacitor to battery behavior in electrochemical energy storage

    SciTech Connect

    Conway, B.E. . Dept. of Chemistry)

    1991-06-01

    In this paper the storage of electrochemical energy in battery, supercapacitor, and double-layer capacitor devices is considered. A comparison of the mechanisms and performance of such systems enables their essential features to be recognized and distinguished, and the conditions for transition between supercapacitor and battery behavior to be characterized. Supercapacitor systems based on two-dimensional underpotential deposition reactions are highly reversible and their behavior arises from the pseudocapaccitance associated with potential-dependence of two-dimensional coverage of electroactive adatoms on an electrode substrate surface. Such capacitance can be 10-100 times the double-layer capacitance of the same electrode area. An essential fundamental difference from battery behavior arises because, in such systems, the chemical and associated electrode potentials are a continuous function of degree of charge, unlike the thermodynamic behavior of single-phase battery reactants. Quai-two-dimensional systems, such as hyperextended hydrous RuP{sub 2}, also exhibit large pseudocapacitance which, in this case, is associated with a sequence of redox redox processes that are highly reversible.

  4. Replacing energy by von Neumann entropy in quantum phase transitions

    SciTech Connect

    Kopp, Angela; Jia Xun; Chakravarty, Sudip . E-mail: sudip@physics.ucla.edu

    2007-06-15

    We propose that quantum phase transitions are generally accompanied by non-analyticities of the von Neumann (entanglement) entropy. In particular, the entropy is non-analytic at the Anderson transition, where it exhibits unusual fractal scaling. We also examine two dissipative quantum systems of considerable interest to the study of decoherence and find that non-analyticities occur if and only if the system undergoes a quantum phase transition.

  5. Comment on ``Induced transitions and energy of a damped oscillator''

    NASA Astrophysics Data System (ADS)

    Papadopoulos, George J.; Hadjiagapiou, Ioannis A.

    1999-04-01

    In a recent paper Croxson [Phys. Rev. A 49, 588 (1994)] reported dissipation-induced transition probabilities from the ground state to higher states for a quantum harmonic oscillator. A partial approximate result was given for the oscillator to remain in its ground state, while for higher transitions the situation became complicated. Our approach provides an exact simple form closed expression for any order of transition. In addition, we supply the evolution of the work done by the system on its environment.

  6. Method for making an aluminum or copper substrate panel for selective absorption of solar energy

    NASA Technical Reports Server (NTRS)

    Roberts, M. L.; Sharpe, M. H.; Krupnick, A. C. (Inventor)

    1978-01-01

    A panel is described for selectively absorbing solar energy comprising an aluminum substrate. A zinc layer was covered by a layer of nickel and an outer layer of solar energy absorbing nickel oxide or a copper substrate with a nickel layer. A layer of solar energy absorbing nickel oxide distal from the copper substrate was included. A method for making these panels is disclosed.

  7. Energy balance in the solar transition region. II - Effects of pressure and energy input on hydrostatic models

    NASA Technical Reports Server (NTRS)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1991-01-01

    The radiation of energy by hydrogen lines and continua in hydrostatic energy-balance models of the transition region between the solar chromosphere and corona is studied using models which assume that mechanical or magnetic energy is dissipated in the hot corona and is then transported toward the chromosphere down the steep temperature gradient of the transition region. These models explain the average quiet sun and also the entire range of variability of the Ly-alpha lines. The relations between the downward energy flux, the pressure of the transition region, and the different hydrogen emission are described.

  8. Energy Transition Initiative: Island Energy Snapshot - U.S. Virgin Islands (Fact Sheet)

    SciTech Connect

    Not Available

    2015-03-01

    This profile provides a snapshot of the energy landscape of the U.S. Virgin Islands (USVI) - St. Thomas, St. John, and St. Croix. The Virgin Islands archipelago makes up the northern portion of the Lesser Antilles and the western island group of the Leeward Islands, forming the border between the Atlantic Ocean and the Caribbean Sea.

  9. Transition in Education: Policy Making and the Key Educational Policy Areas in the Central-European and Baltic Countries.

    ERIC Educational Resources Information Center

    Rado, Peter

    This report examines transition in educational systems and identifies key policy areas in Central-Eastern European countries. It summarizes policy implications of the transition process within the educational context of these countries. Chapter 1, "Transition and Education," outlines key characteristics of the transition process and describes the…

  10. Viscosity, glass transition and activation energy of solid cis-polyisoprene and trans-polyisoprene blends

    NASA Astrophysics Data System (ADS)

    Baboo, Mahesh; Sharma, Kananbala; Saxena, N. S.

    2011-11-01

    Blends of cis-polyisoprene (CPI) and trans-polyisoprene (TPI) have been prepared by solution casting to study viscosity, glass transition temperature and activation energy for the glass transition. The viscosity of blends having different weight ratios has been obtained through a single experiment measuring storage and loss modulus using the dynamic mechanical analyser technique. The glass transition temperature is determined through the temperature at which the minimum of temperature derivative curve of viscosity falls. The activation energy of glass transition and fragility index have been obtained by employing the Vogel-Fulchar-Tammann (VFT) equation by assuming non-Arrhenius behaviour of viscosity of polymer blends. Results indicate that both glass transition and activation energy for the glass transition are influenced by composition and crosslink density of the blend.

  11. A space bourne crystal diffraction telescope for the energy range of nuclear transitions

    SciTech Connect

    von Ballmoos, P.; Naya, J.E.; Albernhe, F.; Vedrenne, G.; Smither, R.K.; Faiz, M.; Fernandez, P.; Graber, T.

    1995-10-01

    Recent experimental work of the Toulouse-Argonne collaboration has opened for perspective of a focusing gamma-ray telescope operating in the energy range of nuclear transitions, featuring unprecedented sensitivity, angular and energy resolution. The instrument consists of a tunable crystal diffraction lens situated on a stabilized spacecraft, focusing gamma-rays onto a small array of Germanium detectors perched on an extendible boom. While the weight of such an instrument is less than 500 kg, it features an angular resolution of 15 in., an energy resolution of 2 keV and a 3 {sigma} narrow line sensitivity of a few times 10{sup {minus}7} photons s{sup {minus}1} cm{sup {minus}2} (10{sup 6} sec observation). This instrumental concept permits observation of any identified source at any selected line-energy in a range of typically 200 keV to 1300 keV. The resulting ``sequential`` operation mode makes sites of explosive nucleosynthesis natural scientific objectives for such a telescope: the nuclear lines of extragalactic supernovae ({sup 56}Ni, {sup 44}Ti, {sup 60}Fe) and galactic novae (p{sup {minus}}p{sup +} line, {sup 7}Be) are accessible to observation, one at a time, due to the erratic appearance and the sequence of half-lifes of these events. Other scientific objectives, include the narrow 511 keV line from galactic broad class annihilators (such as 1E1740-29, nova musca) and possible redshifted annihilation lines from AGN`s.

  12. SunShot Initiative: Making Solar Energy Affordable for All Americans (Fact Sheet)

    SciTech Connect

    Not Available

    2013-10-01

    Through SunShot, DOE supports efforts by private companies, universities, and national laboratories to drive down the cost of solar electricity to $0.06 per kilowatt-hour, making solar energy affordable for more American families and businesses.

  13. Critical behavior in the inverse to forward energy transition in two-dimensional magnetohydrodynamic flow.

    PubMed

    Seshasayanan, Kannabiran; Alexakis, Alexandros

    2016-01-01

    We investigate the critical transition from an inverse cascade of energy to a forward energy cascade in a two-dimensional magnetohydrodynamic flow as the ratio of magnetic to mechanical forcing amplitude is varied. It is found that the critical transition is the result of two competing processes. The first process is due to hydrodynamic interactions and cascades the energy to the large scales. The second process couples small-scale magnetic fields to large-scale flows, transferring the energy back to the small scales via a nonlocal mechanism. At marginality the two cascades are both present and cancel each other. The phase space diagram of the transition is sketched. PMID:26871152

  14. Energy and Greenhouse Gas Emissions in China: Growth, Transition, and Institutional Change

    NASA Astrophysics Data System (ADS)

    Kahrl, Fredrich James

    support further improvements in efficiency and scale up renewable generation at an acceptable level of cost and reliability. Chapter 6 examines energy use and GHG emissions from nitrogen fertilizer use, arguing that energy use and GHG emissions from nitrogen fertilizer use in China are high relative to other countries because of China's historical support for small and medium-sized enterprises using domestic technology; its continued provision of energy subsidies to fertilizer producers; and its lack of a well-functioning agricultural extension system. The case studies illustrate the limits of energy and climate policy in China without institutional reform. China's leaders have historically relied on economic growth to defer the difficult changes in political economy that accompany economic and social transition. However, many of the challenges of energy and climate policy require political decisions that reallocate resources among stakeholders. For instance, restructuring the Chinese economy away from heavy industrial investment and toward a higher GDP share of consumption will require financial sector reforms, such as interest rate liberalization or higher dividend payments for state-owned enterprises, that reallocate income from the industrial sector to households. Increasing power system flexibility will require price reforms that reallocate revenues and costs among generators, between generators and the grid companies, between producers and ratepayers, among ratepayer classes, and between and among provinces. Strong public interest institutions are needed to make these changes, which suggests that China's energy and GHG emissions trajectories will be determined, to a large extent, by the politics of institutional reform.

  15. [Transition to adult care for children with chronic neurological disorders; which is the best way to make it?].

    PubMed

    Moreno Villares, José Manuel

    2014-01-01

    Chronic neurological disorders in children have significant effects on adult medical and social function. Transition from pediatric to adult services is a complex process. No objective data are available to inform physicians about the most effective approach. Nevertheless the most recommended approach is a joint pediatric/adult transition clinic. Malnutrition, either under or overnutrition, is a common condition among neurologically impaired children. Undernutrition is most prevalent, and its causes are diverse: insufficient caloric intake, excessive nutrient losses and abnormal energy metabolism. Malnutrition is associated with significant morbidity, while nutritional rehabilitation improves overall health as well as quality of life. It is not easy to determine which the nutritional needs in these patients are. Besides, they often present difficulties for oral feeding, mainly due to oromotor dysfunction. Gastrointestinal symptoms, gastro esophageal reflux and constipation, as well as spasticity, scoliosis and joint deformities contribute to these difficulties. Because of that, an assessment of nutritional status should be performed periodically, and to assess efficacy and security of oral intake. If modifying oral diet we cannot confirm an adequate support, a nasogastric tube or a gastrostomy need to be considered. Often, a fundoplication is associated to the placement of a gastrostomy. Although the outcomes in a better nutritional status and quality of life are often obtained, it is not an easy decision for families. PMID:25077342

  16. Making the Transition

    ERIC Educational Resources Information Center

    Clark, Wayne

    2011-01-01

    The role of universities in contributing to lifelong learning is likely to undergo significant change in the next few years as the higher education sector grapples with the government's overhaul of university funding. Opportunities for progression to university for those studying outside of A-levels are particularly uncertain in the emerging…

  17. Energy surface and minimum energy paths for Fréedericksz transitions in bistable cholesteric liquid crystals

    NASA Astrophysics Data System (ADS)

    Ivanov, A. V.; Bessarab, P. F.; Aksenova, E. V.; Romanov, V. P.; Uzdin, V. M.

    2016-04-01

    The multidimensional energy surface of a cholesteric liquid crystal in a planar cell is investigated as a function of spherical coordinates determining the director orientation. Minima on the energy surface correspond to the stable states with particular director distribution. External electric and magnetic fields deform the energy surface and positions of minima. It can lead to the transitions between states, known as the Fréedericksz effect. Transitions can be continuous or discontinuous depending on parameters of the liquid crystal which determine an energy surface. In a case of discontinuous transition when a barrier between stable states is comparable with the thermal energy, the activation transitions may occur, and it leads to the modification of characteristics of the Fréedericksz effect with temperature without explicit temperature dependencies of liquid crystal parameters. A minimum energy path between stable states on the energy surface for the Fréedericksz transition is found using the geodesic nudged elastic band method. Knowledge of this path, which has maximal statistical weight among all other paths, gives the information about a barrier between stable states and configuration of director orientation during the transition. It also allows one to estimate the stability of states with respect to the thermal fluctuations and their lifetime when the system is close to the Fréedericksz transition.

  18. Power lines: Urban space, energy development and the making of the modern Southwest

    NASA Astrophysics Data System (ADS)

    Needham, Todd Andrew

    "Power Lines: Urban Space, Energy Development, and the Making of the Modern Southwest" explores the social and environmental transformation of the postwar Southwest and the resulting disputes between urban boosters, federal officials, Native Americans, and environmental activists. The dissertation focuses on the infrastructure built to provide the burgeoning populations of Phoenix, Los Angeles, and other Southwestern cities with electricity. This infrastructure allowed metropolitan boosters in the Southwest to attract Cold War defense manufacturing and to build a new suburban landscape even as industrialization on Indian lands provided electricity for those landscapes. Tracing the transition of electrical generation from a dispersed geography relying on local resources to a centralized geography utilizing primarily coal from Navajo land, "Power Lines" demonstrates the increasing centrality of Indian lands and labor to the metropolitan Southwest. Paying close attention to these networks reveals the far-reaching changes caused by postwar metropolitan growth. "Power Lines" challenges understandings of urban space that neglect the material resources that allow cities to "live." As the nation's cities and suburbs became increasingly energy-intensive, electrical utilities reached deep into the metropolitan periphery, transforming landscapes hundreds of miles from city centers into urban space. The construction of the new "geography of power" in the Southwest also reflects the impact of growth liberalism on postwar growth, as federal money funded suburban, manufacturing, and infrastructure developments. This pursuit of growth produced new political struggles, both as the development of energy resources conflicted with emerging environmentalist sensibilities and as American Indians increasingly resented the industrialization of their land for the benefit of others. By the 1970s, the simultaneous pursuit and criticism of growth came to define the modern Southwest. The

  19. Maine Yankee: Making the Transition from an Operating Plant to an Independent Spent Fuel Storage Installation (ISFSI)

    SciTech Connect

    Norton, W.; McGough, M. S.

    2002-02-26

    The purpose of this paper is to describe the challenges faced by Maine Yankee Atomic Power Company in making the transition from an operating nuclear power plant to an Independent Spent Fuel Storage Installation (ISFSI). Maine Yankee (MY) is a 900-megawatt Combustion Engineering pressurized water reactor whose architect engineer was Stone & Webster. Maine Yankee was put into commercial operation on December 28, 1972. It is located on an 820-acre site, on the shores of the Back River in Wiscasset, Maine about 40 miles northeast of Portland, Maine. During its operating life, it generated about 1.2 billion kilowatts of power, providing 25% of Maine's electric power needs and serving additional customers in New England. Maine Yankee's lifetime capacity factor was about 67% and it employed more than 450 people. The decision was made to shutdown Maine Yankee in August of 1997, based on economic reasons. Once this decision was made planning began on how to accomplish safe and cost effective decommissioning of the plant by 2004 while being responsive to the community and employees.

  20. Control of valence and conduction band energies in layered transition metal phosphates via surface functionalization.

    PubMed

    Lentz, Levi C; Kolb, Brian; Kolpak, Alexie M

    2016-05-18

    Layered transition metal phosphates and phosphites (TMPs) are a class of materials composed of layers of 2D sheets bound together via van der Waals interactions and/or hydrogen bonds. Explored primarily for use in proton transfer, their unique chemical tunability also makes TMPs of interest for forming large-scale hybrid materials. Further, unlike many layered materials, TMPs can readily be solution exfoliated to form single 2D sheets or bilayers, making them exciting candidates for a variety of applications. However, the electronic properties of TMPs have largely been unstudied to date. In this work, we use first-principles computations to investigate the atomic and electronic structure of TMPs with a variety of stoichiometries. We demonstrate that there exists a strong linear relationship between the band gap and the ionic radius of the transition metal cation in these materials, and show that this relationship, which opens opportunities for engineering new compositions with a wide range of band gaps, arises from constraints imposed by the phosphorus-oxygen bond geometry. In addition, we find that the energies of the valence and conduction band edges can be systematically tuned over a range of ∼3 eV via modification of the functional group extending from the phosphorus. Based on the Hammett constant of this functional group, we identify a simple, predictive relationship for the ionization potential and electron affinity of layered TMPs. Our results thus provide guidelines for systematic design of TMP-derived functional materials, which may enable new approaches for optimizing charge transfer in electronics, photovoltaics, electrocatalysts, and other applications. PMID:27157509

  1. Energy states and energy flow near the transition states of unimolecular reactions

    SciTech Connect

    Moore, C.B. |

    1994-10-01

    The use of lasers with jet-cooled samples has improved energy and angular momentum resolution for the reactant and time resolution for the rate constant by orders of magnitude. The resolution of product quantum states has added a new dimension to unimolecular dynamics. In the past, the geometry, barrier height and vibrational frequencies of the transition state in RRKM theory were adjusted to fit thermal unimolecular reaction rate data. There have been successful quantitative tests of the ability of ab initio theory to calculate transition state geometries accurately and barrier heights to a few kJ/mol for simple molecules. Predicted frequencies tend to be somewhat too high for the softest modes which are of most importance in determining rates; however, the basic normal modes and sequence of frequencies seem to be correctly predicted. RRKM theory can be used with ab initio results to predict rate constants to within a factor of two or three and may be used for quantitative extrapolation to conditions not accessible in the laboratory but important in practical situations. Experiments on single molecular eigenstates have revealed quantum statistical fluctuations in rates which are predicted quantitatively in the appropriate extension of RRKM theory. Many experiments seeking to demonstrate non-statistical or non-RRKM dynamics have demonstrated the very wide range of applicability of the RRKM model. A few such experiments have demonstrated a lack of complete vibrational energy randomization in a reactant molecule. Dynamical theory has provided an exact quantum analog to RRKM theory which will combine with future experiments to define the extent to which quantized motion along the reaction coordinate and coupling between the reaction coordinate and vibrational degrees of freedom at the transition state are important. 42 refs., 11 figs.

  2. Transition radiation at radio frequencies from ultrahigh-energy neutrino-induced showers

    NASA Astrophysics Data System (ADS)

    Motloch, Pavel; Alvarez-Muñiz, Jaime; Privitera, Paolo; Zas, Enrique

    2016-02-01

    Coherent radiation at radio frequencies from high-energy showers fully contained in a dense radio-transparent medium—like ice, salt, soil, or regolith—has been extensively investigated as a promising technique to search for ultrahigh-energy neutrinos. Additional emission in the form of transition radiation may occur when a neutrino-induced shower produced close to the Earth's surface emerges from the ground into atmospheric air. We present the first detailed evaluation of transition radiation from high-energy showers crossing the boundary between two different media. We found that transition radiation is sizable over a wide solid angle and coherent up to ˜1 GHz . These properties encourage further work to evaluate the potential of a large-aperture ultrahigh-energy neutrino experiment based on the detection of transition radiation.

  3. Requirements for supercomputing in energy research: The transition to massively parallel computing

    SciTech Connect

    Not Available

    1993-02-01

    This report discusses: The emergence of a practical path to TeraFlop computing and beyond; requirements of energy research programs at DOE; implementation: supercomputer production computing environment on massively parallel computers; and implementation: user transition to massively parallel computing.

  4. Fuel Cell Transit Bus Evaluations: Joint Evaluation Plan for the U.S. Department of Energy and the Federal Transit Administration (Report and Appendix)

    SciTech Connect

    Eudy, L.; Chandler, K.

    2010-11-01

    This document describes the fuel cell transit bus evaluations performed by the National Renewable Energy Laboratory (NREL) and funded by the U.S. Department of Energy (DOE) and the U.S. Department of Transportation's Federal Transit Administration (FTA). This document provides a description of the demonstration sites, funding sources, and data collection activities for fuel cell transit bus evaluations currently planned from FY10 through FY12.

  5. Beyond the Chinese Dream: How Women Executives Working in Multinational Corporations in the People's Republic of China Describe and Make Meaning of Midlife Transition

    ERIC Educational Resources Information Center

    Woo, Marjorie J.

    2012-01-01

    The purpose of this study is to gain understanding of Chinese women executives going beyond the Chinese dream, to learn how they describe and make meaning of their midlife transition experience. A narrative inquiry and holistic content and form approach was used to explore two-stage life stories: narratives of self-actualization of women…

  6. Mathematical Under-Preparedness: The Influence of the Pre-Tertiary Mathematics Experience on Students' Ability to Make a Successful Transition to Tertiary Level Mathematics Courses in Ireland

    ERIC Educational Resources Information Center

    Hourigan, M.; O'Donoghue, J.

    2007-01-01

    Internationally, the consequences of the "Mathematics problem" are a source of concern for the education sector and governments alike. Growing consensus exists that the inability of students to successfully make the transition to tertiary level mathematics education lies in the substantial mismatch between the nature of entrants' pre-tertiary…

  7. High-pressure phase transition makes B4.3C boron carbide a wide-gap semiconductor

    NASA Astrophysics Data System (ADS)

    Hushur, Anwar; Manghnani, Murli H.; Werheit, Helmut; Dera, Przemyslaw; Williams, Quentin

    2016-02-01

    Single-crystal B4.3C boron carbide is investigated through the pressure-dependence and inter-relation of atomic distances, optical properties and Raman-active phonons up to ~70 GPa. The anomalous pressure evolution of the gap width to higher energies is striking. This is obtained from observations of transparency, which most rapidly increases around 55 GPa. Full visible optical transparency is approached at pressures of  >60 GPa indicating that the band gap reaches ~3.5 eV at high pressure, boron carbide is a wide-gap semiconductor. The reason is that the high concentration of structural defects controlling the electronic properties of boron carbide at ambient conditions initially decreases and finally vanishes at high pressures. The structural parameters and Raman-active phonons indicate a pressure-dependent phase transition in single-crystal natB4.3C boron carbide near 40 GPa, likely related to structural changes in the C-B-C chains, while the basic icosahedral structure appears to be less affected.

  8. High-pressure phase transition makes B4.3C boron carbide a wide-gap semiconductor.

    PubMed

    Hushur, Anwar; Manghnani, Murli H; Werheit, Helmut; Dera, Przemyslaw; Williams, Quentin

    2016-02-01

    Single-crystal B4.3C boron carbide is investigated through the pressure-dependence and inter-relation of atomic distances, optical properties and Raman-active phonons up to ~70 GPa. The anomalous pressure evolution of the gap width to higher energies is striking. This is obtained from observations of transparency, which most rapidly increases around 55 GPa. Full visible optical transparency is approached at pressures of  >60 GPa indicating that the band gap reaches ~3.5 eV; at high pressure, boron carbide is a wide-gap semiconductor. The reason is that the high concentration of structural defects controlling the electronic properties of boron carbide at ambient conditions initially decreases and finally vanishes at high pressures. The structural parameters and Raman-active phonons indicate a pressure-dependent phase transition in single-crystal (nat)B4.3C boron carbide near 40 GPa, likely related to structural changes in the C-B-C chains, while the basic icosahedral structure appears to be less affected. PMID:26751337

  9. Scaling Relationships for Adsorption Energies of C2 Hydrocarbons on Transition Metal Surfaces

    SciTech Connect

    Jones, G

    2011-08-18

    Using density functional theory calculations we show that the adsorption energies for C{sub 2}H{sub x}-type adsorbates on transition metal surfaces scale with each other according to a simple bond order conservation model. This observation generalizes some recently recognized adsorption energy scaling laws for AH{sub x}-type adsorbates to unsaturated hydrocarbons and establishes a coherent simplified description of saturated as well as unsaturated hydrocarbons adsorbed on transition metal surfaces. A number of potential applications are discussed. We apply the model to the dehydrogenation of ethane over pure transition metal catalysts. Comparison with the corresponding full density functional theory calculations shows excellent agreement.

  10. Universal empirical formula for optical transition energies of semiconducting single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Jamal, G. R. Ahmed; Mominuzzaman, S. M.

    2016-01-01

    A general empirical relation for calculating first seven optical transition energies of semiconducting single wall carbon nanotubes (SWCNTs) is proposed here for the first time. The proposed formula effectively relates first seven optical transition energies of semiconducting SWCNTs with their chiral indices (n, m) through exponential form containing two specific terms (n+2m) and (2n-m). Both mod 1 and mod 2 types of semiconducting tubes are considered here over a wide diameter range from 0.4 nm to 4.75 nm. It was observed that the proposed empirical relations can predict the recent experimental data of those optical transitions with high accuracy.

  11. Energy harvesting from localized dynamic transitions in post-buckled elastic beams under quasi-static loading

    NASA Astrophysics Data System (ADS)

    Borchani, Wassim

    The deployability of structural health monitoring self-powered sensors relies on their capability to harvest energy from signals being monitored. Many of the signals required to assess the structure condition are quasi-static events which limits the levels of power that can be extracted. Several vibration-based techniques have been proposed to increase the transferred level of power and broaden the harvester operating bandwidth. However, these techniques require vibration input excitations at frequencies higher than dominant structural response frequencies which makes them inefficient and not suitable for ambient quasi-static excitations. This research proposes a novel sensing and energy harvesting technique at low frequencies using mechanical energy concentrators and triggers. These mechanisms consist of axially-loaded bilaterally-constrained beams with attached piezoelectric energy harvesters. When the quasi-static axial load reaches a certain mechanical threshold, a sudden snap-through mode-switching occurs. These transitions excite the attached piezoelectric scavengers with high-rate input accelerations, generating then electric power. The main objectives are to understand and model the post-buckling behavior of bilaterally-constrained beams, control it by tailoring geometry and material properties of the buckled elements or stacking them into system assemblies, and finally characterize the energy harvesting and sensing capability of the system under quasi-static excitations. The fundamental principle relies on the following concept. Under axial load, a straight slender beam buckles in the first buckling mode. The increased transverse deformations from a buckled shape lead to contact interaction with the lateral boundaries. The contact interaction generates transverse forces that induce the development of higher order buckling configurations. Transitions between the buckled configurations occur not only during loading, but also unloading. In this work, the post

  12. Energy Transition Initiative: Island Energy Snapshot - Puerto Rico (Fact Sheet); NREL(National Renewable Energy Laboratory)

    SciTech Connect

    2015-03-01

    This profile provides a snapshot of the energy landscape of the Commonwealth of Puerto Rico - a U.S. territory located about 60 miles east of the Dominican Republic and directly west of the U.S. Virgin Islands.

  13. The Role of Grain Boundary Energy on Grain Boundary Complexion Transitions

    SciTech Connect

    Bojarski, Stephanie A.; Rohrer, Gregory S.

    2014-09-01

    Grain boundary complexions are distinct equilibrium structures and compositions of a grain boundary and complexion transformations are transition from a metastable to an equilibrium complexion at a specific thermodynamic and geometric conditions. Previous work indicates that, in the case of doped alumina, a complexion transition that increased the mobility of transformed boundaries and resulted in abnormal grain growth also caused a decrease in the mean relative grain boundary energy as well as an increase in the anisotropy of the grain boundary character distribution (GBCD). The current work will investigate the hypothesis that the rates of complexion transitions that result in abnormal grain growth (AGG) depend on grain boundary character and energy. Furthermore, the current work expands upon this understanding and tests the hypothesis that it is possible to control when and where a complexion transition occurs by controlling the local grain boundary energy distribution.

  14. Making Sustainable Energy Choices: Insights on the Energy/Water/Land Nexus

    SciTech Connect

    Not Available

    2014-10-01

    This periodic publication summarizes insights from the body of NREL analysis work. In this issue of Analysis Insights, we examine the implications of our energy choices on water, land use, climate, developmental goals, and other factors. Collectively, NREL's work helps policymakers and investors understand and evaluate energy choices within the complex web of connections, or nexus, between energy, water, and land.

  15. Treatment of Electronic Energy Level Transition and Ionization Following the Particle-Based Chemistry Model

    NASA Technical Reports Server (NTRS)

    Liechty, Derek S.; Lewis, Mark

    2010-01-01

    A new method of treating electronic energy level transitions as well as linking ionization to electronic energy levels is proposed following the particle-based chemistry model of Bird. Although the use of electronic energy levels and ionization reactions in DSMC are not new ideas, the current method of selecting what level to transition to, how to reproduce transition rates, and the linking of the electronic energy levels to ionization are, to the author s knowledge, novel concepts. The resulting equilibrium temperatures are shown to remain constant, and the electronic energy level distributions are shown to reproduce the Boltzmann distribution. The electronic energy level transition rates and ionization rates due to electron impacts are shown to reproduce theoretical and measured rates. The rates due to heavy particle impacts, while not as favorable as the electron impact rates, compare favorably to values from the literature. Thus, these new extensions to the particle-based chemistry model of Bird provide an accurate method for predicting electronic energy level transition and ionization rates in gases.

  16. Correlation between oxygen adsorption energy and electronic structure of transition metal macrocyclic complexes

    SciTech Connect

    Liu, Kexi; Lei, Yinkai; Wang, Guofeng

    2013-11-28

    Oxygen adsorption energy is directly relevant to the catalytic activity of electrocatalysts for oxygen reduction reaction (ORR). In this study, we established the correlation between the O{sub 2} adsorption energy and the electronic structure of transition metal macrocyclic complexes which exhibit activity for ORR. To this end, we have predicted the molecular and electronic structures of a series of transition metal macrocyclic complexes with planar N{sub 4} chelation, as well as the molecular and electronic structures for the O{sub 2} adsorption on these macrocyclic molecules, using the density functional theory calculation method. We found that the calculated adsorption energy of O{sub 2} on the transition metal macrocyclic complexes was linearly related to the average position (relative to the lowest unoccupied molecular orbital of the macrocyclic complexes) of the non-bonding d orbitals (d{sub z{sup 2}}, d{sub xy}, d{sub xz}, and d{sub yz}) which belong to the central transition metal atom. Importantly, our results suggest that varying the energy level of the non-bonding d orbitals through changing the central transition metal atom and/or peripheral ligand groups could be an effective way to tuning their O{sub 2} adsorption energy for enhancing the ORR activity of transition metal macrocyclic complex catalysts.

  17. The Life Course in the Making: Gender and the Development of Adolescents' Expected Timing of Adult Role Transitions

    ERIC Educational Resources Information Center

    Crockett, Lisa J.; Beal, Sarah J.

    2012-01-01

    Adolescents' expectations about the timing of adult role transitions have the potential to shape their actual transitions, setting the stage for their adult lives. Although expectations about timing emerge by early adolescence, little is known about how these expectations develop across adolescence. This longitudinal study examined developmental…

  18. Glass transition and random walks on complex energy landscapes.

    PubMed

    Baronchelli, Andrea; Barrat, Alain; Pastor-Satorras, Romualdo

    2009-08-01

    We present a simple mathematical model of glassy dynamics seen as a random walk in a directed weighted network of minima taken as a representation of the energy landscape. Our approach gives a broader perspective to previous studies focusing on particular examples of energy landscapes obtained by sampling energy minima and saddles of small systems. We point out how the relation between the energies of the minima and their number of neighbors should be studied in connection with the network's global topology and show how the tools developed in complex network theory can be put to use in this context. PMID:19792062

  19. Transition report, United States Department of Energy: A report to the President-Elect. Volume 2

    SciTech Connect

    Not Available

    1988-11-01

    This report is a description of the Department of Energy transition issues. The topics of the report include: Congressional, Intergovernmental and Public Affairs; Conservation and Renewable Energy; Defense Programs; New Production Reactors; Economic Regulatory Administration; Energy Information Administration; energy research; environment, safety and health; fossil energy; General Counsel; hearings and appeals, Inspector General, international affairs and energy emergencies; management and administration, minority economic impact; nuclear energy; policy, planning and analysis, radioactive waste management; and power marketing administrations: Bonneville Power Administration, Western Area Power Administration, Alaska Power Administration, Southeastern Power Administration, and Southwestern Power Administration.

  20. Surface free energy of alkali and transition metal nanoparticles

    NASA Astrophysics Data System (ADS)

    Aqra, Fathi; Ayyad, Ahmed

    2014-09-01

    This paper addresses an interesting issue on the surface free energy of metallic nanoparticles as compared to the bulk material. Starting from a previously reported equation, a theoretical model, that involves a specific term for calculating the cohesive energy of nanoparticle, is established in a view to describe the behavior of surface free energy of metallic nanoparticles (using different shapes of particle: sphere, cube and disc). The results indicate that the behavior of surface energy is very appropriate for spherical nanoparticle, and thus, it is the most realistic shape of a nanoparticle. The surface energy of copper, silver, gold, platinum, tungsten, molybdenum, tantalum, paladium and alkali metallic nanoparticles is only prominent in the nanoscale size, and it decreases with the decrease of nanoparticle size. Thus, the surface free energy plays a more important role in determining the properties of nanoparticles than in bulk materials. It differs from shape to another, and falls down as the number of atoms (nanoparticle size) decreases. In the case of spherical nanoparticles, the onset of the sharp decrease in surface energy is observed at about 110 atom. A decrease of 16% and 45% in surface energy is found by moving from bulk to 110 atom and from bulk to 5 atom, respectively. The predictions are consistent with the reported data.

  1. Use of energy policy research and/or analysis in congressional decision making

    SciTech Connect

    Ahiarah, S.C.O.

    1985-01-01

    Regardless of what anyone thinks about it, policy science, as conceived by Lasswell, has become a discipline that is breeding new professionals who are producing policy researches and/or analyses decision making. But are they so used - is the intended marriage between PRA information and public policy decision making taking place. Many think they are, although others are skeptical. This study goes beyond the question of whether or not PRAs are used in public policy decision making, to investigate the purposes for which they are used therein. The public-policy decision making context selected is the legislative (congressional) decision making occasions in energy issues between 1979 and 1982; the objects of use are the energy PRAs from three congressional support agencies - the General Accounting Office, the Office of Technology Assessment, and the Congressional Budget Office. The findings are that when use is defined as congressional admission of the PRAs, all support agency PRAs are used, but when use is defined in terms of Congress Considering or adapting the PRAs in its decision making contexts, only a portion of all the support agency PRAs get used. The PRAs that are consideratively or adaptively used are more likely to be used for enlightenment, position support, and/or symbolic-propagandistic purposes.

  2. Reference free, high-precision measurements of transition energies in few electron argon ions

    NASA Astrophysics Data System (ADS)

    Szabo, Csilla I.; Amaro, Pedro; Guerra, Mauro; Schlesser, Sophie; Gumberidze, Alexander; Santos, José Paulo; Indelicato, Paul

    2013-04-01

    The use of a vacuum double crystal spectrometer, coupled to an electron-cyclotron resonance ion source (ECRIS), allows to measure low-energy x-ray transitions energies in highly-charged ions with accuracies of the order of a few parts per million. We have used this installation to measure the 1s2p 1 P1 → 1s2 1 S0 diagram line and the 1s2s 3 S1 → 1s2 1 S0 forbidden M1 transition energies in helium-like argon, the 1s2s2p 2 Pj → 1s2 2s 2 S1/2 transitions in lithium-like argon and the 1s2s2 2p 1 P1 → 1s2 2s2 1 S0 transition in beryllium-like argon. These transition measurements have accuracies between 2 and 4 ppm depending on the line intensity. Thanks to the excellent agreement between the simulations and the measurements, we were also able to measure the transition width of all the allowed transitions. The results are compared to recent QED and relativistic many-body calculations.

  3. Astronomy in Sustainable Energy: A New Approach to Make It Matter

    NASA Astrophysics Data System (ADS)

    Ruzhitskaya, Lanika; Speck, A.

    2012-01-01

    We present a study of a new approach to teaching non-science students concepts of sustainable energy using astronomy, real life and fictional scenarios. Teaching non-science majors about energy is important because of the challenge that scientific (il)literacy poses for tangible and political problems like energy. We have established a course in which students are involved in critical thinking and the process of scientific reasoning while discovering the nature of energy and its role in our lives and its presentation in the fiction genre. In the course, students construct and apply their knowledge of transformation of energy to understanding of the concepts of the formation of the sun and the planets. Along with these concepts, students learn about ways of harnessing energy for sustaining life on Earth. During the course students transform their "Why do I care?” to "What can I do?” We are achieving this change by starting with a broad introduction of the concepts and physical laws involved in understanding of the Solar Nebular hypothesis during which we discuss the role of different forms of energy involved in the process. In the next step we narrow down the discussion to importance and use of energy on Earth and then we discuss the role of different forms of energy in maintaining our individual lives. Thus students go from intangible notions about energy to making informed decisions on what type of sustainable energy makes sense to use in their houses and how many burgers they want to eat per day. Moving towards sustainable energy technologies requires a public who understands the science behind the issues. The work presented here is aimed at providing a mechanism for increase literacy regarding these issues and testing this mechanism's success.

  4. Energy Transition Initiative: Island Energy Snapshot - Guadeloupe; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-05-27

    This profile provides a snapshot of the energy landscape of Guadeloupe, an overseas region of France located in the eastern Caribbean Sea. Guadeloupe’s utility rates are approximately $0.18 U.S. dollars (USD) per kilowatt-hour (kWh), below the Caribbean regional average of $0.33 USD/kWh.

  5. Energy Transition Initiative: Island Energy Snapshot - Antigua and Barbuda; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-05-20

    This profile provides a snapshot of the energy landscape of Antigua and Barbuda, an independent nation in the Leeward Islands in the eastern Caribbean Sea. Antigua and Barbuda’s utility rates are approximately $0.37 U.S. dollars (USD) per kilowatt-hour (kWh), which is above the Caribbean regional average of $0.33 USD/kWh.

  6. Energy Transition Initiative: Island Energy Snapshot - Trinidad and Tobago; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-05-20

    This profile provides a snapshot of the energy landscape of Trinidad and Tobago, a two-island nation located off the coast of Venezuela. Trinidad and Tobago’s electricity rates are some of the lowest in the Caribbean at approximately $0.04 per kilowatt-hour (kWh), well below the regional average of $0.33/kWh.

  7. IBS and possible luminosity improvement for RHIC operation below transition energy

    SciTech Connect

    Fedotov,A.V.

    2009-05-04

    There is a strong interest in low-energy RHIC collisions in the energy range below present RHIC transition energy. These collisions win help to answer one of the key questions in the field of QCD about the existence and location of a critical point on the QCD phase diagram. For such low-energy RHIC operation, particle losses from the RF bucket are of particular concern since the longitudinal beam size is comparable to the existing RF bucket at low energies. In this paper, we explore an Intrabeam Scattering (IBS) feature below transition energy that drives the transverse and longitudinal beam temperatures towards equilibrium to see whether we can minimize longitudinal diffusion due to IBS and predict some luminosity improvement for the low-energy RHIC project.

  8. Energy Independence for North America - Transition to the Hydrogen Economy

    SciTech Connect

    Eberhardt, J.

    2003-08-24

    The U.S. transportation sector is almost totally dependent on liquid hydrocarbon fuels, primarily gasoline and diesel fuel from conventional oil. In 2002, the transportation sector accounted for 69 percent of the U.S. oil use; highway vehicles accounted for 54 percent of the U.S. oil use. Of the total energy consumed in the U.S., more than 40 percent came from oil. More significantly, more than half of this oil is imported and is projected by the Energy Information Agency (EIA) to increase to 68 percent by 2025 [1]. The supply and price of oil have been dictated by the Organization of Petroleum Exporting Countries (OPEC). In 2002, OPEC accounted for 39 percent of world oil production and this is projected by the EIA to increase to 50 percent in 2025. Of the world's oil reserves, about 80 percent is owned by OPEC members. Major oil price shocks have disrupted world energy markets four times in the past 30 years (1973-74, 1979-80, 1990-1991, and 1999- 2000) and with each came either a recession or slowdown in the GDP (Gross Domestic Product) of the United States. In addition, these market upheavals have cost the U.S. approximately $7 trillion (in 1998 dollars) in total economic costs [2]. Finally, it is estimated that military expenditures for defending oil supplies in the Middle East range from $6 billion to $60 billion per year [3] and do not take into account the costs of recent military operations in Iraq (i.e., Operation Iraqi Freedom, 2003). At the outset of his administration in 2001, President George W. Bush established the National Energy Policy Development (NEPD) Group to develop a national energy policy to promote dependable, affordable, and environmentally sound energy for the future in order to avert potential energy crises. In the National Energy Policy report [4], the NEPD Group urges action by the President to meet five specific national goals that America must meet--''modernize conservation, modernize our energy infrastructure, increase energy

  9. Systemic aspects of the transition to sustainable energy

    NASA Astrophysics Data System (ADS)

    Schlögl, R.

    2015-08-01

    The supply of free energy to our societies is today an intricate system comprising the regimes of technologies, regulatory frameworks, socio-economic impacts and techno-ecological interactions. As a consequence it is challenging to define clear directions or even device a master plan for the transformation of a single national energy system into a sustainable future. Even the term "sustainable" needs extensive discussion in this context that should not be defined solely in technological or ecological senses. The contribution illustrates some of the elements of the energy system and their interdependencies. It will become clear that multiple reasons exist to change the traditional generation and use of energy even when climate protection is not a sufficiently strong argument for a change.

  10. Thinking Globally: How ISO 50001 - Energy Management can make industrial energy efficiency standard practice

    SciTech Connect

    McKane, Aimee; Desai, Deann; Matteini, Marco; Meffert, William; Williams, Robert; Risser, Roland

    2009-08-01

    Industry utilizes very complex systems, consisting of equipment and their human interface, which are organized to meet the production needs of the business. Effective and sustainable energy efficiency programs in an industrial setting require a systems approach to optimize the integrated whole while meeting primary business requirements. Companies that treat energy as a manageable resource and integrate their energy program into their management practices have an organizational context to continually seek opportunities for optimizing their energy use. The purpose of an energy management system standard is to provide guidance for industrial and commercial facilities to integrate energy efficiency into their management practices, including fine-tuning production processes and improving the energy efficiency of industrial systems. The International Organization for Standardization (ISO) has identified energy management as one of its top five priorities for standards development. The new ISO 50001 will establish an international framework for industrial, commercial, or institutional facilities, or entire companies, to manage their energy, including procurement and use. This standard is expected to achieve major, long-term increases in energy efficiency (20percent or more) in industrial, commercial, and institutional facilities and to reduce greenhouse gas (GHG) emissions worldwide.This paper describes the impetus for the international standard, its purpose, scope and significance, and development progress to date. A comparative overview of existing energy management standards is provided, as well as a discussion of capacity-building needs for skilled individuals to assist organizations in adopting the standard. Finally, opportunities and challenges are presented for implementing ISO 50001 in emerging economies and developing countries.

  11. Modeling and control of distributed energy systems during transition between grid connected and standalone modes

    NASA Astrophysics Data System (ADS)

    Arafat, Md Nayeem

    Distributed generation systems (DGs) have been penetrating into our energy networks with the advancement in the renewable energy sources and energy storage elements. These systems can operate in synchronism with the utility grid referred to as the grid connected (GC) mode of operation, or work independently, referred to as the standalone (SA) mode of operation. There is a need to ensure continuous power flow during transition between GC and SA modes, referred to as the transition mode, in operating DGs. In this dissertation, efficient and effective transition control algorithms are developed for DGs operating either independently or collectively with other units. Three techniques are proposed in this dissertation to manage the proper transition operations. In the first technique, a new control algorithm is proposed for an independent DG which can operate in SA and GC modes. The proposed transition control algorithm ensures low total harmonic distortion (THD) and less voltage fluctuation during mode transitions compared to the other techniques. In the second technique, a transition control is suggested for a collective of DGs operating in a microgrid system architecture to improve the reliability of the system, reduce the cost, and provide better performance. In this technique, one of the DGs in a microgrid system, referred to as a dispatch unit , takes the additional responsibility of mode transitioning to ensure smooth transition and supply/demand balance in the microgrid. In the third technique, an alternative transition technique is proposed through hybridizing the current and droop controllers. The proposed hybrid transition control technique has higher reliability compared to the dispatch unit concept. During the GC mode, the proposed hybrid controller uses current control. During the SA mode, the hybrid controller uses droop control. During the transition mode, both of the controllers participate in formulating the inverter output voltage but with different

  12. CEOS Contributions to Informing Energy Management and Policy Decision Making Using Space-Based Earth Observations

    NASA Technical Reports Server (NTRS)

    Eckman, Richard S.

    2009-01-01

    Earth observations are playing an increasingly significant role in informing decision making in the energy sector. In renewable energy applications, space-based observations now routinely augment sparse ground-based observations used as input for renewable energy resource assessment applications. As one of the nine Group on Earth Observations (GEO) societal benefit areas, the enhancement of management and policy decision making in the energy sector is receiving attention in activities conducted by the Committee on Earth Observation Satellites (CEOS). CEOS has become the "space arm" for the implementation of the Global Earth Observation System of Systems (GEOSS) vision. It is directly supporting the space-based, near-term tasks articulated in the GEO three-year work plan. This paper describes a coordinated program of demonstration projects conducted by CEOS member agencies and partners to utilize Earth observations to enhance energy management end-user decision support systems. I discuss the importance of engagement with stakeholders and understanding their decision support needs in successfully increasing the uptake of Earth observation products for societal benefit. Several case studies are presented, demonstrating the importance of providing data sets in formats and units familiar and immediately usable by decision makers. These projects show the utility of Earth observations to enhance renewable energy resource assessment in the developing world, forecast space-weather impacts on the power grid, and improve energy efficiency in the built environment.

  13. Large impact of reorganization energy on photovoltaic conversion due to interfacial charge-transfer transitions.

    PubMed

    Fujisawa, Jun-ichi

    2015-05-14

    Interfacial charge-transfer (ICT) transitions are expected to be a novel charge-separation mechanism for efficient photovoltaic conversion featuring one-step charge separation without energy loss. Photovoltaic conversion due to ICT transitions has been investigated using several TiO2-organic hybrid materials that show organic-to-inorganic ICT transitions in the visible region. In applications of ICT transitions to photovoltaic conversion, there is a significant problem that rapid carrier recombination is caused by organic-inorganic electronic coupling that is necessary for the ICT transitions. In order to solve this problem, in this work, I have theoretically studied light-to-current conversions due to the ICT transitions on the basis of the Marcus theory with density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. An apparent correlation between the reported incident photon-to-current conversion efficiencies (IPCE) and calculated reorganization energies was clearly found, in which the IPCE increases with decreasing the reorganization energy consistent with the Marcus theory in the inverted region. This activation-energy dependence was systematically explained by the equation formulated by the Marcus theory based on a simple excited-state kinetic scheme. This result indicates that the reduction of the reorganization energy can suppress the carrier recombination and enhance the IPCE. The reorganization energy is predominantly governed by the structural change in the chemical-adsorption moiety between the ground and ICT excited states. This work provides crucial knowledge for efficient photovoltaic conversion due to ICT transitions. PMID:25892453

  14. A new US energy agenda: US leadership in transition

    SciTech Connect

    Not Available

    1992-11-20

    For the first time since the Carter Administration at the end of 1980, the US is embarked upon energy management beyond laissez faire' free market determination. The election of Bill Clinton to the Presidency could mean the release of years-old pressures to greatly increase efficiency, dramatically reduce hydrocarbon dependency, and curtail pollution to unheard of degrees. Doubtlessly, it will also unleash debates about how to do this without imposing protectionism or further slowing the domestic economy. In this issue a veteran energy analyst, J. Lange Winckler, assesses the changes to be expected. ED supplements the text with graphics that illustrate four scenarios of energy growth and utilization over the next 40 years. This issue also includes the following: (1) the ED Refining Netback Data for the US Gulf and West Coasts, Rotterdam and Singapore as of November 6, 1992; and (2) the ED Fuel Price/Tax Series for countries of the Western Hemisphere, November 1992 Edition.

  15. Free energy and phase transition of the matrix model on a plane wave

    SciTech Connect

    Hadizadeh, Shirin; Ramadanovic, Bojan; Semenoff, Gordon W.; Young, Donovan

    2005-03-15

    It has recently been observed that the weakly coupled plane-wave matrix model has a density of states which grows exponentially at high energy. This implies that the model has a phase transition. The transition appears to be of first order. However, its exact nature is sensitive to interactions. In this paper, we analyze the effect of interactions by computing the relevant parts of the effective potential for the Polyakov loop operator in the finite temperature plane-wave matrix model to three-loop order. We show that the phase transition is indeed of first order. We also compute the correction to the Hagedorn temperature to order two loops.

  16. SUBMILLIMETER ARRAY OBSERVATIONS OF THE RX J1633.9-2442 TRANSITION DISK: EVIDENCE FOR MULTIPLE PLANETS IN THE MAKING

    SciTech Connect

    Cieza, Lucas A.; Mathews, Geoffrey S.; Williams, Jonathan P.; Kraus, Adam L.; Menard, Francois C.; Schreiber, Matthias R.; Romero, Gisela A.; Orellana, Mariana; Ireland, Michael J.

    2012-06-10

    We present continuum high-resolution Submillimeter Array (SMA) observations of the transition disk object RX J1633.9-2442, which is located in the Ophiuchus molecular cloud and has recently been identified as a likely site of ongoing giant planet formation. The observations were taken at 340 GHz (880 {mu}m) with the SMA in its most extended configuration, resulting in an angular resolution of 0.''3 (35 AU at the distance of the target). We find that the disk is highly inclined (i {approx} 50 Degree-Sign ) and has an inner cavity {approx}25 AU in radius, which is clearly resolved by our observations. We simultaneously model the entire optical to millimeter wavelength spectral energy distribution and SMA visibilities of RX J1633.9-2442 in order to constrain the structure of its disk. We find that an empty cavity {approx}25 AU in radius is inconsistent with the excess emission observed at 12, 22, and 24 {mu}m. Instead, the mid-IR excess can be modeled by either a narrow, optically thick ring at {approx}10 AU or an optically thin region extending from {approx}7 AU to {approx}25 AU. The inner disk (r {approx}< 5 AU) is mostly depleted of small dust grains as attested by the lack of detectable near-IR excess. We also present deep Keck aperture masking observations in the near-IR, which rule out the presence of a companion up to 500 times fainter than the primary star (in K band) for projected separations in the 5-20 AU range. We argue that the complex structure of the RX J1633.9-2442 disk is best explained by multiple planets embedded within the disk. We also suggest that the properties and incidence of objects such as RX J1633.9-2442, T Cha, and LkCa 15 (and those of the companions recently identified to these two latter objects) are most consistent with the runaway gas accretion phase of the core accretion model, when giant planets gain their envelopes and suddenly become massive enough to open wide gaps in the disk.

  17. Porous nanoarchitectures of spinel-type transition metal oxides for electrochemical energy storage systems.

    PubMed

    Park, Min-Sik; Kim, Jeonghun; Kim, Ki Jae; Lee, Jong-Won; Kim, Jung Ho; Yamauchi, Yusuke

    2015-12-14

    Transition metal oxides possessing two kinds of metals (denoted as AxB3-xO4, which is generally defined as a spinel structure; A, B = Co, Ni, Zn, Mn, Fe, etc.), with stoichiometric or even non-stoichiometric compositions, have recently attracted great interest in electrochemical energy storage systems (ESSs). The spinel-type transition metal oxides exhibit outstanding electrochemical activity and stability, and thus, they can play a key role in realising cost-effective and environmentally friendly ESSs. Moreover, porous nanoarchitectures can offer a large number of electrochemically active sites and, at the same time, facilitate transport of charge carriers (electrons and ions) during energy storage reactions. In the design of spinel-type transition metal oxides for energy storage applications, therefore, nanostructural engineering is one of the most essential approaches to achieving high electrochemical performance in ESSs. In this perspective, we introduce spinel-type transition metal oxides with various transition metals and present recent research advances in material design of spinel-type transition metal oxides with tunable architectures (shape, porosity, and size) and compositions on the micro- and nano-scale. Furthermore, their technological applications as electrode materials for next-generation ESSs, including metal-air batteries, lithium-ion batteries, and supercapacitors, are discussed. PMID:26549729

  18. Relevance of behavioral and social models to the study of consumer energy decision making and behavior

    SciTech Connect

    Burns, B.A.

    1980-11-01

    This report reviews social and behavioral science models and techniques for their possible use in understanding and predicting consumer energy decision making and behaviors. A number of models and techniques have been developed that address different aspects of the decision process, use different theoretical bases and approaches, and have been aimed at different audiences. Three major areas of discussion were selected: (1) models of adaptation to social change, (2) decision making and choice, and (3) diffusion of innovation. Within these three areas, the contributions of psychologists, sociologists, economists, marketing researchers, and others were reviewed. Five primary components of the models were identified and compared. The components are: (1) situational characteristics, (2) product characteristics, (3) individual characteristics, (4) social influences, and (5) the interaction or decision rules. The explicit use of behavioral and social science models in energy decision-making and behavior studies has been limited. Examples are given of a small number of energy studies which applied and tested existing models in studying the adoption of energy conservation behaviors and technologies, and solar technology.

  19. The life course in the making: gender and the development of adolescents' expected timing of adult role transitions.

    PubMed

    Crockett, Lisa J; Beal, Sarah J

    2012-11-01

    Adolescents' expectations about the timing of adult role transitions have the potential to shape their actual transitions, setting the stage for their adult lives. Although expectations about timing emerge by early adolescence, little is known about how these expectations develop across adolescence. This longitudinal study examined developmental trajectories of adolescents' anticipated ages of school completion, job entry, marriage, and parenthood over the high school years, focusing on gender differences. Latent growth curve analysis of data from 411 rural youths followed from Grades 9 through 12 (age at Grade 9: M = 14.35, SD = 0.77) indicated a significant increase in adolescents' anticipated ages of entry into work and parenthood as well as gender differences in the trajectory of the expected age of marriage. Gender role attitudes, school performance, romantic relationships, and expected educational and occupational attainment were associated with the anticipated timing of role transitions, with significant variations by gender. Adolescents' expected ages of entry into adult family roles predicted their educational attainment and family role transitions in early adulthood. The findings provide insights into the process through which adolescent boys and girls construct their expectations regarding the transition to adulthood and, in turn, their future life course. PMID:22448985

  20. Study of Early Transition Metal Carbides for Energy Storage Applications

    NASA Astrophysics Data System (ADS)

    Dall'Agnese, Yohan

    An increase in energy and power density is needed to match the growing energy storage demands linked with the development of renewable energy production, and portable electronics. Several energy storage technologies exist including lithium-ion batteries, sodium-ion batteries, fuel cells and supercapacitors. These systems are mutually complementary. For example, supercapacitors can deliver high power densities whereas batteries can be used for high energy density applications. The first objective of this work was to investigate the electrochemical performances of a new family of 2-D materials called MXenes by cyclic voltammetry and galvanostatic charge-discharge measurements and to propose new solutions to tackle the energy storage concern. To achieve this goal, several directions have been explored. The first part of the research focused on Ti3C 2-based MXenes behavior as electrode materials for supercapacitors in aqueous electrolytes. The charge storage mechanisms in basic and neutral aqueous electrolytes, investigated by X-ray diffraction, were demonstrated to be attributed to cations intercalation between Ti3C2 layers. X-ray photoelectron spectroscopy highlighted the contribution of oxygenated functional groups on surface redox reactions in sulfuric acid. High capacitances were achieved, up to 520 F/cm3 and 325 F/g. Then the electrochemical behaviors of MXenes in sodium-based organic electrolytes were explored. A new hybrid system of sodium-ion capacitor was proposed. It was demonstrated that V2C-based MXene electrodes were suitable to be used as positive electrodes with an operating potential from 1 V to 3.5 V vs. Na+/Na. Continuous intercalation and de-intercalation of sodium ions between the V2C layers during sodiation and desodiation were showed by X-ray diffraction. An asymmetric sodium-ion capacitor full cell was assembled using hard carbon as negative electrode and showed promising results, with a capacity of 50 mAh/g. The last part was focused on the

  1. Minimal cooling speed for glass transition in a simple solvable energy landscape model

    NASA Astrophysics Data System (ADS)

    Toledo-Marín, J. Quetzalcóatl; Castillo, Isaac Pérez; Naumis, Gerardo G.

    2016-06-01

    The minimal cooling speed required to form a glass is obtained for a simple solvable energy landscape model. The model, made from a two-level system modified to include the topology of the energy landscape, is able to capture either a glass transition or a crystallization depending on the cooling rate. In this setup, the minimal cooling speed to achieve glass formation is then found to be related with the crystallization relaxation time, energy barrier and with the thermal history. In particular, we obtain that the thermal history encodes small fluctuations around the equilibrium population which are exponentially amplified near the glass transition, which mathematically corresponds to the boundary layer of the master equation. The change in the glass transition temperature is also found as a function of the cooling rate. Finally, to verify our analytical results, a kinetic Monte Carlo simulation was implemented.

  2. Theoretical Study of Energy Levels and Transition Probabilities of Boron Atom

    NASA Astrophysics Data System (ADS)

    Tian Yi, Zhang; Neng Wu, Zheng

    2009-08-01

    Full Text PDF Though the electrons configuration for boron atom is simple and boron atom has long been of interest for many researchers, the theoretical studies for properties of BI are not systematic, there are only few results reported on energy levels of high excited states of boron, and transition measurements are generally restricted to transitions involving ground states and low excited states without considering fine structure effects, provided only multiplet results, values for transitions between high excited states are seldom performed. In this article, by using the scheme of the weakest bound electron potential model theory calculations for energy levels of five series are performed and with the same method we give the transition probabilities between excited states with considering fine structure effects. The comprehensive set of calculations attempted in this paper could be of some value to workers in the field because of the lack of published calculations for the BI systems. The perturbations coming from foreign perturbers are taken into account in studying the energy levels. Good agreement between our results and the accepted values taken from NIST has been obtained. We also reported some values of energy levels and transition probabilities not existing on the NIST data bases.

  3. Energy and environmental policy in a period of transition

    SciTech Connect

    Stalon, C.G.

    1995-12-31

    This paper discusses governance aspects of electric industry restructuring. The creation and preservation of a governance system to ensure reliable and efficient trades within interconnected and independent trading areas is the main topic. The closely related issue of defining and imposing responsibilities on non-utility generators is also discussed in detail. It is recommended that the Federal Energy Regulatory Commission promote private governance of interconnections. 1 tab.

  4. Land cover change using an energy transition paradigm in a statistical mechanics approach

    NASA Astrophysics Data System (ADS)

    Zachary, Daniel S.

    2013-10-01

    This paper explores a statistical mechanics approach as a means to better understand specific land cover changes on a continental scale. Integrated assessment models are used to calculate the impact of anthropogenic emissions via the coupling of technoeconomic and earth/atmospheric system models and they have often overlooked or oversimplified the evolution of land cover change. Different time scales and the uncertainties inherent in long term projections of land cover make their coupling to integrated assessment models difficult. The mainstream approach to land cover modelling is rule-based methodology and this necessarily implies that decision mechanisms are often removed from the physical geospatial realities, therefore a number of questions remain: How much of the predictive power of land cover change can be linked to the physical situation as opposed to social and policy realities? Can land cover change be understood using a statistical approach that includes only economic drivers and the availability of resources? In this paper, we use an energy transition paradigm as a means to predict this change. A cost function is applied to developed land covers for urban and agricultural areas. The counting of area is addressed using specific examples of a Pólya process involving Maxwell-Boltzmann and Bose-Einstein statistics. We apply an iterative counting method and compare the simulated statistics with fractional land cover data with a multi-national database. An energy level paradigm is used as a basis in a flow model for land cover change. The model is compared with tabulated land cover change in Europe for the period 1990-2000. The model post-predicts changes for each nation. When strong extraneous factors are absent, the model shows promise in reproducing data and can provide a means to test hypothesis for the standard rules-based algorithms.

  5. Career Decision Making for Male Students with Attention Deficit Hyperactivity Disorder: A Model of Critical Factors Aiding in Transitional Efforts

    ERIC Educational Resources Information Center

    Gray, Gregory B.

    2009-01-01

    This study is intended to reveal helpful information that will guide high school practitioners in serving students with attention deficit hyperactivity disorder (ADHD) more effectively. ADHD is neurological in origin, making it invisible. This disorder makes people susceptible to distractibility, impulsivity, disorganization, frustration, anxiety,…

  6. State transitions redistribute rather than dissipate energy between the two photosystems in Chlamydomonas.

    PubMed

    Nawrocki, Wojciech J; Santabarbara, Stefano; Mosebach, Laura; Wollman, Francis-André; Rappaport, Fabrice

    2016-01-01

    Photosynthesis converts sunlight into biologically useful compounds, thus fuelling practically the entire biosphere. This process involves two photosystems acting in series powered by light harvesting complexes (LHCs) that dramatically increase the energy flux to the reaction centres. These complexes are the main targets of the regulatory processes that allow photosynthetic organisms to thrive across a broad range of light intensities. In microalgae, one mechanism for adjusting the flow of energy to the photosystems, state transitions, has a much larger amplitude than in terrestrial plants, whereas thermal dissipation of energy, the dominant regulatory mechanism in plants, only takes place after acclimation to high light. Here we show that, at variance with recent reports, microalgal state transitions do not dissipate light energy but redistribute it between the two photosystems, thereby allowing a well-balanced influx of excitation energy. PMID:27249564

  7. Intensity transitions in Cyg XR-1 observed at high energies from OSO 8

    NASA Technical Reports Server (NTRS)

    Dolan, J. F.; Crannell, C. J.; Dennis, B. R.; Frost, K. J.; Orwig, L. E.

    1977-01-01

    The observed transitions at energies above 20 keV show that the spectrum of Cyg XR-1 exhibits the pivoting effect during intensity transitions expected from two-temperature accretion disk models of the X-ray emitting region. Cyg XR-1 was observed with the high-energy X-ray spectrometer on board the OSO-8 satellite from November 11-19, 1975 and from October 27 to November 15, 1976 (excluding the period from November 1 to November 7, 1976).

  8. Relativistic M-subshell radiationless transition probabilities and energies for Zn, Cd and Hg

    SciTech Connect

    Sampaio, J.M.; Parente, F.; Indelicato, P.; Marques, J.P.

    2014-09-15

    Theoretical calculations of radiationless transition probabilities and energies for M-subshell vacancies in Zn, Cd, and Hg are tabulated using the Dirac–Fock method. Transition probabilities between an initial vacancy state and a final two-vacancies state are presented for each initial and final atomic angular momentum quantum number. Calculations were performed in the single configuration approach with the Breit interaction, self-energy and (Uehling) vacuum polarization corrections included in the self-consistent method. Higher-order retardation corrections and QED effects were also included as perturbations.

  9. Development regulation changes local elected leaders can make to promote energy conservation

    SciTech Connect

    Kron, Jr, N F

    1980-07-01

    This report lists actions that local officials can make to change their community's development regulations and thereby lessen the effects of local energy problems. The term development regulations, as used here, is a general reference to local or state controls over land use and development that affect design, orientation, placement, location, and related characteristics of buildings and infrastructure. The regulations include items such as zoning, subdivision controls, setbacks, yard and height requirements, and solar-access ordinances.

  10. Wind Power: A Renewable Energy Source for Mars Transit Vehicle

    NASA Technical Reports Server (NTRS)

    Flynn, Michael; Kohout, Lisa; Kliss, Mark (Technical Monitor)

    1998-01-01

    The Martian environment presents significant design challenges for the development of power generation systems. Nuclear-based systems may not be available due to political and safety concerns. The output of photovoltaics are limited by a solar intensity of 580 W/sqm as compared to 1353 W/sqm on Earth. The presence of dust particles in the Mars atmosphere will further reduce the photovoltaic output. Also, energy storage for a 12-hour night period must be provided. In this challenging environment, wind power generation capabilities may provide a viable option as a Martian power generation system. This paper provides an analysis of the feasibility of such a system.

  11. Helping Children on the Autism Spectrum Make a Successful Transition from Middle School to High School and Beyond

    ERIC Educational Resources Information Center

    Connell, Diane; Hutnick, Marilyn; Glover, Sandi; Glover, Curtis

    2012-01-01

    Transitioning from middle school to high school is a tremendous change for all students; it is especially important for learners on the Autism Spectrum. In this article, the authors discuss the move to high school and give seven tips for successfully navigating these years. We draw upon the experiences of Mrs. Sandi Glover and her 21-year-old son…

  12. Helping Low-Income Urban Youth Make the Transition to Early Adulthood: A Retrospective Study of the YMCA Youth Institute

    ERIC Educational Resources Information Center

    O'Donnell, Julie; Kirkner, Sandra L.

    2016-01-01

    Low-income urban youth of color often face challenges in their transition to early adulthood. High school out-of-school time (OST) programs that promote positive youth development may help youth to better negotiate this period. However, little research exists on the long-term impact of such programs on young adults. The authors conducted a pilot…

  13. Helping Students Make the Transition into High School: The Effect of Ninth Grade Academies on Students' Academic and Behavioral Outcomes

    ERIC Educational Resources Information Center

    Somers, Marie-Andrée; Garcia, Ivonne

    2016-01-01

    Ninth Grade Academies (NGAs)--also called Freshman Academies--have attracted national attention as a particularly intensive and promising approach for supporting a successful transition for high school freshmen. An NGA is a self-contained learning community for ninth-graders that operates as a school within a school. NGAs have four core structural…

  14. Sexual Communication, Sexual Goals, and Students' Transition to College: Implications for Sexual Assault, Decision-Making, and Risky Behaviors

    ERIC Educational Resources Information Center

    Lindgren, Kristen P.; Schacht, Rebecca L.; Pantalone, David W.; Blayney, Jessica A.; George, William H.

    2009-01-01

    A qualitative study was conducted to understand college students' experiences and perceptions of sexual communication and sexual goals, and how they were affected by the transition from high school to college. Participants were heterosexual college students (N = 29). Single-sex focus groups were conducted and analyzed for themes. Major themes…

  15. What Can Be Learned from the Roller Coaster Journeys of Young People Making Ultimately Successful Transitions beyond School?

    ERIC Educational Resources Information Center

    Bryce, Jennifer; Anderson, Michelle

    2008-01-01

    This project investigated the interrelationships between family expectations and young people's post-school plans. All of the participants were from financially disadvantaged families. The research used interviews to understand these young people's perspectives of their transition experiences: the ways in which young people's school experiences…

  16. Seamless Transitions: Collaborations That Benefit Children and Their Families Making the Move from Preschool to Early Elementary.

    ERIC Educational Resources Information Center

    Velazquez, Sheila Roman, Ed.

    This report summarizes the proceedings of two clinics on early childhood clinics and provides descriptions of successful preschool-to-elementary transition programs. The two clinics brought together Head Start representatives, public and private day care personnel, elementary school teachers and administrators, state department of education staff,…

  17. Geo-portal as a planning instrument: supporting decision making and fostering market potential of Energy efficiency in buildings

    NASA Astrophysics Data System (ADS)

    Cuca, Branka; Brumana, Raffaella; Oreni, Daniela; Iannaccone, Giuliana; Sesana, Marta Maria

    2014-03-01

    Steady technological progress has led to a noticeable advancement in disciplines associated with Earth observation. This has enabled information transition regarding changing scenarios, both natural and urban, to occur in (almost) real time. In particular, the need for integration on a local scale with the wider territorial framework has occurred in analysis and monitoring of built environments over the last few decades. The progress of Geographic Information (GI) science has provided significant advancements when it comes to spatial analysis, while the almost free availability of the internet has ensured a fast and constant exchange of geo-information, even for everyday users' requirements. Due to its descriptive and semantic nature, geo-spatial information is capable of providing a complete overview of a certain phenomenon and of predicting the implications within the natural, social and economic context. However, in order to integrate geospatial data into decision making processes, it is necessary to provide a specific context, which is well supported by verified data. This paper investigates the potentials of geo-portals as planning instruments developed to share multi-temporal/multi-scale spatial data, responding to specific end-users' demands in the case of Energy efficiency in Buildings (EeB) across European countries. The case study regards the GeoCluster geo-portal and mapping tool (Project GE2O, FP7), built upon a GeoClustering methodology for mapping of indicators relevant for energy efficiency technologies in the construction sector.

  18. Modeling the Oil Transition: A Summary of the Proceedings of the DOE/EPA Workshop on the Economic and Environmental Implications of Global Energy Transitions

    SciTech Connect

    Greene, David L

    2007-02-01

    The global energy system faces sweeping changes in the next few decades, with potentially critical implications for the global economy and the global environment. It is important that global institutions have the tools necessary to predict, analyze and plan for such massive change. This report summarizes the proceedings of an international workshop concerning methods of forecasting, analyzing, and planning for global energy transitions and their economic and environmental consequences. A specific case, it focused on the transition from conventional to unconventional oil and other energy sources likely to result from a peak in non-OPEC and/or global production of conventional oil. Leading energy models from around the world in government, academia and the private sector met, reviewed the state-of-the-art of global energy modeling and evaluated its ability to analyze and predict large-scale energy transitions.

  19. Statistical mechanics model for the transit free energy of monatomic liquids

    NASA Astrophysics Data System (ADS)

    Wallace, Duane C.; Chisolm, Eric D.; Bock, N.; de Lorenzi-Venneri, G.

    2010-04-01

    In applying vibration-transit (V-T) theory of liquid dynamics to the thermodynamic properties of monatomic liquids, the point has been reached where an improved model is needed for the small (˜10%) transit contribution. Toward this goal, an analysis of the available high-temperature experimental entropy data for elemental liquids was recently completed [D. C. Wallace, E. D. Chisolm, and N. Bock, Phys. Rev. E 79, 051201 (2009)]. This analysis yields a common curve of transit entropy vs T/θtr , where T is temperature and θtr is a scaling temperature for each element. In the present paper, a statistical mechanics model is constructed for the transit partition function, and is calibrated to the experimental transit entropy curve. The model has two scalar parameters, and captures the temperature scaling of experiment. The calibrated model fits the experimental liquid entropy to high accuracy at all temperatures. With no additional parameters, the model also agrees with both experiment and molecular dynamics for the internal energy vs. T for Na. With the calibrated transit model, V-T theory provides equations subject to ab initio evaluation for thermodynamic properties of monatomic liquids. This will allow the range of applicability of the theory, and its overall accuracy, to be determined. More generally, the hypothesis of V-T theory, which divides the many-atom potential energy valleys into random and symmetric classes, can also be tested for its application beyond monatomic systems.

  20. Energy star product specification development framework: Using data and analysis to make program decisions

    SciTech Connect

    McWhinney, Marla; Fanara, Andrew; Clark, Robin; Hershberg, Craig; Schmeltz, Rachel; Roberson, Judy

    2003-09-12

    The Product Development Team (PD) in the US Environmental Protection Agency's ENERGY STAR Labeling Program fuels the long-term market transformation process by delivering new specifications. PD's goal is to expand the reach and visibility of ENERGY STAR as well as the market for new energy-efficient products. Since 2000, PD has launched nine new ENERGY STAR specifications and continues to evaluate new program opportunities. To evaluate the ENERGY STAR carbon savings potential for a diverse group of products, PD prepared a framework for developing new and updating existing specifications that rationalizes new product opportunities and draws upon the expertise and resources of other stakeholders, including manufacturers, utilities, environmental groups and other government agencies. By systematically reviewing the potential of proposed product areas, PD makes informed decisions as to whether or not to proceed with developing a specification. In support of this strategy, PD ensures that new product specifications are consistent with the ENERGY STAR guidelines and that these guidelines are effectively communicated to stakeholders during the product development process. To date, the framework has been successful in providing consistent guidance on collecting the necessary information on which to base sound program decisions. Through the application of this framework, PD increasingly recognizes that each industry has unique market and product characteristics that can require reconciliation with the ENERGY STAR guidelines. The new framework allows PD to identify where reconciliation is needed to justify program decisions.

  1. Electron Energy Levels in the 1D-2D Transition

    NASA Astrophysics Data System (ADS)

    Pepper, Michael; Sanjeev, Kumar; Thomas, Kalarikad; Creeth, Graham; English, David; Ritchie, David; Griffiths, Jonathan; Farrer, Ian; Jones, Geraint

    Using GaAs-AlGaAs heterostructures we have investigated the behaviour of electron energy levels with relaxation of the potential confining a 2D electron gas into a 1D configuration. In the ballistic regime of transport, when the conductance shows quantized plateaux, different types of behaviour are found according to the spins of interacting levels, whether a magnetic field is applied and lifting of the momentum degeneracy with a source-drain voltage. We have observed both crossing and anti-crossing of levels and have investigated the manner in which they can be mutually converted. In the presence of a magnetic field levels can cross and lock together as the confinement is altered in a way which is characteristic of parallel channels. The overall behaviour is discussed in terms of electron interactions and the wavefunction flexibility allowed by the increasing two dimensionality of the electron distribution as the confinement is weakened. Work supported by UK EPSRC.

  2. Energy transitions in superhydrophobicity: low adhesion, easy flow and bouncing

    NASA Astrophysics Data System (ADS)

    Nosonovsky, Michael; Bhushan, Bharat

    2008-10-01

    The concept of superhydrophobicity was introduced in the 1990s as a result of the investigation of the microstructure of extremely water-repellent plant leaves. Since that time, artificial superhydrophobic surfaces have been developed and implemented, stimulated by advances in nanotechnology, and giving one of the most successful examples of a bio-inspired technology transferred into engineering applications. Superhydrophobicity is usually defined as the ability of a surface to have (i) a very high water contact angle (CA) and (ii) low CA hysteresis. Here we argue that the ability of a water droplet to bounce off a surface constitutes a third property that is crucial for applications. Furthermore, this property is naturally related to the first two properties, since the energy barriers separating the 'sticky' and 'non-sticky' states needed for bouncing droplets have the same origin as those needed for high CA and for low CA hysteresis.

  3. Precise Determination of the Lyman-1 Transition Energy in Hydrogen-like Gold Ions with Microcalorimeters

    NASA Astrophysics Data System (ADS)

    Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Grabitz, P.; Kilbourne, C.; Kiselev, O.; McCammon, D.; Scholz, P.

    2014-09-01

    The precise determination of the transition energy of the Lyman-1 line in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. We report the determination of the Lyman-1 transition energy of gold ions (Au) with microcalorimeters at the experimental storage ring at GSI. X-rays produced by the interaction of 125 MeV/u Au ions with an internal argon gas-jet target were detected. The detector array consisted of 14 pixels with silicon thermistors and Sn absorbers, for which an energy resolution of 50 eV for an X-ray energy of 59.5 keV was obtained in the laboratory. The Lyman-1 transition energy was determined for each pixel in the laboratory frame, then transformed into the emitter frame and averaged. A Dy-159 source was used for energy calibration. The absolute positions of the detector pixels, which are needed for an accurate correction of the Doppler shift, were determined by topographic measurements and by scanning a collimated Am-241 source across the cryostat window. The energy of the Lyman-1 line in the emitter frame is eV, in good agreement with theoretical predictions. The systematic error is dominated by the uncertainty in the position of the cryostat relative to the interaction region of beam and target.

  4. Spectroscopic elucidation of uncoupled transition energies in the major photosynthetic light-harvesting complex, LHCII

    PubMed Central

    Schlau-Cohen, Gabriela S.; Calhoun, Tessa R.; Ginsberg, Naomi S.; Ballottari, Matteo; Bassi, Roberto; Fleming, Graham R.

    2010-01-01

    Electrostatic couplings between chromophores in photosynthetic pigment–protein complexes, and interactions of pigments with the surrounding protein environment, produce a complicated energy landscape of delocalized excited states. The resultant electronic structure absorbs light and gives rise to energy transfer steps that direct the excitation toward a site of charge separation with near unity quantum efficiency. Knowledge of the transition energies of the uncoupled chromophores is required to describe how the wave functions of the individual pigments combine to form this manifold of delocalized excited states that effectively harvests light energy. In an investigation of the major light-harvesting complex of photosystem II (LHCII), we develop a method based on polarized 2D electronic spectroscopy to experimentally access the energies of the S0–S1 transitions in the chromophore site basis. Rotating the linear polarization of the incident laser pulses reveals previously hidden off-diagonal features. We exploit the polarization dependence of energy transfer peaks to find the angles between the excited state transition dipole moments. We show that these angles provide a spectroscopic method to directly inform on the relationship between the delocalized excitons and the individual chlorophylls through the site energies of the uncoupled chromophores. PMID:20622154

  5. STABILITY IN BCC TRANSITION METALS: MADELUNG AND BAND-ENERGY EFFECTS DUE TO ALLOYING

    SciTech Connect

    Landa, A; Soderlind, P; Ruban, A; Peil, O; Vitos, L

    2009-08-28

    The phase stability of the bcc Group VB (V, Nb, and Ta) transition metals is explored by first-principles electronic-structure calculations. Alloying with a small amount of a neighboring metal can either stabilize or destabilize the bcc phase. This counterintuitive behavior is explained by competing mechanisms that dominate depending on particular dopand. We show that band-structure effects dictate stability when a particular Group VB metal is alloyed with its nearest neighbors within the same d-transition series. In this case, the neighbor with less (to the left) and more (to the right) d electrons, destabilize and stabilize bcc, respectively. When alloying with neighbors of different d-transition series, electrostatic Madelung energy dominates over the band energy and always stabilizes the bcc phase.

  6. Quantum transition state dynamics of the cyclooctatetraene unimolecular reaction on ab initio potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Tokizaki, Chihiro; Yoshida, Takahiko; Takayanagi, Toshiyuki

    2016-05-01

    The cyclooctatetraene (COT) anion has a stable D4h structure that is similar to the transition state configurations of the neutral C-C bond-alternation (D4h ↔ D8h ↔ D4h) and ring-inversion (D2d ↔ D4h ↔ D2d) unimolecular reactions. The previously measured photodetachment spectrum of COT- revealed the reaction dynamics in the vicinity of the two transition states on the neutral potential energy surface. In this work, the photodetachment spectrum is calculated quantum mechanically on ab initio-level potential energy surfaces within a three degree-of-freedom reduced-dimensionality model. Very good agreement has been obtained between theory and experiment, providing reliable interpretations for the experimental spectrum. A detailed picture of the reactive molecular dynamics of the COT unimolecular reaction in the transition state region is also discussed.

  7. Large conversion of energy in dielectric elastomers by electromechanical phase transition

    NASA Astrophysics Data System (ADS)

    Lu, Tong-Qing; Suo, Zhi-Gang

    2012-08-01

    When air is pumped in, a tubular balloon initially inflates slightly and homogeneously. A short section of the balloon then forms a bulge, which coexists with the unbulged section of the balloon. As more air is pumped in, the bulged section elongates at the expense of the unbulged section, until the entire balloon is bulged. The phenomenon is analogous to the liquid-to-vapor phase transition. Here we study the bulging transition in a dielectric elastomer tube as air is pumped into the balloon and a voltage is applied through the thickness of the membrane. We formulate the condition for coexistent budged and unbulged sections, and identify allowable states set by electrical breakdown and mechanical rupture. We find that the bulging transition dramatically amplifies electromechanical energy conversion. Energy converted in an electromechanical cycle consisting of unbulged and bulged states is thousands of times that in an electromechanical cycle consisting of only unbulged states.

  8. Energy levels and radiative transition rates for Ge XXXI, As XXXII, and Se XXXIII

    SciTech Connect

    Aggarwal, Sunny Singh, J.; Jha, A.K.S.; Mohan, Man

    2014-07-15

    Fine-structure energies of the 67 levels belonging to the 1s{sup 2}, 1s 2l, 1s3l, 1s4l, 1s5l, and 1s6l configurations of Ge XXXI, As XXXII, and Se XXXIII have been calculated using the General-Purpose Relativistic Atomic Structure Package. In addition, radiative rates, oscillator strengths, transition wavelengths, and line strengths have been calculated for all electric dipole, magnetic dipole, electric quadrupole, and magnetic quadrupole transitions among these levels. Lifetimes are also presented for all excited levels of these three ions. We have compared our results with the results available in the literature and the accuracy of the data is assessed. We predict new energy levels, oscillator strengths, and transition probabilities where no other theoretical or experimental results are available, which will form the basis for future experimental work.

  9. Energy transfer enhancement by oxygen perturbation of spin-forbidden electronic transitions in aromatic systems

    NASA Astrophysics Data System (ADS)

    Monguzzi, A.; Tubino, R.; Salamone, M. M.; Meinardi, F.

    2010-09-01

    Triplet-triplet energy transfer in multicomponent organic systems is usually entirely ascribed to a Dexter-type mechanism involving only short-range donor/acceptor interactions. We demonstrate that the presence of molecular oxygen introduces a perturbation to the electronic structure of one of the involved moieties which can induce a large increase in the spin-forbidden transition oscillator strength so that the otherwise negligible Förster contribution dominates the overall energy transfer rate.

  10. Free energy contributions to the hcp-bcc transformation in transition metals

    SciTech Connect

    Moroni, E.G.; Grimvall, G.; Jarlborg, T.

    1996-04-01

    The electronic and vibrational free energies of some hcp and bcc transition metals are computed {ital ab} {ital initio}. The vibrational part is obtained from a total-energy calculation over lattices with atoms randomly displaced according to a Gaussian distribution. The relative importance of electronic and vibrational excitations in the stabilization of the high-temperature bcc structure is clarified. {copyright} {ital 1996 The American Physical Society.}

  11. The vibrational energy flow transition in organic molecules: Theory meets experiment

    PubMed Central

    Bigwood, R.; Gruebele, M.; Leitner, D. M.; Wolynes, P. G.

    1998-01-01

    Most large dynamical systems are thought to have ergodic dynamics, whereas small systems may not have free interchange of energy between degrees of freedom. This assumption is made in many areas of chemistry and physics, ranging from nuclei to reacting molecules and on to quantum dots. We examine the transition to facile vibrational energy flow in a large set of organic molecules as molecular size is increased. Both analytical and computational results based on local random matrix models describe the transition to unrestricted vibrational energy flow in these molecules. In particular, the models connect the number of states participating in intramolecular energy flow to simple molecular properties such as the molecular size and the distribution of vibrational frequencies. The transition itself is governed by a local anharmonic coupling strength and a local state density. The theoretical results for the transition characteristics compare well with those implied by experimental measurements using IR fluorescence spectroscopy of dilution factors reported by Stewart and McDonald [Stewart, G. M. & McDonald, J. D. (1983) J. Chem. Phys. 78, 3907–3915]. PMID:9600899

  12. Surface energy from order parameter profile: At the QCD phase transition

    NASA Technical Reports Server (NTRS)

    Frei, Z.; Patkos, A.

    1989-01-01

    The order parameter profile between coexisting confined and plasma regions at the quantum chromodynamic (QCD) phase transition is constructed. The dimensionless combination of the surface energy (Sigma) and the correlation length (Zeta) is estimated to be Sigma Zeta 3 approximately equals 0.8.

  13. Determination of electron bunch shape using transition radiation and phase-energy measurements

    SciTech Connect

    Crosson, E.R.; Berryman, K.W.; Richman, B.A.

    1995-12-31

    We present data comparing microbunch temporal information obtained from electron beam phase-energy measurements with that obtained from transition radiation auto-correlation measurements. The data was taken to resolve some of the ambiguities in previous transition radiation results. By measuring the energy spectrum of the electron beam as a function of its phase relative to the accelerating field, phase-energy information was extracted. This data was analyzed using tomographic techniques to reconstruct the phase-space distribution assuming an electron energy dependence of E({var_phi}) = E{sub o} + E{sub acc}cos({var_phi}), where E{sub o} is the energy of an electron entering the field, E{sub acc} is the peak energy gain, and {var_phi} is the phase between the crest of the RF wave and an electron. Temporal information about the beam was obtained from the phase space distribution by taking the one dimensional projection along the time axis. We discuss the use of this technique to verify other transition radiation analysis methods.

  14. Statistical simulation of internal energy exchange in shock waves using explicit transition probabilities

    NASA Astrophysics Data System (ADS)

    Torres, Erik; Magin, Thierry

    2012-11-01

    A statistical model originally developed for electronic-translational energy transfer in atoms having multiple electronic states (Anderson et al, RGD15, 1986) is applied to the study of internal energy exchange in a polyatomic gas. The model is well-suited for gas kinetic simulations, because it provides an explicit expression for the transition probabilities between internal energy levels. All molecules possessing a given internal energy level are treated as a separate chemical species and all collisions involving exchange of internal energy thus become pseudo-chemical reactions. Post-collision energy levels of the two partners are determined by conserving the total energy of the collision pair and taking into account detailed balance. In the present work, DSMC simulations of relaxation in a stationary gas are performed and compared to those obtained by Anderson et al. Additionally, we apply the model to the simulation of rotational relaxation behind a normal shock wave.

  15. Transition from a matter-dominated era to a dark energy universe

    NASA Astrophysics Data System (ADS)

    Nojiri, Shin'Ichi; Odintsov, Sergei D.; Štefančić, Hrvoje

    2006-10-01

    We develop a general program of the unification of a matter-dominated era with an acceleration epoch for scalar-tensor theory or a dark fluid. The general reconstruction of the scalar-tensor theory is fulfilled. The explicit form of the scalar potential for which the theory admits a matter-dominated era, a transition to an acceleration, and an (asymptotically de Sitter) acceleration epoch consistent with Wilkinson Microwave Anisotropy Probe data is found. The interrelation of the epochs of deceleration-acceleration transition and matter dominance-dark energy transition for dark fluids with a general equation of state (EOS) is investigated. We give several examples of such models with explicit EOS (using redshift parametrization) where matter-dark energy domination transition may precede the deceleration-acceleration transition. As a by-product, the reconstruction scheme is applied to scalar-tensor theory to define the scalar potentials which may produce the dark matter effect. The obtained modification of Newton potential may explain the rotation curves of galaxies.

  16. Sexual Communication, Sexual Goals, and Students’ Transition to College: Implications for Sexual Assault, Decision-Making, and Risky Behaviors

    PubMed Central

    Lindgren, Kristen P.; Schacht, Rebecca L.; Pantalone, David W.; Blayney, Jessica A.

    2009-01-01

    A qualitative study was conducted to understand college students’ experiences and perceptions of sexual communication and sexual goals, and how they were affected by the transition from high school to college. Participants were heterosexual college students (N = 29). Single-sex focus groups were conducted and analyzed for themes. Major themes included gender differences in communication of sexual interest, with men reportedly perceiving more sexualized intentions than women intended to communicate. Gender similarities were observed related to preferring indirect and nonverbal communication and to having more freedom to pursue sexual goals in college. Men focused more intently on casual sex goals, whereas women reported more relationship goals and concerns about reputation. PMID:20502624

  17. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    PubMed

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements. PMID:23955030

  18. Large Hybrid Energy Systems for Making Low CO2 Load-Following Power and Synthetic Fuel

    SciTech Connect

    Robert S. Cherry; Richard D. Boardman; Steven Aumeier

    2012-02-01

    Hybrid energy systems using nuclear heat sources can economically produce load-following electrical power by exploiting the surplus generation capacity available at night or seasonally to make synthetic fuel. Vehicle fuel is the only current energy use large enough to absorb all the energy capacity that might be diverted from the power industry, and its ease of storage obviates problems with discontinuous synfuel production. The potential benefits and challenges of synfuels integration are illustrated by the production of methanol from natural gas (as a source of carbon) using steam from a light water nuclear power reactor which is assumed to be available in accord with a year's worth of power demand data. Methanol's synthesis process is easily adapted to using 300 C heat from a light water reactor and this simple compound can be further processed into gasoline, biodiesel, or dimethyl ether, fuels which can be used with the current vehicle fleet. A supplemental feed to the methanol process of natural gas (for energy) allows operation at constant full rate when the nuclear heat is being used to produce electrical power. The higher capital costs of such a system are offset by a lower cost of heat and power production from a large base load type of plant and by reduced costs associated with much lower CO2 emissions. Other less tangible economic benefits of this and similar hybrid systems include better use of natural resource for fuels and greater energy services security from the domestic production of vehicle fuel.

  19. Making Homes Part of the Climate Solution: Policy Options To Promote Energy Efficiency

    SciTech Connect

    Brown, Dr. Marilyn Ann; Chandler, Jess; Lapsa, Melissa Voss; Ally, Moonis

    2009-06-01

    In the area of energy efficiency, advanced technologies combined with best practices appear to afford not only large, but also cost-effective options to conserve energy and reduce greenhouse gas emissions (McKinsey & Company, 2007). In practice, however, the realization of this potential has often proven difficult. Progress appears to require large numbers of individuals to act knowledgeably, and each individual must often act with enabling assistance from others. Even when consumer education is effective and social norms are supportive, the actions of individuals and businesses can be impeded by a broad range of barriers, many of which are non-technical in nature. Title XVI of the Energy Policy Act of 2005 included a mandate to examine barriers to progress and make recommendations in this regard. A detailed report on barriers as well as the National strategy for overcoming barriers met this requirement (Brown et al, 2008; CCCSTI, 2009). Following up on this mandate, the U.S. Climate Change Technology Program (CCTP) chose to focus next on the development of policy options to improve energy efficiency in residential buildings, with supporting analysis of pros and cons, informed in part by behavioral research. While this work is sponsored by CCTP, it has been undertaken in coordination with DOE's Building Technologies Program and Office of Electricity Delivery and Energy Reliability.

  20. Pressure makes mercury a transition metal: a first-principles study of HgF4 solid phases

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoli; Lin, Haiqing; Ma, Yanming; Miao, Maosheng

    2012-02-01

    Mercury is considered as a post-transition metal, because its d shell is filled and does not involve in forming chemical bonds. Yet, because the large relativistic effect pushes up the outmost d level, there is a high expectation that Hg can be stabilized in a higher oxidation state. The HgF4 molecule has been predicted by calculations, and an evidence of such molecule is shown by IR absorption recently. However, there is neither computation nor experiment report on possible high oxidation state of Hg in solid. By using first-principles density functional theory and a structure-searching method, we studied the structural change of a solid system of Hg and F under pressures from 0 to 300 GPa. We found that at lower pressure, the stable structure consists of HgF2 and F2 molecules. At about 25 GPa, the system undergoes a structural change and forms HgF4 planar molecules featuring d8 configuration. The calculations show that the d orbitals of Hg involve in chemical bonding, which is the signature of a transition metal.

  1. Calculation of Zeeman splitting and Zeeman transition energies of spherical quantum dot in uniform magnetic field

    NASA Astrophysics Data System (ADS)

    Çakır, Bekir; Atav, Ülfet; Yakar, Yusuf; Özmen, Ayhan

    2016-08-01

    In this study we report a detailed theoretical investigation of the effect of an external magnetic field on the 1s-, 2p-, 3d- and 4f-energy states of a spherical quantum dot. We treat the contribution of the diamagnetic term as a perturbation and discuss the effect of the diamagnetic term on the 1s-, 2p-, 3d- and 4f-energy states. We also have calculated the Zeeman transition energies between 2p → 1s and 3d → 2p states with m = 0, ±1 and 0, ±1, ±2 as a function of dot radius and the magnetic field strength. The results show that the magnetic field, impurity charge and dot radius have a strong influence on the energy states and the Zeeman transitions. It is found that the energies of the electronic states with m < 0 addition of the diamagnetic term firstly decrease toward a minimum, and then increase with the increasing magnetic field strength. We have seen that as magnetic field intensity is adjusted, frequency of the emitted light can be changed for Zeeman transitions.

  2. Energy levels, radiative rates, and lifetimes for transitions in W LVIII

    NASA Astrophysics Data System (ADS)

    Aggarwal, Kanti M.; Keenan, Francis P.

    2014-11-01

    Energy levels and radiative rates are reported for transitions in Cl-like W LVIII. Configuration interaction (CI) has been included among 44 configurations (generating 4978 levels) over a wide energy range up to 363 Ryd, and the general-purpose relativistic atomic structure package (GRASP) adopted for the calculations. Since no other results of comparable complexity are available, calculations have also been performed with the flexible atomic code (FAC), which help in assessing the accuracy of our results. Energies are listed for the lowest 400 levels (with energies up to ˜98 Ryd), which mainly belong to the 3s23p5, 3s3p6, 3s23p43d, 3s23p33d2, 3s3p43d2, 3s23p23d3, and 3p63d configurations, and radiative rates are provided for four types of transitions, i.e. E1, E2, M1, and M2. Our energy levels are assessed to be accurate to better than 0.5%, whereas radiative rates (and lifetimes) should be accurate to better than 20% for a majority of the strong transitions.

  3. Energy levels, radiative rates, and lifetimes for transitions in W LVIII

    SciTech Connect

    Aggarwal, Kanti M. Keenan, Francis P.

    2014-11-15

    Energy levels and radiative rates are reported for transitions in Cl-like W LVIII. Configuration interaction (CI) has been included among 44 configurations (generating 4978 levels) over a wide energy range up to 363 Ryd, and the general-purpose relativistic atomic structure package (GRASP) adopted for the calculations. Since no other results of comparable complexity are available, calculations have also been performed with the flexible atomic code (FAC), which help in assessing the accuracy of our results. Energies are listed for the lowest 400 levels (with energies up to ∼98 Ryd), which mainly belong to the 3s{sup 2}3p{sup 5}, 3s3p{sup 6}, 3s{sup 2}3p{sup 4}3d, 3s{sup 2}3p{sup 3}3d{sup 2}, 3s3p{sup 4}3d{sup 2}, 3s{sup 2}3p{sup 2}3d{sup 3}, and 3p{sup 6}3d configurations, and radiative rates are provided for four types of transitions, i.e. E1, E2, M1, and M2. Our energy levels are assessed to be accurate to better than 0.5%, whereas radiative rates (and lifetimes) should be accurate to better than 20% for a majority of the strong transitions.

  4. Ultrasonic guided wave propagation across waveguide transitions: energy transfer and mode conversion.

    PubMed

    Puthillath, Padmakumar; Galan, Jose M; Ren, Baiyang; Lissenden, Cliff J; Rose, Joseph L

    2013-05-01

    Ultrasonic guided wave inspection of structures containing adhesively bonded joints requires an understanding of the interaction of guided waves with geometric and material discontinuities or transitions in the waveguide. Such interactions result in mode conversion with energy being partitioned among the reflected and transmitted modes. The step transition between an aluminum layer and an aluminum-adhesive-aluminum multi-layer waveguide is analyzed as a model structure. Dispersion analysis enables assessment of (i) synchronism through dispersion curve overlap and (ii) wavestructure correlation. Mode-pairs in the multi-layer waveguide are defined relative to a prescribed mode in a single layer as being synchronized and having nearly perfect wavestructure matching. Only a limited number of mode-pairs exist, and each has a unique frequency range. A hybrid model based on semi-analytical finite elements and the normal mode expansion is implemented to assess mode conversion at a step transition in a waveguide. The model results indicate that synchronism and wavestructure matching is associated with energy transfer through the step transition, and that the energy of an incident wave mode in a single layer is transmitted almost entirely to the associated mode-pair, where one exists. This analysis guides the selection of incident modes that convert into transmitted modes and improve adhesive joint inspection with ultrasonic guided waves. PMID:23654370

  5. Calculating Transition Energy Barriers and Characterizing Activation States for Steps of Fusion.

    PubMed

    Ryham, Rolf J; Klotz, Thomas S; Yao, Lihan; Cohen, Fredric S

    2016-03-01

    We use continuum mechanics to calculate an entire least energy pathway of membrane fusion, from stalk formation, to pore creation, and through fusion pore enlargement. The model assumes that each structure in the pathway is axially symmetric. The static continuum stalk structure agrees quantitatively with experimental stalk architecture. Calculations show that in a stalk, the distal monolayer is stretched and the stored stretching energy is significantly less than the tilt energy of an unstretched distal monolayer. The string method is used to determine the energy of the transition barriers that separate intermediate states and the dynamics of two bilayers as they pass through them. Hemifusion requires a small amount of energy independently of lipid composition, while direct transition from a stalk to a fusion pore without a hemifusion intermediate is highly improbable. Hemifusion diaphragm expansion is spontaneous for distal monolayers containing at least two lipid components, given sufficiently negative diaphragm spontaneous curvature. Conversely, diaphragms formed from single-component distal monolayers do not expand without the continual injection of energy. We identify a diaphragm radius, below which central pore expansion is spontaneous. For larger diaphragms, prior studies have shown that pore expansion is not axisymmetric, and here our calculations supply an upper bound for the energy of the barrier against pore formation. The major energy-requiring deformations in the steps of fusion are: widening of a hydrophobic fissure in bilayers for stalk formation, splay within the expanding hemifusion diaphragm, and fissure widening initiating pore formation in a hemifusion diaphragm. PMID:26958888

  6. Energy harvesting based on FE-FE transition in ferroelectric single crystals.

    PubMed

    Guyomar, Daniel; Pruvost, Sebastien; Sebald, Gael

    2008-02-01

    The pyroelectric properties of Pb(Zn(1/3)Nb(2/3))(0955)Ti(0.045)O(3) single crystals versus an electric field have been studied for energy harvesting in this paper. Two thermodynamic cycles (Stirling and Ericsson) were used for this purpose. By applying an electric field, a FE-FE transition was induced, abruptly increasing the polarization. This transition minimized the supplied energy and improved the harvested energy. By discharging the single crystal at a higher temperature, a gain of 1100% was obtained with the Stirling cycle at 1 kV/mm (gain is defined as harvested energy divided by supplied energy). The study revealed that Stirling cycles are more interesting for low electric fields. Based on experimental results, simulations were carried out to estimate energy harvesting in high electric fields to evaluate the performances of thin samples (single crystals or oriented thin films). At high electric fields, both cycles gave almost the same energy harvesting, but Ericsson cycles were more appropriate to control the voltage on the sample. The simulation led to a harvested energy of 500 mJ/g for an applied electric field equal to 50 kV/mm. The efficiency with respect to Carnot was raised 20%. PMID:18334334

  7. Activation energy for a model ferrous-ferric half reaction from transition path sampling

    NASA Astrophysics Data System (ADS)

    Drechsel-Grau, Christof; Sprik, Michiel

    2012-01-01

    Activation parameters for the model oxidation half reaction of the classical aqueous ferrous ion are compared for different molecular simulation techniques. In particular, activation free energies are obtained from umbrella integration and Marcus theory based thermodynamic integration, which rely on the diabatic gap as the reaction coordinate. The latter method also assumes linear response, and both methods obtain the activation entropy and the activation energy from the temperature dependence of the activation free energy. In contrast, transition path sampling does not require knowledge of the reaction coordinate and directly yields the activation energy [C. Dellago and P. G. Bolhuis, Mol. Simul. 30, 795 (2004), 10.1080/08927020412331294869]. Benchmark activation energies from transition path sampling agree within statistical uncertainty with activation energies obtained from standard techniques requiring knowledge of the reaction coordinate. In addition, it is found that the activation energy for this model system is significantly smaller than the activation free energy for the Marcus model, approximately half the value, implying an equally large entropy contribution.

  8. Measurements of the spectrum and energy dependence of X-ray transition radiation

    NASA Technical Reports Server (NTRS)

    Cherry, M. L.

    1978-01-01

    The results of experiments designed to test the theory of X-ray transition radiation and to verify the predicted dependence of the characteristic features of the radiation on the radiator dimensions are presented. The X-ray frequency spectrum produced by 5- to 9-GeV electrons over the range 4 to 30 keV was measured with a calibrated single-crystal Bragg spectrometer, and at frequencies up to 100 keV with an NaI scintillator. The interference pattern in the spectrum and the hardening of the radiation with increasing foil thickness are clearly observed. The energy dependence of the total transition-radiation intensity was studied using a radiator with large dimensions designed to yield energy-dependent signals at very high particle energies, up to E/mc-squared approximately equal to 100,000. The results are in good agreement with the theoretical predictions.

  9. Low-energy description of the metal-insulator transition in the rare-earth nickelates

    NASA Astrophysics Data System (ADS)

    Subedi, Alaska; Peil, Oleg E.; Georges, Antoine

    2015-02-01

    We propose a simple theoretical description of the metal-insulator transition of rare-earth nickelates. The theory involves only two orbitals per nickel site, corresponding to the low-energy antibonding eg states. In the monoclinic insulating state, bond-length disproportionation splits the manifold of eg bands, corresponding to a modulation of the effective on-site energy. We show that, when subject to a local Coulomb repulsion U and Hund's coupling J , the resulting bond-disproportionated state is a paramagnetic insulator for a wide range of interaction parameters. Furthermore, we find that when U -3 J is small or negative, a spontaneous instability to bond disproportionation takes place for large enough J . This minimal theory emphasizes that a small or negative charge-transfer energy, a large Hund's coupling, and a strong coupling to bond disproportionation are the key factors underlying the transition. Experimental consequences of this theoretical picture are discussed.

  10. Energy Levels and Transition Rates for GA-Like Ions (Xe XXIV-Pr XXIX)

    NASA Astrophysics Data System (ADS)

    El-Sayed, F.

    2015-07-01

    Energy levels, wavelengths, transition probabilities, oscillator strengths, and line strengths have been calculated for allowed electric dipole 4s 2 4p-4s4p 2 and 4s 2 4p-4s 2 4d transitions of Gallium-like ions from Z = 54 to 59, Xe XXIV, Cs XXV, Ba XXVI, La XXVII, Ce XXVIII, and Pr XXIX. The fully relativistic multiconfiguration Dirac-Fock method, taking into account both correlations within the n = 4 complex and the quantum electrodynamic effects, has been used in the calculations. The results have been compared with the available experimental and other theoretical results.

  11. Energies, Wavelengths, and Transition Rates for Ga-Like Ions (Nd XXX-Tb XXXV)

    NASA Astrophysics Data System (ADS)

    El-Sayed, Fatma; Attia, S. M.

    2016-03-01

    Energies, wavelengths, transition probabilities, oscillator strengths, and line strengths have been calculated for 4s24p-4s4p2 and 4s24p-4s24d transitions in gallium-like ions from Z = 60 to 65, for Nd XXX, Pm XXXI, Sm XXXII, Eu XXXIII, Gd XXXIV, and Tb XXXV using the fully relativistic multiconfi guration Dirac-Fock method. The correlation with the n = 4 complex and the quantum electrodynamic effects have been considered in the calculations. The obtained results have been compared with the available experimental and other theoretical results.

  12. Energies and Electric Dipole Transitions for Low-Lying Levels of Protactinium IV and Uranium V

    NASA Astrophysics Data System (ADS)

    Ürer, Güldem; Özdemir, Leyla

    2012-02-01

    We have reported a relativistic multiconfiguration Dirac-Fock (MCDF) study on low-lying level structures of protactinium IV (Z =91) and uranium V (Z =92) ions. Excitation energies and electric dipole (E1) transition parameters (wavelengths, oscillator strengths, and transition rates) for these low-lying levels have been given. We have also investigated the influence of the transverse Breit and quantum electrodynamic (QED) contributions besides correlation effects on the level structure. A comparison has been made with a few available data for these ions in the literature.

  13. The DeStress for Success Program: effects of a stress education program on cortisol levels and depressive symptomatology in adolescents making the transition to high school.

    PubMed

    Lupien, S J; Ouellet-Morin, I; Trépanier, L; Juster, R P; Marin, M F; Francois, N; Sindi, S; Wan, N; Findlay, H; Durand, N; Cooper, L; Schramek, T; Andrews, J; Corbo, V; Dedovic, K; Lai, B; Plusquellec, P

    2013-09-26

    Various studies have shown that increased activity of the hypothalamic-pituitary-adrenal (HPA) axis can predict the onset of adolescent depressive symptomatology. We have previously shown that adolescents making the transition to high school present a significant increase in cortisol levels, the main product of HPA axis activation. In the present study, we evaluated whether a school-based education program developed according to the current state of knowledge on stress in psychoneuroendocrinology decreases cortisol levels and/or depressive symptoms in adolescents making the transition to high school. Participants were 504 Year 7 high school students from two private schools in the Montreal area. Adolescents of one school were exposed to the DeStress for Success Program while adolescents from the other school served as controls. Salivary cortisol levels and depressive symptomatology were measured before, immediately after as well as 3 months after exposure to the program. Measures of negative mood were obtained at baseline in order to determine whether adolescents starting high school with specific negative moods were differentially responsive to the program. The results show that only adolescents starting high school with high levels of anger responded to the intervention with a significant decrease in cortisol levels. Moreover, we found that adolescents who took part in the intervention and showed decreasing cortisol levels following the intervention (responders) were 2.45 times less at risk to suffer from clinical and subclinical depressive states three months post-intervention in comparison to adolescents who showed increasing cortisol levels following the intervention (nonresponders). This study provides the first evidence that a school-based program on stress is effective at decreasing cortisol levels and depressive symptomatology in adolescents making the transition to high school and it helps explain which adolescents are sensitive to the program and what

  14. Minimum Free Energy Path of Ligand-Induced Transition in Adenylate Kinase

    PubMed Central

    Matsunaga, Yasuhiro; Fujisaki, Hiroshi; Terada, Tohru; Furuta, Tadaomi; Moritsugu, Kei; Kidera, Akinori

    2012-01-01

    Large-scale conformational changes in proteins involve barrier-crossing transitions on the complex free energy surfaces of high-dimensional space. Such rare events cannot be efficiently captured by conventional molecular dynamics simulations. Here we show that, by combining the on-the-fly string method and the multi-state Bennett acceptance ratio (MBAR) method, the free energy profile of a conformational transition pathway in Escherichia coli adenylate kinase can be characterized in a high-dimensional space. The minimum free energy paths of the conformational transitions in adenylate kinase were explored by the on-the-fly string method in 20-dimensional space spanned by the 20 largest-amplitude principal modes, and the free energy and various kinds of average physical quantities along the pathways were successfully evaluated by the MBAR method. The influence of ligand binding on the pathways was characterized in terms of rigid-body motions of the lid-shaped ATP-binding domain (LID) and the AMP-binding (AMPbd) domains. It was found that the LID domain was able to partially close without the ligand, while the closure of the AMPbd domain required the ligand binding. The transition state ensemble of the ligand bound form was identified as those structures characterized by highly specific binding of the ligand to the AMPbd domain, and was validated by unrestrained MD simulations. It was also found that complete closure of the LID domain required the dehydration of solvents around the P-loop. These findings suggest that the interplay of the two different types of domain motion is an essential feature in the conformational transition of the enzyme. PMID:22685395

  15. Specific Energy as an Index to Identify the Critical Failure Mode Transition Depth in Rock Cutting

    NASA Astrophysics Data System (ADS)

    He, Xianqun; Xu, Chaoshui

    2016-04-01

    Rock cutting typically involves driving a rigid cutter across the rock surface at certain depth of cut and is used to remove rock material in various engineering applications. It has been established that there exist two distinct failure modes in rock cutting, i.e. ductile mode and brittle mode. The ductile mode takes precedence when the cut is shallow and the increase in the depth of cut leads to rock failure gradually shifted to brittle-dominant mode. The threshold depth or the critical transition depth, at which rock failure under cutting changes from the ductile to the brittle mode, is associated with not only the rock properties but also the cutting operational parameters and the understanding of this threshold is important to optimise the tool design and operational parameters. In this study, a new method termed the specific cutting energy transition model is proposed from an energy perspective which is demonstrated to be much more effective in identifying the critical transition depth compared with existing approaches. In the ductile failure cutting mode, the specific cutting energy is found to be independent of the depth of cut; but in the brittle failure cutting mode, the specific cutting energy is found to be dependent on the depth of cut following a power-law relationship. The critical transition depth is identified as the intersection point between these two relationships. Experimental tests on two types of rocks with different combinations of cutting velocity, depth of cut and back rake angle are conducted and the application of the proposed model on these cutting datasets has demonstrated that the model can provide a very effective tool to analyse the cutting mechanism and to identify the critical transition depth.

  16. Critical high-dimensional state transitions in cell populations or why cancers follow the principle ``What does not kill me makes me stronger''

    NASA Astrophysics Data System (ADS)

    Huang, Sui

    Transitions between high-dimensional attractor states in the quasi-potential landscape of the gene regulatory network, induced by environmental perturbations and/or facilitated by mutational rewiring of the network, underlie cell phenotype switching in development as well as in cancer progression, including acquisition of drug-resistant phenotypes. Considering heterogeneous cell populations as statistical ensembles of cells, and single-cell resolution gene expression profiling of cell populations undergoing a cell phenotype shift allow us now to map the topography of the landscape and its distortion. From snapshots of single-cell expression patterns of a cell population measured during major transitions we compute a quantity that identifies symmetry-breaking destabilization of attractors (bifurcation) and concomitant dimension-reduction of the state space manifold (landscape distortion) which precede critical transitions to new attractor states. The model predicts, and we show experimentally, the almost inevitable generation of aberrant cells associated with such critical transitions in multi-attractor landscapes: therapeutic perturbations which seek to push cancer cells to the apoptotic state, almost always produce ``rebellious'' cells which move in the ``opposite direction'': instead of dying they become more stem-cell-like and malignant. We show experimentally that the inadvertent generation of more malignant cancer cells by therapy indeed results from transition of surviving (but stressed) cells into unforeseen attractor states and not simply from selection of inherently more resistant cells. Thus, cancer cells follow not so much Darwin, as generally thought (survival of the fittest), but rather Nietzsche (What does not kill me makes me stronger). Supported by NIH (NCI, NIGMS), Alberta Innovates.

  17. Scaling Properties of Adsorption Energies for Hydrogen-Containing Molecules on Transition-Metal Surfaces

    NASA Astrophysics Data System (ADS)

    Abild-Pedersen, F.; Greeley, J.; Studt, F.; Rossmeisl, J.; Munter, T. R.; Moses, P. G.; Skúlason, E.; Bligaard, T.; Nørskov, J. K.

    2007-07-01

    Density functional theory calculations are presented for CHx, x=0,1,2,3, NHx, x=0,1,2, OHx, x=0,1, and SHx, x=0,1 adsorption on a range of close-packed and stepped transition-metal surfaces. We find that the adsorption energy of any of the molecules considered scales approximately with the adsorption energy of the central, C, N, O, or S atom, the scaling constant depending only on x. A model is proposed to understand this behavior. The scaling model is developed into a general framework for estimating the reaction energies for hydrogenation and dehydrogenation reactions.

  18. Improving energy efficiency: Strategies for supporting sustained market evolution in developing and transitioning countries

    SciTech Connect

    Meyers, S.

    1998-02-01

    This report presents a framework for considering market-oriented strategies for improving energy efficiency that recognize the conditions of developing and transitioning countries, and the need to strengthen the effectiveness of market forces in delivering greater energy efficiency. It discusses policies that build markets in general, such as economic and energy pricing reforms that encourage competition and increase incentives for market actors to improve the efficiency of their energy use, and measures that reduce the barriers to energy efficiency in specific markets such that improvement evolves in a dynamic, lasting manner. The report emphasizes how different policies and measures support one another and can create a synergy in which the whole is greater than the sum of the parts. In addressing this topic, it draws on the experience with market transformation energy efficiency programs in the US and other industrialized countries.

  19. Risk for Arrest: The Role of Social Bonds in Protecting Foster Youth Making the Transition to Adulthood

    PubMed Central

    Cusick, Gretchen Ruth; Havlicek, Judy R.; Courtney, Mark E.

    2012-01-01

    This study examines a sample of foster youth at the onset of the transition to adulthood and explores how social bonds are related to the risk of arrest during adulthood. Drawing from official arrest records, event history models are used to examine the time to arrest. Because individuals may be at risk for different types of crime, competing risk regression models are used to distinguish among arrests for drug-related, nonviolent, or violent crimes. Between the ages of 17–18 and 24, 46% of former foster youth experience an arrest. Arrests were evenly distributed across drug, nonviolent, and violent crimes columns. Although findings fail to support the significance of social bonds to interpersonal domains, bonds to employment and education are associated with a lower risk for arrest. Child welfare policy and practice implications for building connections and protections around foster youth are discussed. PMID:22239390

  20. Energy Efficiency Improvement and Cost Saving Opportunities for Cement Making. An ENERGY STAR Guide for Energy and Plant Managers

    SciTech Connect

    Galitsky, Christina; Worrell, Ernst; Galitsky, Christina

    2008-01-01

    The cost of energy as part of the total production costs in the cement industry is significant, warranting attention for energy efficiency to improve the bottom line. Historically, energy intensity has declined, although more recently energy intensity seems to have stabilized with the gains. Coal and coke are currently the primary fuels for the sector, supplanting the dominance of natural gas in the 1970s. Most recently, there is a slight increase in the use of waste fuels, including tires. Between 1970 and 1999, primary physical energy intensity for cement production dropped 1 percent/year from 7.3 MBtu/short ton to 5.3 MBtu/short ton. Carbon dioxide intensity due to fuel consumption and raw material calcination dropped 16 percent, from 609 lb. C/ton of cement (0.31 tC/tonne) to 510 lb. C/ton cement (0.26 tC/tonne). Despite the historic progress, there is ample room for energy efficiency improvement. The relatively high share of wet-process plants (25 percent of clinker production in 1999 in the U.S.) suggests the existence of a considerable potential, when compared to other industrialized countries. We examined over 40 energy efficient technologies and measures and estimated energy savings, carbon dioxide savings, investment costs, and operation and maintenance costs for each of the measures. The report describes the measures and experiences of cement plants around the wold with these practices and technologies. Substantial potential for energy efficiency improvement exists in the cement industry and in individual plants. A portion of this potential will be achieved as part of (natural) modernization and expansion of existing facilities, as well as construction of new plants in particular regions. Still, a relatively large potential for improved energy management practices exists.

  1. Test and Evaluation Metrics of Crew Decision-Making And Aircraft Attitude and Energy State Awareness

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Ellis, Kyle K. E.; Stephens, Chad L.

    2013-01-01

    NASA has established a technical challenge, under the Aviation Safety Program, Vehicle Systems Safety Technologies project, to improve crew decision-making and response in complex situations. The specific objective of this challenge is to develop data and technologies which may increase a pilot's (crew's) ability to avoid, detect, and recover from adverse events that could otherwise result in accidents/incidents. Within this technical challenge, a cooperative industry-government research program has been established to develop innovative flight deck-based counter-measures that can improve the crew's ability to avoid, detect, mitigate, and recover from unsafe loss-of-aircraft state awareness - specifically, the loss of attitude awareness (i.e., Spatial Disorientation, SD) or the loss-of-energy state awareness (LESA). A critical component of this research is to develop specific and quantifiable metrics which identify decision-making and the decision-making influences during simulation and flight testing. This paper reviews existing metrics and methods for SD testing and criteria for establishing visual dominance. The development of Crew State Monitoring technologies - eye tracking and other psychophysiological - are also discussed as well as emerging new metrics for identifying channelized attention and excessive pilot workload, both of which have been shown to contribute to SD/LESA accidents or incidents.

  2. Probing Critical Point Energies of Transition Metal Dichalcogenides: Surprising Indirect Gap of Single Layer WSe2.

    PubMed

    Zhang, Chendong; Chen, Yuxuan; Johnson, Amber; Li, Ming-Yang; Li, Lain-Jong; Mende, Patrick C; Feenstra, Randall M; Shih, Chih-Kang

    2015-10-14

    By using a comprehensive form of scanning tunneling spectroscopy, we have revealed detailed quasi-particle electronic structures in transition metal dichalcogenides, including the quasi-particle gaps, critical point energy locations, and their origins in the Brillouin zones. We show that single layer WSe2 surprisingly has an indirect quasi-particle gap with the conduction band minimum located at the Q-point (instead of K), albeit the two states are nearly degenerate. We have further observed rich quasi-particle electronic structures of transition metal dichalcogenides as a function of atomic structures and spin-orbit couplings. Such a local probe for detailed electronic structures in conduction and valence bands will be ideal to investigate how electronic structures of transition metal dichalcogenides are influenced by variations of local environment. PMID:26389585

  3. Method for finding mechanism and activation energy of magnetic transitions, applied to skyrmion and antivortex annihilation

    NASA Astrophysics Data System (ADS)

    Bessarab, Pavel F.; Uzdin, Valery M.; Jónsson, Hannes

    2015-11-01

    A method for finding minimum energy paths of transitions in magnetic systems is presented. The path is optimized with respect to orientation of the magnetic vectors while their magnitudes are fixed or obtained from separate calculations. The curvature of the configuration space is taken into account by: (1) using geodesics to evaluate distances and displacements of the system during the optimization, and (2) projecting the path tangent and the magnetic force on the tangent space of the manifold defined by all possible orientations of the magnetic vectors. The method, named geodesic nudged elastic band (GNEB), and its implementation are illustrated with calculations of complex transitions involving annihilation and creation of skyrmion and antivortex states. The lifetime of the latter was determined within harmonic transition state theory using a noncollinear extension of the Alexander-Anderson model.

  4. Energy Transition Initiative: Island Energy Snapshot - Belize; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-03-01

    This profile provides a snapshot of the energy landscape of Belize, a Central American country bordering Mexico to the north, Guatemala to the west and south, and the Caribbean Sea to the east. Although not an island nation, Belize is included in this energy snapshot series because it is a member of the Caribbean Community (CARICOM), an alliance of 15 Caribbean nations in the region.

  5. Energy levels, radiative rates and electron impact excitation rates for transitions in C III

    NASA Astrophysics Data System (ADS)

    Aggarwal, Kanti M.; Keenan, Francis P.

    2015-06-01

    We report energy levels, radiative rates (A-values) and lifetimes for the astrophysically important Be-like ion C III. For the calculations, 166 levels belonging to the n ≤ 5 configurations are considered and the GRASP (General-purpose Relativistic Atomic Structure Package) is adopted. Einstein A-coefficients are provided for all E1, E2, M1 and M2 transitions, while lifetimes are compared with available measurements as well as theoretical results, and no large discrepancies noted. Our energy levels are assessed to be accurate to better than 1 per cent for a majority of levels, and A-values to better than 20 per cent for most transitions. Collision strengths are also calculated, for which the Dirac Atomic R-matrix Code (DARC) is used. A wide energy range, up to 21 Ryd, is considered and resonances resolved in a fine energy mesh in the thresholds region. The collision strengths are subsequently averaged over a Maxwellian velocity distribution to determine effective collision strengths up to a temperature of 8.0 × 105 K, sufficient for most astrophysical applications. Our data are compared with the recent R-matrix calculations of Fernández-Menchero et al., and significant differences (up to over an order of magnitude) are noted for several transitions over the complete temperature range of the results.

  6. Low-Energy Asteroid and Comet Transit Analysis using Isolating Blocks

    NASA Astrophysics Data System (ADS)

    Anderson, Rodney L.; Chodas, Paul; Easton, Robert W.; Lo, Martin W.

    2016-05-01

    It is well known that asteroids and comets typically capture or transit near a planet by traveling through the L1 and L2 libration point gateways. These regions are therefore key to understanding the mechanism by which these captures, transits, and potential impacts occur. Recently, Anderson, Easton, and Lo (2015) explored the L2 region in the Earth-Moon system using isolating blocks in the circular restricted three-body problem (CRTBP). Isolating blocks provide a theoretically rigorous method for computing the invariant manifolds of libration point periodic orbits and all possible transit trajectories at a particular Jacobi constant in the CRTBP. Using isolating block methods allows us to directly compute and study the transit trajectories used by comets and asteroids in the low-energy regimes common for these types of bodies. In this study, both L1 and L2 isolating blocks are computed for the Sun-Earth and Sun-Jupiter CRTBP systems to compute trajectories transiting near the Earth and Jupiter. Statistics based on transit time, periapse passages, and exit location are first computed. Then individual trajectory solutions corresponding to different trajectory types are analyzed. The transit trajectories are also characterized using their orbital elements and compared to known comets and asteroids. These results show that the invariant manifolds of the orbits in the isolating block control and guide the dynamics of comets and asteroids as they temporarily capture between the L1 and L2 region of a planet or satellite.Reference: Anderson, R. L., R. W. Easton, M. W. Lo (2015), AAS/AIAA Astrodynamics Conf., AAS 15-615.

  7. Effects of the Menopausal Transition on Factors Related to Energy Balance. A MONET group Study

    PubMed Central

    Karine, Duval; Denis, Prud’homme; Rémi, Rabasa-Lhoret; Irene, Strychar; Martin, Brochu; Jean-Marc, Lavoie; Éric, Doucet

    2016-01-01

    Objectives Factors that influence weight gain during the menopausal transition are not fully understood. The purpose of this study was to investigate changes in energy expenditure (EE) across the menopausal transition. Methods One hundred and two premenopausal women (age: 49.9 ± 1.9 yrs; BMI: 23.3 ± 2.2 kg/m2) were followed for 5 years. Body composition (DXA), physical activity EE (accelerometer), resting EE and thermic effect of food (indirect calorimetry) were measured annually. Results Total EE decreased significantly over time in postmenopausal women (P < 0.05), which was mostly due to a decrease in physical activity EE (P < 0.05). Although average resting EE remained stable over time in postmenopausal women, a significant increase, over the 5-year period, was noted in women who were in the menopausal transition by year 5 (P < 0.05). Finally, the time spent in moderate physical activity decreased and the time spent in sedentary physical activity increased during the menopausal transition (P < 0.05). Conclusion These results suggest that menopausal transition is accompanied with a decline in EE mainly characterized by a decrease in physical activity EE and a shift to a more sedentary lifestyle. PMID:23422924

  8. Landau-Zener transitions mediated by an environment: Population transfer and energy dissipation

    SciTech Connect

    Dodin, Amro; Simine, Lena; Segal, Dvira; Garmon, Savannah

    2014-03-28

    We study Landau-Zener transitions between two states with the addition of a shared discretized continuum. The continuum allows for population decay from the initial state as well as indirect transitions between the two states. The probability of nonadiabatic transition in this multichannel model preserves the standard Landau-Zener functional form except for a shift in the usual exponential factor, reflecting population transfer into the continuum. We provide an intuitive explanation for this behavior assuming individual, independent transitions between pairs of states. In contrast, the ground state survival probability at long time shows a novel, non-monotonic, functional form with an oscillatory behavior in the sweep rate at low sweep rate values. We contrast the behavior of this open-multistate model to other generalized Landau-Zener models incorporating an environment: the stochastic Landau-Zener model and the dissipative case, where energy dissipation and thermal excitations affect the adiabatic region. Finally, we present evidence that the continuum of states may act to shield the two-state Landau-Zener transition probability from the effect of noise.

  9. Landau-Zener transitions mediated by an environment: population transfer and energy dissipation.

    PubMed

    Dodin, Amro; Garmon, Savannah; Simine, Lena; Segal, Dvira

    2014-03-28

    We study Landau-Zener transitions between two states with the addition of a shared discretized continuum. The continuum allows for population decay from the initial state as well as indirect transitions between the two states. The probability of nonadiabatic transition in this multichannel model preserves the standard Landau-Zener functional form except for a shift in the usual exponential factor, reflecting population transfer into the continuum. We provide an intuitive explanation for this behavior assuming individual, independent transitions between pairs of states. In contrast, the ground state survival probability at long time shows a novel, non-monotonic, functional form with an oscillatory behavior in the sweep rate at low sweep rate values. We contrast the behavior of this open-multistate model to other generalized Landau-Zener models incorporating an environment: the stochastic Landau-Zener model and the dissipative case, where energy dissipation and thermal excitations affect the adiabatic region. Finally, we present evidence that the continuum of states may act to shield the two-state Landau-Zener transition probability from the effect of noise. PMID:24697472

  10. Europe's battery: The making of the Alpine energy landscape, 1870-1955

    NASA Astrophysics Data System (ADS)

    Landry, Marc D., II

    iconic landscapes. It sheds light on the hydroelectric energy transition and shows the environmental impacts of electrification. Finally the history of Europe's Battery illuminates an alternative regional history of energy development and industrialization in Europe, one based on water and electricity and not coal.

  11. On the transition from strombolian to fountaining activity: a thermal energy-based driver

    NASA Astrophysics Data System (ADS)

    Bombrun, Maxime; Spampinato, Letizia; Harris, Andrew; Barra, Vincent; Caltabiano, Tommaso

    2016-02-01

    Since 1999, Mount Etna's (Italy) South-East crater system has been characterised by episodic lava fountaining. Each episode is characterised by initial strombolian activity followed by transition to sustained fountaining to feed high-effusion rate lava flow. Here, we use thermal infrared data recorded by a permanent radiometer station to characterise the transition to sustained fountaining fed by the New South-East crater that developed on the eastern flank of the South-East crater starting from January 2011. We cover eight fountaining episodes that occurred between 2012 and 2013. We first developed a routine to characterise event waveforms apparent in the precursory, strombolian phase. This allowed extraction of a database for thermal energy and waveform shape for 1934 events. We detected between 66 and 650 events per episode, with event durations being between 4 and 55 s. In total, 1508 (78 %) of the events had short waxing phases and dominant waning phases. Event frequency increased as climax was approached. Events had energies of between 3.0 × 106 and 5.8 × 109 J, with rank order analysis indicating the highest possible event energy of 8.1 × 109 J. To visualise the temporal evolution of retrieved parameters during the precursory phase, we applied a dimensionality reduction technique. Results show that weaker events occur during an onset period that forms a low-energy "sink". The transition towards fountaining occurs at 107 J, where subsequent events have a temporal trend towards the highest energies, and where sustained fountaining occurs when energies exceed 109 J. Such an energy-based framework allows researchers to track the evolution of fountaining episodes and to predict the time at which sustained fountaining will begin.

  12. Helping Students make the transition from novice learner of ground-water concepts to expert using the Plume Busters software

    USGS Publications Warehouse

    Macfarlane, P.A.; Bohling, G.; Thompson, K.W.; Townsend, M.

    2006-01-01

    Environmental and earth science students are novice learners and lack the experience needed to rise to the level of expert. To address this problem we have developed the prototype Plume Busters?? software as a capstone educational experience, in which students take on the role of an environmental consultant. Following a pipeline spill, the environmental consultant is hired by the pipeline owner to locate the resulting plume created by spill and remediate the contaminated aquifer at minimum monetary and time cost. The contamination must be removed from the aquifer before it reaches the river and eventually a downstream public water supply. The software consists of an interactive Java application and accompanying HTML linked pages. The application simulates movement of a plume from a pipeline break throug h a shallow alluvial aquifer towards the river. The accompanying web pages establish the simulated contamination scenario and provide students with background material on ground-water flow and transport principles. To make the role-play more realistic, the student must consider cost and time when making decisions about siting observation wells and wells for the pump-and-treat remediation system.

  13. Locating all transition states and studying the reaction pathways of potential energy surfaces

    NASA Astrophysics Data System (ADS)

    Westerberg, K. M.; Floudas, C. A.

    1999-05-01

    We propose a new method for calculating all stationary states, including saddle points of all orders, of a potential energy surface based on the αBB deterministic branch and bound global optimization algorithm. This method is based on rigorous optimization methods and offers a theoretical guarantee of enclosing all solutions to the equation ∇V=0. We apply this method to Murrel-Sorbie analytic potential energy surfaces of HCN, HSiN, HBO, and CS2, and to the Empirical Conformational Energy Program for Peptides (ECEPP/3) potential energy surfaces of alanine, alanine dipeptide, and tetra-alanine. For alanine, alanine dipeptide, and tetra-alanine, we proceed to analyze the topography of the potential energy surface by calculating reaction pathways, transition rate matrices, time-evolution of occupation probabilities, and rate disconnectivity graphs.

  14. Diffusion Monte Carlo for Accurate Dissociation Energies of 3d Transition Metal Containing Molecules.

    PubMed

    Doblhoff-Dier, Katharina; Meyer, Jörg; Hoggan, Philip E; Kroes, Geert-Jan; Wagner, Lucas K

    2016-06-14

    Transition metals and transition metal compounds are important to catalysis, photochemistry, and many superconducting systems. We study the performance of diffusion Monte Carlo (DMC) applied to transition metal containing dimers (TMCDs) using single-determinant Slater-Jastrow trial wavefunctions and investigate the possible influence of the locality and pseudopotential errors. We find that the locality approximation can introduce nonsystematic errors of up to several tens of kilocalories per mole in the absolute energy of Cu and CuH if Ar or Mg core pseudopotentials (PPs) are used for the 3d transition metal atoms. Even for energy differences such as binding energies, errors due to the locality approximation can be problematic if chemical accuracy is sought. The use of the Ne core PPs developed by Burkatzki et al. (J. Chem. Phys. 2008, 129, 164115), the use of linear energy minimization rather than unreweighted variance minimization for the optimization of the Jastrow function, and the use of large Jastrow parametrizations reduce the locality errors. In the second section of this article, we study the general performance of DMC for 3d TMCDs using a database of binding energies of 20 TMCDs, for which comparatively accurate experimental data is available. Comparing our DMC results to these data for our results that compare best with experiment, we find a mean unsigned error (MUE) of 4.5 kcal/mol. This compares well with the achievable accuracy in CCSDT(2)Q (MUE = 4.6 kcal/mol) and the best all-electron DFT results (MUE = 4.5 kcal/mol) for the same set of systems (Truhlar et al. J. Chem. Theory Comput. 2015, 11, 2036-2052). The mean errors in DMC depend less on the exchange-correlation functionals used to generate the trial wavefunction than the corresponding mean errors in the underlying DFT calculations. Furthermore, the QMC results obtained for each molecule individually vary less with the functionals used. These observations are relevant for systems such as

  15. Modulating energy arriving at photochemical reaction centers: orange carotenoid protein-related photoprotection and state transitions.

    PubMed

    Kirilovsky, Diana

    2015-10-01

    Photosynthetic organisms tightly regulate the energy arriving to the reaction centers in order to avoid photodamage or imbalance between the photosystems. To this purpose, cyanobacteria have developed mechanisms involving relatively rapid (seconds to minutes) changes in the photosynthetic apparatus. In this review, two of these processes will be described: orange carotenoid protein(OCP)-related photoprotection and state transitions which optimize energy distribution between the two photosystems. The photoactive OCP is a light intensity sensor and an energy dissipater. Photoactivation depends on light intensity and only the red-active OCP form, by interacting with phycobilisome cores, increases thermal energy dissipation at the level of the antenna. A second protein, the "fluorescence recovery protein", is needed to recover full antenna capacity under low light conditions. This protein accelerates OCP conversion to the inactive orange form and plays a role in dislodging the red OCP protein from the phycobilisome. The mechanism of state transitions is still controversial. Changes in the redox state of the plastoquinone pool induce movement of phycobilisomes and/or photosystems leading to redistribution of energy absorbed by phycobilisomes between PSII and PSI and/or to changes in excitation energy spillover between photosystems. The different steps going from the induction of redox changes to movement of phycobilisomes or photosystems remain to be elucidated. PMID:25139327

  16. Energy calibration of superconducting transition edge sensors for x-ray detection using pulse analysis

    SciTech Connect

    Hollerith, C.; Simmnacher, B.; Weiland, R.; Feilitzsch, F. v.; Isaila, C.; Jochum, J.; Potzel, W.; Hoehne, J.; Phelan, K.; Wernicke, D.; May, T.

    2006-05-15

    Transition edge sensors (TESs) have been developed to be used as high-resolution x-ray detectors. They show excellent energy resolution and can be used in many applications. TESs are a special kind of calorimeters that can determine small temperature changes after x-ray absorption. Such a temperature change causes a strong resistance change (superconducting to normal-conducting phase transition) that can be measured. The energy calibration of a TES based spectrometer is problematic due to the nonlinear behavior of the detector response. In this article, a method is introduced to calibrate the energy scale of TES spectra. This is accomplished by calculating the energy dependence of the response of the detector operated in electrothermal feedback mode. Using this method a calibration accuracy of a few eV for an x-ray energy of 6 keV can be achieved. Examples of energy dispersive x-ray spectroscopy (EDS) measurements demonstrate the high quality of this method for everyday use of TES EDS detectors in material analysis. However, because the method relies only on a few very general assumptions, it should also be useful for other kinds of TES detectors.

  17. A cautionary approach in transitioning to 'green' energy technologies and practices is required.

    PubMed

    Matatiele, Puleng; Gulumian, Mary

    2016-06-01

    Renewable energy technologies (wind turbines, solar cells, biofuels, etc.) are often referred to as 'clean' or 'green' energy sources, while jobs linked to the field of environmental protection and energy efficiency are referred to as 'green' jobs. The energy efficiency of clean technologies, which is likely to reduce and/or eliminate reliance on fossil fuels, is acknowledged. However, the potential contribution of green technologies and associated practices to ill health and environmental pollution resulting from consumption of energy and raw materials, generation of waste, and the negative impacts related to some life cycle phases of these technologies are discussed. Similarly, a point is made that the green jobs theme is mistakenly oversold because the employment opportunities generated by transitioning to green technologies are not necessarily safe and healthy jobs. Emphasis is put on identifying the hazards associated with these green designs, assessing the risks to the environment and worker health and safety, and either eliminating the hazards or minimizing the risks as essential elements to the design, construction, operation, and maintenance of green technologies. The perception that it is not always economically possible to consider all risk factors associated with renewable energy technologies at the beginning without hampering their implementation, especially in the poor developing countries, is dismissed. Instead, poor countries are encouraged to start implementing environmentally sound practices while transitioning to green technologies in line with their technological development and overall economic growth. PMID:27180334

  18. Inverse parabolic quantum dot: The transition energy under magnetic field effect

    NASA Astrophysics Data System (ADS)

    Safwan, S. A.; El Meshed, Nagwa

    2016-08-01

    We present here, the evolution of the transition energy with a static magnetic field, when the electron and the hole are confined in inverse parabolic quantum dot (IPQD). The unexpected behavior is found, at the weak confinement regime the conduction band minimum and the top of valance band change from s-state to p-state or d-state for confined electron and hole inside IPQD, respectively. The strength of the inverse parabolic potential (potential hump) inside a quantum dot has the upper hand in tuning the ground state momentum for both electron and hole, and consequently their interband transition energy is changed. Knowing that this is not the case for the other types of potentials. The quantum size, the magnetic field and inverse potential hump effects on electron and hole ground and excited states are discussed.

  19. Non-resonant electromechanical energy harvesting using inter-ferroelectric phase transitions

    SciTech Connect

    Pérez Moyet, Richard; Rossetti, George A.; Stace, Joseph; Amin, Ahmed; Finkel, Peter

    2015-10-26

    Non-resonant electromechanical energy harvesting is demonstrated under low frequency excitation (<50 Hz) using [110]{sub C}-poled lead indium niobate-lead magnesium niobate-lead titanate relaxor ferroelectric single crystals with compositions near the morphotropic phase boundary. The efficiency of power generation at the stress-induced phase transition between domain-engineered rhombohedral and orthorhombic ferroelectric states is as much as four times greater than is obtained in the linear piezoelectric regime under identical measurement conditions but during loading below the coercive stress of the phase change. The phase transition mode of electromechanical transduction holds potential for non-resonant energy harvesting from low-frequency vibrations and does not require mechanical frequency up-conversion.

  20. Non-resonant electromechanical energy harvesting using inter-ferroelectric phase transitions

    NASA Astrophysics Data System (ADS)

    Pérez Moyet, Richard; Stace, Joseph; Amin, Ahmed; Finkel, Peter; Rossetti, George A.

    2015-10-01

    Non-resonant electromechanical energy harvesting is demonstrated under low frequency excitation (<50 Hz) using [110]C-poled lead indium niobate-lead magnesium niobate-lead titanate relaxor ferroelectric single crystals with compositions near the morphotropic phase boundary. The efficiency of power generation at the stress-induced phase transition between domain-engineered rhombohedral and orthorhombic ferroelectric states is as much as four times greater than is obtained in the linear piezoelectric regime under identical measurement conditions but during loading below the coercive stress of the phase change. The phase transition mode of electromechanical transduction holds potential for non-resonant energy harvesting from low-frequency vibrations and does not require mechanical frequency up-conversion.

  1. Energy levels and radiative rates for transitions in Cr-like Co IV and Ni V

    NASA Astrophysics Data System (ADS)

    Aggarwal, K. M.; Bogdanovich, P.; Karpuškienė, R.; Keenan, F. P.; Kisielius, R.; Stancalie, V.

    2016-01-01

    We report calculations of energy levels and radiative rates (A-values) for transitions in Cr-like Co IV and Ni V. The quasi-relativistic Hartree-Fock (QRHF) code is adopted for calculating the data although GRASP (general-purpose relativistic atomic structure package) and flexible atomic code (FAC) have also been employed for comparison purposes. No radiative rates are available in the literature to compare with our results, but our calculated energies are in close agreement with those compiled by NIST for a majority of the levels. However, there are discrepancies for a few levels of up to 3%. The A-values are listed for all significantly contributing E1, E2 and M1 transitions, and the corresponding lifetimes reported, although unfortunately no previous theoretical or experimental results exist to compare with our data.

  2. Study of phase transition and cohesive energy in MgO

    NASA Astrophysics Data System (ADS)

    Munjal, N.; Bhambhani, P.; Sharma, G.; Vyas, V.; Sharma, B. K.

    2012-07-01

    In this paper, we present first-principles study of phase transition and cohesive energy of MgO. The calculations are performed on the basis of density functional theory (DFT) based on linear combination of atomic orbitals (LCAO) method. In the present calculations, the generalized gradient approximation (GGA) proposed by Perdew-Burke- Ernzerhof (PBE) and Becke's scheme are considered to treat the correlation and exchange effects respectively. The study reveals that the stable phase of MgO is B1. The study also suggests B1 to B2 phase transition at 260.75 GPa and 10.98 eV cohesive energy of MgO in the stable phase. The calculated data are found in good agreement with the previous theoretical and experimental investigations.

  3. Fragment transition density method to calculate electronic coupling for excitation energy transfer

    SciTech Connect

    Voityuk, Alexander A.

    2014-06-28

    A general approach, the Fragment Transition Density (FTD) scheme, is introduced to estimate electronic coupling for excitation energy transfer in a molecular system. Within this method, the excitation energies and transition densities of the system are used to derive the coupling matrix element. The scheme allows one to treat systems where exciton donor and acceptor are close together and their exchange interaction and orbital overlap are significant. The FTD method can be applied in combination with any quantum mechanical approach to treat excited states of general nature including single-, double-, and higher excitations. Using FTD approach, we derive excitonic couplings for several systems computed with the CIS, TD DFT and MS-CASPT2 methods. In particular, it is shown that the estimated coupling values in DNA π-stacks are strongly affected by the short-range electronic interaction of adjacent nucleobases.

  4. Energy Transition Initiative: Island Energy Snapshot - Barbados; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of Barbados, an independent nation in the Lesser Antilles island chain in the eastern Caribbean. Barbados’ electricity rates are approximately $0.28 per kilowatt-hour (kWh), below the Caribbean regional average of $0.33/kWh.

  5. Energy Transition Initiative: Island Energy Snapshot - Palau; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of Palau, an independent island nation geographically located in the Micronesia region. Palau’s residential electricity rates are approximately $0.28 U.S. dollars (USD) per kilowatt-hour (kWh), more than twice the average U.S. residential rate of $0.13 USD/kWh.

  6. Energy Transition Initiative: Island Energy Snapshot - Curacao; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of Curacao, an autonomous member of the Kingdom of the Netherlands located off the coast of Venezuela. Curacao’s utility rates are approximately $0.26 per kilowatt-hour (kWh), below the Caribbean regional average of $0.33/kWh.

  7. Energy Transition Initiative: Island Energy Snapshot - American Samoa; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of American Samoa, the southernmost territory of the United States. American Samoa’s residential electricity rates are approximately $0.29 U.S. dollars (USD) per kilowatt-hour (kWh), more than twice the average U.S. residential rate of $0.13 USD/kWh.

  8. Energy Transition Initiative: Island Energy Snapshot - Haiti; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of Haiti, an independent nation that occupies the western portion of the island of Hispaniola in the northern Caribbean Sea. Haiti’s utility rates are roughly $0.35 U.S. dollars (USD) per kilowatt-hour (kWh), above the Caribbean regional average of $0.33 USD/kWh.

  9. Energy Transition Initiative: Island Energy Snapshot - Bonaire; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of Bonaire, a special municipality of the Kingdom of the Netherlands located off the coast of Venezuela. Bonaire’s utility rates are approximately $0.35 per kilowatt-hour (kWh), above the Caribbean regional average of $0.33/kWh.

  10. Energy levels, radiative rates and electron impact excitation rates for transitions in Si II

    NASA Astrophysics Data System (ADS)

    Aggarwal, Kanti M.; Keenan, Francis P.

    2014-07-01

    Energies for the lowest 56 levels, belonging to the 3s2 3p, 3s 3p2, 3p3, 3s2 3d, 3s 3p 3d, 3s2 4ℓ and 3s2 5ℓ configurations of Si II, are calculated using the General-purpose Relativistic Atomic Structure Package (GRASP) code. Analogous calculations have also been performed (for up to 175 levels) using the Flexible Atomic Code (FAC). Furthermore, radiative rates are calculated for all E1, E2, M1 and M2 transitions. Extensive comparisons are made with available theoretical and experimental energy levels, and the accuracy of the present results is assessed to be better than 0.1 Ryd. Similarly, the accuracy for radiative rates (and subsequently lifetimes) is estimated to be better than 20 per cent for most of the (strong) transitions. Electron impact excitation collision strengths are also calculated, with the Dirac Atomic R-matrix Code (DARC), over a wide energy range up to 13 Ryd. Finally, to determine effective collision strengths, resonances are resolved in a fine energy mesh in the thresholds region. These collision strengths are averaged over a Maxwellian velocity distribution and results listed over a wide range of temperatures, up to 105.5 K. Our data are compared with earlier R-matrix calculations and differences noted, up to a factor of 2, for several transitions. Although scope remains for improvement, the accuracy for our results of collision strengths and effective collision strengths is assessed to be about 20 per cent for a majority of transitions.

  11. K-shell energy levels and radiative rates for transitions in Si ix

    NASA Astrophysics Data System (ADS)

    Wei, H. G.; Shi, J. R.; Wang, F. L.; Zhong, J. Y.; Liang, G. Y.; Zhao, G.

    2014-06-01

    Context. Accurate atomic data are needed to analyze the Si ix K-shell features in astrophysical X-ray spectra. Relative large discrepancies in the existing atomic data have impeded this progress. Aims: We present the accurate Si ix K-shell transition data, including K-shell energy levels, wavelengths, radiative rates, and oscillator strengths. Methods: The flexible atomic code (FAC), which is a fully relativistic atomic code with configuration interaction (CI) included, was employed to calculate these data. To investigate the CI effects, calculations with different configurations included were carried out. Results: The K-shell atomic data of Si ix transitions between 1s22s22p2, 1s22s2p3, 1s22p4, 1s2s22p3, 1s2s2p4, and 1s2p5 are reported. The accuracy of our data is demonstrated by comparing them with the available experimental measurements and theoretical calculations. The energy levels are accurate to 3.5 eV, the wavelengths to within 15 mÅ. For most transitions, the radiative rates an accuracy of 20%. The effects of CI from high-energy configurations were investigated as well. Full Tables 3 and 4 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/566/A105

  12. Energy Transition Initiative: Island Energy Snapshot - Guam; U.S. Department of Energy (DOE), NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This profile provides a snapshot of the energy landscape of Guam, an island territory of the United States located in the western Pacific Ocean. Guam’s electricity rates for residential customers start at $0.21 U.S. dollars (USD) per kilowatt-hour (kWh), above the average U.S. rate of $0.13 USD/kWh.1,2 Like

  13. Nucleon scattering from very light nuclei: Intermediate energy expansions for transition potentials and breakup processes

    SciTech Connect

    Elster, C.; Gloeckle, W.

    1997-03-01

    Transition potentials for elastic p-d scattering and the coupled processes p+{sup 3}He {r_arrow} p+{sup 3}He and n+{sup 3}He {r_arrow} d+d are derived in the Faddeev-Yakubovsky framework with special emphasis on leading order terms, which are expected to be valid at intermediate energies. In addition, equations for the fragmentations {sup 3}He(p,ppp)n and {sup 3}He(p,pp)d are derived within the same framework. Again leading order terms for intermediate energies are considered. {copyright} {ital 1997} {ital The American Physical Society}

  14. High-energy cosmic-ray electrons - A new measurement using transition-radiation detectors

    NASA Technical Reports Server (NTRS)

    Hartmann, G.; Mueller, D.; Prince, T.

    1977-01-01

    A new detector for cosmic-ray electrons, consisting of a combination of a transition-radiation detector and a shower detector, has been constructed, calibrated at accelerator beams, and exposed in a balloon flight under 5 g/sq cm of atmosphere. The design of this instrument and the methods of data analysis are described. Preliminary results in the energy range 9-300 GeV are presented. The energy spectrum of electrons is found to be significantly steeper than that of protons, consistent with a long escape lifetime of cosmic rays in the galaxy.

  15. Students' Energy Concepts at the Transition Between Primary and Secondary School

    NASA Astrophysics Data System (ADS)

    Opitz, Sebastian T.; Harms, Ute; Neumann, Knut; Kowalzik, Kristin; Frank, Arne

    2015-10-01

    Energy is considered both a core idea and a crosscutting concept in science education. A thorough understanding of the energy concept is thought to help students learn about other (related) concepts within and across science subjects, thereby fostering scientific literacy. This study investigates students' progression in understanding the energy concept in biological contexts at the transition from primary to lower secondary school by employing a quantitative, cross-sectional study in grades 3-6 ( N = 540) using complex multiple-choice items. Based on a model developed in a previous study, energy concepts were assessed along four aspects of energy: (1) forms and sources of energy, (2) transfer and transformation, (3) degradation and dissipation, and (4) energy conservation. Two parallel test forms (A and B) indicated energy concept scores to increase significantly by a factor of 2.3 (A)/1.7 (B) from grade 3 to grade 6. Students were observed to progress in their understanding of all four aspects of the concept and scored highest on items for energy forms. The lowest scores and the smallest gain across grades were found for energy conservation. Based on our results, we argue that despite numerous learning opportunities, students lack a more integrated understanding of energy at this stage, underlining the requirement of a more explicit approach to teaching energy to young learners. Likewise, more interdisciplinary links for energy learning between relevant contexts in each science discipline may enable older students to more efficiently use energy as a tool and crosscutting concept with which to analyze complex content.

  16. The energy balance and pressure in the solar transition zone for network and active region features

    NASA Technical Reports Server (NTRS)

    Nicolas, K. R.; Bartoe, J.-D. F.; Brueckner, G. E.; Vanhoosier, M. E.

    1979-01-01

    The electron pressure and energy balance in the solar transition zone are determined for about 125 network and active region features on the basis of high spectral and spatial resolution extreme ultraviolet spectra. Si III line intensity ratios obtained from the Naval Research Laboratory high-resolution telescope and spectrograph during a rocket flight are used as diagnostics of electron density and pressure for solar features near 3.5 x 10 to the 4th K. Observed ratios are compared with the calculated dependence of the 1301 A/1312 A and 1301 A/1296 A line intensity ratios on electron density, temperature and pressure. Electron densities ranging from 2 x 10 to the 10th/cu cm to 10 to the 12th/cu cm and active region pressures from 3 x 10 to the 15th to 10 to the 16th/cu cm K are obtained. Energy balance calculations reveal the balance of the divergence of the conductive flux and turbulent energy dissipation by radiative energy losses in a plane-parallel homogeneous transition zone (fill factor of 1), and an energy source requirement for a cylindrical zone geometry (fill factor less than 0.04).

  17. Transition Region Emission and the Energy Input to Thermal Plasma in Solar Flares

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.; Holman, Gordon D.; Dennis, Brian R.; Haga, Leah; Raymond, John C.; Panasyuk, Alexander

    2005-01-01

    Understanding the energetics of solar flares depends on obtaining reliable determinations of the energy input to flare plasma. X-ray observations of the thermal bremsstrahlung from hot flare plasma provide temperatures and emission measures which, along with estimates of the plasma volume, allow the energy content of this hot plasma to be computed. However, if thermal energy losses are significant or if significant energy goes directly into cooler plasma, this is only a lower limit on the total energy injected into thermal plasma during the flare. We use SOHO UVCS observations of O VI flare emission scattered by coronal O VI ions to deduce the flare emission at transition region temperatures between 100,000 K and 1 MK for the 2002 July 23 and other flares. We find that the radiated energy at these temperatures significantly increases the deduced energy input to the thermal plasma, but by an amount that is less than the uncertainty in the computed energies. Comparisons of computed thermal and nonthermal electron energies deduced from RHESSI, GOES, and UVCS are shown.

  18. Optical transition radiation used in the diagnostic of low energy and low current electron beams in particle accelerators

    SciTech Connect

    Silva, T. F.; Bonini, A. L.; Lima, R. R.; Maidana, N. L.; Malafronte, A. A.; Pascholati, P. R.; Vanin, V. R.; Martins, M. N.

    2012-09-15

    Optical transition radiation (OTR) plays an important role in beam diagnostics for high energy particle accelerators. Its linear intensity with beam current is a great advantage as compared to fluorescent screens, which are subject to saturation. Moreover, the measurement of the angular distribution of the emitted radiation enables the determination of many beam parameters in a single observation point. However, few works deals with the application of OTR to monitor low energy beams. In this work we describe the design of an OTR based beam monitor used to measure the transverse beam charge distribution of the 1.9-MeV electron beam of the linac injector of the IFUSP microtron using a standard vision machine camera. The average beam current in pulsed operation mode is of the order of tens of nano-Amps. Low energy and low beam current make OTR observation difficult. To improve sensitivity, the beam incidence angle on the target was chosen to maximize the photon flux in the camera field-of-view. Measurements that assess OTR observation (linearity with beam current, polarization, and spectrum shape) are presented, as well as a typical 1.9-MeV electron beam charge distribution obtained from OTR. Some aspects of emittance measurement using this device are also discussed.

  19. Optical transition radiation used in the diagnostic of low energy and low current electron beams in particle accelerators.

    PubMed

    Silva, T F; Bonini, A L; Lima, R R; Maidana, N L; Malafronte, A A; Pascholati, P R; Vanin, V R; Martins, M N

    2012-09-01

    Optical transition radiation (OTR) plays an important role in beam diagnostics for high energy particle accelerators. Its linear intensity with beam current is a great advantage as compared to fluorescent screens, which are subject to saturation. Moreover, the measurement of the angular distribution of the emitted radiation enables the determination of many beam parameters in a single observation point. However, few works deals with the application of OTR to monitor low energy beams. In this work we describe the design of an OTR based beam monitor used to measure the transverse beam charge distribution of the 1.9-MeV electron beam of the linac injector of the IFUSP microtron using a standard vision machine camera. The average beam current in pulsed operation mode is of the order of tens of nano-Amps. Low energy and low beam current make OTR observation difficult. To improve sensitivity, the beam incidence angle on the target was chosen to maximize the photon flux in the camera field-of-view. Measurements that assess OTR observation (linearity with beam current, polarization, and spectrum shape) are presented, as well as a typical 1.9-MeV electron beam charge distribution obtained from OTR. Some aspects of emittance measurement using this device are also discussed. PMID:23020369

  20. Energy levels and transition rates for helium-like ions with Z = 10-36

    NASA Astrophysics Data System (ADS)

    Si, R.; Guo, X. L.; Wang, K.; Li, S.; Yan, J.; Chen, C. Y.; Brage, T.; Zou, Y. M.

    2016-08-01

    Aims: Helium-like ions provide an important X-ray spectral diagnostics in astrophysical and high-temperature fusion plasmas. An interpretation of the observed spectra provides information on temperature, density, and chemical compositions of the plasma. Such an analysis requires information for a wide range of atomic parameters, including energy levels and transition rates. Our aim is to provide a set of accurate energy levels and transition rates for helium-like ions with Z = 10-36. Methods: The second-order many-body perturbation theory (MBPT) was adopted in this paper. To support our MBPT results, we performed an independent calculation using the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. Results: We provide accurate energies for the lowest singly excited 70 levels among 1snl(n ≤ 6,l ≤ (n-1)) configurations and the lowest doubly excited 250 levels arising from the K-vacancy 2ln'l'(n' ≤ 6,l' ≤ (n'-1)) configurations of helium-like ions with Z = 10-36. Wavelengths, transition rates, oscillator strengths, and line strengths are calculated for the E1, M1, E2, and M2 transitions among these levels. The radiative lifetimes are reported for all the calculated levels. Conclusions: Our MBPT results for singly excited n ≤ 2 levels show excellent agreement with other elaborate calculations, while those for singly excited n ≥ 3 and doubly excited levels show significant improvements over previous theoretical results. Our results will be very helpful for astrophysical line identification and plasma diagnostics. Full Tables 1 and 2 are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/592/A141

  1. The energy transition and the macroeconomy: A framework for policy analysis

    NASA Astrophysics Data System (ADS)

    Sterman, J. D.

    1981-12-01

    An integrating framework designed to evaluate the effects of depletion and rising energy prices on economic growth, inflation, and other key economic and energy indicators over the time frame 1980 to 2050 is discussed. The framework provides a general disequilibrium representation of the major linkages between the energy sector and the economy. Gross national product, consumption, investment, wages and prices, and other major energy and economic aggregates are determined endogenously. Though the framework generates the macroeconomic dynamics of the economy, it is based on an explicity behavioral theory of economic decision-making at the microeconomic level of individuals and firms. Results show a substantial potential for the first-order effects of depletion (rising capital requirements for energy production, rising real energy prices) to be amplified by feedback mechanisms in the economy, worsening economic performance.

  2. Characterizing metastable states beyond energies and lifetimes: Dyson orbitals and transition dipole moments

    NASA Astrophysics Data System (ADS)

    Jagau, Thomas-C.; Krylov, Anna I.

    2016-02-01

    The theoretical description of electronic resonances is extended beyond calculations of energies and lifetimes. We present the formalism for calculating Dyson orbitals and transition dipole moments within the equation-of-motion coupled-cluster singles and doubles method for electron-attached states augmented by a complex absorbing potential (CAP-EOM-EA-CCSD). The capabilities of the new methodology are illustrated by calculations of Dyson orbitals of various transient anions. We also present calculations of transition dipole moments between transient and stable anionic states as well as between different transient states. Dyson orbitals characterize the differences between the initial neutral and final electron-attached states without invoking the mean-field approximation. By extending the molecular-orbital description to correlated many-electron wave functions, they deliver qualitative insights into the character of resonance states. Dyson orbitals and transition moments are also needed for calculating experimental observables such as spectra and cross sections. Physically meaningful results for those quantities are obtained only in the framework of non-Hermitian quantum mechanics, e.g., in the presence of a complex absorbing potential (CAP), when studying resonances. We investigate the dependence of Dyson orbitals and transition moments on the CAP strength and illustrate how Dyson orbitals help understand the properties of metastable species and how they are affected by replacing the usual scalar product by the so-called c-product.

  3. Negotiating Northern Resource Development Frontiers: People, Energy, and Decision-Making in Yamal

    NASA Astrophysics Data System (ADS)

    Osipov, Igor A.

    This dissertation examines contemporary models of co-existence and partnerships negotiated between local communities, government, and resource corporations in the Russian District of Purovsky (Arctic Yamal), with a particular focus on the relations of these partnerships to Russia's wider socio-cultural and political contexts and, more broadly, the circumpolar world. Yamal has Eurasia's richest oil and gas reserves, and is an important crossroads region where various geopolitical and financial interests intersect. With the opening up of new gas and oil fields, and construction of roads and pipelines, Yamal is experiencing rapid changes; and is being challenged to reshape its many 'frontiers' in which people, energy, and decisions are closely linked to one another. Since the late 1970s, resource development projects have had significant impacts on the lives of the local people in the Purovsky tundra. Along with experiencing negative consequences, such as water and soil contamination, impacts on land, wildlife, and local communities have also nurtured creative ways of adaptation, decision-making, and self-organization. Since 1998, a number of unique models of co-existence and participatory dialogue, involving public project reviews, and sound participation of local indigenous activist groups have been developed and implemented in Yamal. Furthermore, during the past decade the Purovsky District has served as a unique decision-making polygon for the Northeastern Urals. Several joint community-industry-government political and economic cooperation models have been tested and their elements have subsequently been implemented in other Arctic Russian localities. From 2006-2008 this project was focused on documenting these important developments by investigating and explicating the on-the-ground models of agreement-making in the context that these models have been developing since the 1970s. This project, as such, strives to benefit the areas of anthropology, political

  4. A Cumulative Energy Demand indicator (CED), life cycle based, for industrial waste management decision making

    SciTech Connect

    Puig, Rita; Fullana-i-Palmer, Pere; Bala, Alba

    2013-12-15

    Highlights: • We developed a methodology useful to environmentally compare industrial waste management options. • The methodology uses a Net Energy Demand indicator which is life cycle based. • The method was simplified to be widely used, thus avoiding cost driven decisions. • This methodology is useful for governments to promote the best environmental options. • This methodology can be widely used by other countries or regions around the world. - Abstract: Life cycle thinking is a good approach to be used for environmental decision-support, although the complexity of the Life Cycle Assessment (LCA) studies sometimes prevents their wide use. The purpose of this paper is to show how LCA methodology can be simplified to be more useful for certain applications. In order to improve waste management in Catalonia (Spain), a Cumulative Energy Demand indicator (LCA-based) has been used to obtain four mathematical models to help the government in the decision of preventing or allowing a specific waste from going out of the borders. The conceptual equations and all the subsequent developments and assumptions made to obtain the simplified models are presented. One of the four models is discussed in detail, presenting the final simplified equation to be subsequently used by the government in decision making. The resulting model has been found to be scientifically robust, simple to implement and, above all, fulfilling its purpose: the limitation of waste transport out of Catalonia unless the waste recovery operations are significantly better and justify this transport.

  5. Transitions, cross sections and neutron binding energy in 186Re by Prompt Gamma Activation Analysis

    NASA Astrophysics Data System (ADS)

    Lerch, A. G.; Hurst, A. M.; Firestone, R. B.; Revay, Zs.; Szentmiklosi, L.; McHale, S. R.; McClory, J. W.; Detwiler, B.; Carroll, J. J.

    2014-03-01

    The nuclide 186Re possesses an isomer with 200,000 year half-life while its ground state has a half-life of 3.718 days. It is also odd-odd and well-deformed nucleus, so should exhibit a variety of other interesting nuclear-structure phenomena. However, the available nuclear data is rather sparse; for example, the energy of the isomer is only known to within + 7 keV and, with the exception of the J?=1- ground state, every proposed level is tentative in the ENSDF. Previously, Prompt Gamma Activation Analysis (PGAA) was utilized to study natRe with 186,188Re being produced via thermal neutron capture. Recently, an enriched 185Re target was irradiated by thermal neutrons at the Budapest Research Reactor to build on those results. Prompt (primary and secondary) and delayed gamma-ray transitions were measured with a large-volume, Compton-suppressed HPGe detector. Absolute cross sections for each gamma transition were deduced and corrected for self attenuation within the sample. Fifty-two primary gamma-ray transitions were newly identified and used to determine a revised value of the neutron binding energy. DICEBOX was used to simulate the decay scheme and the total radiative thermal neutron capture cross section was found to be 97+/-3 b Supported by DTRA (Detwiler) through HDTRA1-08-1-0014.

  6. Excitation energies, polarizabilities, multipole transition rates, and lifetimes of ions along the francium isoelectronic sequence

    SciTech Connect

    Safronova, U. I.; Johnson, W. R.; Safronova, M. S.

    2007-10-15

    Relativistic many-body perturbation theory is applied to study properties of ions of the francium isoelectronic sequence. Specifically, energies of the 7s, 7p, 6d, and 5f states of Fr-like ions with nuclear charges Z=87-100 are calculated through third order; reduced matrix elements, oscillator strengths, transition rates, and lifetimes are determined for 7s-7p, 7p-6d, and 6d-5f electric-dipole transitions; and 7s-6d, 7s-5f, and 5f{sub 5/2}-5f{sub 7/2} multipole matrix elements are evaluated to obtain the lifetimes of low-lying excited states. Moreover, for the ions Z=87-92 calculations are also carried out using the relativistic all-order single-double method, in which single and double excitations of Dirac-Fock wave functions are included to all orders in perturbation theory. With the aid of the single-double wave functions, we obtain accurate values of energies, transition rates, oscillator strengths, and the lifetimes of these six ions. Ground state scalar polarizabilities in Fr I, Ra II, Ac III, and Th IV are calculated using relativistic third-order and all-order methods. Ground state scalar polarizabilities for other Fr-like ions are calculated using a relativistic second-order method. These calculations provide a theoretical benchmark for comparison with experiment and theory.

  7. Efficient dynamical correction of the transition state theory rate estimate for a flat energy barrier.

    PubMed

    Mökkönen, Harri; Ala-Nissila, Tapio; Jónsson, Hannes

    2016-09-01

    The recrossing correction to the transition state theory estimate of a thermal rate can be difficult to calculate when the energy barrier is flat. This problem arises, for example, in polymer escape if the polymer is long enough to stretch between the initial and final state energy wells while the polymer beads undergo diffusive motion back and forth over the barrier. We present an efficient method for evaluating the correction factor by constructing a sequence of hyperplanes starting at the transition state and calculating the probability that the system advances from one hyperplane to another towards the product. This is analogous to what is done in forward flux sampling except that there the hyperplane sequence starts at the initial state. The method is applied to the escape of polymers with up to 64 beads from a potential well. For high temperature, the results are compared with direct Langevin dynamics simulations as well as forward flux sampling and excellent agreement between the three rate estimates is found. The use of a sequence of hyperplanes in the evaluation of the recrossing correction speeds up the calculation by an order of magnitude as compared with the traditional approach. As the temperature is lowered, the direct Langevin dynamics simulations as well as the forward flux simulations become computationally too demanding, while the harmonic transition state theory estimate corrected for recrossings can be calculated without significant increase in the computational effort. PMID:27609008

  8. Roles of Energy Dissipation in a Liquid-Solid Transition of Out-of-Equilibrium Systems

    NASA Astrophysics Data System (ADS)

    Komatsu, Yuta; Tanaka, Hajime

    2015-07-01

    Self-organization of active matter as well as driven granular matter in nonequilibrium dynamical states has attracted considerable attention not only from the fundamental and application viewpoints but also as a model to understand the occurrence of such phenomena in nature. These systems share common features originating from their intrinsically out-of-equilibrium nature, and how energy dissipation affects the state selection in such nonequilibrium states remains elusive. As a simple model system, we consider a nonequilibrium stationary state maintained by continuous energy input, relevant to industrial processing of granular materials by vibration and/or flow. More specifically, we experimentally study roles of dissipation in self-organization of a driven granular particle monolayer. We find that the introduction of strong inelasticity entirely changes the nature of the liquid-solid transition from two-step (nearly) continuous transitions (liquid-hexatic-solid) to a strongly discontinuous first-order-like one (liquid-solid), where the two phases with different effective temperatures can coexist, unlike thermal systems, under a balance between energy input and dissipation. Our finding indicates a pivotal role of energy dissipation and suggests a novel principle in the self-organization of systems far from equilibrium. A similar principle may apply to active matter, which is another important class of out-of-equilibrium systems. On noting that interaction forces in active matter, and particularly in living systems, are often nonconservative and dissipative, our finding may also shed new light on the state selection in these systems.

  9. State-to-State Mode Specificity: Energy Sequestration and Flow Gated by Transition State.

    PubMed

    Zhao, Bin; Sun, Zhigang; Guo, Hua

    2015-12-23

    Energy flow and sequestration at the state-to-state level are investigated for a prototypical four-atom reaction, H2 + OH → H + H2O, using a transition-state wave packet (TSWP) method. The product state distribution is found to depend strongly on the reactant vibrational excitation, indicating mode specificity at the state-to-state level. From a local-mode perspective, it is shown that the vibrational excitation of the H2O product derives from two different sources, one attributable to the energy flow along the reaction coordinate into the newly formed OH bond and the other due to the sequestration of the vibrational energy in the OH spectator moiety during the reaction. The analysis provided a unified interpretation of some seemingly contradicting experimental observations. It is further shown that the transfer of vibrational energy from the OH reactant to H2O product is gated by the transition state, accomplished coherently by multiple TSWPs with the corresponding OH vibrational excitation. PMID:26613942

  10. Highly correlated systems. Excitation energies of first row transition metals Sc--Cu

    SciTech Connect

    Raghavachari, K.; Trucks, G. W.

    1989-07-15

    The low-lying /ital d//sup /ital n/s//sup 2//r arrow//ital d//sup /ital n/+1//ital s//sup 1/ excitation energies of the first row transition metal atoms Sc--Cu are calculated using fourth-order M/congruent/ller--Plesset perturbation theory (MP4) as well as quadratic configuration interaction (QCI) techniques with large /ital spd/ and /ital spdf/ basis sets. The MP4 method performs well for Sc--Mn but fails dramatically for Fe--Cu. In contrast, the QCI technique performs uniformly for all excitation energies with a mean deviation from experiment of only 0.14 eV after including relativistic corrections. /ital f/ functions contribute 0.1--0.4 eV to the excitation energies for these systems. The highly correlated /ital d//sup 10/ state of the Ni atom is also considered in detail. The QCI technique obtains the /ital d//sup 9//ital s1//r arrow//ital d10/ splitting of the Ni atom with an error of only 0.13 eV. The results show that single-configuration Hartree--Fock based methods can be successful in calculating excitation energies of transition metal atoms.

  11. Energy and environmental policy in a period of transition. Proceedings of the twenty-third annual Illinois energy conference

    SciTech Connect

    1995-12-31

    The Twenty-Third Annual Illinois Energy Conference entitled, ``Energy and Environmental Policy in a Period of Transition`` was held in Chicago, Illinois on November 20--21, 1995. The conference program explored how federal policy in energy and environment is changing and how these shifts will impact the economy of the Midwest. The conference was divided in four plenary sessions. Session 1 focused on the national policy scene where speakers discussed proposed legislation to change federal energy and environmental policy. Session 2 looked at the future structure of the energy industry, projecting the roles of natural gas, the electric utility industry, and independent power producers in the overall energy system of the 21st century. Session 3 examined current federal policy in research and development as a baseline for discussing the future role of government and industry in supporting research and development. In particular, it looked at the relationship between energy research and development and global competitiveness. Finally, Session 4 attempted to tie these issues together and consider the impact of national policy change on Illinois and the Midwest.

  12. Wetting transition in liquid Ga Bi alloys: light scattering study of surface energy and entropy

    NASA Astrophysics Data System (ADS)

    Ayyad, A. H.; Freyland, W.

    2002-05-01

    We have studied the surface energy, surface entropy and, partly, have received an estimate of the viscosity of liquid Ga-Bi alloys at compositions mainly in the Ga-rich phase region and at temperatures up to 620 K. Measurements have been performed by the noninvasive method of capillary wave spectroscopy which has been applied for the first time to investigate the surface properties of a liquid alloy at high temperatures. Analysis of the concentration dependence of the surface energy according to the Gibbs adsorption equation yields that in the composition range of 10 -2≲ xBi≲10 -1 and at temperatures of 450 K≲ T≲500 K a surface excess of ΓBi˜1.36×10 -5 mol m -2 resides at the liquid-vapour interface corresponding to pure Bi. At lower xBi a reduction of ΓBi occurs which is indicative of a prewetting transition. The variations of surface energy and entropy with composition are not consistent with a description by a simple monolayer model as was deduced from X-ray reflectivity results. Instead it is found that a multilayer model qualitatively accounts for the characteristic change of the surface quantities. The thickness of the multilayer interfacial region is estimated from the change of the relative surface entropy. This yields values between 10 and 20 Å with a trend for an increasing number of surface layers towards the complete wetting transition at the monotectic point. All isopleths of the surface energy exhibit clear kinks at temperatures 10-20 K above the liquidus curve for compositions below the monotectic point. The corresponding discontinuity of the surface entropy is consistent with a first order transition of surface freezing reported recently for the Ga-Bi system.

  13. Energy levels, radiative rates, and lifetimes for transitions in W XL

    SciTech Connect

    Aggarwal, Kanti M. Keenan, Francis P.

    2014-11-15

    Energy levels and radiative rates are reported for transitions in Br-like tungsten, W XL, calculated with the general-purpose relativistic atomic structure package (GRASP). Configuration interaction (CI) has been included among 46 configurations (generating 4215 levels) over a wide energy range up to 213 Ryd. However, for conciseness results are only listed for the lowest 360 levels (with energies up to ∼43 Ryd), which mainly belong to the 4s{sup 2}4p{sup 5},4s{sup 2}4p{sup 4}4d,4s{sup 2}4p{sup 4}4f,4s4p{sup 6},4p{sup 6}4d,4s4p{sup 5}4d,4s{sup 2}4p{sup 3}4d{sup 2}, and 4s{sup 2}4p{sup 3}4d4f configurations, and provided for four types of transitions, E1, E2, M1, and M2. Comparisons are made with existing (but limited) results. However, to fully assess the accuracy of our data, analogous calculations have been performed with the flexible atomic code, including an even larger CI than in GRASP. Our energy levels are estimated to be accurate to better than 0.02 Ryd, whereas results for radiative rates (and lifetimes) should be accurate to better than 20% for a majority of the strong transitions.

  14. Optical transition energies of isolated molecular monomers and weakly interacting two-dimensional aggregates

    NASA Astrophysics Data System (ADS)

    Forker, Roman; Dienel, Thomas; Krause, Andreas; Gruenewald, Marco; Meissner, Matthias; Kirchhuebel, Tino; Gröning, Oliver; Fritz, Torsten

    2016-04-01

    The optical excitation energies of organic dye molecules are often said to depend sensitively on the polarizability of the utilized substrate. To this end, we employ differential reflectance spectroscopy (DRS) to analyze the S0→S1 fundamental transition energies observed for 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA) as a function of coverage on various surfaces, such as sp2-bonded insulating layers [graphene and hexagonal boron nitride (h-BN)], and noble metals pre-covered by a molecular wetting layer which prevents hybridization of the second-layer molecules with the metal states. We elucidate the optical absorbance behavior of PTCDA layers grown on h-BN/Rh(111) and on h-BN/Pt(111) and characterize their structures by means of scanning tunneling microscopy. Surprisingly, although the dielectric properties of the employed substrates differ substantially, only two main transition energies are observed: (i) PTCDAHE essentially mimics the behavior of isolated monomers on surfaces (particularly at submonolayer coverage), while (ii) PTCDALE, red-shifted by ≈70 meV (≈560 cm-1 ), is attributed to two-dimensional densely packed aggregates. This red-shift is in remarkable accordance with previous investigations for PTCDA on NaCl(100) and, therefore, likely arises from the same physical effects, namely the formation of two-dimensional excitonic bands and the polarizability of neighboring molecules within the monolayer. In distinction from earlier studies, we conclude that the polarizabilities of the employed substrates do not constitute the dominant contribution to the molecular S0→S1 transition energies observed here.

  15. Alternative fuel transit buses

    SciTech Connect

    Motta, R.; Norton, P.; Kelly, K.

    1996-10-01

    The National Renewable Energy Laboratory (NREL) is a U.S. Department of Energy (DOE) national laboratory; this project was funded by DOE. One of NREL`s missions is to objectively evaluate the performance, emissions, and operating costs of alternative fuel vehicles so fleet managers can make informed decisions when purchasing them. Alternative fuels have made greater inroads into the transit bus market than into any other. Each year, the American Public Transit Association (APTA) surveys its members on their inventory and buying plans. The latest APTA data show that about 4% of the 50,000 transit buses in its survey run on an alternative fuel. Furthermore, 1 in 5 of the new transit buses that members have on order are alternative fuel buses. This program was designed to comprehensively and objectively evaluate the alternative fuels in use in the industry.

  16. Phase Transitions as a Novel Mechanism for High-Speed Energy Storage

    NASA Astrophysics Data System (ADS)

    Bernholc, Jerry

    2013-03-01

    In many energy applications there is an urgent need to store and quickly discharge large amounts of electrical energy. Since capacitors can be discharged far quicker than batteries and fuel cells, they have much higher power densities. At present, highly insulating polymers with large breakdown fields, such as polypropylene, are the dielectrics of choice in high-power capacitors. However, their energy densities are quite low because of small dielectric constants. Ferroelectric polymers from the PVDF family have significantly larger dielectric constants, yet their energy densities are still rather low. This can be traced to early saturation of their displacement fields with the applied electric field, and to somewhat lower breakdown fields. However, an admixture of a small amount of another polymer, such as CTFE, results in a dramatic increase in the stored energy. We show that this highly non-linear increase in the energy density is due to the formation of disordered nanodomains with different copolymer concentrations, which undergo first-order non-polar to polar phase transitions with an increase of the applied field. The resulting energy density profile reproduces well the experimental data, while its variation with co-polymer concentration and distribution suggest avenues for additional substantial improvements in the stored energy. Most recently, we have identified a low-activation-energy pathway for these successive phase transformations. It provides further confirmation of the viability of the suggested energy storage mechanism and also enables fine-tuning of the kinetics of energy release by informed choices of suitable co-polymers. In collaboration with V. Ranjan, L. Yu, M. Buongiorno Nardelli and R. Dong.

  17. Theoretical study on K, L, and M X-ray transition energies and rates of neptunium and its ions

    NASA Astrophysics Data System (ADS)

    Ismail Abdalla, Saber; Dong, Chen-Zhong; Wang, Xiang-Li; Zhou, Wei-Dong; Wu, Zhong-Wen

    2014-02-01

    The transition energies and electric dipole (E1) transition rates of the K, L, and M lines in neutral Np have been theoretically determined from the MultiConfiguration Dirac—Fock (MCDF) method. In the calculations, the contributions from Breit interaction and quantum electrodynamics (QED) effects (vacuum polarization and self-energy), as well as nuclear finite mass and volume effects, are taken into account. The calculated transition energies and rates are found to be in good agreement with other experimental and theoretical results. The accuracy of the results is estimated and discussed. Furthermore, we calculated the transition energies of the same lines radiating from the decaying transitions of the K-, L-, and M-shell hole states of Np ions with the charge states Np1+ to Np6+ for the first time. We found that for a specific line, the corresponding transition energies relating to all the Np ions are almost the same; it means the outermost electrons have a very small influence on the inner-shell transition processes.

  18. Energy balance in the solar transition region. I - Hydrostatic thermal models with ambipolar diffusion

    NASA Technical Reports Server (NTRS)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1990-01-01

    The energy balance in the lower transition region is analyzed by constructing theoretical models which satisfy the energy balance constraint. The energy balance is achieved by balancing the radiative losses and the energy flowing downward from the corona. This energy flow is mainly in two forms: conductive heat flow and hydrogen ionization energy flow due to ambipolar diffusion. Hydrostatic equilibrium is assumed, and, in a first calculation, local mechanical heating and Joule heating are ignored. In a second model, some mechanical heating compatible with chromospheric energy-balance calculations is introduced. The models are computed for a partial non-LTE approach in which radiation departs strongly from LTE but particles depart from Maxwellian distributions only to first order. The results, which apply to cases where the magnetic field is either absent, or uniform and vertical, are compared with the observed Lyman lines and continuum from the average quiet sun. The approximate agreement suggests that this type of model can roughly explain the observed intensities in a physically meaningful way, assuming only a few free parameters specified as chromospheric boundary conditions.

  19. Accurate nonrelativistic ground-state energies of 3d transition metal atoms

    SciTech Connect

    Scemama, A.; Applencourt, T.; Giner, E.; Caffarel, M.

    2014-12-28

    We present accurate nonrelativistic ground-state energies of the transition metal atoms of the 3d series calculated with Fixed-Node Diffusion Monte Carlo (FN-DMC). Selected multi-determinantal expansions obtained with the CIPSI (Configuration Interaction using a Perturbative Selection made Iteratively) method and including the most prominent determinants of the full configuration interaction expansion are used as trial wavefunctions. Using a maximum of a few tens of thousands determinants, fixed-node errors on total DMC energies are found to be greatly reduced for some atoms with respect to those obtained with Hartree-Fock nodes. To the best of our knowledge, the FN-DMC/(CIPSI nodes) ground-state energies presented here are the lowest variational total energies reported so far. They differ from the recently recommended non-variational values of McCarthy and Thakkar [J. Chem. Phys. 136, 054107 (2012)] only by a few percents of the correlation energy. Thanks to the variational property of FN-DMC total energies, our results provide exact lower bounds for the absolute value of all-electron correlation energies, |E{sub c}|.

  20. Surface energy exchanges along a tundra-forest transition and feedbacks to climate

    USGS Publications Warehouse

    Beringer, J.; Chapin, F. S., III; Thompson, Catharine Copass; McGuire, A.D.

    2005-01-01

    Surface energy exchanges were measured in a sequence of five sites representing the major vegetation types in the transition from arctic tundra to forest. This is the major transition in vegetation structure in northern high latitudes. We examined the influence of vegetation structure on the rates of sensible heating and evapotranspiration to assess the potential feedbacks to climate if high-latitude warming were to change the distribution of these vegetation types. Measurements were made at Council on the Seward Peninsula, Alaska, at representative tundra, low shrub, tall shrub, woodland (treeline), and boreal forest sites. Structural differences across the transition from tundra to forest included an increase in the leaf area index (LAI) from 0.52 to 2.76, an increase in canopy height from 0.1 to 6.1 m, and a general increase in canopy complexity. These changes in vegetation structure resulted in a decrease in albedo from 0.19 to 0.10 as well as changes to the partitioning of energy at the surface. Bulk surface resistance to water vapor flux remained virtually constant across sites, apparently because the combined soil and moss evaporation decreased while transpiration increased along the transect from tundra to forest. In general, sites became relatively warmer and drier along the transect with the convective fluxes being increasingly dominated by sensible heating, as evident by an increasing Bowen ratio from 0.94 to 1.22. The difference in growing season average daily sensible heating between tundra and forest was 21 W m-2. Fluxes changed non-linearly along the transition, with both shrubs and trees substantially enhancing heat transfer to the atmosphere. These changes in vegetation structure that increase sensible heating could feed back to enhance warming at local to regional scales. The magnitude of these vegetation effects on potential high-latitude warming is two to three times greater than suggested by previous modeling studies. ?? 2005 Elsevier B.V. All

  1. Variational Calculations of Ro-Vibrational Energy Levels and Transition Intensities for Tetratomic Molecules

    NASA Technical Reports Server (NTRS)

    Schwenke, David W.; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    A description is given of an algorithm for computing ro-vibrational energy levels for tetratomic molecules. The expressions required for evaluating transition intensities are also given. The variational principle is used to determine the energy levels and the kinetic energy operator is simple and evaluated exactly. The computational procedure is split up into the determination of one dimensional radial basis functions, the computation of a contracted rotational-bending basis, followed by a final variational step coupling all degrees of freedom. An angular basis is proposed whereby the rotational-bending contraction takes place in three steps. Angular matrix elements of the potential are evaluated by expansion in terms of a suitable basis and the angular integrals are given in a factorized form which simplifies their evaluation. The basis functions in the final variational step have the full permutation symmetries of the identical particles. Sample results are given for HCCH and BH3.

  2. The confinement error corrections for the exchange energy in transition metal oxides

    NASA Astrophysics Data System (ADS)

    Hao, Feng; Armiento, Rickard; Mattsson, Ann E.

    2011-03-01

    We present some recent advances towards a straightforward scheme to correct for the confinement errors of the exchange energy of the transition metal oxides (TMO). This approach includes two steps: (i) identifying the spatial regions where the confinement errors exist, using local density and kinetic energy density information, and (ii) mapping these spatial regions to harmonic-oscillator (HO) models, and quantifying and correcting the relative confinement errors based on the model system. The scheme has been applied to calculations with several local and semi-local functionals, and a trend of improvement for the equilibrium structure is obtained after applying these confinement error corrections. Sandia is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

  3. Thermodynamic free energy methods to investigate shape transitions in bilayer membranes

    PubMed Central

    Ramakrishnan, N.; Tourdot, Richard W.

    2016-01-01

    The conformational free energy landscape of a system is a fundamental thermodynamic quantity of importance particularly in the study of soft matter and biological systems, in which the entropic contributions play a dominant role. While computational methods to delineate the free energy landscape are routinely used to analyze the relative stability of conformational states, to determine phase boundaries, and to compute ligand-receptor binding energies its use in problems involving the cell membrane is limited. Here, we present an overview of four different free energy methods to study morphological transitions in bilayer membranes, induced either by the action of curvature remodeling proteins or due to the application of external forces. Using a triangulated surface as a model for the cell membrane and using the framework of dynamical triangulation Monte Carlo, we have focused on the methods of Widom insertion, thermodynamic integration, Bennett acceptance scheme, and umbrella sampling and weighted histogram analysis. We have demonstrated how these methods can be employed in a variety of problems involving the cell membrane. Specifically, we have shown that the chemical potential, computed using Widom insertion, and the relative free energies, computed using thermodynamic integration and Bennett acceptance method, are excellent measures to study the transition from curvature sensing to curvature inducing behavior of membrane associated proteins. The umbrella sampling and WHAM analysis has been used to study the thermodynamics of tether formation in cell membranes and the quantitative predictions of the computational model are in excellent agreement with experimental measurements. Furthermore, we also present a method based on WHAM and thermodynamic integration to handle problems related to end-point-catastrophe that are common in most free energy methods.

  4. Energy Transition Initiative: Island Energy Snapshot - Saint Martin/Sint Maarten

    SciTech Connect

    2015-09-01

    This profile provides a snapshot of the energy landscape of the northeast Caribbean island Saint Martin. The island is divided between two nations, France in the north (Saint-Martin) and the Netherlands in the south (Sint Maarten).

  5. IBS and Potential Luminosity Improvement for RHIC Operation Below Transition Energy

    SciTech Connect

    Fedotov,A.

    2009-01-02

    There is a strong interest in low-energy RHIC operations in the single-beam total energy range of 2.5-25 GeV/nucleon [1-3]. Collisions in this energy range, much of which is below nominal RHIC injection energy, will help to answer one of the key questions in the field of QeD about the existence and location of a critical point on the QCD phase diagram [4]. There have been several short test runs during 2006-2008 RHIC operations to evaluate RHIC operational challenges at these low energies [5]. Beam lifetimes observed during the test runs were limited by machine nonlinearities. This performance limit can be improved with sufficient machine tuning. The next luminosity limitation comes from transverse and longitudinal Intra-beam Scattering (IBS), and ultimately from the space-charge limit. Detailed discussion of limiting beam dynamics effects and possible luminosity improvement with electron cooling can be found in Refs. [6-8]. For low-energy RHIC operation, particle losses from the RF bucket are of particular concern since the longitudinal beam size is comparable to the existing RF bucket at low energies. However, operation below transition energy allows us to exploit an Intra-beam Scattering (IBS) feature that drives the transverse and longitudinal beam temperatures towards equilibrium by minimizing the longitudinal diffusion rate using a high RF voltage. Simulation studies were performed with the goal to understand whether one can use this feature of IBS to improve luminosity of RHIC collider at low-energies. This Note presents results of simulations which show that additional luminosity improvement for low-energy RHIC project may be possible with high RF voltage from a 56 MHz superconducting RF cavity that is presently under development for RHIC.

  6. Risk perception & strategic decision making :general insights, a framework, and specific application to electricity generation using nuclear energy.

    SciTech Connect

    Brewer, Jeffrey D.

    2005-11-01

    The objective of this report is to promote increased understanding of decision making processes and hopefully to enable improved decision making regarding high-consequence, highly sophisticated technological systems. This report brings together insights regarding risk perception and decision making across domains ranging from nuclear power technology safety, cognitive psychology, economics, science education, public policy, and neural science (to name a few). It forms them into a unique, coherent, concise framework, and list of strategies to aid in decision making. It is suggested that all decision makers, whether ordinary citizens, academics, or political leaders, ought to cultivate their abilities to separate the wheat from the chaff in these types of decision making instances. The wheat includes proper data sources and helpful human decision making heuristics; these should be sought. The chaff includes ''unhelpful biases'' that hinder proper interpretation of available data and lead people unwittingly toward inappropriate decision making ''strategies''; obviously, these should be avoided. It is further proposed that successfully accomplishing the wheat vs. chaff separation is very difficult, yet tenable. This report hopes to expose and facilitate navigation away from decision-making traps which often ensnare the unwary. Furthermore, it is emphasized that one's personal decision making biases can be examined, and tools can be provided allowing better means to generate, evaluate, and select among decision options. Many examples in this report are tailored to the energy domain (esp. nuclear power for electricity generation). The decision making framework and approach presented here are applicable to any high-consequence, highly sophisticated technological system.

  7. Shape of the absorption and fluorescence spectra of condensed phases and transition energies.

    PubMed

    Lagos, Miguel; Paredes, Rodrigo

    2014-11-13

    General integral expressions for the temperature-dependent profile of the spectral lines of photon absorption and emission by atomic or molecular species in a condensed environment are derived with no other hypothesis than: (a) The acoustic vibrational modes of the condensed host medium constitute the thermodynamic energy reservoir at a given constant temperature, and local electronic transitions modifying the equilibrium configuration of the surroundings are multiphonon events, regardless of the magnitude of the transition energy. (b) Electron-phonon coupling is linear in the variations of the bond length. The purpose is to develop a theoretical tool for the analysis of the spectra, allowing us to grasp highly accurate information from fitting the theoretical line shape function to experiment, including those spectra displaying wide features. The method is illustrated by applying it to two dyes, Lucifer Yellow CH and Coumarin 1, which display fluorescence maxima of 0.41 and 0.51 eV fwhm. Fitting the theoretical curves to the spectra indicates that the neat excitation energies are 2.58 eV ± 2.5% and 3.00 eV ± 2.0%, respectively. PMID:25321927

  8. Microbial modulation of energy availability in the colon regulates intestinal transit.

    PubMed

    Wichmann, Anita; Allahyar, Ava; Greiner, Thomas U; Plovier, Hubert; Lundén, Gunnel Östergren; Larsson, Thomas; Drucker, Daniel J; Delzenne, Nathalie M; Cani, Patrice D; Bäckhed, Fredrik

    2013-11-13

    Gut microbiota contribute to host metabolic efficiency by increasing energy availability through the fermentation of dietary fiber and production of short-chain fatty acids (SCFAs) in the colon. SCFAs are proposed to stimulate secretion of the proglucagon (Gcg)-derived incretin hormone GLP-1, which stimulates insulin secretion (incretin response) and inhibits gastric emptying. We find that germ-free (GF) and antibiotic-treated mice, which have severely reduced SCFA levels, have increased basal GLP-1 levels in the plasma and increased Gcg expression in the colon. Increasing energy supply, either through colonization with polysaccharide-fermenting bacteria or through diet, suppressed colonic Gcg expression in GF mice. Increased GLP-1 levels in GF mice did not improve the incretin response but instead slowed intestinal transit. Thus, microbiota regulate the basal levels of GLP-1, and increasing these levels may be an adaptive response to insufficient energy availability in the colon that slows intestinal transit and allows for greater nutrient absorption. PMID:24237703

  9. Hybrid density functional calculations of redox potentials and formation energies of transition metal compounds

    NASA Astrophysics Data System (ADS)

    Chevrier, V. L.; Ong, S. P.; Armiento, R.; Chan, M. K. Y.; Ceder, G.

    2010-08-01

    We compare the accuracy of conventional semilocal density functional theory (DFT), the DFT+U method, and the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional for structural parameters, redox reaction energies, and formation energies of transition metal compounds. Conventional DFT functionals significantly underestimate redox potentials for these compounds. Zhou [Phys. Rev. B 70, 235121 (2004)]10.1103/PhysRevB.70.235121 addressed this issue with DFT+U and a linear-response scheme for calculating U values. We show that the Li intercalation potentials of prominent Li-ion intercalation battery materials, such as the layered LixMO2 ( M=Co and Ni), LixTiS2 ; olivine LixMPO4 ( M=Mn , Fe, Co, and Ni); and spinel-like LixMn2O4 , LixTi2O4 , are also well reproduced by HSE06, due to the self-interaction error correction from the partial inclusion of Hartree-Fock exchange. For formation energies, HSE06 performs well for transition metal compounds, which typically are not well reproduced by conventional DFT functionals but does not significantly improve the results of nontransition metal oxides. Hence, we find that hybrid functionals provide a good alternative to DFT+U for transition metal applications when the large extra computational effort is compensated by the benefits of (i) avoiding species-specific adjustable parameters and (ii) a more universal treatment of the self-interaction error that is not exclusive to specific atomic orbital projections on selected ions.

  10. MACHETE: A transit imaging atmospheric Cherenkov telescope to survey half of the very high energy γ-ray sky

    NASA Astrophysics Data System (ADS)

    Cortina, J.; López-Coto, R.; Moralejo, A.

    2016-01-01

    Current imaging atmospheric Cherenkov telescopes for very high energy γ-ray astrophysics are pointing instruments with a field of view up to a few tens of sq deg. We propose to build an array of two non-steerable (drift) telescopes. Each of the telescopes would have a camera with a FOV of 5 × 60 sq deg oriented along the meridian. About half of the sky drifts through this FOV in a year. We have performed a Monte Carlo simulation to estimate the performance of this instrument. We expect it to survey this half of the sky with an integral flux sensitivity of ˜0.77% of the steady flux of the Crab Nebula in 5 years, an analysis energy threshold of ˜150 GeV and an angular resolution of ˜0.1°. For astronomical objects that transit over the telescope for a specific night, we can achieve an integral sensitivity of 12% of the Crab Nebula flux in a night, making it a very powerful tool to trigger further observations of variable sources using steerable IACTs or instruments at other wavelengths.

  11. Generation of hard x rays from transition radiation using high-density foils and moderate-energy electrons

    SciTech Connect

    Piestrup, M.A. ); Moran, M.J. ); Boyers, D.G.; Pincus, C.I. ); Kephart, J.O. ); Gearhart, R.A. ); Maruyama, X.K. )

    1991-03-01

    In experiments using targets consisting of many thin metal foils, we have demonstrated that a narrow, forward-directed cone of transition radiation in the 8- to 60-keV spectral range can be generated by electron beams with moderate energies (between 100 and 500 MeV). The theory suggests that high-density, moderate-atomic-number metals are the optimum foil materials and that the foil thickness can be chosen to maximize photon production within a desired spectral range. The three targets used in the experiments consisted of 10 foils of 1-{mu}m-thick gold, 40 foils of 8.5-{mu}m stainless steel, and 20 foils of 7.9-{mu}m copper. The efficiency with which hard x rays are generated, and the fact that the requisite electron-beam energies are lower by a factor of 5 to 10, make such a radiation source an attractive alternative to synchrotron radiation for applications such as medical imaging, spectroscopy, and microscopy.

  12. Computational Study of Deflagration to Detonation Transition in a Straight Duct: Effect of Energy Release

    NASA Astrophysics Data System (ADS)

    Dou, Hua-Shu; Hu, Zongmin; Khoo, Boo Cheong

    Numerical simulation based on the Euler equation and one-step reaction model is carried out to investigate the process of deflagration to detonation transition (DDT) occurring in a straight duct. The numerical method used includes a high resolution fifth-order weighted essentially nonoscillatory scheme for spatial discretization, coupled with a third order total variation diminishing Runge-Kutta time stepping method. In particular, effect of energy release on the DDT process is studied. The model parameters used are the heat release at q=50, 30, 25, 20, 15, 10 and 5, the specific heat ratio at 1.2, and the activation temperature at Ti=15, respectively. For all the cases, the initial energy in the spark is about the same compared to the detonation energy at the Chapman-Jouguet (CJ) state. It is found from the simulation that the DDT occurrence strongly depends on the magnitude of the energy release. The run-up distance of DDT occurrence decreases with the increase of the energy release for q=50 20, and increases with the increase of the energy release for q=50 20. It is concluded from the simulations that the interaction of the shock wave and the flame front is the main reason for leading to DDT.

  13. ENERGY CONVERSION FOR THE TRANSITION FROM Al TO γ-Al2O3 NANOPARTICLES

    NASA Astrophysics Data System (ADS)

    Wang, Shulin; Li, Shengjuan; Xu, Bo; Jian, Dunliang; Zhu, Yufang

    2013-07-01

    We have successfully converted large volume Al particles into γ-Al2O3 nanostructures by vibration milling at room temperature and successive treatment. We show that there exist special relationships among stacking fault energy (SFE), strain energy (SRE), and surface energy (SE) of the materials, including interdependence, intercompetition, and interconversion during the phase transition. SFE and SRE perform the same changing tendency, while SE just does the opposite. However, it is not the particle size but the energy state that determines the reactivity of the materials. And it is the SE that can directly determine the physical chemical reaction and the conversion into the end product rather than SFE and SRE. When SE goes up, the material reactivity and the product yield will be enhanced; and when SE goes down, the reaction and the product yield will decay. However, the state of SE depends closely on the change tendency of the SFE and SRE. That is, when SFE and SRE goes up, SE will goes down; if SFE and SRE goes down, SE will goes up. It seems that energy conservation law may be followed in a sense in the particle system if the external input keeps constant. The work may be significant for energy conversion in nano-scale and mechanosynthesis of oxide nanoparticles.

  14. X-alpha calculation of transition energies in multiply ionized atoms

    NASA Technical Reports Server (NTRS)

    Ringers, D. A.; Chen, M. H.

    1974-01-01

    It is shown that the accuracy of calculations can be improved if appropriate (different) values of alpha are used for each configuration. Alternatively, the Slater Transition state can be used, wherein a total energy difference is related to a difference in single electron eigenvalues. By a series expansion, the value of alpha for an excited configuration can be related to its value for the ground state configuration. The terms Delta alpha (delta Epsilon/delta alpha) exhibit a similar dependence on atomic number as the ground state values of alpha. Results of sample calculations are reported and compared with experiment.

  15. Energy levels and transition probabilities in the neutron-rich lanthanide nucleus sup 156 Sm

    SciTech Connect

    Hellstroem, M.; Fogelberg, B.; Spanier, L.; Mach, H. )

    1990-05-01

    The decay of {sup 156}Pm has been studied resulting in the first detailed information on the excited states of {sup 156}Sm. About 25 levels were found, of which two were {gamma}-decaying isomers. The expected low-lying quadrupole vibrational levels could not be identified. The observed decay rates for {beta} and {gamma} transitions have enabled the classification of some levels, including the {beta}-decaying ground state of {sup 156}Pm, in terms of specific two-quasiparticle states. The total beta-decay energy of {sup 156}Pm was obtained as 5.155(35) MeV.

  16. Level Energies, Oscillator Strengths and Lifetimes for Transitions in Pb IV

    SciTech Connect

    Colon, C.; Alonso-Medina, A.; Zanon, A.; Albeniz, J.

    2008-10-22

    Oscillator strengths for several lines of astrophysical interest arising from some configurations and some levels radiative lifetimes of Pb IV have been calculated. These values were obtained in intermediate coupling (IC) and using ab initio relativistic Hartree-Fock calculations. We use for the IC calculations the standard method of least square fitting of experimental energy levels by means of computer codes from Cowan. Transition Probabilities and oscillator strengths obtained, although in general agreement with the rare experimental data, do present some noticeable discrepancies that are studied in the text.

  17. Performance of diffusion Monte Carlo for the first dissociation energies of transition metal carbonyls

    NASA Astrophysics Data System (ADS)

    Diedrich, Christian; Lüchow, Arne; Grimme, Stefan

    2005-01-01

    Fixed node diffusion Monte Carlo (FNDMC) calculations are carried out for the first ligand dissociation energies of the prototype transition metal carbonyls Cr(CO)6, Fe(CO)5, Ni(CO)4, and Fe(CO)4N2. Since Hartree-Fock theory performs particularly badly for these type of compounds they are difficult to treat with conventional ab initio methods. We find that a Kohn-Sham determinant from a standard density functional provides a balanced description of the fermionic nodal hyper surfaces of all compounds involved in the dissociation reaction. With one exception, the experimental dissociation enthalpies are reproduced by FNDMC within the statistical accuracy of the method.

  18. Coupling of surface energy with electric potential makes superhydrophobic surfaces corrosion-resistant.

    PubMed

    Ramachandran, Rahul; Nosonovsky, Michael

    2015-10-14

    We study the correlation of wetting properties and corrosion rates on hydrophobized cast iron. Samples of different surface roughnesses (abraded by sandpaper) are studied without coating and with two types of hydrophobic coatings (stearic acid and a liquid repelling spray). The contact angles and contact angle hysteresis are measured using a goniometer while corrosion rates are measured by a potentiodynamic polarization test. The data show a decrease in corrosion current density and an increase in corrosion potential after superhydrophobization. A similar trend is also found in the recent literature data. We conclude that a decrease in the corrosion rate can be attributed to the changing open circuit potential of a coated surface and increased surface area making the non-homogeneous (Cassie-Baxter) state possible. We interpret these results in light of the idea that the inherent surface energy is coupled with the electric potential in accordance with the Lippmann law of electrowetting and Le Châtelier's principle and, therefore, hydrophobization leads to a decrease in the corrosion potential. This approach can be used for novel anti-corrosive coatings. PMID:26344151

  19. Jahn-Teller effects in transition-metal compounds with small charge-transfer energy

    NASA Astrophysics Data System (ADS)

    Mizokawa, Takashi

    2013-04-01

    We have studied Jahn-Teller effects in Cs2Au2Br6, ACu3Co4O12(A=Ca or Y), and IrTe2 in which the ligand p-to-transition-metal d charge-transfer energy is small or negative. The Au+/Au3+ charge disproportionation of Cs2Au2Br6 manifests in Au 4f photoemission spectra. In Cs2Au2Br6 with negative Δ and intermediate U, the charge disproportionation can be described using effective d orbitals constructed from the Au 5d and Br 4p orbitals and is stabilized by the Jahn-Teller distortion of the Au3+ site with low-spin d8 configuration. In ACu3Co4O12, Δs for Cu3+ and Co4+ are negative and Us are very large. The Zhang-Rice picture is valid to describe the electronic state, and the valence change from Cu2+/Co4+ to Cu3+/Co3+ can be viewed as the O 2p hole transfer from Co to Cu or d9 + d6L → d9L + d6. In IrTe2, both Δ and U are small and the Ir 5d and Te 5p electrons are itinerant to form the multi-band Fermi surfaces. The ideas of band Jahn-Teller transition and Peierls transition are useful to describe the structural instabilities.

  20. Spin-glass phase transitions and minimum energy of the random feedback vertex set problem.

    PubMed

    Qin, Shao-Meng; Zeng, Ying; Zhou, Hai-Jun

    2016-08-01

    A feedback vertex set (FVS) of an undirected graph contains vertices from every cycle of this graph. Constructing a FVS of sufficiently small cardinality is very difficult in the worst cases, but for random graphs this problem can be efficiently solved by converting it into an appropriate spin-glass model [H.-J. Zhou, Eur. Phys. J. B 86, 455 (2013)EPJBFY1434-602810.1140/epjb/e2013-40690-1]. In the present work we study the spin-glass phase transitions and the minimum energy density of the random FVS problem by the first-step replica-symmetry-breaking (1RSB) mean-field theory. For both regular random graphs and Erdös-Rényi graphs, we determine the inverse temperature β_{l} at which the replica-symmetric mean-field theory loses its local stability, the inverse temperature β_{d} of the dynamical (clustering) phase transition, and the inverse temperature β_{s} of the static (condensation) phase transition. These critical inverse temperatures all change with the mean vertex degree in a nonmonotonic way, and β_{d} is distinct from β_{s} for regular random graphs of vertex degrees K>60, while β_{d} are identical to β_{s} for Erdös-Rényi graphs at least up to mean vertex degree c=512. We then derive the zero-temperature limit of the 1RSB theory and use it to compute the minimum FVS cardinality. PMID:27627285

  1. Energy level structure and quantum phase transitions of spin systems with nonaxially symmetric Hamiltonians

    NASA Astrophysics Data System (ADS)

    López-Moreno, Enrique; Grether, M.; Velázquez, Víctor

    2011-11-01

    A general spin system with a nonaxially symmetric Hamiltonian containing Jx, Jz-linear and Jz-quadratic terms, widely used in many-body fermionic and bosonic systems and in molecular magnetism, is considered for the variations of general parameters describing intensity interaction changes of each of its terms. For this model Hamiltonian, a semiclassical energy surface (ES) is obtained by means of the coherent-state formalism. An analysis of this ES function, based on catastrophe theory, determines the separatrix in the control parameter space of the system Hamiltonian: the loci of singularities representing semiclassical phase transitions. Here we show that distinct regions of qualitatively different spectrum structures, as well as a singular behavior of quantum states, are ruled by this separatrix: here we show that the separatrix not only describes ground-state singularities, which have been associated with quantum phase transitions, but also reveals the structure of the excited spectrum, distinguishing different quantum phases within the parameter space. Finally, we consider magnetic susceptibility and heat capacity of the system at finite temperature, in order to study thermal properties and thermodynamical phase transitions in the perspective of the separatrix of this Hamiltonian system.

  2. Dynamics of driven transitions between minima of a complex energy landscapes

    NASA Astrophysics Data System (ADS)

    Pusuluri, Sai Teja; Lang, Alex H.; Mehta, Pankaj; Castillo, Horacio E.

    We recently modeled cellular interconvertion dynamics by using an epigenetic landscape model inspired by neural network models. Given an arbitrary set of patterns, the model can be used to construct an energy landscape in which those patterns are the global minima. Here we study the transitions between stable states of the landscapes thus constructed, under the effect of an external driving force. We consider three different cases: i) choosing the patterns to be random and independendently distributed ii) choosing a set of patterns directly derived from the experimental cellular transcription factor expression data for a representative set of cell types in an organism and iii) choosing randomly generated trees of hierarchically correlated patterns, inspired by biology. For each of the three cases, we study the stability of the global minima against thermal fluctuations and external driving forces, and the dynamics of the driven transitions away from global minima. We compare the results obtained in the three cases defined above, and in particular we explore to what degree the correlations between patterns affect the transition dynamics.

  3. The IUPAC Database of Rotational-Vibrational Energy Levels and Transitions of Water Isotopologues from Experiment and Theory

    NASA Astrophysics Data System (ADS)

    Császár, Attila G.; Furtenbacher, T.; Tennyson, Jonathan; Bernath, Peter F.; Brown, Linda R.; Campargue, Alain; Daumont, Ludovic; Gamache, Robert R.; Hodges, Joseph T.; Naumenko, Olga V.; Polyansky, Oleg L.; Rothman, Laurence S.; Vandaele, Ann Carine; Zobov, Nikolai F.

    2014-06-01

    The results of an IUPAC Task Group formed in 2004 on "A Database of Water Transitions from Experiment and Theory" (Project No. 2004-035-1-100) are presented. Energy levels and recommended labels involving exact and approximate quantum numbers for the main isotopologues of water in the gas phase, H216O, H218O, H217O, HD16O, HD18O, HD17O, D216O, D218O, and D217O, are determined from measured transition wavenumbers. The transition wavenumbers and energy levels are validated using the MARVEL (measured active rotational-vibrational energy levels) approach and first-principles nuclear motion computations. The extensive data, e.g., more than 200,000 transitions have been handled for H216O, including lines and levels that are required for analysis and synthesis of spectra, thermochemical applications, the construction of theoretical models, and the removal of spectral contamination by ubiquitous water lines. These datasets can also be used to assess where measurements are lacking for each isotopologue and to provide accurate frequencies for many yet-to-be measured transitions. The lack of high-quality frequency calibration standards in the near infrared is identified as an issue that has hindered the determination of high-accuracy energy levels at higher frequencies. The generation of spectra using the MARVEL energy levels combined with transition intensities computed using high accuracy ab initio dipole moment surfaces are discussed.

  4. New energy geographics: Powershed politics and hydropower decision making in Yunnan, China

    NASA Astrophysics Data System (ADS)

    Magee, Darrin L.

    This study analyzes decision making related to large-scale hydropower in China's Yunnan Province. The study has five aims: to contribute empirical knowledge about hydropower development on the Lancang (upper Mekong) and Nu (upper Salween) Rivers; to explain the institutional, legal, and political economic factors affecting decisions about large-scale hydropower; to use the peculiarities of water to complicate models of center-local and interprovincial relations; to underscore the importance of geographic constructs in framing and legitimizing certain development patterns; and to contribute to debates on China's "civil society." After reviewing literature in political ecology, China geography and area studies, and scale theory, I develop an analytical framework called a powershed. Like a watershed, a powershed reflects a space over which a resource is collected. It also has political meaning: first, as a way of understanding how policies and investments are deployed to facilitate electric power transfers from Yunnan to Guangdong; and second, as a means for signaling the importance of geographic constructs in legitimizing certain discourses, actions, actors, and policies while de-legitimizing others. Most importantly, it provides a dynamic, context-specific analytical framework that enables us to trace the processes of hydropower development. Next, I provide details of Lancang and Nu hydropower and of the energy geographies to which the projects belong. My analysis picks apart decision flows from blueprint to dam, identifying two distinctly different perspectives. I conclude by arguing first that supra-provincial institutions such as watershed commissions, hydropower companies, and grid companies are important in shaping relations between Guangdong and Yunnan vis-a-vis electricity production, distribution, and consumption. A corollary is that reforms in the electricity and water sectors have created overlapping responsibilities and unclear jurisdiction among

  5. Exclusive Measurements of the b to s gamma Transition Rate and Photon Energy Spectrum

    SciTech Connect

    Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Palano, A.; Eigen, G.; Stugu, B.; Brown, David Nathan; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; Khan, A.; Blinov, V.E.; Buzykaev, A.R.; /more authors..

    2012-08-30

    We use 429 fb{sup -1} of e{sup +}e{sup -} collision data collected at the {Upsilon}(4S) resonance with the BABAR detector to measure the radiative transition rate of b {yields} s{gamma} with a sum of 38 exclusive final states. The inclusive branching fraction with a minimum photon energy of 1.9 GeV is found to be {Beta}({bar B} {yields} Xs{gamma}) = (3.29 {+-} 0.19 {+-} 0.48) x 10{sup -4} where the first uncertainty is statistical and the second is systematic. We also measure the first and second moments of the photon energy spectrum and extract the best fit values for the heavy-quark parameters, m{sub b} and {mu}{sub {pi}}{sup 2}, in the kinetic and shape function models.

  6. Multiscale theory on energy transfer for nanosystems and structural transitions in vault nanoparticles

    NASA Astrophysics Data System (ADS)

    Espinosa Duran, John Michael

    Recently, insights about nanoscale phenomena have been gained from theoretical and computational studies, filling gaps due to the lack of temporal and spatial resolution of some experimental characterization techniques to study dynamic phenomena. In this work, initially, two multiscale simulation approaches filling this gap are presented for studying the heat transfer problem between a system and its bath at nano/meso scale. In the first approach, an exploratory study, the internal energy of the system is used as a coarse-grained variable to study time evolution in biological nanosystems. In the second approach, the spatial profile of the energy density of the composite system is considered a field variable and it is evaluated at the nodes of a 3D grid to validate whether this variable varies slowly; the systems considered are some nanocrystals and a protein. Finally, some dynamic features of the temperature triggered structural transitions in Vault nanoparticles are revealed using classical molecular dynamics simulations.

  7. Calculation of energy levels and transition amplitudes for barium and radium.

    SciTech Connect

    Dzuba, V. A.; Flambaum, V. V.; Physics; Univ. of New South Wales

    2007-01-01

    The radium atom is a promising system for studying parity and time invariance violating weak interactions. However, available experimental spectroscopic data for radium are insufficient for designing an optimal experimental setup. We calculate the energy levels and transition amplitudes for radium states of significant interest. Forty states corresponding to all possible configurations consisting of the 7s, 7p and 6d single-electron states as well as the states of the 7s8s, 7s8p and 7s7d configurations have been calculated. The energies of ten of these states corresponding to the 6d{sup 2}, 7s8s, 7p{sup 2} and 6d7p configurations are not known from experiment. Calculations for barium are used to control the accuracy.

  8. Dry period plane of energy: Effects on glucose tolerance in transition dairy cows.

    PubMed

    Mann, S; Leal Yepes, F A; Duplessis, M; Wakshlag, J J; Overton, T R; Cummings, B P; Nydam, D V

    2016-01-01

    Overfeeding energy in the dry period can affect glucose metabolism and the energy balance of transition dairy cows with potential detrimental effects on the ability to successfully adapt to early lactation. The objectives of this study were to investigate the effect of different dry cow feeding strategies on glucose tolerance and on resting concentrations of blood glucose, glucagon, insulin, nonesterified fatty acids (NEFA), and β-hydroxybutyrate (BHB) in the peripartum period. Cows entering second or greater lactation were enrolled at dry-off (57 d before expected parturition) into 1 of 3 treatment groups following a randomized block design: cows that received a total mixed ration (TMR) formulated to meet but not exceed energy requirements during the dry period (n=28, controlled energy); cows that received a TMR supplying approximately 150% of energy requirements during the dry period (n=28, high energy); and cows that were fed the same diet as the controlled energy group for the first 28 d, after which the TMR was formulated to supply approximately 125% of energy requirements until calving (n=28, intermediate energy). Intravenous glucose tolerance tests (IVGTT) with rapid administration of 0.25 g of glucose/kg of body weight were performed 28 and 10d before expected parturition, as well as at 4 and 21 d after calving. Area under the curve for insulin and glucose, maximal concentration and time to half-maximal concentration of insulin and glucose, and clearance rates were calculated. Insulin resistance (IR) indices were calculated from baseline samples obtained during IVGTT and Spearman rank correlations determined between IVGTT parameters and IR indices. Treatment did not affect IVGTT parameters at any of the 4 time points. Correlation between IR indices and IVGTT parameters was generally poor. Overfeeding cows energy in excess of predicted requirements by approximately 50% during the entire dry period resulted in decreased postpartum basal plasma glucose and

  9. Calculation of energy levels, {ital E}1 transition amplitudes, and parity violation in francium

    SciTech Connect

    Dzuba, V.A.; Flambaum, V.V.; Sushkov, O.P.

    1995-05-01

    Many-body perturbation theory in the screened Coulomb interaction was used to calculate energy levels, {ital E}1 trransition amplitudes, and the parity-nonconserving (PNC) {ital E}1 amplitude of the 7{ital s}-8{ital s} transition in francium. The method takes into account the core-polarization effect, the second-order correlations, and the three dominating sequences of higher-order correlation diagrams: screening of the electron-electron interaction, particle-hole interaction, and the iterations of the self-energy operator. The result for the PNC amplitude for {sup 223}Fr is {ital E}1(7{ital s}-8{ital s})=(1.59{plus_minus}{similar_to}1%){times}10{sup {minus}10}{ital iea}{sub {ital B}}({minus}{ital Q}{sub {ital W}}/{ital N}), where {ital Q}{sub {ital W}} is the weak charge of the nucleus, {ital N}=136 is the number of neutrons, {ital e}={vert_bar}{ital e}{vert_bar} is the elementary charge, and {ital a}{sub {ital B}} is the Bohr radius. Our prediction for the position of the 8{ital s} energy level of Fr, which has not been measured yet, is 13 110 cm{sup {minus}1} below the limit of the continuous spectrum. The accuracy of the calculations was controlled by comparison with available experimental data and analogous calculations for cesium. It is estimated to be {similar_to}0.1% for the energy levels and {similar_to}1% for the transition amplitudes.

  10. Nonequilibrium self-energy functional approach to the dynamical Mott transition

    NASA Astrophysics Data System (ADS)

    Hofmann, Felix; Eckstein, Martin; Potthoff, Michael

    2016-06-01

    The real-time dynamics of the Fermi-Hubbard model, driven out of equilibrium by quenching or ramping the interaction parameter, is studied within the framework of the nonequilibrium self-energy functional theory. A dynamical impurity approximation with a single auxiliary bath site is considered as a reference system, and the time-dependent hybridization is optimized as prescribed by the variational principle. The dynamical two-site approximation turns out to be useful to study the real-time dynamics on short and intermediate time scales. Depending on the strength of the interaction in the final state, two qualitatively different response regimes are observed. For both weak and strong couplings, qualitative agreement with previous results of nonequilibrium dynamical mean-field theory is found. The two regimes are sharply separated by a critical point at which the low-energy bath degree of freedom decouples in the course of time. We trace the dependence of the critical interaction of the dynamical Mott transition on the duration of the interaction ramp from sudden quenches to adiabatic dynamics and therewith link the dynamical to the equilibrium Mott transition.

  11. Rotational transitions induced by collisions of HD+ ions with low-energy electrons

    NASA Astrophysics Data System (ADS)

    Motapon, O.; Pop, N.; Argoubi, F.; Mezei, J. Zs; Epee, M. D. Epee; Faure, A.; Telmini, M.; Tennyson, J.; Schneider, I. F.

    2014-07-01

    A series of computations based on multichannel quantum defect theory have been performed in order to produce the cross sections of rotational transitions (excitations Ni+-2→ Ni+, deexcitations Ni+ → Ni+-2, with Ni+=2 to 10) and of their competitive process, the dissociative recombination, induced by collisions of HD+ ions with electrons in the energy range 10-5 to 0.3 eV. Maxwell anisotropic rate coefficients, obtained from these cross sections in the conditions of the Heidelberg Test Storage Ring (TSR) experiments (kBTt=2.8 meV and kBTl=45 μeV), have been reported for those processes in the same electronic energy range. Maxwell isotropic rate coefficients have been presented as well for electronic temperatures up to a few hundred Kelvins. Very good overall agreement is found between our results for rotational transitions and the former theoretical computations as well as with experiment. Furthermore, due to the full rotational computations performed, the accuracy of the resulting dissociative recombination cross sections is improved considerably.

  12. Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy

    NASA Technical Reports Server (NTRS)

    Bhatia, Anand K.; Sinha, Chandana

    2009-01-01

    We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very low incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it The scattering wave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts, the exchange approximation has only been considered. We calculate the laser-assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

  13. Free-Free Transitions in the Presence of Laser Fields at Very Low Incident Electron Energy

    NASA Technical Reports Server (NTRS)

    Bhatia, A. K.; Sinha, Chandana

    2010-01-01

    We study the free-free transition in electron-hydrogenic systems in ground state in presence of an external laser field at very loud incident energies. The laser field is treated classically while the collision dynamics is treated quantum mechanically. The laser field is chosen to be monochromatic, linearly polarized and homogeneous. The incident electron is considered to be dressed by the laser in a nonperturbative manner by choosing a Volkov wave function for it. The scattering weave function for the electron is solved numerically by taking into account the effect of the electron exchange, short-range as well as of the long-range interactions to get the S and P wave phase shifts while for the higher angular momentum phase shifts the exchange approximation has only been considered. We calculate the laser assisted differential cross sections (LADCS) for the aforesaid free-free transition process for single photon absorption/emission. The laser intensity is chosen to be much less than the atomic field intensity. A strong suppression is noted in the LADCS as compared to the field free (FF) cross sections. Unlike the FF ones, the LADCS exhibit some oscillations having a distinct maximum at a low value of the scattering angle depending on the laser parameters as well as on the incident energies.

  14. Dynamics of ground and excited state vibrational relaxation and energy transfer in transition metal carbonyls.

    PubMed

    Delor, Milan; Sazanovich, Igor V; Towrie, Michael; Spall, Steven J; Keane, Theo; Blake, Alexander J; Wilson, Claire; Meijer, Anthony J H M; Weinstein, Julia A

    2014-10-01

    Nonlinear vibrational spectroscopy provides insights into the dynamics of vibrational energy transfer in and between molecules, a crucial phenomenon in condensed phase physics, chemistry, and biology. Here we use frequency-domain 2-dimensional infrared (2DIR) spectroscopy to investigate the vibrational relaxation (VR) and vibrational energy transfer (VET) rates in different solvents in both the electronic ground and excited states of Re(Cl)(CO)3(4,4'-diethylester-2,2'-bipyridine), a prototypical transition metal carbonyl complex. The strong C≡O and ester C═O stretch infrared reporters, located on opposite sides of the molecule, were monitored in the 1600-2100 cm(-1) spectral region. VR in the lowest charge transfer triplet excited state ((3)CT) is found to be up to eight times faster than in the ground state. In the ground state, intramolecular anharmonic coupling may be solvent-assisted through solvent-induced frequency and charge fluctuations, and as such VR rates are solvent-dependent. In contrast, VR rates in the solvated (3)CT state are surprisingly solvent-insensitive, which suggests that predominantly intramolecular effects are responsible for the rapid vibrational deactivation. The increased VR rates in the excited state are discussed in terms of intramolecular electrostatic interactions helping overcome structural and thermodynamic barriers for this process in the vicinity of the central heavy atom, a feature which may be of significance to nonequilibrium photoinduced processes observed in transition metal complexes in general. PMID:25198700

  15. Water films on transition metal surfaces: A physical disclosure of adsorption energy

    NASA Astrophysics Data System (ADS)

    Revilla-López, Guillem; López, Nuria; Theoretical Heterogeneous Catalysis Group Team

    2014-03-01

    Our work reports novel physical models derived from DFT calculations including van der Waals forces for the adsorption of different water motifs: ice bilayer, √37 x √37-R 25.3° and rosette on transition metal surfaces. This energy decomposition scheme is obtained by analyzing the two driving energies of adsorption: water-water and water-metal interactions. The former explained by single water adsorption and the latter by ice resonance stabilization. These two magnitudes drive, to different extent, the adsorption of ice bilayer and √37 whereas rosette motif lacks the resonance contribution. The equations successfully reproduce and predict the experimental results for the wettability and the dissociation of water films on the fcc(111) and hcp(0001) facets of Pd, Pt, Ru Ir, Rh, Au, and Ag. So happens for the temperature of the hydrophobic/hydrophilic water film transition and for the effect of the surface roughness on it. Furthermore, the metastability and the wettability of other water films like √39 x √39-R 16.1° can be anticipated by the rationalization of their geometry and their dissociation state. The authors thank the ERC-2010-StG-258406 Bio2chem-d project, MINECO (CTQ2012-33826) and BSC-RES for supporting this work.

  16. Abrupt onset of a second energy gap at the superconducting transition of underdoped Bi2212

    SciTech Connect

    Hussain, Zahid; Lee, W.S.; Vishik, I.M.; Tanaka, K.; Lu, D.H.; Sasagawa, T.; Nagaosa, N.; Devereaux, T.P.; Hussain, Z.; Shen, Z.-X.

    2007-05-26

    he superconducting gap--an energy scale tied to the superconducting phenomena--opens on the Fermi surface at the superconducting transition temperature (Tc) in conventional BCS superconductors. In underdoped high-Tc superconducting copper oxides, a pseudogap (whose relation to the superconducting gap remains a mystery) develops well above Tc (refs 1, 2). Whether the pseudogap is a distinct phenomenon or the incoherent continuation of the superconducting gap above Tc is one of the central questions in high-Tc research3, 4, 5, 6, 7, 8. Although some experimental evidence suggests that the two gaps are distinct9, 10, 11, 12, 13, 14, 15, 16, 17, 18, this issue is still under intense debate. A crucial piece of evidence to firmly establish this two-gap picture is still missing: a direct and unambiguous observation of a single-particle gap tied to the superconducting transition as function of temperature. Here we report the discovery of such an energy gap in underdoped Bi2Sr2CaCu2O8+delta in the momentum space region overlooked in previous measurements. Near the diagonal of Cu?O bond direction (nodal direction), we found a gap that opens at Tc and has a canonical (BCS-like) temperature dependence accompanied by the appearance of the so-called Bogoliubov quasi-particles, a classical signature of superconductivity. This is in sharp contrast to the pseudogap near the Cu?O bond direction (antinodal region) measured in earlier experiments19, 20, 21.

  17. Spectra, energy levels, and energy transition of lanthanide complexes with cinnamic acid and its derivatives.

    PubMed

    Zhou, Kaining; Feng, Zhongshan; Shen, Jun; Wu, Bing; Luo, Xiaobing; Jiang, Sha; Li, Li; Zhou, Xianju

    2016-04-01

    High resolution spectra and luminescent lifetimes of 6 europium(III)-cinnamic acid complex {[Eu2L6(DMF)(H2O)]·nDMF·H2O}m (L=cinnamic acid I, 4-methyl-cinnamic acid II, 4-chloro-cinnamic acid III, 4-methoxy-cinnamic acid IV, 4-hydroxy-cinnamic acid V, 4-nitro-cinnamic acid VI; DMF=N, N-dimethylformamide, C3H7NO) were recorded from 8 K to room temperature. The energy levels of Eu(3+) in these 6 complexes are obtained from the spectra analysis. It is found that the energy levels of the central Eu(3+) ions are influenced by the nephelauxetic effect, while the triplet state of ligand is lowered by the p-π conjugation effect of the para-substituted functional groups. The best energy matching between the ligand triplet state and the central ion excited state is found in complex I. While the other complexes show poorer matching because the gap of (5)D0 and triplet state contracts. PMID:26802538

  18. Spectra, energy levels, and energy transition of lanthanide complexes with cinnamic acid and its derivatives

    NASA Astrophysics Data System (ADS)

    Zhou, Kaining; Feng, Zhongshan; Shen, Jun; Wu, Bing; Luo, Xiaobing; Jiang, Sha; Li, Li; Zhou, Xianju

    2016-04-01

    High resolution spectra and luminescent lifetimes of 6 europium(III)-cinnamic acid complex {[Eu2L6(DMF)(H2O)]·nDMF·H2O}m (L = cinnamic acid I, 4-methyl-cinnamic acid II, 4-chloro-cinnamic acid III, 4-methoxy-cinnamic acid IV, 4-hydroxy-cinnamic acid V, 4-nitro-cinnamic acid VI; DMF = N, N-dimethylformamide, C3H7NO) were recorded from 8 K to room temperature. The energy levels of Eu3 + in these 6 complexes are obtained from the spectra analysis. It is found that the energy levels of the central Eu3 + ions are influenced by the nephelauxetic effect, while the triplet state of ligand is lowered by the p-π conjugation effect of the para-substituted functional groups. The best energy matching between the ligand triplet state and the central ion excited state is found in complex I. While the other complexes show poorer matching because the gap of 5D0 and triplet state contracts.

  19. Involving the public in decision-making at federal facilities: The Department of Energy experience

    SciTech Connect

    Gesalman, C.M.

    1996-12-31

    The Department of Energy is involved in cleanup of a wide variety of sites used in the development and production of nuclear weapons. Substantial and increasing efforts have been made to involve the public in the planning and implementation of the cleanup projects. Early in the program, public participation was mainly an information transfer effort. More recently, innovative techniques have been used to increase public understanding of the tradeoffs required in making cleanup decisions (e.g., more stringent cleanup standards lead to higher costs). Sites now realize that relationships are key and are working to develop them. Advisory boards have been established at several sites. The methods of forming the boards have varied from site to site, as have the size of the group and the issues addressed. The effectiveness of the boards in their goal of improving public participation at the sites will be evaluated in the next fiscal year. DOE has sought public input on an increasing number of issues, such as future use of its facilities, environmental justice concerns, and budget development. Assumptions about future use of sites are crucial to setting realistic cleanup standards and controlling costs. Decisions made in the early phases of the budget process are now based in part on stakeholder input regarding priorities; for example, stakeholder concerns about and support for emphasizing plutonium cleanup at Rocky Flats have led to changes in priorities between the materials stabilization and environmental restoration programs. Environmental justice has become an increasing issue; sites must ensure that public participation programs effectively reach minority and low-income populations.

  20. Computation of intersubband transition energy in normal and inverted core-shell quantum dots using finite difference technique

    NASA Astrophysics Data System (ADS)

    Deyasi, Arpan; Bhattacharyya, S.; Das, N. R.

    2013-08-01

    In this paper, intersubband transition energy is computed for core-shell (normal and inverted) quantum dots (CSQD) of cubic and spherical geometries by solving time-independent Schrödinger equation using finite-difference technique. Sparse, structured Hamiltonian matrices of order N3 × N3 for cubic and N × N for spherical dots are produced considering N discrete points in spatial direction. The matrices are diagonalized to obtain eigenstates for electrons. Computed results for the lowest three eigenstates and intersubband transitions are shown for different structural parameters taking GaAs/AlxGa1-xAs based CSQD as example. Transition energy decreases with increase in core thickness. When compared, spherical CSQDs show higher transition energy between two subbands than cubic CSQDs of similar size and same material composition. Also, in inverted configuration, transition energy decreases for a cubic dot while increases for a spherical dot as core size is increased. Wide tuning range for intersubband transition by tailoring dot dimensions indicates important applications for optical emitters/detectors.

  1. Interband optical transition energy and oscillator strength in a lead based CdSe quantum dot quantum well heterostructure

    SciTech Connect

    Saravanamoorthy, S. N.; Peter, A. John

    2015-06-24

    Binding energies of the exciton and the interband optical transition energies are studied in a CdSe/Pb{sub 1-x}Cd{sub x}Se/CdSe spherical quantum dot-quantum well nanostructure taking into account the geometrical confinement effect. The core and shell are taken as the same material. The initial and final states of energy and the overlap integrals of electron and hole wave functions are determined by the oscillator strength. The oscillator strength and the radiative transition life time with the dot radius are investigated for various Cd alloy content in the core and shell materials.

  2. Evidence and future scenarios of a low-carbon energy transition in Central America: a case study in Nicaragua

    NASA Astrophysics Data System (ADS)

    Barido, Diego Ponce de Leon; Johnston, Josiah; Moncada, Maria V.; Callaway, Duncan; Kammen, Daniel M.

    2015-10-01

    The global carbon emissions budget over the next decades depends critically on the choices made by fast-growing emerging economies. Few studies exist, however, that develop country-specific energy system integration insights that can inform emerging economies in this decision-making process. High spatial- and temporal-resolution power system planning is central to evaluating decarbonization scenarios, but obtaining the required data and models can be cost prohibitive, especially for researchers in low, lower-middle income economies. Here, we use Nicaragua as a case study to highlight the importance of high-resolution open access data and modeling platforms to evaluate fuel-switching strategies and their resulting cost of power under realistic technology, policy, and cost scenarios (2014-2030). Our results suggest that Nicaragua could cost-effectively achieve a low-carbon grid (≥80%, based on non-large hydro renewable energy generation) by 2030 while also pursuing multiple development objectives. Regional cooperation (balancing) enables the highest wind and solar generation (18% and 3% by 2030, respectively), at the least cost (US127 MWh-1). Potentially risky resources (geothermal and hydropower) raise system costs but do not significantly hinder decarbonization. Oil price sensitivity scenarios suggest renewable energy to be a more cost-effective long-term investment than fuel oil, even under the assumption of prevailing cheap oil prices. Nicaragua’s options illustrate the opportunities and challenges of power system decarbonization for emerging economies, and the key role that open access data and modeling platforms can play in helping develop low-carbon transition pathways.

  3. Energy landscape view of phase transitions and slow dynamics in thermotropic liquid crystals

    PubMed Central

    Chakrabarti, Dwaipayan; Bagchi, Biman

    2006-01-01

    Thermotropic liquid crystals are known to display rich phase behavior on temperature variation. Although the nematic phase is orientationally ordered but translationally disordered, a smectic phase is characterized by the appearance of a partial translational order in addition to a further increase in orientational order. In an attempt to understand the interplay between orientational and translational order in the mesophases that thermotropic liquid crystals typically exhibit upon cooling from the high-temperature isotropic phase, we investigate the potential energy landscapes of a family of model liquid crystalline systems. The configurations of the system corresponding to the local potential energy minima, known as the inherent structures, are determined from computer simulations across the mesophases. We find that the depth of the potential energy minima explored by the system along an isochor grows through the nematic phase as temperature drops in contrast to its insensitivity to temperature in the isotropic and smectic phases. The onset of the growth of the orientational order in the parent phase is found to induce a translational order, resulting in a smectic-like layer in the underlying inherent structures; the inherent structures, surprisingly, never seem to sustain orientational order alone if the parent nematic phase is sandwiched between the high-temperature isotropic phase and the low-temperature smectic phase. The Arrhenius temperature dependence of the orientational relaxation time breaks down near the isotropic–nematic transition. We find that this breakdown occurs at a temperature below which the system explores increasingly deeper potential energy minima. PMID:16648269

  4. Relative edge energy in the stability of transition metal nanoclusters of different motifs.

    PubMed

    Zhao, X J; Xue, X L; Guo, Z X; Li, S F

    2016-07-01

    When a structure is reduced to a nanometer scale, the proportion of the edge atoms increases significantly, which can play a crucial role in determining both their geometric and electronic properties, as demonstrated by the recently established generalized Wulff construction principle [S. F. Li, et al., Phys. Rev. Lett., 2013, 111, 115501]. Consequently, it is of great interest to clarify quantitatively the role of the edge atoms that dominate the motifs of these nanostructures. In principle, establishing an effective method valid for determining the absolute value of the surface energy and particularly the edge energy for a given nanostructure is expected to resolve such a problem. However, hitherto, it is difficult to obtain the absolute edge energy of transition metal clusters, particularly when their sizes approach the nanometer regime. In this paper, taking Ru nanoclusters as a prototypical example, our first-principles calculations introduce the concept of relative edge energy (REE), reflecting the net edge atom effect over the surface (facet) atom effect, which is fairly powerful to quasi-quantitatively estimate the critical size at which the crossover occurs between different configurations of a given motif, such as from an icosahedron to an fcc nanocrystal. By contrast, the bulk effect should be re-considered to rationalize the power of the REE in predicting the relative stability of larger nanostructures between different motifs, such as fcc-like and hcp-like nanocrystals. PMID:27296770

  5. Students' Socioscientific Reasoning and Decision-making on Energy-related Issues—Development of a measurement instrument

    NASA Astrophysics Data System (ADS)

    Sakschewski, Mark; Eggert, Sabina; Schneider, Susanne; Bögeholz, Susanne

    2014-09-01

    The concept of energy is one key component of science education curricula worldwide. While it is still being taught in many science classrooms from a mainly conceptual knowledge perspective, the need to frame the concept of energy as a socioscientific issue and implement it in the context of citizenship education and education for sustainable development, is getting more and more explicit. As we will be faced with limited fossil fuels and the consequences of global climate change in the future, students have to be supported in becoming literate citizens who are able to reach informed energy-related decisions. In this article, we focus on students' reasoning and decision-making processes about socioscientific energy-related issues. In more detail, we developed a paper-and-pencil measurement instrument to assess secondary school students' competencies in this domain. The functioning of the measurement instrument was analysed with a sample of 850 students from grades 6, 8, 10 and 12 using item response theory. Findings show that the measurement instrument functions in terms of reliability and validity. Concerning student ability, elaborate reasoning and decision-making was characterised by the use of trade-offs and the ability to weigh arguments and to reflect on the structure of reasoning and decision-making processes. The developed measurement instrument provides a complement for existing test instruments on conceptual knowledge about the concept of energy. It aims to contribute to a change in teaching about energy, especially in physics education in the sense of education for sustainable development.

  6. Students' Meaning Making in Science: Solving Energy Resource Problems in Virtual Worlds Combined with Spreadsheets to Develop Graphs

    ERIC Educational Resources Information Center

    Krange, Ingeborg; Arnseth, Hans Christian

    2012-01-01

    The aim of this study is to scrutinize the characteristics of conceptual meaning making when students engage with virtual worlds in combination with a spreadsheet with the aim to develop graphs. We study how these tools and the representations they contain or enable students to construct serve to influence their understanding of energy resource…

  7. Energy budget increases reduce mean streamflow more than snow–rain transitions: using integrated modeling to isolate climate change impacts on Rocky Mountain hydrology

    NASA Astrophysics Data System (ADS)

    Foster, Lauren M.; Bearup, Lindsay A.; Molotch, Noah P.; Brooks, Paul D.; Maxwell, Reed M.

    2016-04-01

    In snow-dominated mountain regions, a warming climate is expected to alter two drivers of hydrology: (1) decrease the fraction of precipitation falling as snow; and (2) increase surface energy available to drive evapotranspiration. This study uses a novel integrated modeling approach to explicitly separate energy budget increases via warming from precipitation phase transitions from snow to rain in two mountain headwaters transects of the central Rocky Mountains. Both phase transitions and energy increases had significant, though unique, impacts on semi-arid mountain hydrology in our simulations. A complete shift in precipitation from snow to rain reduced streamflow between 11% and 18%, while 4 °C of uniform warming reduced streamflow between 19% and 23%, suggesting that changes in energy-driven evaporative loss, between 27% and 29% for these uniform warming scenarios, may be the dominant driver of annual mean streamflow in a warming climate. Phase changes induced a flashier system, making water availability more susceptible to precipitation variability and eliminating the runoff signature characteristic of snowmelt-dominated systems. The impact of a phase change on mean streamflow was reduced as aridity increased from west to east of the continental divide.

  8. Theoretical Study of the Energy Spectrum of the 2p3 3p in S IX and Related Electron Transitions

    NASA Astrophysics Data System (ADS)

    Boganovich, P.; Karpuškienė, R.; Udris, A.

    The energy spectrum of S IX was calculated by the configuration interaction method. Calculated wavelengths and oscillator strengths of the electric dipole transitions 2s22p33p-2s22p33d, 2s22p33s-2s22p33p and the two-electron transitions 2s2p5-2s22p33p are presented. The results obtained were compared with the available experimental data.

  9. Free Volume, Energy, and Entropy at the Polymer Glass Transition: New Results and Connections with Widely Used Treatments

    NASA Astrophysics Data System (ADS)

    White, Ronald; Lipson, Jane

    Free volume has a storied history in polymer physics. To introduce our own results, we consider how free volume has been defined in the past, e.g. in the works of Fox and Flory, Doolittle, and the equation of Williams, Landel, and Ferry. We contrast these perspectives with our own analysis using our Locally Correlated Lattice (LCL) model where we have found a striking connection between polymer free volume (analyzed using PVT data) and the polymer's corresponding glass transition temperature, Tg. The pattern, covering over 50 different polymers, is robust enough to be reasonably predictive based on melt properties alone; when a melt hits this T-dependent boundary of critical minimum free volume it becomes glassy. We will present a broad selection of results from our thermodynamic analysis, and make connections with historical treatments. We will discuss patterns that have emerged across the polymers in the energy and entropy when quantified as ''per LCL theoretical segment''. Finally we will relate the latter trend to the point of view popularized in the theory of Adam and Gibbs. The authors gratefully acknowledge support from NSF DMR-1403757.

  10. Some behavioral aspects of energy descent: how a biophysical psychology might help people transition through the lean times ahead

    PubMed Central

    De Young, Raymond

    2014-01-01

    We may soon face biophysical limits to perpetual growth. Energy supplies may tighten and then begin a long slow descent while defensive expenditures rise to address problems caused by past resource consumption. The outcome may be significant changes in daily routines at the individual and community level. It is difficult to know when this scenario might begin to unfold but it clearly would constitute a new behavioral context, one that the behavioral sciences least attends to. Even if one posits a less dramatic scenario, people may still need to make many urgent and perhaps unsettling transitions. And while a robust response would be needed, it is not at all clear what should be the details of that response. Since it is likely that no single response will fix things everywhere, for all people or for all time, it would be useful to conduct many social experiments. Indeed, a culture of small experiments should be fostered which, at the individual and small group level, can be described as behavioral entrepreneurship. This may have begun, hidden in plain sight, but more social experiments are needed. To be of help, it may be useful to both package behavioral insights in a way that is practitioner-oriented and grounded in biophysical trends and to propose a few key questions that need attention. This paper begins the process of developing a biophysical psychology, incomplete as it is at this early stage. PMID:25404926

  11. Some behavioral aspects of energy descent: how a biophysical psychology might help people transition through the lean times ahead.

    PubMed

    De Young, Raymond

    2014-01-01

    We may soon face biophysical limits to perpetual growth. Energy supplies may tighten and then begin a long slow descent while defensive expenditures rise to address problems caused by past resource consumption. The outcome may be significant changes in daily routines at the individual and community level. It is difficult to know when this scenario might begin to unfold but it clearly would constitute a new behavioral context, one that the behavioral sciences least attends to. Even if one posits a less dramatic scenario, people may still need to make many urgent and perhaps unsettling transitions. And while a robust response would be needed, it is not at all clear what should be the details of that response. Since it is likely that no single response will fix things everywhere, for all people or for all time, it would be useful to conduct many social experiments. Indeed, a culture of small experiments should be fostered which, at the individual and small group level, can be described as behavioral entrepreneurship. This may have begun, hidden in plain sight, but more social experiments are needed. To be of help, it may be useful to both package behavioral insights in a way that is practitioner-oriented and grounded in biophysical trends and to propose a few key questions that need attention. This paper begins the process of developing a biophysical psychology, incomplete as it is at this early stage. PMID:25404926

  12. Difference in variation of glass transition activation energy between 1,2-propanediamine and 1,2-propanediol

    NASA Astrophysics Data System (ADS)

    Terashima, Yukio

    2016-05-01

    Variations of the effective activation energy (Eα) throughout the glass transition were determined for 1,2-propanediamine (12PDA) and 1,2-propanediol (12PDO) by applying an isoconversional method to differential scanning calorimetry (DSC) data. Eα was found to markedly decrease throughout the glass transition of 12PDA, whereas such drastic change in Eα was not observed for 12PDO. Although the two simple liquids are similar in molecular structure and size, their trends in Eα and fragility m throughout the glass transition can be quite different. The significant disparity in the kinetic parameters can be caused by differences in hydrogen-bonding structure between 12PDA and 12PDO.

  13. What can prevent us from making Moscow an energy-efficient city?

    NASA Astrophysics Data System (ADS)

    Vasil'Ev, G. P.

    2011-08-01

    Problems concerned with energy efficiency and energy conservation are discussed. The need to strengthen the role of the government in shaping the tariff policy is emphasized. Examples illustrating how tariffs are regulated abroad are given.

  14. Austin's Home Performance with Energy Star Program: Making a Compelling Offer to a Financial Institution Partner

    SciTech Connect

    Zimring, Mark

    2011-03-18

    Launched in 2006, over 8,700 residential energy upgrades have been completed through Austin Energy's Home Performance with Energy Star (HPwES) program. The program's lending partner, Velocity Credit Union (VCU) has originated almost 1,800 loans, totaling approximately $12.5 million. Residential energy efficiency loans are typically small, and expensive to originate and service relative to larger financing products. National lenders have been hesitant to deliver attractive loan products to this small, but growing, residential market. In response, energy efficiency programs have found ways to partner with local and regional banks, credit unions, community development finance institutions (CDFIs) and co-ops to deliver energy efficiency financing to homeowners. VCU's experience with the Austin Energy HPwES program highlights the potential benefits of energy efficiency programs to a lending partner.

  15. Metal ferrite spinel energy storage devices and methods for making and using same

    DOEpatents

    Weimer, Alan W.; Perkins, Christopher; Scheffe, Jonathan; George, Steven M.; Lichty, Paul

    2013-03-19

    1-100 nm metal ferrite spinel coatings are provided on substrates, preferably by using an atomic layer deposition process. The coatings are able to store energy such as solar energy, and to release that stored energy, via a redox reaction. The coating is first thermally or chemically reduced. The reduced coating is then oxidized in a second step to release energy and/or hydrogen, carbon monoxide or other reduced species.

  16. Metal ferrite spinel energy storage devices and methods for making and using same

    DOEpatents

    Weimer, Alan W.; Perkins, Christopher; Scheffe, Jonathan; George, Steven M.; Lichty, Paul

    2012-05-29

    1-100 nm metal ferrite spinel coatings are provided on substrates, preferably by using an atomic layer deposition process. The coatings are able to store energy such as solar energy, and to release that stored energy, via a redox reaction. The coating is first thermally or chemically reduced. The reduced coating is then oxidized in a second step to release energy and/or hydrogen, carbon monoxide or other reduced species.

  17. SunShot: Making Solar Energy Cost-Competitive Throughout the United States (Fact Sheet)

    SciTech Connect

    Not Available

    2013-02-01

    The U.S. Department of Energy SunShot Initiative is designed to re-establish American technological leadership, strengthen U.S. economic competitiveness in the global clean energy race, and help America obtain a secure energy future. This fact sheet highlights the achievements of the initiative since 2010.

  18. Flambeau River Papers Makes a Comeback with a Revised Energy Strategy

    SciTech Connect

    2010-03-10

    After the closure of the Flambeau River Papers mill in 2006, a new energy management approach has resulted in $2.6 million in annual energy savings and increased the facility's production by 11.9%. Read about Flambeau's successful energy management approach.

  19. DFT-GGA errors in NO chemisorption energies on (111) transition metal surfaces

    NASA Astrophysics Data System (ADS)

    Huang, Xu; Mason, Sara E.

    2014-03-01

    We investigate whether well-known DFT-GGA errors in predicting the chemisorption energy (Echem) of CO on transition metal surfaces manifest in analogous NO chemisorption systems. While widely investigated in the case of CO/metal, analogous DFT-GGA errors have long been claimed to be absent in NO/metal chemisorption. Here, we provide theoretical evidence of systematic enhanced back-donation in NO/metal chemisorption at the DFT-GGA level. We use electronic structure analysis to show that the partially filled molecular NO 2π* orbital rehybridizes with the transition metal d-band to form new bonding and anti-bonding states. We relate the back-donation charge transfer associated with chemisorption to the promotion of an electron from the 5σ orbital to the 2π* orbital in the gas-phase NO G2Σ- ← X2Π excitation. We establish linear relationships between Echem and ΔEG ← X and formulate an Echem correction scheme in the style of Mason et al. [Physical Review B 69, 161401(R)]. We apply the NO Echem correction method to the (111) surfaces of Pt, Pd, Rh, and Ir, with NO chemisorption modeled at a coverage of 0.25 ML. We note that the slope of Echemvs. ΔEG ← X and the dipole moment depend strongly on adsorption site for each metal, and we construct an approximate correction scheme which we test using NO/Pt(100) chemisorption.

  20. Transition-metal-nitride-based thin films as novel energy harvesting materials

    PubMed Central

    Kerdsongpanya, Sit; Alling, Björn

    2016-01-01

    The last few years have seen a rise in the interest in early transition-metal and rare-earth nitrides, primarily based on ScN and CrN, for energy harvesting by thermoelectricity and piezoelectricity. This is because of a number of important advances, among those the discoveries of exceptionally high piezoelectric coupling coefficient in (Sc,Al)N alloys and of high thermoelectric power factors of ScN-based and CrN-based thin films. These materials also constitute well-defined model systems for investigating thermodynamics of mixing for alloying and nanostructural design for optimization of phase stability and band structure. These features have implications for and can be used for tailoring of thermoelectric and piezoelectric properties. In this highlight article, we review the ScN- and CrN-based transition-metal nitrides for thermoelectrics, and drawing parallels with piezoelectricity. We further discuss these materials as a models systems for general strategies for tailoring of thermoelectric properties by integrated theoretical–experimental approaches. PMID:27358737

  1. Relation between ligand design and transition energy for the praseodymium ion in crystals.

    PubMed

    Zhou, Xianju; Tanner, Peter A

    2015-01-01

    Ten substituted benzoate complexes of Pr(3+) of the type [Pr(XC6H4COO)3(H2O)n(DMF)m]p·(DMF)q (X = OCH3, NO2, OH, F, Cl, NH2) have been synthesized, and for eight of these crystallographic data are available. The electronic absorption and emission spectra of the complexes have been recorded and interpreted at temperatures down to 10 K for transitions involving the (3)P0 and (1)D2 J-multiplet terms. Generally, the electron-withdrawing groups X in the benzoate moiety lead to higher (3)P0 energy than electron-donating groups. Empirical relations have been found between the energies of the (3)P0 and (1)D2(1) levels and the Hammett sigma constants for substituents and the unit cell volume per Pr(3+) ion. The latter relationship is indicative of a correlation between the electronic state energy and the ligand dipole polarizability. This has been confirmed by reference to literature data for the LaX3:Pr(3+) systems, so that the ligand dipole polarizability is a key factor in determining the nephelauxetic shifts of 4f(N) ions in crystals. PMID:25474732

  2. Binding energies of exciton complexes in transition metal dichalcogenide monolayers and effect of dielectric environment

    NASA Astrophysics Data System (ADS)

    Kylänpää, Ilkka; Komsa, Hannu-Pekka

    2015-11-01

    Excitons, trions, biexcitons, and exciton-trion complexes in two-dimensional transition metal dichalcogenide sheets of MoS2, MoSe2, MoTe2, WS2, and WSe2 are studied by means of density functional theory and path-integral Monte Carlo method in order to accurately account for the particle-particle correlations. In addition, the effect of dielectric environment on the properties of these exciton complexes is studied by modifying the effective interaction potential between particles. Calculated exciton and trion binding energies are consistent with previous experimental and computational studies, and larger systems such as biexciton and exciton-trion complex are found highly stable. Binding energies of biexcitons are similar to or higher than those of trions, but the binding energy of the trion depends significantly stronger on the dielectric environment than that of biexciton. Therefore, as a function of an increasing dielectric constant of the environment the exciton-trion complex "dissociates" to a biexciton rather than to an exciton and a trion.

  3. Transition of proton energy scaling using an ultrathin target irradiated by linearly polarized femtosecond laser pulses.

    PubMed

    Kim, I Jong; Pae, Ki Hong; Kim, Chul Min; Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Yu, Tae Jun; Choi, Il Woo; Lee, Chang-Lyoul; Nam, Kee Hwan; Nickles, Peter V; Jeong, Tae Moon; Lee, Jongmin

    2013-10-18

    Particle acceleration using ultraintense, ultrashort laser pulses is one of the most attractive topics in relativistic laser-plasma research. We report proton and/or ion acceleration in the intensity range of 5×10(19) to 3.3×10(20) W/cm2 by irradiating linearly polarized, 30-fs laser pulses on 10-to 100-nm-thick polymer targets. The proton energy scaling with respect to the intensity and target thickness is examined, and a maximum proton energy of 45 MeV is obtained when a 10-nm-thick target is irradiated by a laser intensity of 3.3×10(20) W/cm2. The proton acceleration is explained by a hybrid acceleration mechanism including target normal sheath acceleration, radiation pressure acceleration, and Coulomb explosion assisted-free expansion. The transition of proton energy scaling from I(1/2) to I is observed as a consequence of the hybrid acceleration mechanism. The experimental results are supported by two- and three-dimensional particle-in-cell simulations. PMID:24182274

  4. Test of the Chevallier-Polarski-Linder parametrization for rapid dark energy equation of state transitions

    SciTech Connect

    Linden, Sebastian; Virey, Jean-Marc

    2008-07-15

    We test the robustness and flexibility of the Chevallier-Polarski-Linder (CPL) parametrization of the dark energy equation of state w(z)=w{sub 0}+w{sub a}(z/1+z) in recovering a four-parameter steplike fiducial model. We constrain the parameter space region of the underlying fiducial model where the CPL parametrization offers a reliable reconstruction. It turns out that non-negligible biases leak into the results for recent (z<2.5) rapid transitions, but that CPL yields a good reconstruction in all other cases. The presented analysis is performed with supernova Ia data as forecasted for a space mission like SNAP/JDEM, combined with future expectations for the cosmic microwave background shift parameter R and the baryonic acoustic oscillation parameter A.

  5. Multiphoton transitions between energy levels in a current-biased Josephson tunnel junction.

    PubMed

    Wallraff, A; Duty, T; Lukashenko, A; Ustinov, A V

    2003-01-24

    The escape of a current-biased Josephson tunnel junction from the zero-voltage state in the presence of weak microwave radiation is investigated experimentally at low temperatures. The measurements of the junction switching current distribution indicate the macroscopic quantum tunneling of the phase below a crossover temperature of T small star, filled approximately 280 mK. At temperatures below T small star, filled we observe both single-photon and multiphoton transitions between the junction energy levels by applying microwave radiation in the frequency range between 10 and 38 GHz to the junction. These observations reflect the anharmonicity of the junction potential containing only a small number of levels. PMID:12570519

  6. Energy dissipation in heavy systems: the transition from quasi-elastic to deep-inelastic scattering

    SciTech Connect

    Rehm, K.E.; van den Berg, A.; Kolata, J.J.; Kovar, D.G.; Kutschera, W.; Rosner, G.; Stephans, G.S.F.; Yntema, J.L.; Lee, L.L.

    1984-01-01

    The interaction of medium mass projectiles (A = 28 - 64) with /sup 208/Pb has been studied using a split-pole spectrograph which allows single mass and charge identification. The reaction process in all systems studied so far is dominated by quasi-elastic neutron transfer reactions, especially at incident energies in the vicinity of the Coulomb barrier. In addition to the quasi-elastic component deep inelastic contributions are present in all reaction channels. The good mass and charge separation allows to generate Wilczynski plots for individual channels; for the system /sup 48/Ti + /sup 208/Pb we observe that the transition between the quasi-elastic and deep-inelastic reactions occurs around Q = -(30 to 35) MeV.

  7. Electron-impact dissociative double ionization of N2 and CO: Dependence of transition probability on impact energy

    NASA Astrophysics Data System (ADS)

    Pandey, A.; Kumar, P.; Banerjee, S. B.; Subramanian, K. P.; Bapat, B.

    2016-04-01

    We present an experimental and computational analysis of dissociative double ionization of N2 and CO molecules under electron impact. Experiments are performed at three energies, viz. 1, 3, and 5 keV, in order to observe the effect of impact energy on the dissociative ionization kinematics. We compare the kinetic energy release (KER) distributions of the charge symmetric dissociation channels of N22 + and CO2 + at these impact energies. An approximately linear trend between the transition energy and the expected KER values is inferred on the basis of the calculated potential energy curves of the dications. Experimentally, the normalized differential KER cross sections for these channels show an increasing trend in the low KER range and a decreasing trend in the high KER range as the electron-impact energy is increased. This observation indicates that the transition probability for excitation to different molecular ion states is not only a function of energy difference between the ground and excited states, but also a complicated function of the impact energy. In addition, nature of the observed trend in the differential KER cross sections differs significantly from their differential transition probability, which are calculated using inelastic collision model for fast-electron-impact case.

  8. A life-cycle approach to technology, infrastructure, and climate policy decision making: Transitioning to plug-in hybrid electric vehicles and low-carbon electricity

    NASA Astrophysics Data System (ADS)

    Samaras, Constantine

    In order to mitigate the most severe effects of climate change, large global reductions in the current levels of anthropogenic greenhouse gas (GHG) emissions are required in this century to stabilize atmospheric carbon dioxide (CO2) concentrations at less than double pre-industrial levels. The Intergovernmental Panel on Climate Change (IPCC) fourth assessment report states that GHG emissions should be reduced to 50-80% of 2000 levels by 2050 to increase the likelihood of stabilizing atmospheric CO2 concentrations. In order to achieve the large GHG reductions by 2050 recommended by the IPCC, a fundamental shift and evolution will be required in the energy system. Because the electric power and transportation sectors represent the largest GHG emissions sources in the United States, a unique opportunity for coupling these systems via electrified transportation could achieve synergistic environmental (GHG emissions reductions) and energy security (petroleum displacement) benefits. Plug-in hybrid electric vehicles (PHEVs), which use electricity from the grid to power a portion of travel, could play a major role in reducing greenhouse gas emissions from the transport sector. However, this thesis finds that life cycle GHG emissions from PHEVs depend on the electricity source that is used to charge the battery, so meaningful GHG emissions reductions with PHEVs are conditional on low-carbon electricity sources. Power plants and their associated GHGs are long-lived, and this work argues that decisions made regarding new electricity supplies within the next ten years will affect the potential of PHEVs to play a role in a low-carbon future in the coming decades. This thesis investigates the life cycle engineering, economic, and policy decisions involved in transitioning to PHEVs and low-carbon electricity. The government has a vast array of policy options to promote low-carbon technologies, some of which have proven to be more successful than others. This thesis uses life

  9. Turbulence kinetic energy budget during the afternoon transition - Part 2: A simple TKE model

    NASA Astrophysics Data System (ADS)

    Nilsson, Erik; Lothon, Marie; Lohou, Fabienne; Pardyjak, Eric; Hartogensis, Oscar; Darbieu, Clara

    2016-07-01

    A simple model for turbulence kinetic energy (TKE) and the TKE budget is presented for sheared convective atmospheric conditions based on observations from the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST) field campaign. It is based on an idealized mixed-layer approximation and a simplified near-surface TKE budget. In this model, the TKE is dependent on four budget terms (turbulent dissipation rate, buoyancy production, shear production and vertical transport of TKE) and only requires measurements of three available inputs (near-surface buoyancy flux, boundary layer depth and wind speed at one height in the surface layer) to predict vertical profiles of TKE and TKE budget terms.This simple model is shown to reproduce some of the observed variations between the different studied days in terms of near-surface TKE and its decay during the afternoon transition reasonably well. It is subsequently used to systematically study the effects of buoyancy and shear on TKE evolution using idealized constant and time-varying winds during the afternoon transition. From this, we conclude that many different TKE decay rates are possible under time-varying winds and that generalizing the decay with simple scaling laws for near-surface TKE of the form tα may be questionable.The model's errors result from the exclusion of processes such as elevated shear production and horizontal advection. The model also produces an overly rapid decay of shear production with height. However, the most influential budget terms governing near-surface TKE in the observed sheared convective boundary layers are included, while only second-order factors are neglected. Comparison between modeled and averaged observed estimates of dissipation rate illustrates that the overall behavior of the model is often quite reasonable. Therefore, we use the model to discuss the low-turbulence conditions that form first in the upper parts of the boundary layer during the afternoon transition and are only

  10. Energy levels, wavelengths, and transition rates of multipole transitions (E1, E2, M1, M2) in Au{sup 67+} and Au{sup 66+} ions

    SciTech Connect

    Hamasha, Safeia

    2013-11-15

    The fully relativistic configuration interaction method of the FAC code is used to calculate atomic data for multipole transitions in Mg-like Au (Au{sup 67+}) and Al-like Au (Au{sup 66+}) ions. Generated atomic data are important in the modeling of M-shell spectra for heavy Au ions and Au plasma diagnostics. Energy levels, oscillator strengths and transition rates are calculated for electric-dipole (E1), electric quadrupole (E2), magnetic dipole (M1), and magnetic quadrupole (M2) for transitions between excited and ground states 3l−nl{sup ′}, such that n=4,5,6,7. The local central potential is derived using the Dirac–Fock–Slater method. Correlation effects to all orders are considered by the configuration interaction expansion. All relativistic effects are included in the calculations. Calculated energy levels are compared against published values that were calculated using the multi-reference many body perturbation theory, which includes higher order QED effects. Favorable agreement was observed, with less than 0.15% difference.

  11. Calculations of hydrogen atom multiphoton energy level shifts, transition amplitudes and ionization probabilities

    NASA Astrophysics Data System (ADS)

    Whitney, K. G.; Chang, C. S.

    2008-07-01

    Analyses of the resonant multiphoton ionization of atoms require knowledge of ac Stark energy shifts and of multiphoton, bound-to-bound state, transition amplitudes. In this paper, we consider the three-photon photoionization of hydrogen atoms at frequencies that are at and surrounding the two-photon 1s to 2s resonance. AC energy shift sums of both the 1s and 2s states are calculated as a function of the laser frequency along with two-photon 1s → 2s resonant transition amplitude sums. These quantities are calculated using an extended version of a method, which has often been employed in a variety of ways, of calculating these sums by expressing them in terms of solutions to a variety of differential equations that are derived from the different sums being evaluated. We demonstrate how exact solutions are obtained to these differential equations, which lead to exact evaluations of the corresponding sums. A variety of different cases are analysed, some involving analytic continuation, some involving real number analysis and some involving complex number analysis. A dc Stark sum calculation of the 2s state is carried out to illustrate the case where analytic continuation, pole isolation and pole subtraction are required and where the calculation can be carried out analytically; the 2s state, ac Stark shift sum calculations involve a case where no analytic continuation is required, but where the solution to the differential equation produces complex numbers owing to the finite photoionization lifetime of the 2s state. Results from these calculations are then used to calculate three-photon ionization probabilities of relevance to an analysis of the multiphoton ionization data published by Kyrala and Nichols (1991 Phys. Rev. A 44, R1450).

  12. Universal features of the free-energy functional at the freezing transition for repulsive potentials.

    PubMed

    Verma, Anurag; Ford, David M

    2011-05-01

    The free-energy difference between coexisting solid and liquid phases is studied in the context of classical density functional theory (DFT). A bridge function is used to represent the higher-order (n>2) terms in the perturbative expansion of the excess Helmholtz free energy, and the values of this bridge function within the solid lattice are determined by inversion using literature Monte Carlo simulation results. Four potential models, specifically hard-sphere and inverse twelfth-, sixth-, and fourth-power repulsive, are studied. The face-centered cubic (fcc) solid is considered for the hard-sphere and inverse twelfth- and sixth-power potentials, while the body-centered cubic (bcc) solid is considered for the inverse sixth- and fourth-power potentials. For a given solid structure there is a remarkable similarity among the bridge functions for different potentials that is analogous to the universality in the sum of elementary diagrams, or bridge functions, of liquid-state theory as originally observed by Rosenfeld and Ashcroft [Phys. Rev. A 20, 1208 (1979)]. In further analogy with liquid-state theory, the bridge functions in the present problem are plotted as functionals of the second-order convolution term in the perturbative expansion. In each case, the plot indicates a unique functionality in the dense regions of the solid near the lattice sites but a scattered and nonunique behavior in the void regions. Interestingly, knowledge of the functional relationship in the unique region near the lattice sites seems to be sufficient to quantitatively model the solid-fluid phase transition. These qualitative observations are true for both fcc and bcc solid phases, although there are some quantitative differences between them. The findings suggest that pursuit of a closure-based DFT of solid-fluid transitions may be profitable. PMID:21728493

  13. Energy levels and transition rates for the boron isoelectronic sequence: Si X, Ti XVIII - Cu XXV

    NASA Astrophysics Data System (ADS)

    Jönsson, P.; Ekman, J.; Gustafsson, S.; Hartman, H.; Karlsson, L. B.; du Rietz, R.; Gaigalas, G.; Godefroid, M. R.; Froese Fischer, C.

    2013-11-01

    Relativistic configuration interaction (RCI) calculations are performed for 291 states belonging to the configurations 1s22s22p, 1s22s2p2, 1s22p3, 1s22s23l, 1s22s2p3l, 1s22p23l, 1s22s24l', 1s22s2p4l', and 1s22p24l' (l = 0,1,2 and l' = 0,1,2,3) in boron-like ions Si X and Ti XVIII to Cu XXV. Electron correlation effects are represented in the wave functions by large configuration state function (CSF) expansions. States are transformed from jj-coupling to LS-coupling, and the LS-percentage compositions are used for labeling the levels. Radiative electric dipole transition rates are given for all ions, leading to massive data sets. Calculated energy levels are compared with other theoretical predictions and crosschecked against the Chianti database, NIST recommended values, and other observations. The accuracy of the calculations are high enough to facilitate the identification of observed spectral lines. Research supported in part by the Swedish Research council and the Swedish Institute. Part of this work was supported by the Communauté française of Belgium, the Belgian National Fund for Scientific Research (FRFC/IISN Convention) and by the IUAP-Belgian State Science Policy (BriX network P7/12).Tables of energy levels and transition rates (Tables 3-19) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/559/A100

  14. Relationship between digesta transit time and apparent metabolisable energy value of wheat in chickens.

    PubMed

    Hughes, R J

    2008-11-01

    1. This study tested the hypotheses that: (a) apparent metabolisable energy (AME) values and whole tract transit time (WTTT) were related, and that (b) the relationship between AME and WTTT differed between male and female Ross broiler chickens. 2. Enzyme products with xylanase activity were added to a basal diet to provide 4 dietary treatments comprising control (no enzyme), Avizyme 1300 (1 kg/tonne), Kemzyme W1 (1 kg/tonne), and Bio-Feed Wheat CT (200 g/tonne). The basal diet comprised (in g/kg), 800 wheat, 155 casein, 20 dicalcium phosphate, 11 limestone, 7 D,L-methionine, 2 vitamin and mineral premix, 3 sodium chloride and 2 choline chloride (60%). 3. AME values for diets were determined in a 7-d energy balance study commencing when chickens were 21 d of age. WTTT was the time elapsed (in min), from time of administration by oral gavage of 200 mg ferric oxide in a gelatine capsule, to time of first observation of the distinctive red colouration in droppings. 4. The mean AME value for the wheat was high (15.7 MJ/kg dry matter) and ranged from 14.4 to 16.3 MJ/kg dry matter for individual birds. Mean WTTT was 206 min and ranged from 105 to 429 min. AME and WTTT were unaffected by enzyme addition to the diet, and the interaction between diet and gender was not significant. 5. There was a significant but weak positive relationship between AME and whole tract transit time, with AME increasing by 2.2 kJ/min. This relationship was unaffected by gender of the chicken. PMID:19093244

  15. "Energy is...life": Meaning making through dialogue in a tribal college physics course

    NASA Astrophysics Data System (ADS)

    Antonellis, Jessica Christel

    This research is an exploration of students' meaning making around physical concepts through connections to students' funds of knowledge. This qualitative case study, influenced by Indigenous methodologies, focused on two Native students in a tribal college introductory physics course, exploring the personal, cultural, and philosophical connections that were voiced in dialogic interactions among the students and instructor. The data were collected through audio recordings of class sessions and reflective journaling by the instructor/researcher. Analysis identified dialogues in which meaning making took place, and the funds of knowledge that students brought to bear on these dialogues. The results of the analysis of these meaning-making occasions are presented by physical concept. For both students, the cultural connections they brought in were ways for them to incorporate their out-of-class identities and to consider their cultures from a scientific perspective. The influence of the students' personal connections was just as important as that of the cultural connections; the shared classroom context was also a valuable resource in the for collaborative meaning making. Both students both enjoyed examining the philosophical and spiritual implications of physical ideas; these dialogues provided windows into students' thinking that would not have been accessible in other ways. The students also made meanings about the nature of science that meshed with their identities and created a space for them to identify as scientists, and both came to view science as part of their cultural heritage. Allowing students free reign to make connections and empowering them to make decisions about their own learning were means of encouraging students to develop meaningful conceptual understanding. By investigating the meanings students made around physical content, we can learn about what motivates them, what is important to them, and potentially how to structure curricula that will

  16. Development of Energy Models for Production Systems and Processes to Inform Environmentally Benign Decision-Making

    NASA Astrophysics Data System (ADS)

    Diaz-Elsayed, Nancy

    Between 2008 and 2035 global energy demand is expected to grow by 53%. While most industry-level analyses of manufacturing in the United States (U.S.) have traditionally focused on high energy consumers such as the petroleum, chemical, paper, primary metal, and food sectors, the remaining sectors account for the majority of establishments in the U.S. Specifically, of the establishments participating in the Energy Information Administration's Manufacturing Energy Consumption Survey in 2006, the non-energy intensive" sectors still consumed 4*109 GJ of energy, i.e., one-quarter of the energy consumed by the manufacturing sectors, which is enough to power 98 million homes for a year. The increasing use of renewable energy sources and the introduction of energy-efficient technologies in manufacturing operations support the advancement towards a cleaner future, but having a good understanding of how the systems and processes function can reduce the environmental burden even further. To facilitate this, methods are developed to model the energy of manufacturing across three hierarchical levels: production equipment, factory operations, and industry; these methods are used to accurately assess the current state and provide effective recommendations to further reduce energy consumption. First, the energy consumption of production equipment is characterized to provide machine operators and product designers with viable methods to estimate the environmental impact of the manufacturing phase of a product. The energy model of production equipment is tested and found to have an average accuracy of 97% for a product requiring machining with a variable material removal rate profile. However, changing the use of production equipment alone will not result in an optimal solution since machines are part of a larger system. Which machines to use, how to schedule production runs while accounting for idle time, the design of the factory layout to facilitate production, and even the

  17. MARKAL-MACRO: A methodology for informed energy, economy and environmental decision making. Informal report

    SciTech Connect

    Goldstein, G.A.

    1995-05-16

    Since the mid-1970`s, energy system analysts have been using models to represent the complexities of interactions in energy systems to help shape policy. Since the mid-1980`s, heightened awareness has made it necessary also to consider the environmental impacts of energy policies. MARKAL is a cost-minimizing energy-environment system planning model used to explore mid- to long-term responses to different technological futures, emissions limitations, and policy scenarios. MARKAL-MACRO is an extension of MARKAL that integrates these capabilities directly with a neoclassical macroeconomic growth model. By combining bottom-up engineering and top-down macroeconomic approaches in a single modeling framework, MARKAL-MACR is able to capture the interplay between the energy system, the economy and the environment, allowing the affects on demands of endogenously determined energy prices to be explored.

  18. Review of Life-Cycle Approaches Coupled with Data Envelopment Analysis: Launching the CFP + DEA Method for Energy Policy Making

    PubMed Central

    Vázquez-Rowe, Ian

    2015-01-01

    Life-cycle (LC) approaches play a significant role in energy policy making to determine the environmental impacts associated with the choice of energy source. Data envelopment analysis (DEA) can be combined with LC approaches to provide quantitative benchmarks that orientate the performance of energy systems towards environmental sustainability, with different implications depending on the selected LC + DEA method. The present paper examines currently available LC + DEA methods and develops a novel method combining carbon footprinting (CFP) and DEA. Thus, the CFP + DEA method is proposed, a five-step structure including data collection for multiple homogenous entities, calculation of target operating points, evaluation of current and target carbon footprints, and result interpretation. As the current context for energy policy implies an anthropocentric perspective with focus on the global warming impact of energy systems, the CFP + DEA method is foreseen to be the most consistent LC + DEA approach to provide benchmarks for energy policy making. The fact that this method relies on the definition of operating points with optimised resource intensity helps to moderate the concerns about the omission of other environmental impacts. Moreover, the CFP + DEA method benefits from CFP specifications in terms of flexibility, understanding, and reporting. PMID:25654136

  19. Review of life-cycle approaches coupled with data envelopment analysis: launching the CFP + DEA method for energy policy making.

    PubMed

    Vázquez-Rowe, Ian; Iribarren, Diego

    2015-01-01

    Life-cycle (LC) approaches play a significant role in energy policy making to determine the environmental impacts associated with the choice of energy source. Data envelopment analysis (DEA) can be combined with LC approaches to provide quantitative benchmarks that orientate the performance of energy systems towards environmental sustainability, with different implications depending on the selected LC + DEA method. The present paper examines currently available LC + DEA methods and develops a novel method combining carbon footprinting (CFP) and DEA. Thus, the CFP + DEA method is proposed, a five-step structure including data collection for multiple homogenous entities, calculation of target operating points, evaluation of current and target carbon footprints, and result interpretation. As the current context for energy policy implies an anthropocentric perspective with focus on the global warming impact of energy systems, the CFP + DEA method is foreseen to be the most consistent LC + DEA approach to provide benchmarks for energy policy making. The fact that this method relies on the definition of operating points with optimised resource intensity helps to moderate the concerns about the omission of other environmental impacts. Moreover, the CFP + DEA method benefits from CFP specifications in terms of flexibility, understanding, and reporting. PMID:25654136

  20. Relative edge energy in the stability of transition metal nanoclusters of different motifs

    NASA Astrophysics Data System (ADS)

    Zhao, X. J.; Xue, X. L.; Guo, Z. X.; Li, S. F.

    2016-06-01

    When a structure is reduced to a nanometer scale, the proportion of the lowly-coordinated edge atoms increases significantly, which can play a crucial role in determining both their geometric and electronic properties, as demonstrated by the recently established generalized Wulff construction principle [S. F. Li, et al., Phys. Rev. Lett., 2013, 111, 115501]. Consequently, it is of great interest to clarify quantitatively the role of the edge atoms that dominate the motifs of these nanostructures. In principle, establishing an effective method valid for determining the absolute value of the surface energy and particularly the edge energy for a given nanostructure is expected to resolve such a problem. However, hitherto, it is difficult to obtain the absolute edge energy of transition metal clusters, particularly when their sizes approach the nanometer regime. In this paper, taking Ru nanoclusters as a prototypical example, our first-principles calculations introduce the concept of relative edge energy (REE), reflecting the net edge atom effect over the surface (facet) atom effect, which is fairly powerful to quasi-quantitatively estimate the critical size at which the crossover occurs between different configurations of a given motif, such as from an icosahedron to an fcc nanocrystal. By contrast, the bulk effect should be re-considered to rationalize the power of the REE in predicting the relative stability of larger nanostructures between different motifs, such as fcc-like and hcp-like nanocrystals.When a structure is reduced to a nanometer scale, the proportion of the lowly-coordinated edge atoms increases significantly, which can play a crucial role in determining both their geometric and electronic properties, as demonstrated by the recently established generalized Wulff construction principle [S. F. Li, et al., Phys. Rev. Lett., 2013, 111, 115501]. Consequently, it is of great interest to clarify quantitatively the role of the edge atoms that dominate the

  1. Decision-making by a soaring bird: time, energy and risk considerations at different spatio-temporal scales.

    PubMed

    Harel, Roi; Duriez, Olivier; Spiegel, Orr; Fluhr, Julie; Horvitz, Nir; Getz, Wayne M; Bouten, Willem; Sarrazin, François; Hatzofe, Ohad; Nathan, Ran

    2016-09-26

    Natural selection theory suggests that mobile animals trade off time, energy and risk costs with food, safety and other pay-offs obtained by movement. We examined how birds make movement decisions by integrating aspects of flight biomechanics, movement ecology and behaviour in a hierarchical framework investigating flight track variation across several spatio-temporal scales. Using extensive global positioning system and accelerometer data from Eurasian griffon vultures (Gyps fulvus) in Israel and France, we examined soaring-gliding decision-making by comparing inbound versus outbound flights (to or from a central roost, respectively), and these (and other) home-range foraging movements (up to 300 km) versus long-range movements (longer than 300 km). We found that long-range movements and inbound flights have similar features compared with their counterparts: individuals reduced journey time by performing more efficient soaring-gliding flight, reduced energy expenditure by flapping less and were more risk-prone by gliding more steeply between thermals. Age, breeding status, wind conditions and flight altitude (but not sex) affected time and energy prioritization during flights. We therefore suggest that individuals facing time, energy and risk trade-offs during movements make similar decisions across a broad range of ecological contexts and spatial scales, presumably owing to similarity in the uncertainty about movement outcomes.This article is part of the themed issue 'Moving in a moving medium: new perspectives on flight'. PMID:27528787

  2. Hadronic Transitions from Upsilon (2S) to Upsilon (1s) and Upsilon Dipion Transitions at Energies Near the Upsilon (4S)

    NASA Astrophysics Data System (ADS)

    Kotoy, Sergei Anatolievich

    This dissertation consists of two closely related analyses, both of which were performed using data collected with the CLEO II detector at the Cornell Electron Storage Ring. In the first analysis, using the world largest data sample of Υ(2 S) events, we have investigated the hadronic transitions between the Υ(2S) and the Υ(1S), i.e. decays of the Υ(2S) into the Υ(1S), plus a pair of pions ( p+p- or p0p0 ), a single η or a single p0 . The dipion transitions U(2S)-->U( 1S)pp were studied most closely, by using two different techniques: ``exclusive'' and ``inclusive''. In these measurements we determine the U(2S)-->U( 1S)pp branching ratios, and, by combining the exclusive and inclusive results, we derive the Υ(1S), leptonic branching ratios Bee and Bmm . Parameters of the ππ system in the dipion transitions (dipion invariant mass spectra, angular distributions) were analyzed and found to be consistent with current theoretical models. Lastly, we searched for the η and single π0 transitions and obtained upper limits on the branching ratios B(U(2S) -->U(1S)h ) and B(U(2S) -->U(1S)p 0) . In the second analysis, the data collected at the center of mass energies near the Υ(4S) were used to search for the dipion transition between pairs of Υ resonances. As a result of this search, we established upper limits on the branching ratios of the dipion transitions post='par'>p+p- and U(4S)-->U( 1S)p+p- , and measured the cross-sections for the radiative production of Υ(3 S) and Υ(2S) resonances e+e--->U(nS) g at the center of mass energies of Ecm = 10.58 GeV and Ecm = 10.52 GeV.

  3. A large-scale relativistic configuration-interaction calculation for the 4s-4p and 4p-4d transition energies of copperlike heavy ions

    SciTech Connect

    Cheng, K T; Chen, M H

    2005-06-21

    The 4s-4p and 4p-4d transition energies for high-Z copperlike ions are calculated using the relativistic configuration-interaction (RCI) method. Mass polarization (MP) and quantum electrodynamic (QED) corrections are also evaluated. For the 4s-4p transitions, the present RCI energies agree very well with results from the relativistic many-body perturbation theory. With QED and MP corrections included, our total transition energies are in very good agreement with recent high precision measurements.

  4. Relativistic Many-body Moller-Plesset Perturbation Theory Calculations of the Energy Levels and Transition Probabilities in Na- to P-like Xe Ions

    SciTech Connect

    Vilkas, M J; Ishikawa, Y; Trabert, E

    2007-03-27

    Relativistic multireference many-body perturbation theory calculations have been performed on Xe{sup 43+}-Xe{sup 39+} ions, resulting in energy levels, electric dipole transition probabilities, and level lifetimes. The second-order many-body perturbation theory calculation of energy levels included mass shifts, frequency-dependent Breit correction and Lamb shifts. The calculated transition energies and E1 transition rates are used to present synthetic spectra in the extreme ultraviolet range for some of the Xe ions.

  5. Trap the Energy of the Sun. What We Make. Science and Technology Education in Philippine Society.

    ERIC Educational Resources Information Center

    Philippines Univ., Quezon City. Inst. for Science and Mathematics Education Development.

    Filipino scientists and inventors have tried many ways of using solar energy. One simple device, made of wood and ordinary plastic sheets, traps solar energy to dry palay grains and other agricultural products. In this module, information and activities are provided to help students: (1) learn the advantages of using a solar crop dryer over direct…

  6. Assessment of New Approaches in Geothermal Exploration Decision Making; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Akar, S.; Young, K. R.

    2015-05-11

    This poster describes the findings in a related paper and information gleaned from the project. The aim of the project is to develop a methodology for more objective geothermal decision making, including more solid go/no-go decisions at specific points in the process, and to reduce subjectivity and increase reproducibility in the future.

  7. "Energy Is...life": Meaning Making through Dialogue in a Tribal College Physics Course

    ERIC Educational Resources Information Center

    Antonellis, Jessica Christel

    2013-01-01

    This research is an exploration of students' meaning making around physical concepts through connections to students' funds of knowledge. This qualitative case study, influenced by Indigenous methodologies, focused on two Native students in a tribal college introductory physics course, exploring the personal, cultural, and philosophical…

  8. Scaled free energies, power-law potentials, strain pseudospins, and quasiuniversality for first-order structural transitions

    NASA Astrophysics Data System (ADS)

    Shenoy, S. R.; Lookman, T.; Saxena, A.

    2010-10-01

    We consider ferroelastic first-order phase transitions with NOP order-parameter strains entering Landau free energies as invariant polynomials that have NV structural-variant Landau minima. The total free energy includes (seemingly innocuous) harmonic terms, in the n=6-NOP nonorder-parameter strains. Four three-dimensional (3D) transitions are considered, tetragonal/orthorhombic, cubic/tetragonal, cubic/trigonal, and cubic/orthorhombic unit-cell distortions, with, respectively, NOP=1 , 2, 3, and 2; and NV=2 , 3, 4, and 6. Five two-dimensional (2D) transitions are also considered, as simpler examples. Following Barsch and Krumhansl, we scale the free energy to absorb most material-dependent elastic coefficients into an overall prefactor, by scaling in an overall elastic energy density; a dimensionless temperature variable; and the spontaneous-strain magnitude at transition λ≪1 . To leading order in λ the scaled Landau minima become material independent, in a kind of “quasiuniversality.” The scaled minima in NOP -dimensional order-parameter space, fall at the center and at the NV corners, of a transition-specific polyhedron inscribed in a sphere, whose radius is unity at transition. The “polyhedra” for the four 3D transitions are, respectively, a line, a triangle, a tetrahedron, and a hexagon. We minimize the n terms harmonic in the nonorder-parameter strains, by substituting solutions of the “no dislocation” St Venant compatibility constraints, and explicitly obtain power-law anisotropic, order-parameter interactions, for all transitions. In a reduced discrete-variable description, the competing minima of the Landau free energies induce unit-magnitude pseudospin vectors, with NV+1 values, pointing to the polyhedra corners and the (zero-value) center. The total scaled free energies then become ZNV+1 clocklike pseudospin Hamiltonians, with temperature-dependent local Landau terms, nearest-neighbor Ginzburg couplings, and power-law St Venant

  9. Scaled free energies, power-law potentials, strain pseudospins, and quasiuniversality for first-order structural transitions

    SciTech Connect

    Shenoy, S. R.; Lookman, T.; Saxena, A.

    2010-10-01

    We consider ferroelastic first-order phase transitions with N{sub OP} order-parameter strains entering Landau free energies as invariant polynomials that have N{sub V} structural-variant Landau minima. The total free energy includes (seemingly innocuous) harmonic terms, in the n=6-N{sub OP} nonorder-parameter strains. Four three-dimensional (3D) transitions are considered, tetragonal/orthorhombic, cubic/tetragonal, cubic/trigonal, and cubic/orthorhombic unit-cell distortions, with, respectively, N{sub OP}=1, 2, 3, and 2; and N{sub V}=2, 3, 4, and 6. Five two-dimensional (2D) transitions are also considered, as simpler examples. Following Barsch and Krumhansl, we scale the free energy to absorb most material-dependent elastic coefficients into an overall prefactor, by scaling in an overall elastic energy density; a dimensionless temperature variable; and the spontaneous-strain magnitude at transition {lambda}<<1. To leading order in {lambda} the scaled Landau minima become material independent, in a kind of ''quasiuniversality.'' The scaled minima in N{sub OP}-dimensional order-parameter space, fall at the center and at the N{sub V} corners, of a transition-specific polyhedron inscribed in a sphere, whose radius is unity at transition. The ''polyhedra'' for the four 3D transitions are, respectively, a line, a triangle, a tetrahedron, and a hexagon. We minimize the n terms harmonic in the nonorder-parameter strains, by substituting solutions of the ''no dislocation'' St Venant compatibility constraints, and explicitly obtain power-law anisotropic, order-parameter interactions, for all transitions. In a reduced discrete-variable description, the competing minima of the Landau free energies induce unit-magnitude pseudospin vectors, with N{sub V}+1 values, pointing to the polyhedra corners and the (zero-value) center. The total scaled free energies then become Z{sub N{sub V+1}} clocklike pseudospin Hamiltonians, with temperature-dependent local Landau terms, nearest

  10. Hybrid exchange-correlation energy functionals for strongly correlated electrons: Applications to transition-metal monoxides

    NASA Astrophysics Data System (ADS)

    Tran, Fabien; Blaha, Peter; Schwarz, Karlheinz; Novák, Pavel

    2006-10-01

    For the treatment of strongly correlated electrons, the corresponding Hartree-Fock exchange energy is used instead of the local density approximation (LDA) or generalized gradient approximation (GGA) functional, as suggested recently [P. Novák , Phys. Status Solidi B 243, 563 (2006)]. If this is done only inside the atomic spheres, using an augmented plane wave scheme, a significant simplification and reduction of computational cost is achieved with respect to the usual but costly implementation of the Hartree-Fock formalism in solids. Starting from this, we construct exchange-correlation energy functionals of the hybrid form like B3PW91, PBE0, etc. These functionals are tested on the transition-metal monoxides MnO, FeO, CoO, and NiO, and the results are compared with the LDA, GGA, LDA+U , and experimental ones. The results show that the proposed method, which does not contain any system-dependent input parameter, gives results comparable or superior to the ones obtained with LDA+U which is designed to improve significantly over the LDA and GGA results for systems containing strongly correlated electrons. The computational efficiency, similar to the LDA+U one, and accuracy of the proposed method show that it represents a very good alternative to LDA+U .

  11. Kh a 1,2 hyperesatellites of 3d transition metals and their photoexcitation energy dependence.

    SciTech Connect

    Diamant, R.; Kao, C.; Huotari, S; Hamalainen, K; Sharon, R; Deutsch, M.

    2009-06-25

    Hollow atoms in which the K shell is empty while the outer shells are populated allow studying a variety of important and unusual properties of atoms. The diagram x-ray emission lines of such atoms, the K{sup h} {alpha}{sub 1,2} hypersatellites (HSs), were measured for the 3d transition metals, Z = 23-30, with a high energy resolution using photoexcitation by monochromatized synchrotron radiation. Good agreement with ab initio relativistic multiconfigurational Dirac-Fock calculations was found. The measured HS intensity variation with the excitation energy yields accurate values for the excitation thresholds, excludes contributions from shake-up processes, and indicates domination near threshold of a nonshake process. The Z variation of the HS shifts from the diagram line K{alpha}{sub 1,2}, the K{sup h}{alpha}{sub 1}-K{sup h}{alpha}{sub 2} splitting, and the K{sup h}{alpha}{sub 1}/K{sup h}{alpha}{sub 2} intensity ratio, derived from the measurements, are also discussed with a particular emphasis on the QED corrections and Breit interaction.

  12. Energy Transition Initiative: Island Energy Snapshot - San Andres and Providencia (Fact Sheet); NREL(National Renewable Energy Laboratory)

    SciTech Connect

    2015-03-01

    This profile provides a snapshot of the energy landscape of the Archipelago of San Andres, Providencia, and Santa Catalina (unpopulated), also known as San Andres and Providencia, which is equidistant between Costa Rica and Jamaica and 775 kilometers northwest of Colombia. The archipelago is part of Colombia, though Nicaragua has also laid claim to it.

  13. Free energy of conformational transition paths in biomolecules: The string method and its application to myosin VI

    PubMed Central

    Ovchinnikov, Victor; Karplus, Martin; Vanden-Eijnden, Eric

    2011-01-01

    A set of techniques developed under the umbrella of the string method is used in combination with all-atom molecular dynamics simulations to analyze the conformation change between the prepowerstroke (PPS) and rigor (R) structures of the converter domain of myosin VI. The challenges specific to the application of these techniques to such a large and complex biomolecule are addressed in detail. These challenges include (i) identifying a proper set of collective variables to apply the string method, (ii) finding a suitable initial string, (iii) obtaining converged profiles of the free energy along the transition path, (iv) validating and interpreting the free energy profiles, and (v) computing the mean first passage time of the transition. A detailed description of the PPS↔R transition in the converter domain of myosin VI is obtained, including the transition path, the free energy along the path, and the rates of interconversion. The methodology developed here is expected to be useful more generally in studies of conformational transitions in complex biomolecules. PMID:21361558

  14. Transitions in the surface energy balance during the life cycle of a monsoon season

    NASA Astrophysics Data System (ADS)

    Krishnamurti, T. N.; Biswas, Mrinal K.

    2006-04-01

    In this observational/diagnostic study, we illustrate the time history of some important parameters of the surface energy balance during the life cycle of a single monsoon season. This chronology of the surface energy balance portrays the differential equilibrium state from the preonset phase to the withdrawal phase. This includes an analysis of the time history of base variables such as soil moisture, ground temperature, cloud cover, precipitation and humidity. This is followed by an analysis of the components of the surface energy balance where we note subtle changes in the overall balances as we proceed from one epoch of the monsoon to the next. Of interest here is the transition sequence: preonset, onset, break, revival, break, revival and withdrawal during the year 2001. Computations are all illustrated for a box over central India where the coastal effects were small, data coverage was not sparse and where the semi-arid land mass changes drastically to a lush green area. This region exhibited large changes in the components of surface energy balance. The principal results pertain to what balances the difference among the incoming short wave radiation (at the earth’s surface) and the long wave radiation exhibited by the ground. That difference is balanced by a dominant sensible heat flux and the reflected short wave radiation in the preonset stage. A sudden change in the Bowen ratio going from>1 to <1 is noted soon after the onset of monsoon. Thereafter the latent heat flux from the land surface takes an important role and the sensible heat flux acquires a diminishing role. We also examine the subtle changes that occur in the components of surface energy balance between the break and the active phases. The break phases are seen to be quite different from the preonset phases. This study is aimed to illustrate the major importance of moisture and clouds in the radiative transfer computations that are central to the surface energy balance during each epoch

  15. Developing and Transitioning Numerical Air Quality Models to Improve Air Quality and Public Health Decision-Making in El Salvador and Costa Rica As Part of the Servir Applied Sciences Team

    NASA Astrophysics Data System (ADS)

    Thomas, A.; Huff, A. K.; Gomori, S. G.; Sadoff, N.

    2014-12-01

    In order to enhance the capacity for air quality modeling and improve air quality monitoring and management in the SERVIR Mesoamerica region, members of SERVIR's Applied Sciences Team (AST) are developing national numerical air quality models for El Salvador and Costa Rica. We are working with stakeholders from the El Salvador Ministry of the Environment and Natural Resources (MARN); National University of Costa Rica (UNA); the Costa Rica Ministry of the Environment, Energy, and Telecommunications (MINAET); and Costa Rica National Meteorological Institute (IMN), who are leaders in air quality monitoring and management in the Mesoamerica region. Focusing initially on these institutions will build sustainability in regional modeling activities by developing air quality modeling capability that can be shared with other countries in Mesoamerica. The air quality models are based on the Community Multi-scale Air Quality (CMAQ) model and incorporate meteorological inputs from the Weather Research and Forecasting (WRF) model, as well as national emissions inventories from El Salvador and Costa Rica. The models are being optimized for urban air quality, which is a priority of decision-makers in Mesoamerica. Once experimental versions of the modeling systems are complete, they will be transitioned to servers run by stakeholders in El Salvador and Costa Rica. The numerical air quality models will provide decision support for stakeholders to identify 1) high-priority areas for expanding national ambient air monitoring networks, 2) needed revisions to national air quality regulations, and 3) gaps in national emissions inventories. This project illustrates SERVIR's goal of the transition of science to support decision-making through capacity building in Mesoamerica, and it aligns with the Group on Earth Observations' health societal benefit theme. This presentation will describe technical aspects of the development of the models and outline key steps in our successful

  16. Tryin' to Make It during the Transition from High School: The Role of Family Obligation Attitudes and Economic Context for Latino-Emerging Adults

    ERIC Educational Resources Information Center

    Sanchez, Bernadette; Esparza, Patricia; Colon, Yari; Davis, Katrina E.

    2010-01-01

    The aim of the current study was to examine the role of familial and economic context in the decisions and behaviors of low-income, urban Latinos during the transition from high school. Thirty-two Latino emerging adults who graduated from a public high school participated in one-on-one in-depth interviews about their transition. Participants…

  17. Using all of the Energy from the Sun to Make Power

    SciTech Connect

    Dapkus, P. Daniel; Povinelli, Michelle

    2013-07-18

    Representing the Center for Energy Nanoscience (CEN), this document is one of the entries in the Ten Hundred and One Word Challenge and was awarded "Overall Winner Runner-up." As part of the challenge, the 46 Energy Frontier Research Centers were invited to represent their science in images, cartoons, photos, words and original paintings, but any descriptions or words could only use the 1000 most commonly used words in the English language, with the addition of one word important to each of the EFRCs and the mission of DOE: energy. The mission of the CEN is to explore the light absorption and emission in organic and nanostructure materials and their hybrids for solar energy conversion and solid state lighting.

  18. Compositional dependence of optical transition energies in highly mismatched Zn1-xCdxTe1-yOy alloys

    NASA Astrophysics Data System (ADS)

    Tanaka, Tooru; Mizoguchi, Kosuke; Terasawa, Toshiki; Okano, Yuuki; Saito, Katsuhiko; Guo, Qixin; Nishio, Mitsuhiro; Yu, Kin Man; Walukiewicz, Wladek

    2016-02-01

    Highly mismatched Zn1-xCdxTe1-yOy layers with a wide range of Cd and O compositions of 0-0.7 and 0.005-0.02, respectively, were grown by molecular beam epitaxy for the application of intermediate band solar cells. The electron transition energies from the valence band (VB) to E- and E+ bands decreased with increasing Cd content. The variation of the transition energies was consistent with the theoretical calculation based on the band anticrossing model. The magnitude of the optical absorption due to electron transitions from the VB to E- band was strongly dependent on the Cd content because of the changing character of the E- band.

  19. On a Mechanism for Limiting the Frequency and Energy Characteristics of Lasers on Self-terminating Transitions of Metal Atoms

    NASA Astrophysics Data System (ADS)

    Yudin, N. A.; Yudin, N. N.

    2016-04-01

    Electrophysical approach to estimation of conditions for efficient pumping of active medium of lasers on selfterminating transitions of metal atoms in a gas discharge tube with electrodes in cold buffer zones is used. Existence of processes that enhance the effect of the well-known mechanism of limitation of radiation frequency and energy characteristics caused by the presence of a pre-pulse electron concentration in the discharge circuit of lasers on self-terminating transitions of metal atoms is demonstrated. The mechanism of influence of these processes on frequency and energy characteristics of lasers on self-terminating transitions of metal atoms and the technical methods of neutralization of these processes are considered. It is shown that the practical efficiency of a copper vapor laser can attain ~10% under conditions of neutralization of these processes.

  20. Energy exchange between a laser beam and charged particles using inverse transition radiation and method for its use

    DOEpatents

    Kimura, Wayne D.; Romea, Richard D.; Steinhauer, Loren C.

    1998-01-01

    A method and apparatus for exchanging energy between relativistic charged particles and laser radiation using inverse diffraction radiation or inverse transition radiation. The beam of laser light is directed onto a particle beam by means of two optical elements which have apertures or foils through which the particle beam passes. The two apertures or foils are spaced by a predetermined distance of separation and the angle of interaction between the laser beam and the particle beam is set at a specific angle. The separation and angle are a function of the wavelength of the laser light and the relativistic energy of the particle beam. In a diffraction embodiment, the interaction between the laser and particle beams is determined by the diffraction effect due to the apertures in the optical elements. In a transition embodiment, the interaction between the laser and particle beams is determined by the transition effect due to pieces of foil placed in the particle beam path.

  1. Energy and the environment; application of geosciences to decision-making

    USGS Publications Warehouse

    Carter, Lorna M., (Edited By)

    1995-01-01

    This volume contains 67 extended abstracts that summarize some of the oral and poster presentations of the tenth annual V. E. McKelvey forum on mineral and energy resources, held in Washington, D.C., Feb. 13-17, 1995. The focus is on our energy resources and the environment, new research techniques, and cooperative efforts between the USGS and industry, State and Federal agencies, universities, and other countries.

  2. Considerations for Solar Energy Technologies to Make Progress Towards Grid Price Parity

    SciTech Connect

    Woodhouse, Michael; Fu, Ran; Chung, Donald; Horowitz, Kelsey; Remo, Timothy; Feldman, David; Margolis, Robert

    2015-11-07

    In this seminar the component costs for solar photovoltaics module and system prices will be highlighted. As a basis for comparison to other renewable and traditional energy options, the metric of focus will be total lifecycle cost-of-energy (LCOE). Several innovations to traditional photovoltaics technologies (including crystalline silicon, CdTe, and CIGS) and developing technologies (including organics and perovskites) that may close the gaps in LCOE will be discussed.

  3. Effects of finite size and symmetry energy on the phase transition of stellar matter at subnuclear densities

    NASA Astrophysics Data System (ADS)

    Bao, S. S.; Shen, H.

    2016-02-01

    We study the liquid-gas phase transition of stellar matter with the inclusion of the finite-size effect from surface and Coulomb energies. The equilibrium conditions for two coexisting phases are determined by minimizing the total free energy including the surface and Coulomb contributions, which are different from the Gibbs conditions used in the bulk calculations. The finite-size effect can significantly reduce the region of the liquid-gas mixed phase. The influence of the symmetry energy on the liquid-gas phase transition is investigated with the inclusion of finite-size effects. It is found that the slope of the symmetry energy plays an important role in determining the boundary and properties of the mixed phase.

  4. Does fairness matter in the context of anger about nuclear energy decision making?

    PubMed

    Besley, John C

    2012-01-01

    Several recent studies have questioned whether nonoutcome forms of fairness matter in decision-making situations where individuals feel strongly engaged by the issue at hand. This survey-based study focuses on perceptions about a decision-making process related to a proposal to expand a nuclear power plant in the U.S. Southeast. It finds that anger moderates the impacts of outcome and procedural fairness on willingness to accept a decision process as satisfactory and legitimate. The more anger a person said he or she would feel if a decision were to contradict that person's point of view, the more perceived outcome and procedural fairness mattered. The study also finds that interpersonal fairness is also moderated by anger, but in the opposite direction. Interpersonal fairness had less of an impact on willingness to accept a decision for those who said they would feel angry if the decision did not go their preferred way. PMID:21883331

  5. Leveraging the water-energy-food nexus for a sustainability transition: Institutional and policy design choices in a fragmented world (Invited)

    NASA Astrophysics Data System (ADS)

    Aggarwal, R.

    2013-12-01

    Given the critical - but often subtle - feedbacks between water, energy, and food security, a nexus approach that integrates management and governance across sectors and scales is increasingly being advocated in research and policy circles. As a first step, such an approach calls for an integrated multi-disciplinary assessment of the externalities across sectors and tradeoffs involved in enhancing security in one sector on the other sectors. Recent research efforts have focused on understanding these tradeoffs, say, through estimating the energy costs of expanding irrigation for greater food security; or estimating the embodied land and water costs in increased energy production. While such efforts have increased awareness about the inter-connectedness of such issues, the fundamental question of how such an understanding influences decision-making and how it can lead to coordinated action towards a transition to more sustainable pathways still remains largely unanswered. The long legacy of sectoral organization of political and bureaucratic structures has led to a fragmentary policy and institutional landscape, on which cross-sectoral public action and coordination poses several challenges. Moreover, poorly defined property rights, imperfect or absent markets, and uncertainty about resource dynamics imply that economic signals about relative scarcity in one sector are not necessarily clear to decision makers in the other sectors. In this study, we examine these issues related to water-energy food nexus in the context of semi-arid groundwater irrigated regions of western and southern India. Using a social-ecological systems framework, we begin by characterizing some of the key inter-dependencies among food, water, and energy at the farm household, village and state level. We then examine the factors that influence decision-making at these levels, and the extent to which these decisions internalize the externalities. Specifically, we examine the role of energy

  6. Adsorption energy and spin state of first-row transition metals adsorbed on MgO(100)

    NASA Astrophysics Data System (ADS)

    Markovits, A.; Paniagua, J. C.; López, N.; Minot, C.; Illas, F.

    2003-03-01

    Slab and cluster model spin-polarized calculations have been carried out to study various properties of isolated first-row transition metal atoms adsorbed on the anionic sites of the regular MgO(100) surface. The calculated adsorption energies follow the trend of the metal cohesive energies, indicating that the changes in the metal-support and metal-metal interactions along the series are dominated by atomic properties. In all cases, except for Ni at the generalized gradient approximation level, the number of unpaired electron is maintained as in the isolated metal atom. The energy required to change the atomic state from high to low spin has been computed using the PW91 and B3LYP density-functional-theory-based methods. PW91 fails to predict the proper ground state of V and Ni, but the results for the isolated and adsorbed atom are consistent within the method. B3LYP properly predicts the ground state of all first-row transition atom the high- to low-spin transition considered is comparable to experiment. In all cases, the interaction with the surface results in a reduced high- to low-spin transition energy.

  7. Reducing Subjectivity in Geothermal Exploration Decision Making (Presentation); NREL(National Renewable Energy Laboratory)

    SciTech Connect

    Akar, S.; Young, K.

    2015-01-01

    Geothermal exploration projects have a significant amount of risk associated with uncertainties encountered in the discovery of the geothermal resource. Two of the largest challenges for increased geothermal deployment are 1) understanding when and how to proceed in an exploration program, and 2) when to walk away from a site. Current methodologies for exploration decision-making are formulatedby subjective expert opinion which can be incorrectly biased by expertise (e.g. geochemistry, geophysics), geographic location of focus, and the assumed conceptual model. The aim of this project is to develop a methodology for more objective geothermal exploration decision making at a given location, including go/no-go decision points to help developers and investors decide when to give up on alocation. In this scope, two different approaches are investigated: 1) value of information analysis (VOIA) which is used for evaluating and quantifying the value of a data before they are purchased, and 2) enthalpy-based exploration targeting based on reservoir size, temperature gradient estimates, and internal rate of return (IRR). The first approach, VOIA, aims to identify the value of aparticular data when making decisions with an uncertain outcome. This approach targets the pre-drilling phase of exploration. These estimated VOIs are highly affected by the size of the project and still have a high degree of subjectivity in assignment of probabilities. The second approach, exploration targeting, is focused on decision making during the drilling phase. It starts with a basicgeothermal project definition that includes target and minimum required production capacity and initial budgeting for exploration phases. Then, it uses average temperature gradient, reservoir temperature estimates, and production capacity to define targets and go/no-go limits. The decision analysis in this approach is based on achieving a minimum IRR at each phase of the project. This secondapproach was determined

  8. Accurate Potential Energy Surface, Rovibrational Energy Levels, and Transitions of Ammonia C_{3v} Isotopologues: ^{14}NH_3, ^{15}NH_3, ^{14}ND_3 and ^{14}NT_3

    NASA Astrophysics Data System (ADS)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2009-06-01

    A further refined, global potential energy surface (PES) is computed for the C_{3v} symmetry isotopologues of ammonia, including ^{14}NH_3, ^{15}NH_3, ^{14}ND_3 and ^{14}NT_3. The refinement procedure was similar to that used in our previously reported PES, but now extends to higher J energy levels and other isotopologues. Both the diagonal Born-Oppenheimer correction and the non-adiabatic correction were included. J=0-6 rovibrational energy levels and transition frequencies of ^{14}NH_3 computed on this PES are in excellent agreement with HITRAN data. Statistics on nearly 4100 transitions and more than 1000 energy levels demonstrate the accuracy achieved by the state-of-the-art "Best Theory + Experiment" strategy. Most transition frequencies are of ±0.01-0.02 cm^{-1} accuracy. Similar accuracy has been found on ^{15}NH_3 J=0-3 rovibrational energy levels. Several transitions and energy levels in HITRAN have been identified as unreliable or suspicious, and some have been re-assigned. For ^{14}ND_3 and ^{14}NT_3, J=0-3 calculations have been performed. Agreement for pure rotation-inversion transitions is nearly perfect, with more reliable energy levels presented. On the other hand, our J=0 results suggest a re-analysis on the ^{14}ND_3 ν_1 band origin is needed. Finally, we will discuss possible future refinements leading to an even better final PES for Ammonia. X. Huang, D.W. Schwenke, and T.J. Lee, J. Chem. Phys. 129, 214304 (2008).

  9. Quantum dynamics of rovibrational transitions in H2-H2 collisions: internal energy and rotational angular momentum conservation effects.

    PubMed

    Fonseca dos Santos, S; Balakrishnan, N; Lepp, S; Quéméner, G; Forrey, R C; Hinde, R J; Stancil, P C

    2011-06-01

    We present a full dimensional quantum mechanical treatment of collisions between two H(2) molecules over a wide range of energies. Elastic and state-to-state inelastic cross sections for ortho-H(2) + para-H(2) and ortho-H(2) + ortho-H(2) collisions have been computed for different initial rovibrational levels of the molecules. For rovibrationally excited molecules, it has been found that state-to-state transitions are highly specific. Inelastic collisions that conserve the total rotational angular momentum of the diatoms and that involve small changes in the internal energy are found to be highly efficient. The effectiveness of these quasiresonant processes increases with decreasing collision energy and they become highly state-selective at ultracold temperatures. They are found to be more dominant for rotational energy exchange than for vibrational transitions. For non-reactive collisions between ortho- and para-H(2) molecules for which rotational energy exchange is forbidden, the quasiresonant mechanism involves a purely vibrational energy transfer albeit with less efficiency. When inelastic collisions are dominated by a quasiresonant transition calculations using a reduced basis set involving only the quasiresonant channels yield nearly identical results as the full basis set calculation leading to dramatic savings in computational cost. PMID:21663358

  10. The Effect of Disorder on the Free-Energy for the Random Walk Pinning Model: Smoothing of the Phase Transition and Low Temperature Asymptotics

    NASA Astrophysics Data System (ADS)

    Berger, Quentin; Lacoin, Hubert

    2011-01-01

    We consider the continuous time version of the Random Walk Pinning Model (RWPM), studied in (Berger and Toninelli (Electron. J. Probab., to appear) and Birkner and Sun (Ann. Inst. Henri Poincaré Probab. Stat. 46:414-441, 2010; arXiv:0912.1663). Given a fixed realization of a random walk Y on ℤ d with jump rate ρ (that plays the role of the random medium), we modify the law of a random walk X on ℤ d with jump rate 1 by reweighting the paths, giving an energy reward proportional to the intersection time Lt(X,Y)=int0t {1}_{Xs=Ys} {d}s: the weight of the path under the new measure is exp ( βL t ( X, Y)), β∈ℝ. As β increases, the system exhibits a delocalization/localization transition: there is a critical value β c , such that if β> β c the two walks stick together for almost-all Y realizations. A natural question is that of disorder relevance, that is whether the quenched and annealed systems have the same behavior. In this paper we investigate how the disorder modifies the shape of the free energy curve: (1) We prove that, in dimension d≥3, the presence of disorder makes the phase transition at least of second order. This, in dimension d≥4, contrasts with the fact that the phase transition of the annealed system is of first order. (2) In any dimension, we prove that disorder modifies the low temperature asymptotic of the free energy.

  11. Electron energy-loss near-edge structures of 3d transition metal oxides recorded at high-energy resolution.

    PubMed

    Mitterbauer, C; Kothleitner, G; Grogger, W; Zandbergen, H; Freitag, B; Tiemeijer, P; Hofer, F

    2003-09-01

    Near-edge fine structures of the metal L(2,3) and O K-edges in transition metal-oxides have been studied with a transmission electron microscope equipped with a monochromator and a high-resolution imaging filter. This system enables the recording of EELS spectra with an energy resolution of 0.1eV thus providing new near-edge fine structure details which could not be observed previously by EELS in conventional TEM instruments. EELS-spectra from well-defined oxides like titanium oxide (TiO(2)), vanadium oxide (V(2)O(5)), chromium oxide (Cr(2)O(3)), iron oxide (Fe(2)O(3)), cobalt oxide (CoO) and nickel oxide (NiO) have been measured with the new system. These spectra are compared with EELS data obtained from a conventional microscope and the main spectral features are interpreted. Additionally, the use of monochromised TEMs is discussed in view of the natural line widths of K and L(2,3) edges. PMID:12871809

  12. From the lab to the marketplace: Making America`s buildings more energy efficient

    SciTech Connect

    1995-01-01

    Since the mid 1970s, DOE has invested some $70 million in research and development at Lawrence Berkeley Laboratory (LBL) for energy-efficiency studies of advanced building technologies. That investment has helped spawn a $2.4-billion US market for key products -- energy-efficient lighting and advanced window coatings -- and efficiency standards for residential equipment and computerized tools for more efficient building design. By 1993 DOE`s initial investment had reduced consumers` energy bills by an estimated $5 billion ($1.3 billion in 1993 alone). By 2015 the authors estimate that the products of that investment will save consumers $16 billion annually. But LBL research partnerships address a host of other building technology issues as well-building technology issues whose economic benefits are less easy to quantify but whose overall worth is equally important. They analyze public policy issues such as the role of efficiency options as a mitigation strategy for global climate change. They develop planning and demand-management methodologies for electric and gas utilities. They identify technologies and analytical methods for improving human comfort and the quality of indoor air. They contribute to the information superhighway. They focus on the special problems and opportunities presented by energy use in the public sector. And they do all these things at the local, national, and international levels. At LBL, they are part of the multi-laboratory, interdisciplinary approach to building technology research supported by DOE`s Office of Energy Efficiency and Renewable Energy. They also participate in buildings-related research supported by DOE`s Office of Health and Environmental Research, other federal agencies, and industry. This document describes LBL`s role within this wider effort.

  13. From the lab to the marketplace: Making America`s buildings more energy efficient

    SciTech Connect

    1995-06-01

    Since the mid 1970s, DOE has invested some $70 million in research and development at Lawrence Berkeley Laboratory (LBL) for development of advanced energy-efficient building technologies, software, and standards. That investment has helped spawn a $2.4-billion U.S. market for key products-energy-efficient lighting and advanced window coatings-and efficiency standards for residential equipment and computerized tools for more efficient building design. By 1993 DOE`s initial investment had reduced consumers` energy bills by an estimated $5 billion ($1.3 billion in 1993 alone). By 2015 we estimate that the products of that investment will save consumers $16 billion annually. LBL research partnerships address a host of other building technology issues as well-building technology issues whose economic benefits are less easy to quantify but whose overall worth is equally important. We analyze public policy issues such as the role of efficiency options as a mitigation strategy for global climate change. We develop planning and demand-management methodologies for electric and gas utilities. We identify technologies and analytical methods for improving human comfort and the quality of indoor air. We contribute to the information superhighway. We focus on the special problems and opportunities presented by energy use in the public sector. And we do all these things at the local, national, and international levels. At LBL, we are part of the multi-laboratory, interdisciplinary approach to building technology research supported by DOE`s Office of Energy Efficiency and Renewable Energy. We also participate in buildings-related research supported by DOE`s Office of Health and Environmental Research, other federal agencies, and industry. This document describes LBL`s role within this wider effort.

  14. Evidence for Multi-photon transitions between energy levels in a large Current-Biased Magnesium Diboride Josephson Heterojunction

    NASA Astrophysics Data System (ADS)

    Ramos, Roberto; Carabello, Steven; Lambert, Joseph; Cunnane, Daniel; Dai, Wenqing; Chen, Ke; Li, Qi; Xi, Xiaoxing

    2013-03-01

    When photons are strongly coupled to a quantum system, multiphoton transitions can be observed between two energy levels when the quantum energy of the exciting radiation, multiplied by an integer, matches the level spacing. This phenomenon can be observed in Josephson junction qubits exposed to weak microwave radiation at very low temperatures. At microwave resonance, the transition probability of a junction from superconducting to normal state is enhanced and these are used to map multiphoton transitions. We report observation of single- and multi-photon transitions between ground and first excited states in current-biased MgB2 thin film junctions by applying RF with frequencies between 0.5 and 3 Ghz. These large (up to 0.2mm x 0.3 mm) junctions consist of an MgB2 electrode insulated by native oxide from a lead (Pb) or tin (Sn) counter-electrode, and have areas at least 600 times bigger than Nb junctions previously shown to exhibit multiphoton transitions. The data is consistent with theoretical models of junctions behaving in the quantum limit and show anharmonicity of the junction potential when biased near the critical current.

  15. Influence of Interfacial Energy on Electric-Field-Induced Sphere-to-Cylinder Transition in Block Copolymer Thin Films

    SciTech Connect

    Wang, J.; Chen, W; Russell, T

    2008-01-01

    The effect of the interfacial energy on the electric-field-induced sphere-to-cylinder (S-to-C) transition in polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) copolymer thin films was studied as a function of the difference in the interfacial interactions of the PS and PMMA blocks with the substrate, d. It was found that the interfacial energies altered both the critical electric field strength and the time scales of kinetics. A very strong preferential interfacial interaction suppressed the electric-field-induced S-to-C transition even though such a transition occurred on a neutralized surface where the interfacial interactions were balanced. For a moderate interfacial interaction, the S-to-C transition can be induced by an applied electric field, but the time scale of the morphology change is much longer. Furthermore, the formation of ionic complexes in the BCP was found to enhance the electric-field-induced S-to-C transition even on a native Si substrate without any surface modification, providing a simple route to generate ordered arrays of high-aspect-ratio cylinders oriented normal to a film surface.

  16. Transition of the U.S. Department of Energy Fernald Closure Project (FCP) from Cleanup to Legacy Management

    SciTech Connect

    Powell, J.; Craig, J.R.; Jacobson, C.

    2006-07-01

    The Fernald Closure Project encompasses a 1,050-acre tract of land northwest of Cincinnati, Ohio. Dedicated to the production of uranium feed materials from 1952 until 1989, the site was subsequently included on the U.S. Environmental Protection Agency's National Priorities List and slated for cleanup. Except for contaminated ground water, cleanup of the site will be completed in 2006; remediation of the aquifer will continue for 20 years. Transition of the project from the U.S. Department of Energy Office of Environmental Management to the Office of Legacy Management will be effected when site cleanup is completed, surface restoration is complete, and aquifer remediation is on-going. Office of Legacy Management activities will focus on the monitoring and maintenance of the on-site disposal facility, enforcement of restrictions on site access and use, and the protection of natural and cultural resources. The Site Transition Plan, developed in accordance with Site Transition Framework guidance, identifies organizational and financial responsibilities for attaining closeout. A Transition Matrix details more than 1,000 activities necessary for site transition and allows each task to be tracked. Responsibility Transition Plans address major areas of scope to be transferred, such as records and information management, infrastructure, and environmental monitoring. Much effort has been placed on the retention of staff to perform the identified Office of Legacy Management scope. (authors)

  17. Transitions: A Personal Perspective.

    ERIC Educational Resources Information Center

    Wood, Ann Stace

    1995-01-01

    Distinguishes between unchosen transitions (children maturing and leaving, parents aging, companies downsizing) and chosen ones (moving, divorce, marriage, career changes). Describes the steps one goes through: uneasiness, renewed energy, complaining, exploration, partial transition, and the completed transition. (JOW)

  18. Making the Most of Your Energy Dollars in Home Heating & Cooling. NBS Consumer Information Series 8.

    ERIC Educational Resources Information Center

    Jacobs, Madeleine; Petersen, Stephen R.

    This pamphlet is a homeowner's guide to home weatherization. It provides a step-by-step energy audit that anyone can use to help determine the insulation needs of their home. This is not a "how-to-do-it" booklet, but is a guide by which homeowners can determine the best combination of improvements for their house, climate, and fuel costs. Provided…

  19. Becoming allies: Combining social science and technological perspectives to improve energy research and policy making

    SciTech Connect

    Diamond, Rick; Moezzi, Mithra

    2002-07-01

    Within the energy research community, social sciences tends to be viewed fairly narrowly, often as simply a marketing tool to change the behavior of consumers and decision makers, and to ''attack market barriers''. As we see it, social sciences, which draws on sociology, psychology, political science, business administration, and other academic disciplines, is capable of far more. A social science perspective can re-align questions in ways that can lead to the development of technologies and technology policy that are much stronger and potentially more successful than they would be otherwise. In most energy policies governing commercial buildings, the prevailing R and D directives are firmly rooted in a technology framework, one that is generally more quantitative and evaluative than that fostered by the social sciences. To illustrate how social science thinking would approach the goal of achieving high energy performance in the commercial building sector, they focus on the US Department of Energy's Roadmap for commercial buildings (DOE 2000) as a starting point. By ''deconstructing'' the four strategies provided by the Roadmap, they set the stage for proposing a closer partnership between advocates of technology-based and social science-based approaches.

  20. Primary reflector for solar energy collection systems and method of making same

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1979-01-01

    Solar energy is reflected to a movably supported collector that is kept at the concentrated line focus of the reflector primary by a fixed, linear, ground-based primary reflector having an extended curved sawtooth contoured surface covered with a metalized polymeric reflecting material. The primary reflector was constructed by a process utilizing well-known freeway paving machinery.

  1. Three-dimensional tracking solar energy concentrator and method for making same

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Pohl, J. G. (Inventor)

    1977-01-01

    A three dimensional tracking solar energy concentrator, consisting of a stretched aluminized polymeric membrane supported by a hoop, was presented. The system is sturdy enough to withstand expected windage forces and precipitation. It can provide the high temperature output needed by central station power plants for power production in the multi-megawatt range.

  2. Investigation of the Electronic Structure of Transition Metal Compounds by Photoelectron Spectroscopy with Variable Photon Energy.

    NASA Astrophysics Data System (ADS)

    Kaltsoyannis, Nikolas

    1992-01-01

    Available from UMI in association with The British Library. Requires signed TDF. Relative partial photoionisation cross section (RPPICS) data have been obtained for a variety of transition metal compounds using synchrotron radiation in the incident photon energy range 17-115 eV. Cross section features such as p to d giant resonances, delayed maxima, Cooper minima and molecular shape resonances have been identified and interpreted in terms of the localisation properties of the ionising electrons. The RPPICS behaviour of the photoelectron (PE) band corresponding to ionisation of the 1a_ {rm 1g} highest occupied molecular orbital (HOMO) of (rm Mo(eta -rm C_6H_5Me)_2) indicates that it is essentially metal-localised. The p to d giant resonant absorption enhancement of the cross section is found to be almost coincident in photon energy with a molecular shape resonance. Similar features in the 1e_{rm 2g} ^{-1} and 1e_{ rm 1g}^{-1} bands provide strong evidence for metal-ligand covalency in the associated MOs. In contrast, the monotonic fall off with increasing photon energy of the RPPICS of the 1e_{ rm 1u}^{-1} band is typical of ligand-localised MOs. Studies of the closely related (rm M(eta- rm C_7H_7)(eta- rm C_5H_4R)) (M = Ti, Nb, Mo; R = H: M = Ta; R = Me) reveal a significant degree of both metal and ligand character to the 1e_2 MOs, suggesting that neither the +1 nor the -3 formalism for the charge on the cycloheptatrienyl ring in its complexes is a good one, as they imply a metal- and ligand-localised 1e_2<=vel respectively. The 5e MOs of PF_3, traditionally regarded as fluorine 2p lone pair MOs, have been shown to possess significant phosphorus 3p atomic orbital (AO) character. Comparison of the data obtained on PF _3 with those of (Ni(PF_3 )_4) indicates that the pi back donation from the nickel 3d orbitals to the 7e lowest unoccupied MO of PF_3 also affects the composition of the 5e derived orbitals. A combined experimental and theoretical study has resulted in

  3. Highly correlated systems. Ionization energies of first row transition metals Sc--Zn

    SciTech Connect

    Raghavachari, K.; Trucks, G. W.

    1989-08-15

    The low-lying ionization potentials of the first row transition metal atoms Sc--Zn are calculated using fourth-order Moller--Plesset perturbation theory (MP4) and quadratic configuration interaction (QCI) techniques with large /ital spd/ and /ital spdf/ basis sets. Two ionic states have been considered for each atom yielding a total of 20 different ionization processes which we have included in this study. For Sc/sup +/--Cu/sup +/, the ionic states considered have /ital d//sup /ital n/s//sup 1/ and /ital d//sup /ital n/+1/ orbital occupations and for Zn/sup +/, the /ital d//sup 10//ital s1/ and /ital d//sup 9//ital s2/ states were studied. The MP4 method accurately reproduces the ionization potentials of Sc--Fe, but is found to be inadequate for Co--Zn. In contrast, the QCI technique performs uniformly for all ionization energies with a mean deviation from experiment of only 0.13 eV (with the /ital spdf/ basis set) after inclusion of relativistic corrections.

  4. The Ligand Shell as an Energy Barrier in Surface Reactions on Transition Metal Nanoparticles.

    PubMed

    Smith, Jeremy G; Jain, Prashant K

    2016-06-01

    Transition metal nanoparticles, including those employed in catalytic, electrocatalytic, and photocatalytic conversions, have surfaces that are typically coated with a layer of short or long-chain ligands. There is little systematic understanding of how much this ligand layer affects the reactivity of the underlying surface. We show for Ag nanoparticles that a surface-adsorbed thiol layer greatly impedes the kinetics of an ionic chemical reaction taking place on the Ag surface. The model reaction studied is the galvanic exchange of Ag with Au(3+) ions, the kinetics of which is measured on individual thiol-coated nanoparticles using in situ optical scattering spectroscopy. We observe a systematic lowering of the reactivity of the nanoparticle as the chain length of the thiol is increased, from which we deduce that the ligand layer serves as an energy barrier to the transport of incoming/outgoing reactive ions. This barrier effect can be decreased by light irradiation, resulting from weakened binding of the thiol layer to the metal surface. We find that the influence of the surface ligand layer on reactivity is much stronger than factors such as nanoparticle size, shape, or crystallinity. These findings provide improved understanding of the role of ligand or adsorbates in colloidal catalysis and photocatalysis and have important implications for the transport of reactants and ions to surfaces and for engineering the reactivity of nanoparticles using surface passivation. PMID:27152595

  5. Low energy cyclotron production of multivalent transition metals for PET imaging and therapy

    NASA Astrophysics Data System (ADS)

    Avila-Rodriguez, Miguel Angel

    Recent advances in high-resolution tomographs for small animals require the production of nonconventional long-lived positron emitters to label novel radiopharmaceuticals for PET-based molecular imaging. Radioisotopes with an appropriate half life to match the kinetics of slow biological processes will allow to researchers to study the phamacokinetics of PET ligands over several hours, or even days, on the same animal, with the injection of a single dose. In addition, radionuclides with a suitable half life can potentially be distributed from a central production site making them available in PET facilities that lack an in-house cyclotron. In the last few years there has been a growing interest in the use of PET ligands labeled with radiometals, particularly isotopes of copper, yttrium and zirconium. Future clinical applications of these tracers will require them to be produced reliably and efficiently. This thesis work deals with implementing and optimizing the production of the multivalent transition metals 61,64Cu, 86Y and 89Zr for molecular PET imaging and therapy. Our findings in the production of these radionuclides at high specific activity on an 11 MeV proton-only cyclotron are presented. Local applications of these tracers, including Cu-ATSM for in vivo quantification of hypoxia, synthesis of targeted radiopharmaceuticals using activated esters of DOTA, and a novel development of positron emitting resin microspheres, are also be discussed. As a result of this thesis work, metallic radionuclides are now efficiently produced on a weekly basis in sufficient quality and quantity for collaborating scientists at UW-Madison and external users in other Universities across the country.

  6. Study of electron transition energies between anions and cations in spinel ferrites using differential UV-vis absorption spectra

    NASA Astrophysics Data System (ADS)

    Xue, L. C.; Wu, L. Q.; Li, S. Q.; Li, Z. Z.; Tang, G. D.; Qi, W. H.; Ge, X. S.; Ding, L. L.

    2016-07-01

    It is very important to determine electron transition energies (Etr) between anions and different cations in order to understand the electrical transport and magnetic properties of a material. Many authors have analyzed UV-vis absorption spectra using the curve (αhν)2 vs E, where α is the absorption coefficient and E(=hν) is the photon energy. Such an approach can give only two band gap energies for spinel ferrites. In this paper, using differential UV-vis absorption spectra, dα/dE vs E, we have obtained electron transition energies (Etr) between the anions and cations, Fe2+ and Fe3+ at the (A) and [B] sites and Ni2+ at the [B] sites for the (A)[B]2O4 spinel ferrite samples CoxNi0.7-xFe2.3O4 (0.0≤x≤0.3), CrxNi0.7Fe2.3-xO4 (0.0≤x≤0.3) and Fe3O4. We suggest that the differential UV-vis absorption spectra should be accepted as a general analysis method for determining electron transition energies between anions and cations.

  7. Land use impacts of low-carbon energy system transition - the case of UK bioenergy deployment under the Carbon Plan

    NASA Astrophysics Data System (ADS)

    Konadu, D. D.; Sobral Mourao, Z.; Lupton, R.; Skelton, S.

    2015-12-01

    The UK Department of Energy and Climate Change has developed four low-carbon energy transition pathways - the Carbon Plan - towards achieving the legally binding 80% territorial greenhouse gas emissions reduction, stipulated in the 2008 Climate Change Act by 2050. All the pathways require increase in bioenergy deployment, of which a significant amount could be indigenously sourced from crops. But will increased domestic production of energy crops conflict with other land use and ecosystem priorities? To address this question, a coupled analysis of the four energy transition pathways and land use has been developed using an integrated resource accounting platform called ForeseerTM. The two systems are connected by the bioenergy component, and are projected forward in time to 2050, under different scenarios of energy crop composition and yield, and accounting for various constraints on land use for agriculture and ecosystem services. The results show between 7 and 61% of UK agricultural land could be required to meet bioenergy deployment projections under different combinations of crop yield and compositions for the transition pathways. This could result in competition for land for food production and other socio-economic and ecological land uses. Consequently, the potential role of bioenergy in achieving UK emissions reduction targets may face significant deployment challenges.

  8. Binding energies and spatial structures of small carrier complexes in monolayer transition-metal dichalcogenides via diffusion Monte Carlo

    DOE PAGESBeta

    Mayers, Matthew Z.; Berkelbach, Timothy C.; Hybertsen, Mark S.; Reichman, David R.

    2015-10-09

    Ground-state diffusion Monte Carlo is used to investigate the binding energies and intercarrier radial probability distributions of excitons, trions, and biexcitons in a variety of two-dimensional transition-metal dichalcogenide materials. We compare these results to approximate variational calculations, as well as to analogous Monte Carlo calculations performed with simplified carrier interaction potentials. Our results highlight the successes and failures of approximate approaches as well as the physical features that determine the stability of small carrier complexes in monolayer transition-metal dichalcogenide materials. In conclusion, we discuss points of agreement and disagreement with recent experiments.

  9. Making Energy-Efficiency and Productivity Investments in Commercial Buildings: Choice of Investment Models

    SciTech Connect

    Jones, D.W.

    2002-05-16

    This study examines the decision to invest in buildings and the types of investment decision rules that may be employed to inform the ''go--no go'' decision. There is a range of decision making tools available to help in investment choices, which range from simple rules of thumb such as payback periods, to life-cycle analysis, to decision theoretic approaches. Payback period analysis tends to point toward lower first costs, whereas life-cycle analysis tends to minimize uncertainties over future events that can affect profitability. We conclude that investment models that integrate uncertainty offer better explanations for the behavior that is observed, i.e., people tend to delay investments in technologies that life-cycle analysis finds cost-effective, and these models also lead to an alternative set of policies targeted at reducing of managing uncertainty.

  10. Relativistic many-body calculations of excitation energies, oscillator strengths, transition rates, and lifetimes in samariumlike ions

    NASA Astrophysics Data System (ADS)

    Safronova, U. I.; Safronova, A. S.; Beiersdorfer, P.

    2013-03-01

    The unique atomic properties of samariumlike ions, not yet measured experimentally, are theoretically predicted and studied in this paper. Excitation energies, oscillator strengths, transition probabilities, and lifetimes are calculated for (5s2+5p2+5d2+5s5d+5s5g+5p5f)-(5s5p+5s5f+5p5d+5p5g) electric dipole transitions in Sm-like ions with nuclear charge Z ranging from 74 to 100. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate retarded E1 matrix elements in length and velocity forms. The calculations start from a 1s22s22p63s23p63d104s24p64d104f14 Dirac-Fock potential. First-order perturbation theory is used to obtain intermediate coupling coefficients, and the second-order RMBPT is used to determine the matrix elements. The contributions from negative-energy states are included in the second-order E1 matrix elements to achieve agreement between length-form and velocity-form amplitudes. The resulting transition energies and transition probabilities, and lifetimes for Sm-like W12+ are compared with results obtained by the relativistic Hartree-Fock approximation (cowan code) to estimate contributions of the 4f-core-excited states. Trends of excitation energies and oscillator strengths as the function of nuclear charge Z are shown graphically for selected states and transitions. This work provides a number of yet unmeasured atomic properties of these samariumlike ions for various applications and as a benchmark for testing theory.

  11. Building Student Awareness of Societal Decision-Making Challenges about Energy through the Study of Earth System Data and Innovations in Energy-Related Materials Research

    NASA Astrophysics Data System (ADS)

    Zalles, D. R.; Acker, J. G.; Berding, M.

    2014-12-01

    Energy literacy requires knowledge about the trade-offs inherent in energy alternatives, about how humans use energy and have choices in how much energy to use, and about what changes to the Earth system are occurring from energy uses. It also requires collaborative decision-making skills coupled with awareness about what values we bring to the table as we negotiate solutions that serve both personal needs and the common good. Coming up with a notion of the common good requires delineating how environmental crises occurring in other parts of the world compare to our own. We also need to understand criteria for judging what might be viable solutions. This presentation describes work that SRI International is carrying out to meet these awareness-building needs. SRI educational researchers created a curriculum that immerses students in studying regional climate change data about California in comparison to global climate change. Students ponder solution energy-related strategies and impact analyses. The curriculum will be described, as will a collaboration between SRI educational researchers and materials scientists. The scientists are designing and testing technologies for producing biofuels and solar power, and for sequestering carbon from coal fired power plants. As they apply principles of science and engineering to test materials intended to meet these energy challenges, they understand that even if the tests prove successful, if there is not economic feasibility or environmental advantage, the technology may not stand as a viable solution. This educator-scientist team is using the Essential Energy Principles and Next Generation Science Standards to articulate milestones along a trajectory of energy learning. The trajectory starts with simple understandings of what energy is and what constitute our energy challenges. It ends with more the types of more sophisticated understandings needed for designing and testing energy technology solutions.

  12. A Critical Compilation of Energy Levels, Spectral Lines, and Transition Probabilities of Singly Ionized Silver, Ag II

    PubMed Central

    Kramida, Alexander

    2013-01-01

    All available experimental measurements of the spectrum of the Ag+ ion are critically reviewed. Systematic shifts are removed from the measured wavelengths. The compiled list of critically evaluated wavelengths is used to derive a comprehensive list of energy levels with well-defined uncertainties. Eigenvector compositions and level designations are found in two alternate coupling schemes. Some of the older work is found to be incorrect. A revised value of the ionization energy, 173283(7) cm−1, equivalent to 21.4844(8) eV, is derived from the new energy levels. A set of critically evaluated transition probabilities is given. PMID:26401429

  13. Transition energies and magnetic properties of a neutral donor complex in a Gaussian GaAs quantum dot

    NASA Astrophysics Data System (ADS)

    Boda, Aalu; Chatterjee, Ashok

    2016-09-01

    The problem of a neutral hydrogenic donor (D0) centre located at the centre of a GaAs quantum dot with Gaussian confinement is studied in the presence of an external magnetic field. The ground and the first excited state energies and the corresponding binding energies are obtained as functions of the potential strength, quantum dot radius and the magnetic field using a variational method. It is suggested that the first excited state of the D0 centre is bound for sufficiently strong confinement potential. The 1 s - 2p- transition energy and the magnetic susceptibilities for the ground and the first excited states are also determined.

  14. Making the most of energy in real estate: relevant energy facts for real estate developers, builders, lenders, appraisers, and brokers. Workshop guidelines

    SciTech Connect

    Not Available

    1980-03-01

    Guidelines are presented for implementing a one- or two-day workshop entitled: Making the Most of Energy in Real Estate. Energy information is presented so that the participants in the real estate sector are well informed about energy matters so that real estate decisions will reflect the scarcity of dwindling energy supplies. A step-by-step guide for persons implementing the workshop is given and checklists and forms which may be useful to workshop planners at various stages are shown. Examples of the kinds of promotional materials necessary for the workshop are described. Lesson plans for the use of nine slide/tape shows which are available for the workshop are given. Lesson-by-lesson lists of all handouts are presented. The script necessary to present the information on the slide/tape shows is presented in this guideline. (MCW)

  15. Students' meaning making in science: solving energy resource problems in virtual worlds combined with spreadsheets to develop graphs

    NASA Astrophysics Data System (ADS)

    Krange, Ingeborg; Arnseth, Hans Christian

    2012-09-01

    The aim of this study is to scrutinize the characteristics of conceptual meaning making when students engage with virtual worlds in combination with a spreadsheet with the aim to develop graphs. We study how these tools and the representations they contain or enable students to construct serve to influence their understanding of energy resource consumption. The data were gathered in 1st grade upper-secondary science classes and they constitute the basis for the interaction analysis of students' meaning making with representations. Our analyses demonstrate the difficulties involved in developing students' orientation toward more conceptual orientations to representations of the knowledge domain. Virtual worlds do not in themselves represent a solution to this problem.

  16. Radiative and nonradiative exciton energy transfer in monolayers of two-dimensional group-VI transition metal dichalcogenides

    NASA Astrophysics Data System (ADS)

    Manolatou, Christina; Wang, Haining; Chan, Weimin; Tiwari, Sandip; Rana, Farhan

    2016-04-01

    We present results on the rates of interlayer energy transfer between excitons in monolayers of two-dimensional group-VI transition metal dichalcogenides (TMDs). We consider both radiative (mediated by real photons) and nonradiative (mediated by virtual photons) mechanisms of energy transfer using a unified Green's function approach that takes into account modification of the exciton energy dispersions as a result of interactions. The large optical oscillator strengths associated with excitons in TMDs result in very fast energy transfer rates. The energy transfer times depend on the exciton momentum, exciton linewidth, and the interlayer separation and can range from values less than 100 femtoseconds to more than tens of picoseconds. Whereas inside the light cone the energy transfer rates of longitudinal and transverse excitons are comparable, outside the light cone the energy transfer rates of longitudinal excitons far exceed those of transverse excitons. Average energy transfer times for a thermal ensemble of longitudinal and transverse excitons is temperature dependent and can be smaller than a picosecond at room temperature for interlayer separations smaller than 10 nm. Energy transfer times of localized excitons range from values less than a picosecond to several tens of picoseconds. When the exciton scattering and dephasing rates are small, energy transfer dynamics exhibit coherent oscillations. Our results show that electromagnetic interlayer energy transfer can be an efficient mechanism for energy exchange between TMD monolayers.

  17. Layered reactive particles with controlled geometries, energies, and reactivities, and methods for making the same

    DOEpatents

    Fritz, Gregory M; Knepper, Robert Allen; Weihs, Timothy P; Gash, Alexander E; Sze, John S

    2013-04-30

    An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

  18. Layered reactive particles with controlled geometries, energies, and reactivities, and methods for making the same

    DOEpatents

    Fritz, Gregory M.; Weihs, Timothy P.; Grzyb, Justin A.

    2016-07-05

    An energetic composite having a plurality of reactive particles each having a reactive multilayer construction formed by successively depositing reactive layers on a rod-shaped substrate having a longitudinal axis, dividing the reactive-layer-deposited rod-shaped substrate into a plurality of substantially uniform longitudinal segments, and removing the rod-shaped substrate from the longitudinal segments, so that the reactive particles have a controlled, substantially uniform, cylindrically curved or otherwise rod-contoured geometry which facilitates handling and improves its packing fraction, while the reactant multilayer construction controls the stability, reactivity and energy density of the energetic composite.

  19. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations

    PubMed Central

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D.

    2013-01-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-57Fe-enriched [Fe4S4Cl4]= and 10%-57Fe and 90%-54Fe labeled [Fe4S4Cl4]= has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3–4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements. PMID:23955030

  20. High energy product permanent magnet having improved intrinsic coercivity and method of making same

    DOEpatents

    Ramesh, Ramamoorthy; Thomas, Gareth

    1990-01-01

    A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture. The compressed mixture is then sintered at a temperature above the melting point of the sintering aid and below the melting point of the permanent magnet alloy to thereby coat the particle surfaces of the permanent magnetic alloy particles with the sintering aid while inhibiting migration of the rare earth element in the sintering aid into the permanent magnet alloy particles to thereby raise the intrinsic coercivity of the permanent magnet alloy without substantially lowering the high energy of the permanent magnet alloy.

  1. NASA Earth Observations Informing Renewable Energy Management and Policy Decision Making

    NASA Technical Reports Server (NTRS)

    Eckman, Richard S.; Stackhouse, Paul W., Jr.

    2008-01-01

    The NASA Applied Sciences Program partners with domestic and international governmental organizations, universities, and private entities to improve their decisions and assessments. These improvements are enabled by using the knowledge generated from research resulting from spacecraft observations and model predictions conducted by NASA and providing these as inputs to the decision support and scenario assessment tools used by partner organizations. The Program is divided into eight societal benefit areas, aligned in general with the Global Earth Observation System of Systems (GEOSS) themes. The Climate Application of the Applied Sciences Program has as one of its focuses, efforts to provide for improved decisions and assessments in the areas of renewable energy technologies, energy efficiency, and climate change impacts. The goals of the Applied Sciences Program are aligned with national initiatives such as the U.S. Climate Change Science and Technology Programs and with those of international organizations including the Group on Earth Observations (GEO) and the Committee on Earth Observation Satellites (CEOS). Activities within the Program are funded principally through proposals submitted in response to annual solicitations and reviewed by peers.

  2. NREL's Water Power Software Makes a Splash; NREL Highlights, Research & Development, NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    WEC-Sim is a DOE-funded software tool being jointly developed by NREL and SNL. WEC-Sim computationally models wave energy converters (WEC), devices that generate electricity using movement of water systems such as oceans, rivers, etc. There is great potential for WECs to generate electricity, but as of yet, the industry has yet to establish a commercially viable concept. Modeling, design, and simulations tools are essential to the successful development of WECs. Commercial WEC modeling software tools can't be modified by the user. In contrast, WEC-Sim is a free, open-source, and flexible enough to be modified to meet the rapidly evolving needs of the WEC industry. By modeling the power generation performance and dynamic loads of WEC designs, WEC-Sim can help support the development of new WEC devices by optimizing designs for cost of energy and competitiveness. By being easily accessible, WEC-Sim promises to help level the playing field in the WEC industry. Importantly, WEC-Sim is also excellent at its job! In 2014, WEC-Sim was used in conjunction with NREL’s FAST modeling software to win a hydrodynamic modeling competition. WEC-Sim and FAST performed very well at predicting the motion of a test device in comparison to other modeling tools. The most recent version of WEC-Sim (v1.1) was released in April 2015.

  3. Internal energy and parameters of the order-disorder phase transition in titanium monoxide TiO{sub y}

    SciTech Connect

    Kostenko, M. G.; Rempel, A. A.; Lukoyanov, A. V.

    2013-06-15

    Quantum-mechanical ab initio calculations are used to simulate the free energy functions for titanium monoxide TiO{sub y}. The effect of the long-range order of the Ti{sub 5}O{sub 5} type superstructure on the internal energy of the compound is studied by the supercell method. The dependences of the configuration entropy and free energy on the long-range order parameter are determined. It is found that the order-disorder phase transition in titanium monoxide must occur in accordance with the mechanism of the first-order phase transition with a critical value of the long-range order parameter of 0.971. The calculated parameters of the phase transition are compared with the experimental data and the results obtained using the model of point charges and by calculating the Madelung energy. It is concluded that the short-range order and the phonon entropy must be taken into account in calculating the equilibrium phase diagrams for strongly nonstoichiometric compounds.

  4. Hydrogen Scenario Analysis Summary Report: Analysis of the Transition to Hydrogen Fuel Cell Vehicles and the Potential Hydrogen Energy Infrastructure Requirements

    SciTech Connect

    Greene, David L; Leiby, Paul Newsome; James, Brian; Perez, Julie; Melendez, Margo; Milbrandt, Anelia; Unnasch, Stefan; Rutherford, Daniel; Hooks, Matthew

    2008-03-01

    Achieving a successful transition to hydrogen-powered vehicles in the U.S. automotive market will require strong and sustained commitment by hydrogen producers, vehicle manufacturers, transporters and retailers, consumers, and governments. The interaction of these agents in the marketplace will determine the real costs and benefits of early market transformation policies, and ultimately the success of the transition itself. The transition to hydrogen-powered transportation faces imposing economic barriers. The challenges include developing and refining a new and different power-train technology, building a supporting fuel infrastructure, creating a market for new and unfamiliar vehicles, and achieving economies of scale in vehicle production while providing an attractive selection of vehicle makes and models for car-buyers. The upfront costs will be high and could persist for a decade or more, delaying profitability until an adequate number of vehicles can be produced and moved into consumer markets. However, the potential rewards to the economy, environment, and national security are immense. Such a profound market transformation will require careful planning and strong, consistent policy incentives. Section 811 of the Energy Policy Act (EPACT) of 2005, Public Law 109-59 (U.S. House, 2005), calls for a report from the Secretary of Energy on measures to support the transition to a hydrogen economy. The report was to specifically address production and deployment of hydrogen-fueled vehicles and the hydrogen production and delivery infrastructure needed to support those vehicles. In addition, the 2004 report of the National Academy of Sciences (NAS, 2004), The Hydrogen Economy, contained two recommendations for analyses to be conducted by the U.S. Department of Energy (DOE) to strengthen hydrogen energy transition and infrastructure planning for the hydrogen economy. In response to the EPACT requirement and NAS recommendations, DOE's Hydrogen, Fuel Cells and

  5. Impact of dietary plane of energy during the dry period on lipoprotein parameters in the transition period in dairy cattle.

    PubMed

    Newman, A; Mann, S; Nydam, D V; Overton, T R; Behling-Kelly, E

    2016-02-01

    The high energy demands of dairy cows during the transition period from late gestation into early lactation can place them at an increased risk for the development of metabolic and infectious diseases. Modification of the dry period diet has been investigated as a preventive means to minimize the detrimental aspects of metabolic shifts during the transition period. Studies investigating the impact of dry period diet on lipid parameters during the transition period have largely focused on markers of lipolysis and ketogenesis. Total cholesterol declines during the periparturient period and increases in early lactation. The impact total energy in the dry period diet has on the ability of the cow to maintain total serum cholesterol, as well as its natural high-density lipoprotein-rich status, during this metabolically challenging window is not clear. The impact of lipoproteins on inflammation and immune function may have a clinical impact on the cow's ability to ward off production-related diseases. In this study, we hypothesized that the provision of adequate, but not excessive, total metabolizable energy, would better allow the cow to maintain total cholesterol and a higher relative proportion of HDL throughout the transition period. Cows were allocated to one of three dry period dietary treatment groups following a randomized block design. Total serum triglycerides, cholesterol and lipoprotein fractions were measured on a weekly basis from approximately 7 weeks pre-calving to 6 weeks post-calving. The cows on the high energy diet maintained total serum cholesterol as compared to the cows provided a lower energy diet, but there was no significant increase in the LDL fraction of lipoproteins between diet treatment groups. PMID:25958934

  6. Making solar laws work: a study of state solar energy incentives

    SciTech Connect

    Roessner, J.D.

    1980-11-01

    The results of a research investigation of solar financial and research, demonstration, and development (RD and D) incentive programs in 18 states are summarized. The investigation focuses upon implementation - the organization and administrative processes required to convert a law into a viable program. Eleven financial and 12 RD and D programs were investigated. Results indicate that four conditions are common to successful implementation of both types of incentive programs: the opportunity to use solar energy as a heating source; characteristics of the agency selected to complement the law; involvement of outside groups in program implementation; and the specificity of guidance given to those responsible for implementation. Other conditions specific to the implementation of each type of program are discussed as well as the implications of these findings for state and federal policy makers.

  7. Identifying and tracing potential energy surfaces of electronic excitations with specific character via their transition origins: application to oxirane.

    PubMed

    Li, Jian-Hao; Zuehlsdorff, T J; Payne, M C; Hine, N D M

    2015-05-14

    We show that the transition origins of electronic excitations identified by quantified natural transition orbital (QNTO) analysis can be employed to connect potential energy surfaces (PESs) according to their character across a wide range of molecular geometries. This is achieved by locating the switching of transition origins of adiabatic potential surfaces as the geometry changes. The transition vectors for analysing transition origins are provided by linear response time-dependent density functional theory (TDDFT) calculations under the Tamm-Dancoff approximation. We study the photochemical CO ring opening of oxirane as an example and show that the results corroborate the traditional Gomer-Noyes mechanism derived experimentally. The knowledge of specific states for the reaction also agrees well with that given by previous theoretical work using TDDFT surface-hopping dynamics that was validated by high-quality quantum Monte Carlo calculations. We also show that QNTO can be useful for considerably larger and more complex systems: by projecting the excitations to those of a reference oxirane molecule, the approach is able to identify and analyse specific excitations of a trans-2,3-diphenyloxirane molecule. PMID:25875632

  8. To make people save energy tell them what others do but also who they are: a preliminary study.

    PubMed

    Graffeo, Michele; Ritov, Ilana; Bonini, Nicolao; Hadjichristidis, Constantinos

    2015-01-01

    A way to make people save energy is by informing them that "comparable others" save more. We investigated whether, one can further improve this nudge by manipulating Who the "comparable others" are. We asked participants to imagine receiving feedback stating that their energy consumption exceeded that of "comparable others" by 10%. We varied Who the "comparable others" were in a 2 × 2 design: they were a household that was located either in the same neighborhood as themselves or in a different neighborhood, and its members were either identified (by names and a photograph) or unidentified. We also included two control conditions: one where no feedback was provided, and one where only statistical feedback was provided (feedback about an average household). We found that it matters Who the "comparable others" are. The most effective feedback was when the referent household was from the same neighborhood as the individual's and its members were not identified. PMID:26379603

  9. Comparison of Segmental Colon Transit Time With Total Energy Expenditure in Psychiatry Unit Patients.

    PubMed

    Kim, Yeon Soo; Song, Bong Kil; Lee, On; Kwon, Hyun Jin

    2015-01-01

    Physical activity is associated with a reduced risk of colorectal cancer. We examined the colon transit time (CTT) according to the total energy expenditure (TEE) in psychiatry unit patients. The study participants included 67 adults, with a mean age of 49.8 years. The participants used an accelerometer for 7 days to measure their 1-week TEE. They took a capsule containing 20 radio-opaque markers for 3 days. On the 4th day and 7th day, a supine abdominal radiography was performed. According to the TEE of all study participants, the upper 30%, middle 30%, and lower 40% were classified into groups according to high (H), moderate (M), and low (L) physical activity. The mean total CTT was 52.0 hours. The segmental CTT for the right, left, and recto-sigmoid colon were 15.3 hours, 19.2 hours, and 17.4 hours. Total CTT in the H group was significantly shorter than that in the L group (p = .010). A comparison of the segmental CTT between the L, M, and H groups showed that the right CTT (p = .010) of the H group was significantly shorter than that of the M group. The left CTT of the M group (p = .028) and H group (p = .004) was significantly shorter than that of the L group. The recto-sigmoid CTT (p = .016) of the M group was significantly shorter than that of the L group. The study showed that moderate and high TEE was assisted with reduced CTT. PMID:25181498

  10. Comparison of Segmental Colon Transit Time With Total Energy Expenditure in Psychiatry Unit Patients

    PubMed Central

    Kim, Yeon Soo; Lee, On; Kwon, Hyun Jin

    2015-01-01

    Physical activity is associated with a reduced risk of colorectal cancer. We examined the colon transit time (CTT) according to the total energy expenditure (TEE) in psychiatry unit patients. The study participants included 67 adults, with a mean age of 49.8 years. The participants used an accelerometer for 7 days to measure their 1-week TEE. They took a capsule containing 20 radio-opaque markers for 3 days. On the 4th day and 7th day, a supine abdominal radiography was performed. According to the TEE of all study participants, the upper 30%, middle 30%, and lower 40% were classified into groups according to high (H), moderate (M), and low (L) physical activity. The mean total CTT was 52.0 hours. The segmental CTT for the right, left, and recto-sigmoid colon were 15.3 hours, 19.2 hours, and 17.4 hours. Total CTT in the H group was significantly shorter than that in the L group (p = .010). A comparison of the segmental CTT between the L, M, and H groups showed that the right CTT (p = .010) of the H group was significantly shorter than that of the M group. The left CTT of the M group (p = .028) and H group (p = .004) was significantly shorter than that of the L group. The recto-sigmoid CTT (p = .016) of the M group was significantly shorter than that of the L group. The study showed that moderate and high TEE was assisted with reduced CTT. PMID:25181498

  11. Free energy landscape and transition pathways from Watson–Crick to Hoogsteen base pairing in free duplex DNA

    PubMed Central

    Yang, Changwon; Kim, Eunae; Pak, Youngshang

    2015-01-01

    Houghton (HG) base pairing plays a central role in the DNA binding of proteins and small ligands. Probing detailed transition mechanism from Watson–Crick (WC) to HG base pair (bp) formation in duplex DNAs is of fundamental importance in terms of revealing intrinsic functions of double helical DNAs beyond their sequence determined functions. We investigated a free energy landscape of a free B-DNA with an adenosine–thymine (A–T) rich sequence to probe its conformational transition pathways from WC to HG base pairing. The free energy landscape was computed with a state-of-art two-dimensional umbrella molecular dynamics simulation at the all-atom level. The present simulation showed that in an isolated duplex DNA, the spontaneous transition from WC to HG bp takes place via multiple pathways. Notably, base flipping into the major and minor grooves was found to play an important role in forming these multiple transition pathways. This finding suggests that naked B-DNA under normal conditions has an inherent ability to form HG bps via spontaneous base opening events. PMID:26250116

  12. Spectroscopic analysis of transition state energy levels - Bending-rotational spectrum and lifetime analysis of H3 quasibound states

    NASA Astrophysics Data System (ADS)

    Zhao, Meishan; Mladenovic, Mirjana; Truhlar, Donald G.; Schwenke, David W.; Sharafeddin, Omar

    1989-11-01

    Converged quantum mechanical calculations of scattering matrices and transition probabilities are reported for the reaction of H with H2 with total angular momentum 0, 1, and 4 as functions of total energy in the range 0.85-1.15 eV on an accurate potential energy surface. The resonance structure is illustrated with Argand diagrams. State-to-state reactive collision delay times and lifetimes are presented. For J = 0, 1, and 4, the lowest-energy H3 resonance is at total energies of 0.983, 0.985, and 1.01 eV, respectively, with lifetimes of about 16-17 fs. For J = 1 and 4 there is a higher-energy resonance at 1.10-1.11 eV. For J = 1 the lifetime is about 4 fs and for J = 4 it is about 1 fs.

  13. Spectroscopic analysis of transition state energy levels - Bending-rotational spectrum and lifetime analysis of H3 quasibound states

    NASA Technical Reports Server (NTRS)

    Zhao, Meishan; Mladenovic, Mirjana; Truhlar, Donald G.; Schwenke, David W.; Sharafeddin, Omar

    1989-01-01

    Converged quantum mechanical calculations of scattering matrices and transition probabilities are reported for the reaction of H with H2 with total angular momentum 0, 1, and 4 as functions of total energy in the range 0.85-1.15 eV on an accurate potential energy surface. The resonance structure is illustrated with Argand diagrams. State-to-state reactive collision delay times and lifetimes are presented. For J = 0, 1, and 4, the lowest-energy H3 resonance is at total energies of 0.983, 0.985, and 1.01 eV, respectively, with lifetimes of about 16-17 fs. For J = 1 and 4 there is a higher-energy resonance at 1.10-1.11 eV. For J = 1 the lifetime is about 4 fs and for J = 4 it is about 1 fs.

  14. Temperature-Dependent Energy Gap Shift and Thermally Activated Transition in Multilayer CdTe/ZnTe Quantum Dots.

    PubMed

    Man, Minh Tan; Lee, Hong Seok

    2015-10-01

    We investigated the influence of growth conditions on carrier dynamics in multilayer CdTe/ZnTe quantum dots (QDs) by monitoring the temperature dependence of the photoluminescence emission energy. The results were analyzed using the empirical Varshni and O'Donnell relations for temperature variation of the energy gap shift. Best fit values showed that the thermally activated transition between two different states occurs due to band low-temperature quenching with values separated by 5.0-6.5 meV. The addition of stack periods in multilayer CdTe/ZnTe QDs plays an important role in the energy gap shift, where the exciton binding energy is enhanced, and, conversely, the exciton-phonon coupling strength is suppressed with an average energy of 19.3-19.8 meV. PMID:26726473

  15. Effect of monensin and essential oils on performance and energy metabolism of transition dairy cows.

    PubMed

    Drong, C; Meyer, U; von Soosten, D; Frahm, J; Rehage, J; Breves, G; Dänicke, S

    2016-06-01

    This work examined preventive effects of a dietary and a medical intervention measure on postpartum (p.p.) ketogenesis in dairy cows overconditioned in late pregnancy. Sixty German Holstein cows were allocated 6 weeks antepartum (a.p.) to three high body condition score (BCS) groups (BCS 3.95 ± 0.08) and one low BCS group (LC, BCS 2.77 ± 0.14). Concentrate proportion in diet a.p. was higher (60% vs. 20%) and increase in proportion p.p. from 30% up to 50% decelerated (3 vs. 2 weeks) in high BCS groups. High BCS cows received a monensin controlled-release capsule (CRC) (HC/MO), a blend of essential oils (HC/EO) or formed a control group (HC). Performance parameters and energy status were evaluated in three periods [day (d) -42 until calving, one until 14 days in milk (DIM), 15 until 56 DIM]. Feed efficiency was 65% and 53% higher in HC/MO than in LC (p < 0.001) and HC groups (p = 0.002) in the second period. Milk fat content was higher in HC/EO (5.60 vs. 4.82%; p = 0.012) and milk urea higher in HC/MO (135 mg/kg) than in LC cows (107 mg/kg; p < 0.001). Increased p.p. levels of non-esterified fatty acids in serum were found in HC (p = 0.003), HC/MO (p = 0.068) and HC/EO (p = 0.002) in comparison with LC cows. Prevalence of subclinical and clinical ketosis was 54% and 46%, respectively, in HC group. Monensin decreased the prevalence to 50% and 7% respectively. Ruminal fermentation pattern showed higher proportions of propionate (23.43 mol % and 17.75 mol %, respectively; p < 0.008) and lower acetate:propionate ratio (2.66 vs. 3.76; p < 0.001) in HC/MO than HC group. Results suggest that a monensin CRC improved energy status and feed efficiency of transition dairy cows while essential oils failed to elicit any effect. PMID:26613964

  16. Histomorphological features of resected bladder tumors: Do energy source makes any difference

    PubMed Central

    Saini, Ashish Kumar; Ahuja, Arvind; Seth, Amlesh; Dogra, Prem Nath; Kumar, Rajeev; Singh, Prabhjot; Gupta, Siddhartha Dutta

    2015-01-01

    Context: The recent advent of bipolar energy in bladder tumor resection has raised many questions regarding density of current and its effect on histopathology of the resected transurethral resection of bladder tumor (TURBT) chips. Aims: The aim of this study is to evaluate the histomorphological features in resected bladder tumors comparing bipolar versus conventional (monopolar) energy. Settings and Design: Inclusion criteria were patients with primary presentation of carcinoma urinary bladder undergoing TURBT. The patients with prior resections were excluded as these could jeopardize the results of cautery artifacts. Materials and Methods: From February 2010 to December 2011, 61 patients with primary carcinoma bladder and meeting our inclusion criteria were compared. Group 1 (n = 31) underwent bipolar-TURBT (B-TURBT) and Group 2 (n = 30) monopolar-TURBT (M-TURBT). Two pathologists, who were blinded to the form of electrocautery used, examined the resected tissue. The degree of cautery artifact in each specimen was recorded. The severity of the cautery artifact was graded as absent, mild, moderate, or severe. The mean age, tumor size, and resection time were recorded in both groups. Statistical Analysis Used: Data were analyzed using SPSS 16. Data were compared in between groups using paired t-test and Pearson's Chi-square test. The significance level was set at 0.05. Results: The mean age, tumor size, and resection time were similar in between the two groups. The pathologists had no obscurity in reaching a correct diagnosis in all cases. The cautery artifacts were graded as absent in 10 (32.2%) and 8 (26.67%), mild in 12 (38.7%) and 11 (36.67%), moderate in 5 (16.1%) and 7 (23.33%) and severe in 4 (12.9%) and 5 (16.66%) cases, respectively in Group 1 and 2. There was no statistically significant histomorphogical dissimilarity between specimens according to the type of cautery used. Conclusions: Bladder tissue obtained from B-TURBT is of equivalent

  17. X-ray resonant photoexcitation: linewidths and energies of Kα transitions in highly charged Fe ions.

    PubMed

    Rudolph, J K; Bernitt, S; Epp, S W; Steinbrügge, R; Beilmann, C; Brown, G V; Eberle, S; Graf, A; Harman, Z; Hell, N; Leutenegger, M; Müller, A; Schlage, K; Wille, H-C; Yavaş, H; Ullrich, J; Crespo López-Urrutia, J R

    2013-09-01

    Photoabsorption by and fluorescence of the Kα transitions in highly charged iron ions are essential mechanisms for x-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main Kα transitions in highly charged iron ions from heliumlike to fluorinelike (Fe24+ to Fe17+) using monochromatic x rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in x-ray binary stars and active galactic nuclei. PMID:25166661

  18. Energy balance in the solar transition region. III - Helium emission in hydrostatic, constant-abundance models with diffusion

    NASA Technical Reports Server (NTRS)

    Fontenla, J. M.; Avrett, E. H.; Loeser, R.

    1993-01-01

    In our previous papers we described the mathematical formalism and the computed results for energy-balance hydrostatic models of the solar transition region. In this paper we discuss in some detail the limitations of the hydrostatic and one-dimensional assumptions used. Then we analyze the determination of helium emission when diffusion is included. We use transport coefficients estimated from kinetic theory to determine the helium departures from local ionization balance. We calculate the helium spectra for each of our models and evaluate the role of helium in the energy transport. Also, we investigate the effects of coronal illumination on the structure of the transition region and upper chromosphere, and show how coronal illumination affects various EUV lines and the He I 10830 A line. Comparing with both absolute intensities and detailed line profiles, we show that our models are consistent not only with the observed hydrogen spectra but also with the available helium spectra.

  19. Nuclear Energy R&D Imperative 3: Enable a Transition Away from Fossil Fuel in the Transportation and Industrial Sectors

    SciTech Connect

    David Petti; J. Stephen Herring

    2010-03-01

    As described in the Department of Energy Office of Nuclear Energy’s Nuclear Energy R&D Roadmap, nuclear energy can play a significant role in supplying energy for a growing economy while reducing both our dependence on foreign energy supplies and emissions from the burning of fossil fuels. The industrial and transportation sectors are responsible for more than half of the greenhouse gas emissions in the U.S., and imported oil supplies 70% of the energy used in the transportation sector. It is therefore important to examine the various ways nuclear energy can facilitate a transition away from fossil fuels to secure environmentally sustainable production and use of energy in the transportation and manufacturing industry sectors. Imperative 3 of the Nuclear Energy R&D Roadmap, entitled “Enable a Transition Away from Fossil Fuels by Producing Process Heat for use in the Transportation and Industrial Sectors”, addresses this need. This document presents an Implementation Plan for R&D efforts related to this imperative. The expanded use of nuclear energy beyond the electrical grid will contribute significantly to overcoming the three inter-linked energy challenges facing U.S. industry: the rising and volatile prices for premium fossil fuels such as oil and natural gas, dependence on foreign sources for these fuels, and the risks of climate change resulting from carbon emissions. Nuclear energy could be used in the industrial and transportation sectors to: • Generate high temperature process heat and electricity to serve industrial needs including the production of chemical feedstocks for use in manufacturing premium fuels and fertilizer products, • Produce hydrogen for industrial processes and transportation fuels, and • Provide clean water for human consumption by desalination and promote wastewater treatment using low-grade nuclear heat as a useful additional benefit. Opening new avenues for nuclear energy will significantly enhance our nation’s energy

  20. Graduate Dress Code How Undergraduates Are Planning to Use Hair, Clothes and Make-Up to Smooth Their Transition to the Workplace

    ERIC Educational Resources Information Center

    Cutts, Beth; Hooley, Tristram; Yates, Julia

    2015-01-01

    This article explores the relationship between students' identities, their ideas about professional appearance and their anticipated transition to the world of work. It is based on a series of semi-structured interviews with 13 students from a vocationally-focused university in England. It was found that participants viewed clothing and appearance…