The transition into veterinary practice: Opinions of recent graduates and final year students

Directory of Open Access Journals (Sweden)

Hudson Neil PH

2011-09-01

Full Text Available Abstract Background The transition from veterinary student to member of the veterinary profession is known to be challenging. This study aimed to determine and compare the opinions of final year veterinary students and recent graduates on graduate attributes that ease this transition. Methods The study was carried out across 3 veterinary schools in the United Kingdom. Paper based or electronic surveys were used. Final year students in the 3 schools were surveyed either electronically (school A or on paper (schools B and C. Student cohort sizes were 112, 227 and 102 respectively. Recent graduates were contacted either at a reunion event (school A or electronically from database records (school B and school C. Cohort sizes of contacted graduates were 80, 175 and 91 respectively. Respondents were asked to rate 42 individual attributes on a 5 point Likert scale. Focus groups with final year students and recent graduates and telephone interviews with recent graduates were carried out. Data were analysed by two researchers through a combination of manual coding and thematic analysis. Data were grouped into broad themes then sorted into narrower themes. Data were then searched for counter examples. Results Response rates for final year students were 34% (school A, 36% (school B and 40% (school C. Response rates for recent graduates were 56% (school A, 20% (school B and 11% (school C. There was a high level of agreement between the cohorts with respect to communication skills, problem solving and decision making skills, recognition of own limitations and the ability to cope with pressure all rated unanimously important or very important. Business acumen, knowledge of veterinary practice management and research skills were the 3 attributes ranked at the bottom of the list. Nine attributes were identified with a significantly different (p Conclusions Recent graduates and final year students rate highly the attributes which help foster the client

Transition to a hydrogen fuel cell transit bus fleet for Canadian urban transit system

International Nuclear Information System (INIS)

Ducharme, P.

2004-01-01

'Full text:' The Canadian Transportation Fuel Cell Alliance (CTFCA), created by the Canadian Government as part of its 2000 Climate Change Action Plan, has commissioned MARCON-DDM's Hydrogen Intervention Team (HIT) to provide a roadmap for urban transit systems that wish to move to hydrogen fuel cell-powered bus fleets. HIT is currently in the process of gathering information from hydrogen technology providers, bus manufacturers, fuelling system providers and urban transit systems in Canada, the US and Europe. In September, HIT will be in a position to provide a preview of its report to the CTFCA, due for October 2004. The planned table of contents includes: TOMORROW'S FUEL CELL (FC) URBAN TRANSIT BUS - Powertrain, on-board fuel technologies - FC engine system manufacturers - Bus technical specifications, performances, operating characteristics - FC bus manufacturers TOMORROW'S FC TRANSIT PROPERTY - Added maintenance, facilities and fuelling infrastructure requirements - Supply chain implications - Environmental and safety issues - Alternative operational concepts PATHWAYS TO THE FUTURE - Choosing the future operational concept - 'Gap' assessment - how long from here to there? - Facilities and fleet adjustments, including fuelling infrastructure - Risk mitigation, code compliance measures TRANSITIONAL CONSIDERATIONS - Cost implications - Transition schedule (author)

Economic System and Transition Mode : A Comparative Research on Transition Economies

OpenAIRE

Yang, Liu

2014-01-01

This passage mainly deals with the problem of why different transition countries have different transition mode and different economic performance. According to this research, it has been found that the economic system of the traditional socialist countries played an important role in their process of reform and transition. The socialist countries with their different economic systems had determined the economic performance, the space, as well as the environment of the transition. All of this...

Delivering power system transition in China

International Nuclear Information System (INIS)

Yuan Jiahai; Xu Yan; Hu Zhaoguang

2012-01-01

This paper studies the transition to low carbon power systems in China. The methodology is built on the newly developed multi-level perspective (MLP) transitions, as well as literature on innovation systems. Three lines of thought on the transition process are integrated to probe the possible transition pathways in China's power sector. Five transition pathways, namely reproduction, transformation, substitution, reconfiguration, de-alignment/re-alignment and reconfiguration, with their possible technology options are presented. The requirements for a smart grid in the socio-technical transition process are addressed within the MLP framework. The paper goes further to propose an interactive framework for low carbon transition management in China. Representative technology options are appraised by employing innovation theory to demonstrate the logic of policy design within the framework. The work presented in this paper will be useful in informing policy-makers and other stakeholders in China and it may prove to be a valuable reference for other countries in energy transition management. - Highlights: ► The transition to low carbon power systems is studied from a multi-level perspective. ► Transition pathways with possible technology options are presented. ► An interactive framework is proposed for managing this transition. ► Representative technology options are appraised within the framework to show the logic of policy design.

On Determinism in Modal Transition Systems

DEFF Research Database (Denmark)

Benes, Nikola; Kretinsky, Jan; Larsen, Kim Guldstrand

2009-01-01

Modal transition systems (MTS) is a formalism which extends the classical notion of labelled transition systems by introducing transitions of two types: must transitions that have to be present in any implementation of the MTS and may transitions that are allowed but not required. The MTS framewo....... In the present article, we provide a comprehensive account of the MTS framework in the deterministic setting. We study a number of problems previously considered on MTS and point out to what extend we can expect better results under the restriction of determinism....

Review on Malaysian Rail Transit Operation and Management System: Issues and Solution in Integration

Science.gov (United States)

Masirin, Mohd Idrus Mohd; Salin, Aminah Mohd; Zainorabidin, Adnan; Martin, David; Samsuddin, Norshakina

2017-08-01

In any context, operation and management of transportation systems are key issues which may affect both life quality and economic development. In large urban agglomerations, an efficient public transportation system may help abate the negative externalities of private car use such as congestion, air and noise pollution, accident and fuel consumption, without excessively penalizing user travel times or zone accessibility. Thus, this study is conducted to appraise the Malaysian rural rail transit operation and management system, which are considered important as there are many issues and solution in integration of the services that need to be tackled more conscientiously. The purpose of this paper is to describe some of the most important issues on integration of services and rail transit system in Malaysian and how to solve or reduce these problems and conflicts. In this paper, it consists of the historical development of rail transit construction in Malaysia. This paper also attempts to identify the important issues related to rail transit services and integration in Malaysian rural rail operation and management system. Comparison is also conducted with other countries such as UK, France, and Japan. Finally, a critical analysis is presented in this paper by looking at the possible application for future Malaysian rail transit operation system and management, especially focusing on enhancing the quality of Malaysian rural rail transit. In conclusion, this paper is expected to successfully review and appraise the existing Malaysian rural rail transit operation and management system pertaining to issues & solution in integration. It is also hoped that reformation or transformation of present service delivery quality of the rail transit operation and management will enable Malaysia to succeed in transforming Malaysian transportation system to greater heights.

The impacts of the final phase of transition to IFRS in Brazil

Directory of Open Access Journals (Sweden)

Clênia de Oliveira Pires

2015-08-01

Full Text Available Objective – This article aims to measure the impacts of the final phase of mandatory convergence to IFRS on net income, in equity and total assets of Brazilian publics companies. Design/methodology/approach – It is applied to the inverse of Gray (1980’s Conservatism Index – which allows you to compare the results between different accounting systems – to determine the impacts of the transition between the two phases of the convergence process in Brazil, covered by the law 11,638 and their CPCs. It was compared the 2009 financial results disclosed in BR GAAP and IFRS. Findings – The results show that the final stage of mandatory convergence to IFRS led to significant increases in both net income and the shareholders’ equity of the companies analysed: a mean increase of about 21% in earnings and about 11% in equity, as well as generating an increase, though somewhat less significant, about 7%, the total assets. Practical implications – This research helped to improve understanding of the impacts of convergence of Brazilian accounting to the international standard; as well as to assist business managers and users of financial information, especially those from the capital markets, regulators and academia, about the ultimate effects on the results reported in 2011, after the implementation of the final phase of convergence. Originality/value – The fiscal year of 2009 was a special year for understanding the impact of accounting system in the financial results disclosed in Brazil. The Brazilian publics companies reported their results in BR GAAP and IFRS and this research analysed and compare both reports and improve understanding of the impacts of convergence of Brazilian accounting to the international standard.

Stochastic Stability for Time-Delay Markovian Jump Systems with Sector-Bounded Nonlinearities and More General Transition Probabilities

Directory of Open Access Journals (Sweden)

Dan Ye

2013-01-01

Full Text Available This paper is concerned with delay-dependent stochastic stability for time-delay Markovian jump systems (MJSs with sector-bounded nonlinearities and more general transition probabilities. Different from the previous results where the transition probability matrix is completely known, a more general transition probability matrix is considered which includes completely known elements, boundary known elements, and completely unknown ones. In order to get less conservative criterion, the state and transition probability information is used as much as possible to construct the Lyapunov-Krasovskii functional and deal with stability analysis. The delay-dependent sufficient conditions are derived in terms of linear matrix inequalities to guarantee the stability of systems. Finally, numerical examples are exploited to demonstrate the effectiveness of the proposed method.

Transit forecasting accuracy : ridership forecasts and capital cost estimates, final research report.

Science.gov (United States)

2009-01-01

In 1992, Pickrell published a seminal piece examining the accuracy of ridership forecasts and capital cost estimates for fixed-guideway transit systems in the US. His research created heated discussions in the transit industry regarding the ability o...

Financial system development in transition economies

NARCIS (Netherlands)

Hermes, C.L.M.; Lensink, B.W.

This paper provides an overview of the major issues with respect to financial system development in transition economies, which were discussed at a conference in Groningen, the Netherlands, December 1997. After a brief remark on the role of financial system design during economic transition, the

Robust Guaranteed Cost Observer Design for Singular Markovian Jump Time-Delay Systems with Generally Incomplete Transition Probability

Directory of Open Access Journals (Sweden)

Yanbo Li

2014-01-01

Full Text Available This paper is devoted to the investigation of the design of robust guaranteed cost observer for a class of linear singular Markovian jump time-delay systems with generally incomplete transition probability. In this singular model, each transition rate can be completely unknown or only its estimate value is known. Based on stability theory of stochastic differential equations and linear matrix inequality (LMI technique, we design an observer to ensure that, for all uncertainties, the resulting augmented system is regular, impulse free, and robust stochastically stable with the proposed guaranteed cost performance. Finally, a convex optimization problem with LMI constraints is formulated to design the suboptimal guaranteed cost filters for linear singular Markovian jump time-delay systems with generally incomplete transition probability.

Bus Operation Monitoring Oriented Public Transit Travel Index System and Calculation Models

Directory of Open Access Journals (Sweden)

Jiancheng Weng

2013-01-01

Full Text Available This study proposed a two-dimensional index system which is concerned essentially with urban travel based on travel modes and user satisfaction. First, the public transit was taken as an example to describe the index system establishing process. In consideration of convenience, rapid, reliability, comfort, and safety, a bus service evaluation index system was established. The indicators include the N-minute coverage of bus stops, average travel speed, and fluctuation of travel time between stops and bus load factor which could intuitively describe the characteristics of public transport selected to calculate bus travel indexes. Then, combined with the basic indicators, the calculation models of Convenience Index (CI, Rapid Index (RI, Reliability Index (RBI, and Comfort Index (CTI were established based on the multisource data of public transit including the real-time bus GPS data and passenger IC card data. Finally, a case study of Beijing bus operation evaluation and analysis was conducted by taking real bus operation data including GPS data and passenger transaction recorder (IC card data. The results showed that the operation condition of the public transit was well reflected and scientifically classified by the bus travel index models.

Medical students' preparation for the transition to postgraduate training through final year elective rotations.

Science.gov (United States)

van den Broek, W E Sjoukje; Wijnen-Meijer, Marjo; Ten Cate, Olle; van Dijk, Marijke

2017-01-01

Objectives: This study adds to the ongoing discussion on how to ease the transition from undergraduate medical training to postgraduate training. In the Netherlands there is no central matching system for admission to residency. Medical school graduates just apply for a position in an open job market. Many choose to acquire general or specialty-specific clinical experiences after the medical degree before residency, to further explore career opportunities and to increase their chances to get into their preferred specialty. To shorten this gap between undergraduate and the start of postgraduate training, the sixth and final year of most Dutch medical schools is designed as a "transitional year". Students work with more clinical responsibilities than in the earlier clerkships, and this year includes many elective options. Our study focuses on these elective options and explores how medical students use these transitional year electives to prepare for transition to postgraduate training. Methods: In 2012-2013 we asked all 274 graduating students at one Dutch medical school to complete an open-answer questionnaire with the following topics: their preferred specialty at the start of the transitional year, electives they chose during this year and reasons for these choices, and whether the transitional year electives changed their career considerations. Questionnaire results were coded by two researchers and were discussed with all members of the research team. Results: A total of 235 students responded (86%). Answers about motivation for choices revealed that most electives where chosen for career orientation and to optimize chances to get into a residency program. Students also focused on additional experiences in specialties related to their preferred specialty. Many students chose electives logically related to each other, e.g. combinations of surgery and radiology. About two-thirds of the respondents stated that their elective experiences did confirm their specialty

Stimulating transitions towards sustainable farming systems

NARCIS (Netherlands)

Elzen, B.; Barbier, M.; Cerf, M.; Grin, J.

2012-01-01

How can the dynamics of the agro-food sector in the long run be addressed? We argue that sustainable agro-food systems cannot be developed through a simple improvement of existing systems, but will require a transition. Therefore, we focus on how transitions to sustainability could be initiated and

Perceived stress at transition to workplace: a qualitative interview study exploring final-year medical students’ needs

Directory of Open Access Journals (Sweden)

Moczko TR

2016-01-01

Full Text Available Tobias R Moczko,1,2,* Till J Bugaj,1,* Wolfgang Herzog,1 Christoph Nikendei1 1Department for General Internal and Psychosomatic Medicine, University Hospital of Heidelberg, Heidelberg, 2School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany *These authors contributed equally to this work Objectives: This study was designed to explore final-year medical students’ stressors and coping strategies at the transition to the clinical workplace. Methods: In this qualitative study, semi-standardized interviews with eight final-year medical students (five male, three female; aged 25.9±1.4 years were conducted during their internal medicine rotation. After verbatim transcription, a qualitative content analysis of students’ impressions of stress provoking and easing factors during final-year education was performed. Results: Students’ statements regarding burdens and dealing with stress were classified into four main categories: A perceived stressors and provoking factors, B stress-induced consequences, C personal and external resources for preventing and dealing with stress, and D final-year students’ suggestions for workplace improvement. Conclusion: Final-year medical students perceived different types of stress during their transition to medical wards, and reported both negative consequences and coping resources concerning perceived stress. As supervision, feedback, and coping strategies played an important role in the students’ perception of stress, final-year medical education curricula development should focus on these specifically. Keywords: undergraduate medical education, stress prevention, final-year medical education, workplace learning, qualitative research

Transit Timing Observations from Kepler: IV. Confirmation of 4 Multiple Planet Systems by Simple Physical Models

Energy Technology Data Exchange (ETDEWEB)

Fabrycky, Daniel C.; /UC, Santa Cruz; Ford, Eric B.; /Florida U.; Steffen, Jason H.; /Fermilab; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Moorhead, Althea V.; /Florida U.; Batalha, Natalie M.; /San Jose State U.; Borucki, William J.; /NASA, Ames; Bryson, Steve; /NASA, Ames; Buchhave, Lars A.; /Bohr Inst. /Copenhagen U.; Christiansen, Jessie L.; /SETI Inst., Mtn. View /NASA, Ames /Caltech

2012-01-01

Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present 4 sets of lightcurves from the Kepler spacecraft, which each show multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems architectures, even in cases for which high-precision Doppler follow-up is impractical.

Easing student transition to graduate nurse: a SIMulated Professional Learning Environment (SIMPLE) for final year student nurses.

Science.gov (United States)

Liaw, Sok Ying; Koh, Yiwen; Dawood, Rabiah; Kowitlawakul, Yanika; Zhou, Wentao; Lau, Siew Tiang

2014-03-01

Preparing nursing students for making the transition to graduate nurse is crucial for entry into practice. Final year student nurses at the National University of Singapore (NUS) are required to undergo a consolidated clinical practice to prepare them for their transition to graduate nurse. To describe the development, implementation and evaluation of a simulation program known as SIMulated Professional Learning Environment (SIMPLE) in preparing the final year student nurses for their clinical practicum in transition to graduate nurse practice. A set of simulation features and best practices were used as conceptual framework to develop and implement the simulation program. 94 final year student nurses participated in the 15-hour SIMPLE program that incorporated multiple simulation scenarios based on actual ward clinical practices. Pre and post-tests were conducted to assess the students' preparedness for their clinical practice in transition to graduate nurse practice. The students also completed a satisfaction questionnaire and open questions to evaluate their simulation experiences. The student nurses demonstrated a significant improvement (t=12.06, pnurse practice. They were highly satisfied with their simulation learning. Themes emerged from the comments on the most valuable aspects of the SIMPLE program and ways to improve the program. The study provided evidences on the effectiveness of the SIMPLE program in enhancing the students' preparedness for their transition to graduate nurse practice. A key success of the SIMPLE program was the used of simulation strategy and the involvement of practicing nurses that closely linked the students with the realities of current nursing practice to prepare them for the role of staff nurses. Copyright © 2013 Elsevier Ltd. All rights reserved.

System Geometries and Transit/Eclipse Probabilities

Directory of Open Access Journals (Sweden)

Howard A.

2011-02-01

Full Text Available Transiting exoplanets provide access to data to study the mass-radius relation and internal structure of extrasolar planets. Long-period transiting planets allow insight into planetary environments similar to the Solar System where, in contrast to hot Jupiters, planets are not constantly exposed to the intense radiation of their parent stars. Observations of secondary eclipses additionally permit studies of exoplanet temperatures and large-scale exo-atmospheric properties. We show how transit and eclipse probabilities are related to planet-star system geometries, particularly for long-period, eccentric orbits. The resulting target selection and observational strategies represent the principal ingredients of our photometric survey of known radial-velocity planets with the aim of detecting transit signatures (TERMS.

Health system strategies supporting transition to adult care.

Science.gov (United States)

Hepburn, Charlotte Moore; Cohen, Eyal; Bhawra, Jasmin; Weiser, Natalie; Hayeems, Robin Z; Guttmann, Astrid

2015-06-01

The transition from paediatric to adult care is associated with poor clinical outcomes, increased costs and low patient and family satisfaction. However, little is known about health system strategies to streamline and safeguard care for youth transitioning to adult services. Moreover, the needs of children and youth are often excluded from broader health system reform discussions, leaving this population especially vulnerable to system 'disintegration'. (1) To explore the international policy profile of paediatric-to-adult care transitions, and (2) to document policy objectives, initiatives and outcomes for jurisdictions publicly committed to addressing transition issues. An international policy scoping review of all publicly available government documents detailing transition-related strategies was completed using a web-based search. Our analysis included a comparable cohort of nine wealthy Organisation for Economic Co-operation and Development (OECD) jurisdictions with Beveridge-style healthcare systems (deemed those most likely to benefit from system-level transition strategies). Few jurisdictions address transition of care issues in either health or broader social policy documents. While many jurisdictions refer to standardised practice guidelines, a few report the intention to use powerful policy levers (including physician remuneration and non-physician investments) to facilitate the uptake of best practice. Most jurisdictions do not address the policy infrastructure required to support successful transitions, and rigorous evaluations of transition strategies are rare. Despite the well-documented risks and costs associated with a poor transition from paediatric to adult care, little policy attention has been paid to this issue. We recommend that healthcare providers engage health system planners in the design and evaluation of system-level, policy-sensitive transition strategies. Published by the BMJ Publishing Group Limited. For permission to use (where not

Medical students' preparation for the transition to postgraduate training through final year elective rotations

Directory of Open Access Journals (Sweden)

van den Broek, W. E. Sjoukje

2017-11-01

Full Text Available Objectives: This study adds to the ongoing discussion on how to ease the transition from undergraduate medical training to postgraduate training. In the Netherlands there is no central matching system for admission to residency. Medical school graduates just apply for a position in an open job market. Many choose to acquire general or specialty-specific clinical experiences after the medical degree before residency, to further explore career opportunities and to increase their chances to get into their preferred specialty. To shorten this gap between undergraduate and the start of postgraduate training, the sixth and final year of most Dutch medical schools is designed as a “transitional year”. Students work with more clinical responsibilities than in the earlier clerkships, and this year includes many elective options. Our study focuses on these elective options and explores how medical students use these transitional year electives to prepare for transition to postgraduate training.Methods: In 2012-2013 we asked all 274 graduating students at one Dutch medical school to complete an open-answer questionnaire with the following topics: Questionnaire results were coded by two researchers and were discussed with all members of the research team. Results: A total of 235 students responded (86%. Answers about motivation for choices revealed that most electives where chosen for career orientation and to optimize chances to get into a residency program. Students also focused on additional experiences in specialties related to their preferred specialty. Many students chose electives logically related to each other, e.g. combinations of surgery and radiology. About two-thirds of the respondents stated that their elective experiences did confirm their specialty preferences or resulted in a more clear insight.Conclusion: We conclude that students use the transitional year electives to focus on their future postgraduate training program, i.e. for

Phase transition in finite systems

International Nuclear Information System (INIS)

Chomaz, Ph.; Duflot, V.; Duflot, V.; Gulminelli, F.

2000-01-01

In this paper we present a review of selected aspects of Phase transitions in finite systems applied in particular to the liquid-gas phase transition in nuclei. We show that the problem of the non existence of boundary conditions can be solved by introducing a statistical ensemble with an averaged constrained volume. In such an ensemble the microcanonical heat capacity becomes negative in the transition region. We show that the caloric curve explicitly depends on the considered transformation of the volume with the excitation energy and so does not bear direct informations on the characteristics of the phase transition. Conversely, partial energy fluctuations are demonstrated to be a direct measure of the equation of state. Since the heat capacity has a negative branch in the phase transition region, the presence of abnormally large kinetic energy fluctuations is a signal of the liquid gas phase transition. (author)

Extending Modal Transition Systems with Structured Labels

DEFF Research Database (Denmark)

Bauer, Sebastian S.; Juhl, Line; Larsen, Kim Guldstrand

2012-01-01

We introduce a novel formalism of label-structured modal transition systems that combines the classical may/must modalities on transitions with structured labels that represent quantitative aspects of the model. On the one hand, the specification formalism is general enough to include models like...... weighted modal transition systems and allows the system developers to employ more complex label refinement than in the previously studied theories. On the other hand, the formalism maintains the desirable properties required by any specification theory supporting compositional reasoning. In particular, we...

FINANCIAL SYSTEM STRUCTURE AND STABILITY DURING TRANSITION

Directory of Open Access Journals (Sweden)

Firtescu Bogdan

2012-07-01

Full Text Available The process of transition from socialist economy to market economy was not considered an end in itself, but a necessity, and standing proof to achieve high levels of sustainable development. All former socialist countries are characterized by an early transition recession transformation result of the restructuring, loss of markets, tough competition from foreign products, best quality, or in other cases cheaper. To express the financial system structure in transition we take into discussion data that reflects representatives mutations and restructuring in Central and Eastern European countries, such Bulgaria, Czech Republic, Hungary, Poland and Romania. For all countries we show some important changes of financial system during transition and construct an image matrix that illustrates important indicators of financial system structure and their adjustment.

Note on the Tableau Technique for Commutative Transition Systems

DEFF Research Database (Denmark)

Srba, Jirí

2002-01-01

We define a class of transition systems called effective commutative transition systems (ECTS) and show, by generalising a tableau-based proof for BPP, that strong bisimilarity between any two states of such a transition system is decidable. It gives a general technique for extending decidability...... borders of strong bisimilarity for a wide class of infinite-state transition systems. This is demonstrated for several process formalisms, namely BPP process algebra, lossy BPP processes, BPP systems with interrupt and timed-arc BPP nets....

Listening to Student Views on the Transition from Work Placement to the Final Year

Science.gov (United States)

Anderson, Pamela; Novakovic, Yvonne

2017-01-01

This paper addresses a gap in the literature on student work placements, specifically the challenges of returning to final-year study after a year out. We focus on students in an Accountancy and Finance Department at one UK University who alerted us to the ways in which they struggled during the transition back to full-time study. Their accounts…

TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

International Nuclear Information System (INIS)

Fabrycky, Daniel C.; Ford, Eric B.; Moorhead, Althea V.; Steffen, Jason H.; Rowe, Jason F.; Christiansen, Jessie L.; Carter, Joshua A.; Fressin, Francois; Geary, John; Batalha, Natalie M.; Borucki, William J.; Bryson, Steve; Haas, Michael R.; Buchhave, Lars A.; Ciardi, David R.; Cochran, William D.; Endl, Michael; Fanelli, Michael N.; Fischer, Debra; Hall, Jennifer R.

2012-01-01

Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets' masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems' architectures, even in cases for which high-precision Doppler follow-up is impractical.

TRANSIT TIMING OBSERVATIONS FROM KEPLER. IV. CONFIRMATION OF FOUR MULTIPLE-PLANET SYSTEMS BY SIMPLE PHYSICAL MODELS

Energy Technology Data Exchange (ETDEWEB)

Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, Santa Cruz, CA 95064 (United States); Ford, Eric B.; Moorhead, Althea V. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32111 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Rowe, Jason F.; Christiansen, Jessie L. [SETI Institute, Mountain View, CA 94043 (United States); Carter, Joshua A.; Fressin, Francois; Geary, John [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Borucki, William J.; Bryson, Steve; Haas, Michael R. [NASA Ames Research Center, Moffett Field, CA, 94035 (United States); Buchhave, Lars A. [Department of Astrophysics and Planetary Science, Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91126 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas, Austin TX 78730 (United States); Fanelli, Michael N. [Bay Area Environmental Research Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Fischer, Debra [Astronomy Department, Yale University, New Haven, CT (United States); Hall, Jennifer R., E-mail: daniel.fabrycky@gmail.com [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); and others

2012-05-10

Eighty planetary systems of two or more planets are known to orbit stars other than the Sun. For most, the data can be sufficiently explained by non-interacting Keplerian orbits, so the dynamical interactions of these systems have not been observed. Here we present four sets of light curves from the Kepler spacecraft, each which of shows multiple planets transiting the same star. Departure of the timing of these transits from strict periodicity indicates that the planets are perturbing each other: the observed timing variations match the forcing frequency of the other planet. This confirms that these objects are in the same system. Next we limit their masses to the planetary regime by requiring the system remain stable for astronomical timescales. Finally, we report dynamical fits to the transit times, yielding possible values for the planets' masses and eccentricities. As the timespan of timing data increases, dynamical fits may allow detailed constraints on the systems' architectures, even in cases for which high-precision Doppler follow-up is impractical.

Transits of planets with small intervals in circumbinary systems

International Nuclear Information System (INIS)

Liu, Hui-Gen; Wang, Ying; Zhang, Hui; Zhou, Ji-Lin

2014-01-01

Transit times around single stars can be described well by a linear ephemeris. However, transit times in circumbinary systems are influenced both by the gravitational perturbations and the orbital phase variations of the central binary star. Adopting a coplanar analog of Kepler-16 as an example, we find that circumbinary planets can transit the same star more than once during a single planetary orbit, a phenomenon we call 'tight transits.' In certain geometric architecture, the projected orbital velocity of the planet and the secondary star can approach zero and change sign, resulting in very long transits and/or 2-3 transits during a single binary orbit. Whether tight transits are possible for a particular system depends primarily on the binary mass ratio and the orbital architecture of both the binary and the planet. We derive a time-dependent criterion to judge when tight transits are possible for any circumbinary system. These results are verified with full dynamical integrations that also reveal other tight transit characteristics, i.e., the transit durations and the intervals between tight transits. For the seven currently known circumbinary systems, we estimate these critical parameters both analytically and numerically. Due to the mutual inclination between the planet and the binary, tight transits can only occur across the less massive star B in Kepler-16, -34, -35, and -47 (for both planets). The long-term average frequency of tight transits (compared to typical transits) for Kepler-16, -34, and -35 are estimated to be several percent. Using full numerical integrations, the next tight transit for each system is predicted and the soonest example appears to be Kepler-47b and -47c, which are likely to have tight transits before 2025. These unique and valuable events often deserve special observational scrutiny.

Online transit trip planner for small agencies using Google Transit : final deployment package.

Science.gov (United States)

2011-09-01

Google Transit is a public transportation trip planner that enables travelers to obtain information regarding available transit services between a : given origin and given destination. While transit agencies can publish their service information onto...

Structure-Reactivity Relationships in Multi-Component Transition Metal Oxide Catalysts FINAL Report

Energy Technology Data Exchange (ETDEWEB)

Altman, Eric I. [Yale Univ., New Haven, CT (United States)

2015-10-06

The focus of the project was on developing an atomic-level understanding of how transition metal oxide catalysts function. Over the course of several renewals the specific emphases shifted from understanding how local structure and oxidation state affect how molecules adsorb and react on the surfaces of binary oxide crystals to more complex systems where interactions between different transition metal oxide cations in an oxide catalyst can affect reactivity, and finally to the impact of cluster size on oxide stability and reactivity. Hallmarks of the work were the use of epitaxial growth methods to create surfaces relevant to catalysis yet tractable for fundamental surface science approaches, and the use of scanning tunneling microscopy to follow structural changes induced by reactions and to pinpoint adsorption sites. Key early findings included the identification of oxidation and reduction mechanisms on a tungsten oxide catalyst surface that determine the sites available for reaction, identification of C-O bond cleavage as the rate limiting step in alcohol dehydration reactions on the tungsten oxide surface, and demonstration that reduction does not change the favored reaction pathway but rather eases C-O bond cleavage and thus reduces the reaction barrier. Subsequently, a new reconstruction on the anatase phase of TiO₂ relevant to catalysis was discovered and shown to create sites with distinct reactivity compared to other TiO₂ surfaces. Building on this work on anatase, the mechanism by which TiO₂ enhances the reactivity of vanadium oxide layers was characterized and it was found that the TiO₂ substrate can force thin vanadia layers to adopt structures they would not ordinarily form in the bulk which in turn creates differences in reactivity between supported layers and bulk samples. From there, the work progressed to studying well-defined ternary oxides where synergistic effects between the two cations can induce

Isothermal transitions of a thermosetting system

Science.gov (United States)

Gillham, J. K.; Benci, J. A.; Noshay, A.

1974-01-01

A study of the curing reactions of a cycloaliphatic epoxy resin/anhydride system by torsional braid analysis showed the existence of two critical isothermal temperatures - namely, the maximum glass transition temperature of the thermoset system and the glass transition temperature of the material at its gel point. Two rheologically active kinetic transitions occur during isothermal cure which correspond to gelation and vitrification. Three types of isothermal behavior occur. Methods for determining the time to gel and the time to vitrify, and also the two above-mentioned critical isothermal temperatures, have been developed. The time to gel obeyed the Arrhenius relationship, whereas the time to vitrify passed through a minimum. Application of these results to thermosetting systems in general is discussed in terms of the influence of molecular structure on the values of the critical isothermal temperatures.

Magnetic transition in double perovskite systems

Energy Technology Data Exchange (ETDEWEB)

Navarro, O., E-mail: navarro@servidor.unam.m [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Apdo. Postal 70-360, 04510 Mexico DF (Mexico); Aguilar, B. [Laboratorio Interinstitucional de Magnetismo Natural, Instituto de Geofisica, Sede Michoacan, Universidad Nacional Autonoma de Mexico, Morelia (Mexico); Avignon, M. [Institut Neel, CNRS and Universite Joseph Fourier, BP 166, 38042 Grenoble Cedex 9 (France)

2010-05-15

The search for materials having complete spin polarization and high Curie temperature have received a lot of attention in view of spintronics applications, especially the ferromagnetic (F) Sr{sub 2}FeMoO{sub 6}, because of its fairly high Curie temperature (T{sub C}= 450 K), half-metallic character, large magnetoresistance and potential applications. On the other hand, Sr{sub 2}FeWO{sub 6} is insulating and antiferromagnetic (AF) with T{sub N}=37K. With a double exchange type model it has been shown that F-AF transition can be driven by super-exchange interactions with increasing Fe-M (M=Mo, W) charge transfer energy. So, the charge transfer energy is expected to be larger in FeW than in FeMo compounds. Using a tight-binding model with the renormalized perturbation expansion technique, we determine the density of states for the AF phase and the electronic energy difference for the F- and AF-phases as a function of the Fe-M charge transfer energy. The F-AF transition in the ordered system Sr{sub 2}FeMo{sub x}W{sub 1-x}O{sub 6} occurs for xapprox0.3, in good agreement with the experimental value. We also studied the effect of the diagonal disorder in the variation of the number of conduction electrons on Fe and M sites. Finally, the behavior of the Curie temperature as a function of the Mo/W concentration is determined.

Final Focus Systems in Linear Colliders

International Nuclear Information System (INIS)

Raubenheimer, Tor

1998-01-01

In colliding beam facilities, the ''final focus system'' must demagnify the beams to attain the very small spot sizes required at the interaction points. The first final focus system with local chromatic correction was developed for the Stanford Linear Collider where very large demagnifications were desired. This same conceptual design has been adopted by all the future linear collider designs as well as the SuperConducting Supercollider, the Stanford and KEK B-Factories, and the proposed Muon Collider. In this paper, the over-all layout, physics constraints, and optimization techniques relevant to the design of final focus systems for high-energy electron-positron linear colliders are reviewed. Finally, advanced concepts to avoid some of the limitations of these systems are discussed

Bifurcation of transition paths induced by coupled bistable systems.

Science.gov (United States)

Tian, Chengzhe; Mitarai, Namiko

2016-06-07

We discuss the transition paths in a coupled bistable system consisting of interacting multiple identical bistable motifs. We propose a simple model of coupled bistable gene circuits as an example and show that its transition paths are bifurcating. We then derive a criterion to predict the bifurcation of transition paths in a generalized coupled bistable system. We confirm the validity of the theory for the example system by numerical simulation. We also demonstrate in the example system that, if the steady states of individual gene circuits are not changed by the coupling, the bifurcation pattern is not dependent on the number of gene circuits. We further show that the transition rate exponentially decreases with the number of gene circuits when the transition path does not bifurcate, while a bifurcation facilitates the transition by lowering the quasi-potential energy barrier.

A study on maintenance reliability allocation of urban transit brake system using hybrid neuro-genetic technique

International Nuclear Information System (INIS)

Bae, Chul Ho; Kim, Hyun Jun; Lee, Jung Hwan; Suh, Myung Won; Chu, Yul

2007-01-01

For reasonable establishing of maintenance strategies, safety security and cost limitation must be considered at the same time. In this paper, the concept of system reliability introduces and optimizes as the key of reasonable maintenance strategies. This study aims at optimizing component's reliability that satisfies the target reliability of brake system in the urban transit. First of all, constructed reliability evaluation system is used to predict and analyze reliability. This data is used for the optimization. To identify component reliability in a system, a method is presented in this paper which uses hybrid neuro-genetic technique. Feed-forward multi-layer neural networks trained by back propagation are used to find out the relationship between component reliability (input) and system reliability (output) of a structural system. The inverse problem can be formulated by using neural network. Genetic algorithm is used to find the minimum square error. Finally, this paper presents reasonable maintenance cycle of urban transit brake system by using optimal system reliability

Final focus system for TLC

International Nuclear Information System (INIS)

Oide, K.

1988-11-01

A limit of the chromaticity correction for the final focus system of a TeV Linear Collider (TLC) is investigated. As the result, it becomes possible to increase the aperture of the final doublet with a small increase of the horizontal β function. The new optics design uses a final doublet of 0.5 mm half-aperture and 1.4 T pole-tip field. The length of the system is reduced from 400 m to 200 m by several optics changes. Tolerances for various machine errors with this optics are also studied. 5 refs., 7 figs., 2 tabs

Bivariate- distribution for transition matrix elements in Breit-Wigner to Gaussian domains of interacting particle systems.

Science.gov (United States)

Kota, V K B; Chavda, N D; Sahu, R

2006-04-01

Interacting many-particle systems with a mean-field one-body part plus a chaos generating random two-body interaction having strength lambda exhibit Poisson to Gaussian orthogonal ensemble and Breit-Wigner (BW) to Gaussian transitions in level fluctuations and strength functions with transition points marked by lambda = lambda c and lambda = lambda F, respectively; lambda F > lambda c. For these systems a theory for the matrix elements of one-body transition operators is available, as valid in the Gaussian domain, with lambda > lambda F, in terms of orbital occupation numbers, level densities, and an integral involving a bivariate Gaussian in the initial and final energies. Here we show that, using a bivariate-t distribution, the theory extends below from the Gaussian regime to the BW regime up to lambda = lambda c. This is well tested in numerical calculations for 6 spinless fermions in 12 single-particle states.

Harmony in Career Learning and Scholastic System (Project HI-CLASS). Final Evaluation Report 1992-93. OREA Report.

Science.gov (United States)

Duque, Diana L.

Harmony in Career Learning and Scholastic System (Project HI-CLASS) was a Transitional Bilingual Education Title VII-funded program in its fifth and final year in 1992-93. The project offered instructional and support services to 641 students of limited English proficiency (LEP) at three sites, all of which had many immigrant students, in…

Final focus systems for linear colliders

International Nuclear Information System (INIS)

Erickson, R.A.

1987-11-01

The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are discussed, followed by chromatic aberrations. The design of the final focus system of the SLAC Linear Collider (SLC) is described. Tuning and diagnostics and steering to collision are discussed. Most of the examples illustrating the concepts covered are drawn from the SLC, but the principles and conclusions are said to be generally applicable to other linear collider designs as well. 26 refs., 17 figs

Random matrix theory for transition strengths: Applications and open questions

Science.gov (United States)

Kota, V. K. B.

2017-12-01

Embedded random matrix ensembles are generic models for describing statistical properties of finite isolated interacting quantum many-particle systems. A finite quantum system, induced by a transition operator, makes transitions from its states to the states of the same system or to those of another system. Examples are electromagnetic transitions (then the initial and final systems are same), nuclear beta and double beta decay (then the initial and final systems are different) and so on. Using embedded ensembles (EE), there are efforts to derive a good statistical theory for transition strengths. With m fermions (or bosons) in N mean-field single particle levels and interacting via two-body forces, we have with GOE embedding, the so called EGOE(1+2). Now, the transition strength density (transition strength multiplied by the density of states at the initial and final energies) is a convolution of the density generated by the mean-field one-body part with a bivariate spreading function due to the two-body interaction. Using the embedding U(N) algebra, it is established, for a variety of transition operators, that the spreading function, for sufficiently strong interactions, is close to a bivariate Gaussian. Also, as the interaction strength increases, the spreading function exhibits a transition from bivariate Breit-Wigner to bivariate Gaussian form. In appropriate limits, this EE theory reduces to the polynomial theory of Draayer, French and Wong on one hand and to the theory due to Flambaum and Izrailev for one-body transition operators on the other. Using spin-cutoff factors for projecting angular momentum, the theory is applied to nuclear matrix elements for neutrinoless double beta decay (NDBD). In this paper we will describe: (i) various developments in the EE theory for transition strengths; (ii) results for nuclear matrix elements for 130Te and 136Xe NDBD; (iii) important open questions in the current form of the EE theory.

Geometric transitions and integrable systems

International Nuclear Information System (INIS)

Diaconescu, D.-E.; Dijkgraaf, R.; Donagi, R.; Hofman, C.; Pantev, T.

2006-01-01

We consider B-model large N duality for a new class of noncompact Calabi-Yau spaces modeled on the neighborhood of a ruled surface in a Calabi-Yau threefold. The closed string side of the transition is governed at genus zero by an A 1 Hitchin integrable system on a genus g Riemann surface Σ. The open string side is described by a holomorphic Chern-Simons theory which reduces to a generalized matrix model in which the eigenvalues lie on the compact Riemann surface Σ. We show that the large N planar limit of the generalized matrix model is governed by the same A 1 Hitchin system therefore proving genus zero large N duality for this class of transitions

Liquid-liquid phase transition and glass transition in a monoatomic model system.

Science.gov (United States)

Xu, Limei; Buldyrev, Sergey V; Giovambattista, Nicolas; Stanley, H Eugene

2010-01-01

We review our recent study on the polyamorphism of the liquid and glass states in a monatomic system, a two-scale spherical-symmetric Jagla model with both attractive and repulsive interactions. This potential with a parametrization for which crystallization can be avoided and both the glass transition and the liquid-liquid phase transition are clearly separated, displays water-like anomalies as well as polyamorphism in both liquid and glassy states, providing a unique opportunity to study the interplay between the liquid-liquid phase transition and the glass transition. Our study on a simple model may be useful in understanding recent studies of polyamorphism in metallic glasses.

Liquid-Liquid Phase Transition and Glass Transition in a Monoatomic Model System

Directory of Open Access Journals (Sweden)

Nicolas Giovambattista

2010-12-01

Full Text Available We review our recent study on the polyamorphism of the liquid and glass states in a monatomic system, a two-scale spherical-symmetric Jagla model with both attractive and repulsive interactions. This potential with a parametrization for which crystallization can be avoided and both the glass transition and the liquid-liquid phase transition are clearly separated, displays water-like anomalies as well as polyamorphism in both liquid and glassy states, providing a unique opportunity to study the interplay between the liquid-liquid phase transition and the glass transition. Our study on a simple model may be useful in understanding recent studies of polyamorphism in metallic glasses.

Sustainability and deliberate transition of socio-technical systems

DEFF Research Database (Denmark)

Hansen, Ole Erik; Søndergård, Bent; Stærdahl, Jens

or developing socio-technical systems in order to integrate the concept of sustainability as a driver for the deliberate and purposeful shaping and transition. The article discusses the requirements to effective governance networks and governing of governance networks. Research within innovation systems......The article suggests that deliberate planning for sustainability demands a focus on the transition of socio-technical systems in order to establish robust and more sustainable patterns of production and consumption. This implies the necessity of a new perspective for environmental planning......, transition management and technology systems combined with planning and experimental activities provides both a theoretical and empirical body of knowledge of such governance processes. The article discusses how this perspective can be used in relation to the process of developing bio-fuel systems...

Architecture of Kepler's Multi-transiting Systems: II. New investigations with twice as many candidates

Energy Technology Data Exchange (ETDEWEB)

Fabrycky, Daniel C.; Lissauer, Jack J.; Ragozzine, Darin; Rowe, Jason F.; Steffen, Jason H.; Agol, Eric; Barclay, Thomas; Batalha, Natalie; Borucki, William; Ciardi, David R.; Ford, Eric B.; Gautier, Thomas N.; Geary, John C.; Holman, Matthew J.; Jenkins, Jon M.; Li, Jie; Morehead, Robert C.; Morris, Robert L.; Shporer, Avi; Smith, Jeffrey C.; Still, Martin; Van Cleve, Jeffrey

2014-07-16

Having discovered 885 planet candidates in 361 multiple-planet systems, Kepler has made transits a powerful method for studying the statistics of planetary systems. The orbits of only two pairs of planets in these candidate systems are apparently unstable. This indicates that a high percentage of the candidate systems are truly planets orbiting the same star, motivating physical investigations of the population. Pairs of planets in this sample are typically not in orbital resonances. However, pairs with orbital period ratios within a few percent of a first-order resonance (e.g. 2:1, 3:2) prefer orbital spacings just wide of the resonance and avoid spacings just narrow of the resonance. Finally, we investigate mutual inclinations based on transit duration ratios. We infer that the inner planets of pairs tend to have a smaller impact parameter than their outer companions, suggesting these planetary systems are typically coplanar to within a few degrees.

Chiral-glass transition in a diluted dipolar-interaction Heisenberg system

International Nuclear Information System (INIS)

Zhang Kaicheng; Liu Guibin; Zhu Yan

2011-01-01

Recently, numerical simulations reveal that a spin-glass transition can occur in the three-dimensional diluted dipolar system. By defining the chirality of triple spins in a diluted dipolar Heisenberg spin glass, we study the chiral ordering in the system using parallel tempering algorithm and heat bath method. The finite-size scaling analysis reveals that the system undergoes a chiral-glass transition at finite temperature. - Highlights: → We define the chirality in a diluted dipolar Heisenberg system. → The system undergoes a chiral-glass transition at finite temperature. → We extract the critical exponents of the chiral-glass transition.

Architecture of Kepler's multi-transiting systems. II. New investigations with twice as many candidates

Energy Technology Data Exchange (ETDEWEB)

Fabrycky, Daniel C. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Lissauer, Jack J.; Rowe, Jason F.; Barclay, Thomas; Batalha, Natalie; Borucki, William; Jenkins, Jon M.; Li, Jie; Morris, Robert L.; Smith, Jeffrey C. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ragozzine, Darin; Geary, John C.; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Agol, Eric [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, 770 South Wilson Avenue, MC 100-2, Pasadena, CA 91125 (United States); Ford, Eric B.; Morehead, Robert C. [Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802 (United States); Gautier, Thomas N.; Shporer, Avi, E-mail: fabrycky@uchicago.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); and others

2014-08-01

We report on the orbital architectures of Kepler systems having multiple-planet candidates identified in the analysis of data from the first six quarters of Kepler data and reported by Batalha et al. (2013). These data show 899 transiting planet candidates in 365 multiple-planet systems and provide a powerful means to study the statistical properties of planetary systems. Using a generic mass-radius relationship, we find that only two pairs of planets in these candidate systems (out of 761 pairs total) appear to be on Hill-unstable orbits, indicating ∼96% of the candidate planetary systems are correctly interpreted as true systems. We find that planet pairs show little statistical preference to be near mean-motion resonances. We identify an asymmetry in the distribution of period ratios near first-order resonances (e.g., 2:1, 3:2), with an excess of planet pairs lying wide of resonance and relatively few lying narrow of resonance. Finally, based upon the transit duration ratios of adjacent planets in each system, we find that the interior planet tends to have a smaller transit impact parameter than the exterior planet does. This finding suggests that the mode of the mutual inclinations of planetary orbital planes is in the range 1.°0-2.°2, for the packed systems of small planets probed by these observations.

Architecture of Kepler's multi-transiting systems. II. New investigations with twice as many candidates

International Nuclear Information System (INIS)

Fabrycky, Daniel C.; Lissauer, Jack J.; Rowe, Jason F.; Barclay, Thomas; Batalha, Natalie; Borucki, William; Jenkins, Jon M.; Li, Jie; Morris, Robert L.; Smith, Jeffrey C.; Ragozzine, Darin; Geary, John C.; Holman, Matthew J.; Steffen, Jason H.; Agol, Eric; Ciardi, David R.; Ford, Eric B.; Morehead, Robert C.; Gautier, Thomas N.; Shporer, Avi

2014-01-01

We report on the orbital architectures of Kepler systems having multiple-planet candidates identified in the analysis of data from the first six quarters of Kepler data and reported by Batalha et al. (2013). These data show 899 transiting planet candidates in 365 multiple-planet systems and provide a powerful means to study the statistical properties of planetary systems. Using a generic mass-radius relationship, we find that only two pairs of planets in these candidate systems (out of 761 pairs total) appear to be on Hill-unstable orbits, indicating ∼96% of the candidate planetary systems are correctly interpreted as true systems. We find that planet pairs show little statistical preference to be near mean-motion resonances. We identify an asymmetry in the distribution of period ratios near first-order resonances (e.g., 2:1, 3:2), with an excess of planet pairs lying wide of resonance and relatively few lying narrow of resonance. Finally, based upon the transit duration ratios of adjacent planets in each system, we find that the interior planet tends to have a smaller transit impact parameter than the exterior planet does. This finding suggests that the mode of the mutual inclinations of planetary orbital planes is in the range 1.°0-2.°2, for the packed systems of small planets probed by these observations.

Transition towards Circular Economy in the Food System

Directory of Open Access Journals (Sweden)

Alexandra Jurgilevich

2016-01-01

Full Text Available Growing population and increased demand for food, inefficient resource use and food distribution, environmental impacts, and high rates of food wasted at all stages of the food system are all calling for transition towards more sustainable practices. In this article we apply the concept of circular economy to the case of a sustainable food system. Furthermore, we explore the transition towards a circular food system through the lens of socio-technical transition theory towards sustainability. We discuss challenges and potential solutions for the production stage (focusing on nutrient flow, the consumption stage (focusing on meat consumption, and food waste and surplus management and prevention.

Effects of stressor characteristics on early warning signs of critical transitions and "critical coupling" in complex dynamical systems.

Science.gov (United States)

Blume, Steffen O P; Sansavini, Giovanni

2017-12-01

Complex dynamical systems face abrupt transitions into unstable and catastrophic regimes. These critical transitions are triggered by gradual modifications in stressors, which push the dynamical system towards unstable regimes. Bifurcation analysis can characterize such critical thresholds, beyond which systems become unstable. Moreover, the stochasticity of the external stressors causes small-scale fluctuations in the system response. In some systems, the decomposition of these signal fluctuations into precursor signals can reveal early warning signs prior to the critical transition. Here, we present a dynamical analysis of a power system subjected to an increasing load level and small-scale stochastic load perturbations. We show that the auto- and cross-correlations of bus voltage magnitudes increase, leading up to a Hopf bifurcation point, and further grow until the system collapses. This evidences a gradual transition into a state of "critical coupling," which is complementary to the established concept of "critical slowing down." Furthermore, we analyze the effects of the type of load perturbation and load characteristics on early warning signs and find that gradient changes in the autocorrelation provide early warning signs of the imminent critical transition under white-noise but not for auto-correlated load perturbations. Furthermore, the cross-correlation between all voltage magnitude pairs generally increases prior to and beyond the Hopf bifurcation point, indicating "critical coupling," but cannot provide early warning indications. Finally, we show that the established early warning indicators are oblivious to limit-induced bifurcations and, in the case of the power system model considered here, only react to an approaching Hopf bifurcation.

Symmetry and Phase Transitions in Nuclei

International Nuclear Information System (INIS)

Iachello, F.

2009-01-01

Phase transitions in nuclei have received considerable attention in recent years, especially after the discovery that, contrary to expectations, systems at the critical point of a phase transition display a simple structure. In this talk, quantum phase transitions (QPT), i.e. phase transitions that occur as a function of a coupling constant that appears in the quantum Hamiltonian, H, describing the system, will be reviewed and experimental evidence for their occurrence in nuclei will be presented. The phase transitions discussed in the talk will be shape phase transitions. Different shapes have different symmetries, classified by the dynamic symmetries of the Interacting Boson Model, U(5), SU(3) and SO(6). Very recently, the concept of Quantum Phase Transitions has been extended to Excited State Quantum Phase Transitions (ESQPT). This extension will be discussed and some evidence for incipient ESQPT in nuclei will be presented. Systems at the critical point of a phase transition are called 'critical systems'. Approximate analytic formulas for energy spectra and other properties of 'critical nuclei', in particular for nuclei at the critical point of the second order U(5)-SO(6) transition, called E(5), and along the line of first order U(5)-SU(3) transitions, called X(5), will be presented. Experimental evidence for 'critical nuclei' will be also shown. Finally, the microscopic derivation of shape phase transitions in nuclei within the framework of density functional methods will be briefly discussed.(author)

Quantum phase transitions of strongly correlated electron systems

International Nuclear Information System (INIS)

Imada, Masatoshi

1998-01-01

Interacting electrons in solids undergo various quantum phase transitions driven by quantum fluctuations. The quantum transitions take place at zero temperature by changing a parameter to control quantum fluctuations rather than thermal fluctuations. In contrast to classical phase transitions driven by thermal fluctuations, the quantum transitions have many different features where quantum dynamics introduces a source of intrinsic fluctuations tightly connected with spatial correlations and they have been a subject of recent intensive studies as we see below. Interacting electron systems cannot be fully understood without deep analyses of the quantum phase transitions themselves, because they are widely seen and play essential roles in many phenomena. Typical and important examples of the quantum phase transitions include metal-insulator transitions, (2, 3, 4, 5, 6, 7, 8, 9) metal-superconductor transitions, superconductor-insulator transitions, magnetic transitions to antiferromagnetic or ferromagnetic phases in metals as well as in Mott insulators, and charge ordering transitions. Here, we focus on three different types of transitions

75 FR 62695 - Physical Protection of Irradiated Reactor Fuel in Transit

Science.gov (United States)

2010-10-13

... Irradiated Reactor Fuel in Transit AGENCY: Nuclear Regulatory Commission. ACTION: Proposed rule. SUMMARY: The... nuclear fuel in transit? H. Why require a telemetric position monitoring system or an alternative tracking... nuclear fuel in transit. The interim final rule added 10 CFR 73.37, ``Requirements for Physical Protection...

Atomic final-state effects in nuclear transitions

International Nuclear Information System (INIS)

Griffiths, A.; Vogel, P.

1991-01-01

The interaction of a nuclear gamma radiation with the atomic electron cloud gives rise to a phase shift in the nuclear electromagnetic transition amplitude. The resulting interference parameters ξ(πL) are of significance to the analysis of time-reversal experiments. We calculate these parameters for E1, E2, E3, M1, and M2 gamma transitions in a number of nuclei. We also discuss the implication of these results for simultaneous parity- and time-reversal-violating experiments

Hidden Challenges to Education Systems in Transition Economies.

Science.gov (United States)

Berryman, Sue E.

This book, published by the World Bank, sounds the alarm for education in Europe and Central Asia (ECA). It describes how the transition from communism to free-market economies has left many countries' educational systems in disarray. At the start of transition, ECA education systems had solved problems that plagued other regions of the world,…

A Complete Approximation Theory for Weighted Transition Systems

DEFF Research Database (Denmark)

Hansen, Mikkel; Larsen, Kim Guldstrand; Mardare, Radu Iulian

2016-01-01

We propose a way of reasoning about minimal and maximal values of the weights of transitions in a weighted transition system (WTS). This perspective induces a notion of bisimulation that is coarser than the classic bisimulation: it relates states that exhibit transitions to bisimulation classes...... the image-finiteness restriction, a fact that makes this development general and robust....

Modeling high-order synchronization epochs and transitions in the cardiovascular system

Science.gov (United States)

García-Álvarez, David; Bahraminasab, Alireza; Stefanovska, Aneta; McClintock, Peter V. E.

2007-12-01

We study a system consisting of two coupled phase oscillators in the presence of noise. This system is used as a model for the cardiorespiratory interaction in wakefulness and anaesthesia. We show that longrange correlated noise produces transitions between epochs with different n:m synchronisation ratios, as observed in the cardiovascular system. Also, we see that, the smaller the noise (specially the one acting on the slower oscillator), the bigger the synchronisation time, exactly as happens in anaesthesia compared with wakefulness. The dependence of the synchronisation time on the couplings, in the presence of noise, is studied; such dependence is softened by low-frequency noise. We show that the coupling from the slow oscillator to the fast one (respiration to heart) plays a more important role in synchronisation. Finally, we see that the isolines with same synchronisation time seem to be a linear combination of the two couplings.

H2 Control for the Continuous-Time Markovian Jump Linear Uncertain Systems with Partly Known Transition Rates and Input Quantization

Directory of Open Access Journals (Sweden)

Xin-Gang Zhao

2013-01-01

Full Text Available For a class of continuous-time Markovian jump linear uncertain systems with partly known transition rates and input quantization, the H2 state-feedback control design is considered. The elements in the transition rates matrix include completely known, boundary known, and completely unknown ones. First, an H2 cost index for Markovian jump linear uncertain systems is introduced; then by introducing a new matrix inequality condition, sufficient conditions are formulated in terms of linear matrix inequalities (LMIs for the H2 control of the Markovian jump linear uncertain systems. Less conservativeness is achieved than the result obtained with the existing technique. Finally, a numerical example is given to verify the validity of the theoretical results.

Dynamical Detection of Topological Phase Transitions in Short-Lived Atomic Systems

OpenAIRE

Setiawan, F.; Sengupta, K.; Spielman, I. B.; Sau, Jay D.

2015-01-01

We demonstrate that dynamical probes provide direct means of detecting the topological phase transition (TPT) between conventional and topological phases, which would otherwise be difficult to access because of loss or heating processes. We propose to avoid such heating by rapidly quenching in and out of the short-lived topological phase across the transition that supports gapless excitations. Following the quench, the distribution of excitations in the final conventional phase carries signat...

Transitivity and ergodicity of quantum systems

International Nuclear Information System (INIS)

Narnhofer, H.; Thirring, W.; Wiklicky, H.

1987-01-01

First we try to generalize the notion of a topological transitive or a topologically mixing system for quantum mechanical systems in a consistent way. Furthermore we compare these ergodic properties with the classical results. Finaly we deal with some aspects of nearly abelian systems and investigate some relations between these notions. 11 refs. (Author)

Analysis of developed transition road safety barrier systems.

Science.gov (United States)

Soltani, Mehrtash; Moghaddam, Taher Baghaee; Karim, Mohamed Rehan; Sulong, N H Ramli

2013-10-01

Road safety barriers protect vehicles from roadside hazards by redirecting errant vehicles in a safe manner as well as providing high levels of safety during and after impact. This paper focused on transition safety barrier systems which were located at the point of attachment between a bridge and roadside barriers. The aim of this study was to provide an overview of the behavior of transition systems located at upstream bridge rail with different designs and performance levels. Design factors such as occupant risk and vehicle trajectory for different systems were collected and compared. To achieve this aim a comprehensive database was developed using previous studies. The comparison showed that Test 3-21, which is conducted by impacting a pickup truck with speed of 100 km/h and angle of 25° to transition system, was the most severe test. Occupant impact velocity and ridedown acceleration for heavy vehicles were lower than the amounts for passenger cars and pickup trucks, and in most cases higher occupant lateral impact ridedown acceleration was observed on vehicles subjected to higher levels of damage. The best transition system was selected to give optimum performance which reduced occupant risk factors using the similar crashes in accordance with Test 3-21. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Framework for Supporting Organizational Transition Processes Towards Sustainable Energy Systems

Science.gov (United States)

Buch, Rajesh

organizational transition processes towards sustainable energy systems, using systems and stakeholder mapping, participatory envisioning, and sustainability assessment to prepare the development of transition strategies towards realizing long-term energy sustainability. The energy system at Arizona State University's Tempe campus (ASU) in 2008 was used as a baseline to evaluate the sustainability of the current system. From interviews and participatory workshops, energy system stakeholders provided information to map the current system and measure its performance. Utilizing operationalized principles of energy sustainability, stakeholders envisioned a future sustainable state of the energy system, and then developed strategies to begin transition of the current system to its potential future sustainable state. Key findings include stakeholders recognizing that the current energy system is unsustainable as measured against principles of energy sustainability and an envisioned future sustainable state of the energy system. Also, insufficient governmental stakeholder engagement upstream within the current system could lead to added risk as regulations affect energy supply. Energy demand behavior and consumption patterns are insufficiently understood by current stakeholders, limiting participation and accountability from consumers. In conclusion, although this research study focused on the Tempe campus, ASU could apply this process to other campuses thereby improving overall ASU energy system sustainability. Expanding stakeholder engagement upstream within the energy system and better understanding energy consumption behavior can also improve long-term energy sustainability. Finally, benchmarking ASU's performance against its peer universities could expand the current climate commitment of participants to broader sustainability goals.

Theory of the transition temperature of superconducting amorphous transition metals

International Nuclear Information System (INIS)

Zwicknagel, G.

1979-11-01

In the present paper first the transition temperature Tsub(c) is shown to be a local quantity, which depends on the (average) short range order, and second it is demonstrated how to calculate local electronic properties in the framework of a short range order model and the transition temperature of amorphous systems based on accepted structure models of the amorphous state. In chapter I the theoretical basis of this work is presented in brief. The model used to study the role of short range order (in periodically ordered as well as in disordered system) is described in chapter II. The results of this model for the periodically ordered case are compared in chapter III with band structure calculations. In chapter IV it is shown how to establish short range order models for disordered systems and what kind of information can be obtained with respect to the electronic properties. Finally in chapter V it is discussed to what extend the interpretation of the transition temperature Tsub(c) as being determined by short range order effects can be supported by the electronic properties, which are calculated in the chapters III and IV. (orig.) [de

Final focus systems for linear colliders

International Nuclear Information System (INIS)

Helm, R.; Irwin, J.

1992-08-01

Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We will outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We will discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread, bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, will be described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC will be given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC)

Final focus systems for linear colliders

International Nuclear Information System (INIS)

Helm, R.; Irwing, J.

1992-01-01

Final focus systems for linear colliders present many exacting challenges in beam optics, component design, and beam quality. Efforts to resolve these problems as they relate to a new generation of linear colliders are under way at several laboratories around the world. We outline criteria for final focus systems and discuss the current state of understanding and resolution of the outstanding problems. We discuss tolerances on alignment, field quality and stability for optical elements, and the implications for beam parameters such as emittance, energy spread , bunch length, and stability in position and energy. Beam-based correction procedures, which in principle can alleviate many of the tolerances, are described. Preliminary results from the Final Focus Test Beam (FFTB) under construction at SLAC are given. Finally, we mention conclusions from operating experience at the Stanford Linear Collider (SLC). (Author) 16 refs., 4 tabs., 6 figs

TRANSITIONING BEYOND UNDERGRADUATE HOSPITALITY EDUCATION; A DIALOGIC ANALYSIS OF FINAL YEAR HOSPITALITY STUDENTS’ NARRATIVES OF EMPLOYABILITY

OpenAIRE

Hine, Catherine

2017-01-01

Employability has become a key consideration for graduates, and society. Increasingly the trajectory of individuals at age 18 involves the completion of an undergraduate level degree qualification. This thesis presents a sociologically grounded study into the dialogic construction of employability in final year hospitality students and recent hospitality graduates. Drawing on a nationwide sample of UK based hospitality graduates, as they transition beyond undergraduate level higher educati...

Successfulness of bus rapid transit systems in Asia. Ex-post evaluation

NARCIS (Netherlands)

Kogdenko, Nadja

2010-01-01

SUMMARY Bus Rapid Transit (BRT) can be defined as “a bus-based mass transit system that delivers fast, comfortable, and cost-effective urban mobility”. It offers the opportunity to create a high-quality mass transit system at affordable costs, which is p

A Decidable Recursive Logic for Weighted Transition Systems

DEFF Research Database (Denmark)

Xue, Bingtian; Larsen, Kim Guldstrand; Mardare, Radu Iulian

2014-01-01

In this paper we develop and study the Recursive Weighted Logic (RWL), a multi-modal logic that expresses qualitative and quantitative properties of labelled weighted transition systems (LWSs). LWSs are transition systems labelled with actions and real-valued quantities representing the costs of ...... extends previous results that we have demonstrated for a similar but much more restrictive logic that can only use one variable for each type of resource to encode logical properties....

Simulations of phase transitions in ionic systems

International Nuclear Information System (INIS)

Panagiotopoulos, A Z

2005-01-01

A review of recent simulation work in the area of phase transitions in ionic systems is presented. The vapour-liquid transition for the restricted primitive model has been studied extensively in the past decade. The critical temperature is now known to excellent accuracy and the critical density to moderate accuracy. There is also strong simulation-based evidence that the model is in the Ising universality class. Discretized lattice versions of the model are reviewed. Other systems covered are size- and charge-asymmetric electrolytes, colloid-salt mixtures, realistic salt models and charged chains. Areas of future research needs are briefly discussed

Work plan for transition of SY-101 hydrogen mitigation test project data acquisition and control system (DACS-1)

International Nuclear Information System (INIS)

McClees, J.; Truitt, R.W.

1994-01-01

The purpose of this effort is to transfer operating and maintenance responsibility for the 241-SY-101 data acquisition and control system (DACS-1) from Los Alamos National Laboratory to Westinghouse Hanford Company. This work plan defines the tasks required for a successful turnover. It identifies DACS-1 transition, deliverables, responsible organizations and individuals, interfaces, cost, and schedule. The transition plan will discuss all required hardware, software, documentation, maintenance, operations, and training for use at Hanford Waste Tank 241-SY-101. The transfer of responsibilities for DACS-1 to WHC is contingent on final approval of applicable Acceptance for Beneficial Use documentation by Waste Tank Operations. The DACS-1 was designed to provide data monitoring, display, and storage for Tank 241-SY-101. The DACS-1 also provides alarm and control of all the hydrogen mitigation testing systems, as well as ancillary systems and equipment (HVAC, UPS, etc.) required to achieve safe and reliable operation of the testing systems in the tank

Thermal study of monovalent-divalent phase transition in npBifc-F1TCNQ System

International Nuclear Information System (INIS)

Sato, Michiko; Nishio, Yutaka; Kajita, Koji; Mochida, Tomoyuki

2009-01-01

In a new molecular solid composed of di-neopentyl-biferrocene (npBifc) and fluorotetracyanoquinodimethane (F 1 TCNQ) 3 , Mochida reported the discovery of a reversible valence transfer that can be regarded as an 'ionic(I)-ionic(II)' phase transfer between the monovalent state (D + A - ) and the divalent state (D 2+ A 2- ). We have studied thermo-dynamical properties of this transformation for this complex using the differential thermal analyses (DTA). We observed a broad excess specific heat with multi-peaks attributed to micro-domain structure over the corresponding temperature range (100-150K) accompanied by temperature hysteresis of 7K. The transition entropy (ΔS) was determined to be 22 ± 2 J/mol-K and almost satisfied a Clausius-Clapeyron relation. These experimental results provide an experimental confirmation of the first order phase transition for the monovalent-divalent transfer. At the transition, we observe that the electronic degrees of freedom remained constant values, while large entropy absorbed crossing from low temperature phase to high temperature one is contributed by the lattice one. We finally estimated the internal energy and concluded that delicate energy valance between Madelung, ionization and affinity energies enable this system to exhibit a temperature induce monovalent-divalent phase transition.

Best practices in transit service planning : final report, March 2009.

Science.gov (United States)

2009-03-01

The provision of cost efficient and effective bus transit service is the basic premise upon which transit service is developed and the goal that all public transportations agencies strive to achieve. To attain this goal, public transit agencies must ...

The Topological Analysis of Urban Transit System as a Small-World Network

OpenAIRE

Zhaosheng Yang; Huxing Zhou; Peng Gao; Hong Chen; Nan Zhang

2011-01-01

This paper proposes a topological analysis of urban transit system based on a functional representation network constructed from the urban transit system in Beijing. The representation gives a functional view on nodes named a transit line. Statistical measures are computed and introduced in complex network analysis. It shows that the urban transit system forms small-world networks and exhibits properties different from random networks and regular networks. Furthermore, the topological propert...

Transitions amongst synchronous solutions in the stochastic Kuramoto model

Science.gov (United States)

DeVille, Lee

2012-05-01

We consider the Kuramoto model of coupled oscillators with nearest-neighbour coupling and additive white noise. We show that synchronous solutions which are stable without the addition of noise become metastable and that we have transitions amongst synchronous solutions on long timescales. We compute these timescales and, moreover, compute the most likely path in phase space that transitions will follow. We show that these transition timescales do not increase as the number of oscillators in the system increases, and are roughly constant in the system size. Finally, we show that the transitions correspond to a splitting of one synchronous solution into two communities which move independently for some time and which rejoin to form a different synchronous solution.

Modeling and evaluation of characteristics for on-street Rapid Transit systems

DEFF Research Database (Denmark)

Andersen, Jonas Lohmann Elkjær; Landex, Alex

2012-01-01

to obtain the main objective of introducing a Rapid Transit System. to increase the number of passengers. Variations in the system characteristics have a direct impact on ridership. However, it is difficult to predict the impact of implementing or altering the characteristics. A Rapid Transit system should...... display sufficient service already in the planning phase. That is why pre-acquired knowledge of the impact of the characteristics on the system performance is valuable. Such knowledge could provide a firm basis for planning the service and operation of a Rapid Transit system. This article focuses....... It focuses on the following characteristics for Rapid Transit systems: rail factor, travel time, headway and capacity. It evaluates how the implementation and variation of these characteristics affected the ridership of a case project. It evaluates the magnitude of the impacts for the various characteristics...

Patient care information systems and physicians: the transition from technology icon to health care instrument.

Science.gov (United States)

Bria, W F

1993-11-01

We have discussed several important transitions now occurring in PCIS that promise to improve the utility and availability of these systems for the average physician. Charles Babbage developed the first computers as "thinking machines" so that we may extend our ability to grapple with more and more complex problems. If current trends continue, we will finally witness the evolution of patient care computing from information icons of the few to clinical instruments improving the quality of medical decision making and care for all patients.

Refinement Checking on Parametric Modal Transition Systems

DEFF Research Database (Denmark)

Benes, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

2015-01-01

Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects in the refin...

Verifying duration properties of timed transition systems

DEFF Research Database (Denmark)

Liu, Zhiming; Ravn, Anders P.; Li, Xiaoshan

1998-01-01

This paper proposes a method for formal real-time systems development:Requirements and high level design decisions are time interval properties and are therefore specified in the Duration Calculus (DC), while implementations are described bytimed transition systems (TTS). A link from implementati...

Transition Theory – Sustainable Transition of Socio-Technical Systems

DEFF Research Database (Denmark)

Søndergård, Bent; Holm, Jesper; Stauning, Inger

2015-01-01

Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction......Theories of transition management, transition studies and social practise theory Applied to studies of hosuing and construction...

Modal Transition Systems as the Basis for Interface Theories and Product Lines

DEFF Research Database (Denmark)

Nyman, Ulrik

and a subset of modal transition systems is proved. The developed interface theory, which can describe liveness properties, is also applied as a behavioral variability theory for product line development. The two last papers of the thesis concern themselves with modal and mixed transition systems. The first....... It also proves PSPACE-hardness for consistency of mixed specifications and establishes a number of reductions between the different decision problems. Keywords: Modeling, Software Product Lines, Embedded Software, Modal Refinement, Labeled Transition Systems, Modal Transition Systems, Mixed Transition......This thesis presents research taking its outset in component-based software development, interface theory and software product lines, as well as modeling formalisms for describing component based software systems and their interfaces. The main part of the thesis consists of five papers. The first...

Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system.

Science.gov (United States)

Worsøe, Jonas; Fynne, Lotte; Gregersen, Tine; Schlageter, Vincent; Christensen, Lisbet A; Dahlerup, Jens F; Rijkhoff, Nico J M; Laurberg, Søren; Krogh, Klaus

2011-12-29

Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, φ). Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state. Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1) (p = 0.03). MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system

Directory of Open Access Journals (Sweden)

WorsØe Jonas

2011-12-01

Full Text Available Abstract Background Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. Methods A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4 giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, ϕ. Eight healthy subjects were each investigated three times: (1 with a small magnet mounted on a capsule endoscope (PillCam; (2 with the magnet alone and the small intestine in the fasting state; and (3 with the magnet alone and the small intestine in the postprandial state. Results Experiment (1 showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min and small intestinal transit time (median difference 0.5 min; range: 0-52 min. Comparing experiments (1 and (2 there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2 and (3, short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1 (p = 0.03. Conclusion MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.

A Framework for Relating Timed Transition Systems and Preserving TCTL Model Checking

DEFF Research Database (Denmark)

Jacobsen, Lasse; Jacobsen, Morten; Møller, Mikael Harkjær

2010-01-01

Many formal translations between time dependent models have been proposed over the years. While some of them produce timed bisimilar models, others preserve only reachability or (weak) trace equivalence. We suggest a general framework for arguing when a translation preserves Timed Computation Tree...... Logic (TCTL) or its safety fragment.The framework works at the level of timed transition systems, making it independent of the modeling formalisms and applicable to many of the translations published in the literature. Finally, we present a novel translation from extended Timed-Arc Petri Nets...... to Networks of Timed Automata and using the framework argue that itpreserves the full TCTL. The translation has been implemented in the verification tool TAPAAL....

Final Report on DE-FG02-04ER46107: Glasses, Noise and Phase Transitions

Energy Technology Data Exchange (ETDEWEB)

Yu, Clare C. [Univ. of California, Irvine, CA (United States)

2011-12-31

We showed that noise has distinct signatures at phase transitions in spin systems. We also studied charge noise, critical current noise, and flux noise in superconducting qubits and Josephson junctions.

TRANSITIONAL DISKS AS SIGNPOSTS OF YOUNG, MULTIPLANET SYSTEMS

International Nuclear Information System (INIS)

Dodson-Robinson, Sarah E.; Salyk, Colette

2011-01-01

Although there has yet been no undisputed discovery of a still-forming planet embedded in a gaseous protoplanetary disk, the cleared inner holes of transitional disks may be signposts of young planets. Here, we show that the subset of accreting transitional disks with wide, optically thin inner holes of 15 AU or more can only be sculpted by multiple planets orbiting inside each hole. Multiplanet systems provide two key ingredients for explaining the origins of transitional disks. First, multiple planets can clear wide inner holes where single planets open only narrow gaps. Second, the confined, non-axisymmetric accretion flows produced by multiple planets provide a way for an arbitrary amount of mass transfer to occur through an apparently optically thin hole without overproducing infrared excess flux. Rather than assuming that the gas and dust in the hole are evenly and axisymmetrically distributed, one can construct an inner hole with apparently optically thin infrared fluxes by covering a macroscopic fraction of the hole's surface area with locally optically thick tidal tails. We also establish that other clearing mechanisms, such as photoevaporation, cannot explain our subset of accreting transitional disks with wide holes. Transitional disks are therefore high-value targets for observational searches for young planetary systems.

Discontinuous and heterogeneous glass transition behavior of carbohydrate polymer-plasticizer systems.

Science.gov (United States)

Kawai, Kiyoshi; Hagura, Yoshio

2012-07-01

In order to understand the glass transition properties of carbohydrate polymer-plasticizer systems, glass transition temperatures of dextrin-glucose and dextrin-maltose systems were investigated systematically using differential scanning calorimetry. The onset (Tg(on)) and offset (Tg(off)) of the glass transition decreased with increasing plasticizer (glucose or maltose) content, and showed an abrupt depression at certain plasticizer content. The abrupt depression of Tg(off) occurred at higher plasticizer content than that of Tg(on). The glass transition was much broader for intermediate plasticizer content. From the enthalpy relaxation behavior of samples aged at various temperatures, it was found that two different glass transitions occurred contentiously in the broad glass transition. These results suggested that carbohydrate polymer-plasticizer systems can be classified into three regions: the entrapment of the plasticizer by the polymer, the formations of the polymer-plasticizer and plasticizer-rich domains, and the embedment of polymer into the plasticizer. Copyright © 2012 Elsevier Ltd. All rights reserved.

Phase transitions in two-dimensional systems

International Nuclear Information System (INIS)

Salinas, S.R.A.

1983-01-01

Some experiences are related using synchrotron radiation beams, to characterize solid-liquid (fusion) and commensurate solid-uncommensurate solid transitions in two-dimensional systems. Some ideas involved in the modern theories of two-dimensional fusion are shortly exposed. The systems treated consist of noble gases (Kr,Ar,Xe) adsorbed in the basal plane of graphite and thin films formed by some liquid crystal shells. (L.C.) [pt

Investigating Extra-solar Planetary System Qatar-1 through Transit Observations

Science.gov (United States)

Thakur, Parijat; Mannaday, Vineet Kumar; Jiang, Ing-Guey; Sahu, Devendra Kumar; Chand, Swadesh

2018-04-01

We report the results of the transit timing variation (TTV) analysis of the extra-solar planet Qatar-1b using thirty eight light curves. Our analysis combines thirty five previously available transit light curves with three new transits observed by us between June 2016 and September 2016 using the 2-m Himalayan Chandra Telescope (HCT) at the Indian Astronomical Observatory (Hanle, India). From these transit data, the physical and orbital parameters of the Qatar-1 system are determined. In addition to this, the ephemeris for the orbital period and mid-transit time are refined to investigate the possible TTV. We find that the null-TTV model provides the better fit to the (O-C) data. This indicates that there is no evidence for TTVs to confirm the presence of additional planets in the Qatar-1 system. The use of the 3.6-m Devasthal Optical Telescope (DOT) operated by the Aryabhatta Research Institute of Observational Sciences (ARIES, Nainital, India) could improve the photometric precision to examine the signature of TTVs in this system with a greater accuracy than in the present work.

FTA real-time transit information assessment : white paper on literature review of real-time transit information systems.

Science.gov (United States)

Real-time transit information systems are key technology applications within the transit industry designed to provide better customer service by disseminating timely and accurate information. Riders use this information to make various decisions abou...

Automated transit planning, operation, and applications

CERN Document Server

Liu, Rongfang

2016-01-01

This book analyzes the successful implementations of automated transit in various international locations, such as Paris, Toronto, London, and Kuala Lumpur, and investigates the apparent lack of automated transit applications in the urban environment in the United States. The book begins with a brief definition of automated transit and its historical development. After a thorough description of the technical specifications, the author highlights a few applications from each sub-group of the automated transit spectrum. International case studies display various technologies and their applications, and identify vital factors that affect each system and performance evaluations of existing applications. The book then discusses the planning and operation of automated transit applications at both macro and micro levels. Finally, the book covers a number of less successful concepts, as well as the lessons learned, allow ng readers to gain a comprehensive understanding of the topic.

Thermal study of monovalent-divalent phase transition in npBifc-F{sub 1}TCNQ System

Energy Technology Data Exchange (ETDEWEB)

Sato, Michiko; Nishio, Yutaka; Kajita, Koji [Department of Physics, Faculty of Science, Toho University, Miyama 2-2-1, Funabashi, Chiba, 274-8510 (Japan); Mochida, Tomoyuki, E-mail: nishio@ph.sci.toho-u.ac.j [Department of Chemistry, Faculty of Science, Kobe University, Rokkodai, Nada, Kobe 657-8501 (Japan)

2009-03-01

In a new molecular solid composed of di-neopentyl-biferrocene (npBifc) and fluorotetracyanoquinodimethane (F{sub 1}TCNQ){sub 3}, Mochida reported the discovery of a reversible valence transfer that can be regarded as an 'ionic(I)-ionic(II)' phase transfer between the monovalent state (D{sup +}A{sup -}) and the divalent state (D{sup 2+}A{sup 2-}). We have studied thermo-dynamical properties of this transformation for this complex using the differential thermal analyses (DTA). We observed a broad excess specific heat with multi-peaks attributed to micro-domain structure over the corresponding temperature range (100-150K) accompanied by temperature hysteresis of 7K. The transition entropy (DELTAS) was determined to be 22 +- 2 J/mol-K and almost satisfied a Clausius-Clapeyron relation. These experimental results provide an experimental confirmation of the first order phase transition for the monovalent-divalent transfer. At the transition, we observe that the electronic degrees of freedom remained constant values, while large entropy absorbed crossing from low temperature phase to high temperature one is contributed by the lattice one. We finally estimated the internal energy and concluded that delicate energy valance between Madelung, ionization and affinity energies enable this system to exhibit a temperature induce monovalent-divalent phase transition.

Restructuring energy systems for sustainability? Energy transition policy in the Netherlands

International Nuclear Information System (INIS)

Kern, Florian; Smith, Adrian

2008-01-01

Increasingly, researchers and policy makers are confronting the challenge of restructuring energy systems into more sustainable forms. A 'transition management' model, and its adoption in the Netherlands, is attracting attention. Starting from the socio-technical multi-level theory that informs 'transition management', we analyse the 'energy transition' project carried out by the Dutch Ministry of Economic Affairs. Despite considerable achievements, their approach risks capture by the incumbent energy regime, thereby undermining original policy ambitions for structural innovation of the energy system. This experience presents generic dilemmas for transitions approaches

Noise-induced transition in a quantum system

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Pulak Kumar [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Barik, Debashis [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Ray, Deb Shankar [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)

2005-07-04

We examine the noise-induced transition in a fluctuating bistable potential of a driven quantum system in thermal equilibrium. Making use of a Wigner canonical thermal distribution for description of the statistical properties of the thermal bath, we explore the generic effects of quantization like vacuum field fluctuation and tunneling in the characteristic stationary probability distribution functions undergoing transition from unimodal to bimodal nature and in signal-to-noise ratio characterizing the cooperative effect among the noise processes and the weak periodic signal.

Noise-induced transition in a quantum system

International Nuclear Information System (INIS)

Ghosh, Pulak Kumar; Barik, Debashis; Ray, Deb Shankar

2005-01-01

We examine the noise-induced transition in a fluctuating bistable potential of a driven quantum system in thermal equilibrium. Making use of a Wigner canonical thermal distribution for description of the statistical properties of the thermal bath, we explore the generic effects of quantization like vacuum field fluctuation and tunneling in the characteristic stationary probability distribution functions undergoing transition from unimodal to bimodal nature and in signal-to-noise ratio characterizing the cooperative effect among the noise processes and the weak periodic signal

Managing innovation systems in transition economies

OpenAIRE

Baković, Tomislav

2010-01-01

Successfully managing innovations has become the basic precondition for the development of both companies and national economies. At the national level governments are forming innovation systems whose primary goal is to create conditions at which science and technology can flourish and then transfer their findings trough private sector into new revolutionary products and services. Unfortunately not all countries have the same preconditions for creating such systems and transition economies du...

Fluctuating States: What is the Probability of a Thermodynamical Transition?

Directory of Open Access Journals (Sweden)

Álvaro M. Alhambra

2016-10-01

Full Text Available If the second law of thermodynamics forbids a transition from one state to another, then it is still possible to make the transition happen by using a sufficient amount of work. But if we do not have access to this amount of work, can the transition happen probabilistically? In the thermodynamic limit, this probability tends to zero, but here we find that for finite-sized and quantum systems it can be finite. We compute the maximum probability of a transition or a thermodynamical fluctuation from any initial state to any final state and show that this maximum can be achieved for any final state that is block diagonal in the energy eigenbasis. We also find upper and lower bounds on this transition probability, in terms of the work of transition. As a by-product, we introduce a finite set of thermodynamical monotones related to the thermomajorization criteria which governs state transitions and compute the work of transition in terms of them. The trade-off between the probability of a transition and any partial work added to aid in that transition is also considered. Our results have applications in entanglement theory, and we find the amount of entanglement required (or gained when transforming one pure entangled state into any other.

Final report: Properties of mixtures near a phase transition. February 1, 1992 - January 31, 1996

International Nuclear Information System (INIS)

Hanley, H.J.M.; Friend, D.G.

1999-01-01

This project emphasized the study of systems near phase transitions, and included scattering experiments, computer simulation, and theory of phase transitions. The scattering involved the use of neutrons as well as optical techniques, involved both equilibrium and sheared samples, and included conventional fluids as well as gels, micelles, colloids, and dispersions. Computer simulations and theoretical studies were completed to complement and interpret the microscopic information learned from scattering, and many successes were achieved in furthering our understanding of complex mixtures near the critical locus. The research has led to a number of technical publications and a refinement of our knowledge of phase transition phenomena which has led to improvements in available property databases

Final report : Calgary Transit customer satisfaction survey 2005

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-02-15

This survey was conducted to measure the customer satisfaction of Calgary Transit users and gather information for further service improvements. The survey was conducted by telephone with a total of 500 current customers, and results were compared with previous surveys. The average number of trips per week among regular customers was 7.6, the lowest over the past 6 years. Twenty-six per cent of customers used the service more frequently due to higher gas prices, lack of a vehicle and the higher frequency of services. While most customers used buses, there was an increase in train usage in 2005, which was attributed to an increase in service frequency. Customers typically reported travelling during rush hour periods. Transit customers assigned a global score of 8.2 for service quality satisfaction and loyalty, which was consistent with previous scores. Seventy-two per cent of customers rated service quality as excellent or good. Approximately 1 in 5 customers perceived Calgary Transit to have improved over the previous year. Nearly half of the customers identified themselves as committed users of the service compared to other transportation methods, and most customers stated that having more service during peak hours and in new communities should be priorities. Sixty-four per cent of respondents supported fare increases to fund service additions. It was concluded that there was a significant increase in overall transit use in 2005, which may have been due to its perceived convenience and the influence of economic factors. It was noted that the increase has not affected customers' perceptions of service performance. 8 tabs., 9 figs.

HATS-36b and 24 Other Transiting/Eclipsing Systems from the HATSouth-K2 Campaign 7 Program

Science.gov (United States)

Bayliss, D.; Hartman, J. D.; Zhou, G.; Bakos, G. Á.; Vanderburg, A.; Bento, J.; Mancini, L.; Ciceri, S.; Brahm, R.; Jordán, A.; Espinoza, N.; Rabus, M.; Tan, T. G.; Penev, K.; Bhatti, W.; de Val-Borro, M.; Suc, V.; Csubry, Z.; Henning, Th.; Sarkis, P.; Lázár, J.; Papp, I.; Sári, P.

2018-03-01

We report on the result of a campaign to monitor 25 HATSouth candidates using the Kepler space telescope during Campaign 7 of the K2 mission. We discover HATS-36b (EPIC 215969174b, K2-145b), an eccentric (e=0.105+/- 0.028) hot Jupiter with a mass of 3.216+/- 0.062 {M}{{J}} and a radius of 1.235+/- 0.043 {R}{{J}}, which transits a solar-type G0V star (V = 14.386) in a 4.1752-day period. We also refine the properties of three previously discovered HATSouth transiting planets (HATS-9b, HATS-11b, and HATS-12b) and search the K2 data for TTVs and additional transiting planets in these systems. In addition, we also report on a further three systems that remain as Jupiter-radius transiting exoplanet candidates. These candidates do not have determined masses, however pass all of our other vetting observations. Finally, we report on the 18 candidates that we are now able to classify as eclipsing binary or blended eclipsing binary systems based on a combination of the HATSouth data, the K2 data, and follow-up ground-based photometry and spectroscopy. These range in periods from 0.7 day to 16.7 days, and down to 1.5 mmag in eclipse depths. Our results show the power of combining ground-based imaging and spectroscopy with higher precision space-based photometry, and serve as an illustration as to what will be possible when combining ground-based observations with TESS data.

Mode-locking and the transition to chaos in dissipative systems

International Nuclear Information System (INIS)

Bak, P.; Bohr, T.; Jensen, M.H.

1984-01-01

Dissipative systems with two competing frequencies exhibit transitions to chaos. We have investigated the transition through a study of discrete maps of the circle onto itself, and by constructing and analyzing return maps of differential equations representing some physical systems. The transition is caused by interaction and overlap of mode-locked resonances and takes place at a critical line where the map losses invertibility. At this line the mode-locked intervals trace up a complete Devil's Staircase whose complementary set is a Cantor set with universal fractal dimension D approx. 0.87. Below criticality there is room for quasiperiodic orbits, whose measure is given by an exponent β approx. 0.34 which can be related to D through a scaling relation, just as for second order phase transitions. The Lebesgue measure serves as an order parameter for the transition to chaos. The resistively shunted Josephson junction, and charge density waves (CDWs) in rf electric fields are usually described by the differential equation of the damped driven pendulum. The 2d return map for this equation collapses to ld circle map at and below the transition to chaos. The theoretical results on universal behavior, derived here and elsewhere, can thus readily be checked experimentally by studying real physical systems. Recent experiments on Josephson junctions and CDWs indicating the predicted fractal scaling of mode-locking at criticality are reviewed

Dual-Priced Modal Transition Systems with Time Durations

DEFF Research Database (Denmark)

Beneš, Nikola; Kretínsky, Jan; Larsen, Kim Guldstrand

2012-01-01

Modal transition systems are a well-established specification formalism for a high-level modelling of component-based software systems. We present a novel extension of the formalism called modal transition systems with durations where time durations are modelled as controllable or uncontrollable...... intervals. We further equip the model with two kinds of quantitative aspects: each action has its own running cost per time unit, and actions may require several hardware components of different costs. We ask the question, given a fixed budget for the hardware components, what is the implementation...... with the cheapest long-run average reward. We give an algorithm for computing such optimal implementations via a reduction to a new extension of mean payoff games with time durations and analyse the complexity of the algorithm....

Climate change mitigation through livestock system transitions

Science.gov (United States)

Havlík, Petr; Valin, Hugo; Herrero, Mario; Obersteiner, Michael; Schmid, Erwin; Rufino, Mariana C.; Mosnier, Aline; Thornton, Philip K.; Böttcher, Hannes; Conant, Richard T.; Frank, Stefan; Fritz, Steffen; Fuss, Sabine; Kraxner, Florian; Notenbaert, An

2014-01-01

Livestock are responsible for 12% of anthropogenic greenhouse gas emissions. Sustainable intensification of livestock production systems might become a key climate mitigation technology. However, livestock production systems vary substantially, making the implementation of climate mitigation policies a formidable challenge. Here, we provide results from an economic model using a detailed and high-resolution representation of livestock production systems. We project that by 2030 autonomous transitions toward more efficient systems would decrease emissions by 736 million metric tons of carbon dioxide equivalent per year (MtCO2e⋅y−1), mainly through avoided emissions from the conversion of 162 Mha of natural land. A moderate mitigation policy targeting emissions from both the agricultural and land-use change sectors with a carbon price of US$10 per tCO2e could lead to an abatement of 3,223 MtCO2e⋅y−1. Livestock system transitions would contribute 21% of the total abatement, intra- and interregional relocation of livestock production another 40%, and all other mechanisms would add 39%. A comparable abatement of 3,068 MtCO2e⋅y−1 could be achieved also with a policy targeting only emissions from land-use change. Stringent climate policies might lead to reductions in food availability of up to 200 kcal per capita per day globally. We find that mitigation policies targeting emissions from land-use change are 5 to 10 times more efficient—measured in “total abatement calorie cost”—than policies targeting emissions from livestock only. Thus, fostering transitions toward more productive livestock production systems in combination with climate policies targeting the land-use change appears to be the most efficient lever to deliver desirable climate and food availability outcomes. PMID:24567375

Bisimulation and Open Maps for Timed Transition Systems

DEFF Research Database (Denmark)

Nielsen, Mogens

1999-01-01

Formal models for real-time systems have been studied intensively over the past decade. Much of the theory of untimed systems have been lifted to real-time settings. One example is the notion of bisimulation applied to timed transition systems, which is studied here within the general categorical...

Trap-size scaling in confined-particle systems at quantum transitions

International Nuclear Information System (INIS)

Campostrini, Massimo; Vicari, Ettore

2010-01-01

We develop a trap-size scaling theory for trapped particle systems at quantum transitions. As a theoretical laboratory, we consider a quantum XY chain in an external transverse field acting as a trap for the spinless fermions of its quadratic Hamiltonian representation. We discuss trap-size scaling at the Mott insulator to superfluid transition in the Bose-Hubbard model. We present exact and accurate numerical results for the XY chain and for the low-density Mott transition in the hard-core limit of the one-dimensional Bose-Hubbard model. Our results are relevant for systems of cold atomic gases in optical lattices.

Isotropic–Nematic Phase Transitions in Gravitational Systems

Energy Technology Data Exchange (ETDEWEB)

Roupas, Zacharias; Kocsis, Bence [Institute of Physics, Eötvös University, Pázmány P. s. 1/A, Budapest, 1117 (Hungary); Tremaine, Scott [Institute for Advanced Study, Princeton, NJ 08540 (United States)

2017-06-20

We examine dense self-gravitating stellar systems dominated by a central potential, such as nuclear star clusters hosting a central supermassive black hole. Different dynamical properties of these systems evolve on vastly different timescales. In particular, the orbital-plane orientations are typically driven into internal thermodynamic equilibrium by vector resonant relaxation before the orbital eccentricities or semimajor axes relax. We show that the statistical mechanics of such systems exhibit a striking resemblance to liquid crystals, with analogous ordered-nematic and disordered-isotropic phases. The ordered phase consists of bodies orbiting in a disk in both directions, with the disk thickness depending on temperature, while the disordered phase corresponds to a nearly isotropic distribution of the orbit normals. We show that below a critical value of the total angular momentum, the system undergoes a first-order phase transition between the ordered and disordered phases. At a critical point, the phase transition becomes second order, while for higher angular momenta there is a smooth crossover. We also find metastable equilibria containing two identical disks with mutual inclinations between 90° and 180°.

System and prospects of China's intercity rail transit technology

Science.gov (United States)

Gong, Ming

2018-06-01

City clusters and metropolitan areas in China are flourishing in the midst of the deepening urbanization in the country, thereby resulting in the emergence of intercity rail transit. Intercity railways connect mainline and urban railways for an integrated regional transportation system that underpins and leads the development of city clusters and metropolitan areas. This study explores the development mode and service characteristics of intercity rail transit, as well as proposes overviews on this system and prospects of its future technology in China.

Phase transitions in the urea/n-nonadecane system by calorimetric techniques

International Nuclear Information System (INIS)

Lopez-Echarri, A; Ruiz-Larrea, I; Fraile-RodrIguez, A; Diaz-Hernandez, J; Breczewski, T; Bocanegra, E H

2007-01-01

A calorimetric study of urea/n-nonadecane, CO(NH 2 ) 2 /C 19 H 40 , and the deuterated derivatives, CO(ND 2 ) 2 /C 19 D 40 and CO(NH 2 ) 2 /C 19 D 40 , around the structural phase transition temperature is presented. For this purpose differential scanning (DSC), temperature-modulated (AC) and adiabatic calorimetry have been used and the obtained results are compared. Leaving apart the noticeable peak associated with the main phase transition at 158.5, 149.4 and 154 K respectively, small anomalies of the specific heat are found at lower temperatures and their corresponding entropic and enthalpic changes are reported. Heating and cooling experiments show the influence of the temperature rate and the thermal history on the detailed profile of the specific heat traces. The presence of thermal hysteresis and latent heat as a way to characterize the order of the phase transitions is discussed. Finally, a tentative approach to the urea and the alkyl chain contributions to the specific heat and their influence on the phase transition mechanisms is presented

Some remarks on ‘superradiant’ phase transitions in light-matter systems

International Nuclear Information System (INIS)

Larson, Jonas; Irish, Elinor K

2017-01-01

In this paper we analyze properties of the phase transition that appears in a set of quantum optical models; Dicke, Tavis–Cummings, quantum Rabi, and finally the Jaynes–Cummings model. As the light-matter coupling is increased into the deep strong coupling regime, the ground state turns from vacuum to become a superradiant state characterized by both atomic and photonic excitations. It is pointed out that all four transitions are of the mean-field type, that quantum fluctuations are negligible, and hence these fluctuations cannot be responsible for the corresponding vacuum instability. In this respect, these are not quantum phase transitions. In the case of the Tavis–Cummings and Jaynes–Cummings models, the continuous symmetry of these models implies that quantum fluctuations are not only negligible, but strictly zero. However, all models possess a non-analyticity in the ground state in agreement with a continuous quantum phase transition. As such, it is a matter of taste whether the transitions should be termed quantum or not. In addition, we also consider the modifications of the transitions when photon losses are present. For the Dicke and Rabi models these non-equilibrium steady states remain critical, while the criticality for the open Tavis–Cummings and Jaynes–Cummings models is completely lost, i.e. in realistic settings one cannot expect a true critical behaviour for the two last models. (paper)

Resilience Thinking as an Interdisciplinary Guiding Principle for Energy System Transitions

Directory of Open Access Journals (Sweden)

Frauke Wiese

2016-09-01

Full Text Available Resource usage and environmental consequences of most current energy systems exceed planetary boundaries. The transition to sustainable energy systems is accompanied by a multitude of research methods, as energy systems are complex structures of technical, economical, social and ecological interactions. The description of different discipline’s perspectives in this paper show that a more mutual understanding between disciplines of their respective focus is necessary as they partly create internally competitive views arising from differing emphasis of connected matters. The purpose of this paper is to present a framework for interdisciplinary proceeding in a complex energy system transition process. Resilience thinking is chosen as a core concept for a more holistic view on sustainable energy system development. It is shown that it is already widely used in different disciplines connected to energy system research and is especially suitable due to its wide application across disciplines. The seven principles of resilience thinking (maintain redundancy and diversity, manage connectivity, manage slow variables and feedback, foster complex adaptive systems thinking, encourage learning, broaden participation, and promote polycentric governance systems are chosen as the basis for a procedure that can be utilized to increase the interdisciplinary perspectives of energy system transitions. For energy transition processes based on scenario development, backcasting and pathway definition, resilience thinking principles are used to assess the resilience of the target energy system, the pathway resilience and the design of the scenario process with respect to the probability of a resilient outcome. The described procedure consisting of questions and parameters can be applied as a first attempt for a resilience assessment of energy transition processes. The perspective of resilience in sustainable energy systems strengthens the importance of diversity

Renormalization group theory of phase transitions in square Ising systems

International Nuclear Information System (INIS)

Nienhuis, B.

1978-01-01

Some renormalization group calculations are presented on a number of phase transitions in a square Ising model, both second and first order. Of these transitions critical exponents are calculated, the amplitudes of the power law divergences and the locus of the transition. In some cases attention is paid to the thermodynamic functions also far from the critical point. Universality and scaling are discussed and the renormalization group theory is reviewed. It is shown how a renormalization transformation, which relates two similar systems with different macroscopic dimensions, can be constructed, and how some critical properties of the system follow from this transformation. Several numerical and analytical applications are presented. (Auth.)

The nuclear liquid gas phase transition and phase coexistence

International Nuclear Information System (INIS)

Chomaz, Ph.

2001-01-01

In this talk we will review the different signals of liquid gas phase transition in nuclei. From the theoretical side we will first discuss the foundations of the concept of equilibrium, phase transition and critical behaviors in infinite and finite systems. From the experimental point of view we will first recall the evidences for some strong modification of the behavior of hot nuclei. Then we will review quantitative detailed analysis aiming to evidence phase transition, to define its order and phase diagram. Finally, we will present a critical discussion of the present status of phase transitions in nuclei and we will draw some lines for future development of this field. (author)

The nuclear liquid gas phase transition and phase coexistence

Energy Technology Data Exchange (ETDEWEB)

Chomaz, Ph

2001-07-01

In this talk we will review the different signals of liquid gas phase transition in nuclei. From the theoretical side we will first discuss the foundations of the concept of equilibrium, phase transition and critical behaviors in infinite and finite systems. From the experimental point of view we will first recall the evidences for some strong modification of the behavior of hot nuclei. Then we will review quantitative detailed analysis aiming to evidence phase transition, to define its order and phase diagram. Finally, we will present a critical discussion of the present status of phase transitions in nuclei and we will draw some lines for future development of this field. (author)

Eccentricity from transit photometry

DEFF Research Database (Denmark)

Van Eylen, Vincent; Albrecht, Simon

2015-01-01

and can be described by a Rayleigh distribution with $\\sigma$ = 0.049 $\\pm$ 0.013. This is in full agreement with solar system eccentricities, but in contrast to the eccentricity distributions previously derived for exoplanets from radial velocity studies. Our findings are helpful in identifying which...... (TTVs), and we present some previously unreported TTVs. Finally transit durations help distinguish between false positives and true planets and we use our measurements to confirm six new exoplanets....

SOAP-T: a tool to study the light curve and radial velocity of a system with a transiting planet and a rotating spotted star

Science.gov (United States)

Oshagh, M.; Boisse, I.; Boué, G.; Montalto, M.; Santos, N. C.; Bonfils, X.; Haghighipour, N.

2013-01-01

We present an improved version of SOAP named "SOAP-T", which can generate the radial velocity variations and light curves for systems consisting of a rotating spotted star with a transiting planet. This tool can be used to study the anomalies inside transit light curves and the Rossiter-McLaughlin effect, to better constrain the orbital configuration and properties of planetary systems and the active zones of their host stars. Tests of the code are presented to illustrate its performance and to validate its capability when compared with analytical models and real data. Finally, we apply SOAP-T to the active star, HAT-P-11, observed by the NASA Kepler space telescope and use this system to discuss the capability of this tool in analyzing light curves for the cases where the transiting planet overlaps with the star's spots. The tool's public interface is available at http://www.astro.up.pt/resources/soap-t/

Transitions from vocational education to employment in the Nordic countries

DEFF Research Database (Denmark)

Jørgensen, Christian Helms; Tønder, Anna Hagen

2018-01-01

, market-based regulation and institutionalised negotiation. In addition, it compares the organisation of young peoples’ educational choice and the selection process in the students’ transitions to work and examines employment protection in the four countries. Finally, it compares attempts to revive......This chapter examines how the systems of initial vocational education and training (VET-systems) in four Nordic countries connect to the labour market, and how they support the students’ transition to employment. It employs a conceptual lens of three different coordination regimes: state planning...

BPI Challenge 2012 : the transition system case

NARCIS (Netherlands)

Verbeek, H.M.W.; La Rosa, M.; Soffer, P.

2013-01-01

Using the Transition System Miner as available in ProM6, we have investigated the control-flow perspective, the data perspective, and the resource perspective of the process that underlies the event log provided for the BPI Challenge 2012.

The Kibble-Zurek mechanism in phase transitions of non-equilibrium systems

Science.gov (United States)

Cheung, Hil F. H.; Patil, Yogesh S.; Date, Aditya G.; Vengalattore, Mukund

2017-04-01

We experimentally realize a driven-dissipative phase transition using a mechanical parametric amplifier to demonstrate key signatures of a second order phase transition, including a point where the susceptibilities and relaxation time scales diverge, and where the system exhibits a spontaneous breaking of symmetry. Though reminiscent of conventional equilibrium phase transitions, it is unclear if such driven-dissipative phase transitions are amenable to the conventional Landau-Ginsburg-Wilson paradigm, which relies on concepts of scale invariance and universality, and recent work has shown that such phase transitions can indeed lie beyond such conventional universality classes. By quenching the system past the critical point, we investigate the dynamics of the emergent ordered phase and find that our measurements are in excellent agreement with the Kibble-Zurek mechanism. In addition to verifying the Kibble-Zurek hypothesis in driven-dissipative phase transitions for the first time, we also demonstrate that the measured critical exponents accurately reflect the interplay between intrinsic coherent dynamics and environmental correlations, showing a clear departure from mean field exponents in the case of non-Markovian system-bath interactions. We further discuss how reservoir engineering and the imposition of artificial environmental correlations can result in the stabilization of novel many-body quantum phases and aid in the creation of exotic non-equilibrium states of matter.

Transition From NASA Space Communication Systems to Commerical Communication Products

Science.gov (United States)

Ghazvinian, Farzad; Lindsey, William C.

1994-01-01

Transitioning from twenty-five years of space communication system architecting, engineering and development to creating and marketing of commercial communication system hardware and software products is no simple task for small, high-tech system engineering companies whose major source of revenue has been the U.S. Government. Yet, many small businesses are faced with this onerous and perplexing task. The purpose of this talk/paper is to present one small business (LinCom) approach to taking advantage of the systems engineering expertise and knowledge captured in physical neural networks and simulation software by supporting numerous National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) projects, e.g., Space Shuttle, TDRSS, Space Station, DCSC, Milstar, etc. The innovative ingredients needed for a systems house to transition to a wireless communication system products house that supports personal communication services and networks (PCS and PCN) development in a global economy will be discussed. Efficient methods for using past government sponsored space system research and development to transition to VLSI communication chip set products will be presented along with notions of how synergy between government and industry can be maintained to benefit both parties.

Research for the energy transition. The organization of the energy systems

International Nuclear Information System (INIS)

2017-01-01

The volume on research for the energy transition includes contributions to the FVEE annual meeting 2016 concerning the following issues: status and perspectives of the energy transition, key technologies for the energy transition, political boundary conditions, development trends in photovoltaics, components for the energy supply (wind energy, hydrogen technologies, smart bioenergy concept, contribution of the geosphere), grids and storage systems for the energy transition, research network renewable energies.

The completed design of the SLC Final Focus System

International Nuclear Information System (INIS)

Murray, J.J.; Brown, K.L.; Fieguth, T.

1987-02-01

The design of the SLC Final Focus System has evolved from its initial conceptual design into its final form. This final design is described including a review of the critical decisions influencing the adoption of particular features. The creation of a feasible design has required that these decisions be tempered by practical considerations such as site constraints, correction of optical errors caused by imperfections, and accommodations requested by engineers and particle detector physicists. As this is the first such system to be built, it is hoped that the experience gained will be useful for the design of future systems

Dependence of synchronization transitions on mean field approach in two-way coupled neural system

Science.gov (United States)

Shi, J. C.; Luo, M.; Huang, C. S.

2018-03-01

This work investigates the synchronization transitions in two-way coupled neural system by mean field approach. Results show that, there exists a critical noise intensity for the synchronization transitions, i.e., above (or below) the critical noise intensity, the synchronization transitions are decreased (or hardly change) with increasing the noise intensity. Meanwhile, the heterogeneity effect plays a negative role for the synchronization transitions, and above critical coupling strength, the heterogeneity effect on synchronization transitions can be negligible. Furthermore, when an external signal is introduced into the coupled system, the novel frequency-induced and amplitude-induced synchronization transitions are found, and there exist an optimal frequency and an optimal amplitude of external signal which makes the system to display the best synchronization transitions. In particular, it is observed that the synchronization transitions can not be further affected above critical frequency of external signal.

Zero-temperature Kosterlitz-Thouless transition in a two-dimensional quantum system

International Nuclear Information System (INIS)

Castelnovo, Claudio; Chamon, Claudio; Mudry, Christopher; Pujol, Pierre

2007-01-01

We construct a local interacting quantum dimer model on the square lattice, whose zero-temperature phase diagram is characterized by a line of critical points separating two ordered phases of the valence bond crystal type. On one side, the line of critical points terminates in a quantum transition inherited from a Kosterlitz-Thouless transition in an associated classical model. We also discuss the effect of a longer-range dimer interaction that can be used to suppress the line of critical points by gradually shrinking it to a single point. Finally, we propose a way to generalize the quantum Hamiltonian to a dilute dimer model in presence of monomers and we qualitatively discuss the phase diagram

Phase stability of transition metals and alloys

International Nuclear Information System (INIS)

Hixson, R.S.; Schiferl, D.; Wills, J.M.; Hill, M.A.

1997-01-01

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project was focused on resolving unexplained differences in calculated and measured phase transition pressures in transition metals. Part of the approach was to do new, higher accuracy calculations of transmission pressures for group 4B and group 6B metals. Theory indicates that the transition pressures for these baseline metals should change if alloyed with a d-electron donor metal, and calculations done using the Local Density Approximation (LDA) and the Virtual Crystal Approximation (VCA) indicate that this is true. Alloy systems were calculated for Ti, Zr and Hf based alloys with various solute concentrations. The second part of the program was to do new Diamond Anvil Cell (DAC) measurements to experimentally verify calculational results. Alloys were prepared for these systems with grain size suitable for Diamond Anvil Cell experiments. Experiments were done on pure Ti as well as Ti-V and Ti-Ta alloys. Measuring unambiguous transition pressures for these systems proved difficult, but a new technique developed yielded good results

A numerical scheme for optimal transition paths of stochastic chemical kinetic systems

International Nuclear Information System (INIS)

Liu Di

2008-01-01

We present a new framework for finding the optimal transition paths of metastable stochastic chemical kinetic systems with large system size. The optimal transition paths are identified to be the most probable paths according to the Large Deviation Theory of stochastic processes. Dynamical equations for the optimal transition paths are derived using the variational principle. A modified Minimum Action Method (MAM) is proposed as a numerical scheme to solve the optimal transition paths. Applications to Gene Regulatory Networks such as the toggle switch model and the Lactose Operon Model in Escherichia coli are presented as numerical examples

Development of Final Running Test System for Digital Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Kwang-Dae; Lee, Eui-Jong; Lim, Hee-Taek; Kim, Min-Seok [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In nuclear industry, the newly designed systems to upgrade are qualified to meet IEEE standards and the regulatory guidelines for their functions, performance and reliability requirements. Failure Mode and Effect Analysis, Fault Tree Analysis, and Hazard Analysis have been used to improve the reliability of the control system. To ensure the completeness of the software, the verification and validation processes are carried out during the development process. In spite of the many efforts depending on the analysis and procedures, there are limitations to improve the reliability. The lessons learned from the currently installed system failures show the incompleteness of the final integration test. The current point-to-point and logic-to-logic separate test procedures manually performed by the engineers can cause some procedures missed and have effects on the critical functions. The design processes of the digital systems are met in accordance with the international standards and regulatory guidelines. The lessons learned from the failures of the running digital systems showed the limitations of the current verification and validation efforts. The various improvements and attempts have been considered including the expert review processes and the completeness of the test. In this paper, the Final Running Test Method evaluating the completeness of the digital system using the control patterns and the Test System Architecture are proposed.

Development of Final Running Test System for Digital Systems

International Nuclear Information System (INIS)

Lee, Kwang-Dae; Lee, Eui-Jong; Lim, Hee-Taek; Kim, Min-Seok

2016-01-01

In nuclear industry, the newly designed systems to upgrade are qualified to meet IEEE standards and the regulatory guidelines for their functions, performance and reliability requirements. Failure Mode and Effect Analysis, Fault Tree Analysis, and Hazard Analysis have been used to improve the reliability of the control system. To ensure the completeness of the software, the verification and validation processes are carried out during the development process. In spite of the many efforts depending on the analysis and procedures, there are limitations to improve the reliability. The lessons learned from the currently installed system failures show the incompleteness of the final integration test. The current point-to-point and logic-to-logic separate test procedures manually performed by the engineers can cause some procedures missed and have effects on the critical functions. The design processes of the digital systems are met in accordance with the international standards and regulatory guidelines. The lessons learned from the failures of the running digital systems showed the limitations of the current verification and validation efforts. The various improvements and attempts have been considered including the expert review processes and the completeness of the test. In this paper, the Final Running Test Method evaluating the completeness of the digital system using the control patterns and the Test System Architecture are proposed

Transition control system for procedure prompting

International Nuclear Information System (INIS)

Colley, R.W.

1981-11-01

A system called the Transition Control System (TCS) is being developed at the Hanford Engineering Development Laboratory (HEDL). The purpose of the TCS is to monitor the operational status of a plant's systems and equipment, and provide either operator guidance or direct control. The TCS provides the rule-based information to the operator specific to the plant's current operational status. A schematic of the information flow and control functions of a reactor plant is shown. The basis for the TCS is a methodology called Sequencing Established States (SES). The fundamental precept of this methodology is that all plant states are determined by the operational status of the various plant systems. The operational status of each plant system is determined, in turn, by the operational status of the system's equipment, instrumentation and controllers

REFINED SYSTEM PARAMETERS AND TTV STUDY OF TRANSITING EXOPLANETARY SYSTEM HAT-P-20

Energy Technology Data Exchange (ETDEWEB)

Sun, Leilei; Gu, Shenghong; Wang, Xiaobin; Cao, Dongtao; Wang, Yibo; Xiang, Yue [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Cameron, Andrew Collier [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Hui, Ho-Keung; Kwok, Chi-Tai [Ho Koon Nature Education cum Astronomical Centre, Sik Sik Yuen, Hong Kong (China); Yeung, Bill; Ng, Eric [Hong Kong Astronomical Society, Hong Kong (China); Horta, Ferran Grau, E-mail: wangxb@ynao.ac.cn [Observatori Ca l’Ou, C/de Dalt 18, Sant Martí Sesgueioles (Spain)

2017-01-01

We report new photometric observations of the transiting exoplanetary system HAT-P-20, obtained using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China, from 2010 to 2013, and Observatori Ca l’Ou, Sant Marti Sesgueioles, Spain, from 2013 to 2015. The observed data are corrected for systematic errors according to the coarse de-correlation and SYSREM algorithms, so as to enhance the signal of the transit events. In order to consistently model the star spots and transits of this exoplanetary system, we develop a highly efficient tool STMT based on the analytic models of Mandel and Agol and Montalto et al. The physical parameters of HAT-P-20 are refined by homogeneously analyzing our new data, the radial velocity data, and the earlier photometric data in the literature with the Markov chain Monte Carlo technique. New radii and masses of both host star and planet are larger than those in the discovery paper due to the discrepancy of the radius among K-dwarfs between predicted values by standard stellar models and empirical calibration from observations. Through the analysis of all available mid-transit times calculated with the normal model and spotted model, we conclude that the periodic transit timing variations in these transit events revealed by employing the normal model are probably induced by spot crossing events. From the analysis of the distribution of occulted spots by HAT-P-20b, we constrain the misaligned architecture between the planetary orbit and the spin of the host star.

Evaluation of regional real-time transit communications and data information sharing in the national capital region.

Science.gov (United States)

2015-03-01

This final report documents transit-related enhancements to the Regional Integration Transportation Information System (RITIS), creation of the RITIS Chat Instant Messaging tool, and final project evaluation of the effectiveness of the RITIS Chat too...

The smectite to chlorite transition in the Chipilapa geothermal system, El Salvador

Energy Technology Data Exchange (ETDEWEB)

Robinson, D. [Univ. of Bristol (United Kingdom). Dept. of Earth Sciences; Santana de Zamora, A. [Comision Ejecutiva Hidroelectrica del Rio Lempa (El Salvador)

1999-04-01

Clay mineralogical, X-ray diffraction and electron microprobe studies have been carried out on separated <2 {micro}m fractions from cutting and core material from three wells in the Chipilapa geothermal system in El Salvador. The data indicate that the smectite to chlorite transition is prevalent, but a secondary smectite to illite transition is also present. At depths approximately <750 m, smectite with very minor chlorite mixed-layers (approximately <15%) is dominant, and has a composition midway between a di- and tri-smectite. At {approximately}750 m there is a very clear distinction and sharp transition into discrete chlorite with very minor smectite mixed-layers (approximately <10%). Corrensite is recorded only as a rare and minor phase. Smectite occurs in abundance at temperatures up to {approximately}200 C, and the transition from a smectite-dominant to chlorite-dominant assemblage takes place over a narrow temperature range ({approximately}150 to 200 C). The stability range of smectite is very similar to that recorded in other geothermal systems, whereas the smectite to chlorite transition differs greatly from that recorded in other systems. The transition does not involve continuous chlorite/smectite mixed-layering but a marked step: It is the sharpest and most discontinuous stepped sequence of this mineralogical transition recorded.

Rock mass classification system : transition from RMR to GSI.

Science.gov (United States)

2013-11-01

The AASHTO LRFD Bridge Design Specifications is expected to replace the rock mass rating : (RMR) system with the Geological Strength Index (GSI) system for classifying and estimating : engineering properties of rock masses. This transition is motivat...

A diverse and resilient financial system for investments in the energy transition

NARCIS (Netherlands)

Polzin, F.H.J.|info:eu-repo/dai/nl/413317404; Sanders, M.W.J.L.|info:eu-repo/dai/nl/175620059; Täube, Florian

Diversity makes the financial system more resilient. In addition, there is a diverse investment demand to make the transition to a more sustainable energy system. We need, among others, investment in energy transition, circular resource use, better water management and reducing air pollution. The

Biodiesel Mass Transit Demonstration

Science.gov (United States)

2010-04-01

The Biodiesel Mass Transit Demonstration report is intended for mass transit decision makers and fleet managers considering biodiesel use. This is the final report for the demonstration project implemented by the National Biodiesel Board under a gran...

Effect of Topology Structures on Synchronization Transition in Coupled Neuron Cells System

International Nuclear Information System (INIS)

Liang Li-Si; Zhang Ji-Qian; Xu Gui-Xia; Liu Le-Zhu; Huang Shou-Fang

2013-01-01

In this paper, by the help of evolutionary algorithm and using Hindmarsh—Rose (HR) neuron model, we investigate the effect of topology structures on synchronization transition between different states in coupled neuron cells system. First, we build different coupling structure with N cells, and found the effect of synchronized transition contact not only closely with the topology of the system, but also with whether there exist the ring structures in the system. In particular, both the size and the number of rings have greater effects on such transition behavior. Secondly, we introduce synchronization error to qualitative analyze the effect of the topology structure. Furthermore, by fitting the simulation results, we find that with the increment of the neurons number, there always exist the optimization structures which have the minimum number of connecting edges in the coupling systems. Above results show that the topology structures have a very crucial role on synchronization transition in coupled neuron system. Biological system may gradually acquire such efficient topology structures through the long-term evolution, thus the systems' information process may be optimized by this scheme. (interdisciplinary physics and related areas of science and technology)

75 FR 43197 - Public Housing Assessment System (PHAS): Asset Management Transition Year 2 Extension

Science.gov (United States)

2010-07-23

... System (PHAS): Asset Management Transition Year 2 Extension AGENCY: Office of the Assistant Secretary for...): Asset Management Transition Year 2 Information (75 FR 1632), dated January 12, 2010, for PHAs with... Assessment System (PHAS): Asset Management Transition Year Information and Uniform Financial Reporting...

Tradeoffs between costs and greenhouse gas emissions in the design of urban transit systems

International Nuclear Information System (INIS)

Griswold, Julia B; Madanat, Samer; Horvath, Arpad

2013-01-01

Recent investments in the transit sector to address greenhouse gas emissions have concentrated on purchasing efficient replacement vehicles and inducing mode shift from the private automobile. There has been little focus on the potential of network and operational improvements, such as changes in headways, route spacing, and stop spacing, to reduce transit emissions. Most models of transit system design consider user and agency cost while ignoring emissions and the potential environmental benefit of operational improvements. We use a model to evaluate the user and agency costs as well as greenhouse gas benefit of design and operational improvements to transit systems. We examine how the operational characteristics of urban transit systems affect both costs and greenhouse gas emissions. The research identifies the Pareto frontier for designing an idealized transit network. Modes considered include bus, bus rapid transit (BRT), light rail transit (LRT), and metro (heavy) rail, with cost and emissions parameters appropriate for the United States. Passenger demand follows a many-to-many travel pattern with uniformly distributed origins and destinations. The approaches described could be used to optimize the network design of existing bus service or help to select a mode and design attributes for a new transit system. The results show that BRT provides the lowest cost but not the lowest emissions for our large city scenarios. Bus and LRT systems have low costs and the lowest emissions for our small city scenarios. Relatively large reductions in emissions from the cost-optimal system can be achieved with only minor increases in user travel time. (letter)

Quantum phase transition and critical phenomena

International Nuclear Information System (INIS)

Dutta, A.; Chakrabarti, B.K.

1998-01-01

We intend to describe briefly the generic features associated with the zero temperature transition in quantum mechanical systems. We elucidate the discussion of the introductory section using the very common example of Ising model in a transverse field. We discuss the method of fermionisation for one dimensional systems. The quantum-classical correspondence is discussed using Suzuki-Trotter method. We then introduce the quantum rotor model and discuss its spherical limit. We finally discuss novel features arising due to the presence of quenched randomness in the quantum Ising and rotor systems. (author)

Hawaiian hydrogen mass transit system

International Nuclear Information System (INIS)

Russell, G.W.; Russell, A.

1990-01-01

This paper proposes a joint effort between the scientific and business communities; to create, make and have hydrogen fuel become the primary fuel of the future. Hawaii has abundant, unharnessed renewable resources yet imports almost all of its fuel. Initiating hydrogen production and industrial application in conjunction with a prototype pilot project such as this mass transit system would not only accomplish the joining of science and business but give an environmentally safe energy alternative to the state and people of Hawaii and hopefully the world

Phase transitions, scaling and renormalisation in nonequilibrium systems

International Nuclear Information System (INIS)

Hanney, T.E.

2002-01-01

Nonequilibrium phase transitions and critical phenomena in simple lattice-based interacting particle models are considered. Specific models of interest are exclusion models in low dimensions, with particular reference to the asymmetric simple exclusion process (ASEP) which provides a testbed for many of the calculations. The aim of the thesis is to devise approximate scaling techniques for such models which account for fluctuations and which are more widely applicable than methods pursuing an exact solution. Scaling techniques which have been applied to models described by a linear equation of motion are extended to the case where the equation of motion is nonlinear. These methods capture the dynamic transition in the ASEP but fail to properly account for the nonlinearity in their predictions for the dynamic exponent, z. A new and widely applicable real space renormalisation group procedure is developed. It provides a direct and transparent scaling method to extract universal and non-universal properties of the steady state and dynamic critical behaviour in the boundary-driven ASEP in one dimension. In particular, we obtain a flow diagram for the problem from which we can interpret all the qualitative features of the (exactly known) steady state phase diagram and which predicts the exact value for the critical point. Further, the dynamic scaling is consistent with a crossover between diflusive behaviour near the zero current fixed point and z = 3/2 dynamics at the critical fixed point. Extensions to include disorder, to higher dimensions, and to other models are all possible using the method. Using the mapping between the Master equation and the Schroedinger equation in imaginary time, this scaling procedure is rephrased as a new blocking for quantum-spin systems. Existing methods of real space renormalisation for quantum-spin systems are applied to a variety of previously unconsidered exclusion models. In particular, it is shown how such techniques can be applied

General method for final focus system design for circular colliders

Directory of Open Access Journals (Sweden)

Riccardo de Maria

2008-03-01

Full Text Available Colliders use final focus systems to reduce the transverse beam sizes at the interaction point in order to increase collision event rates. The maximum focal strength (gradient of the quadrupoles, and the maximum beam size in them, together limit the beam size reduction that is possible. The goal of a final focus system design is to find the best compromise between quadrupole aperture and quadrupole gradient, for the magnet technology that is used. This paper develops a design method that identifies the intrinsic limitations of a final focus system, validates the results of the method against realistic designs, and reports its application to the upgrade of the Large Hadron Collider final focus.

Theory of quantum metal to superconductor transitions in highly conducting systems

Energy Technology Data Exchange (ETDEWEB)

Spivak, B.

2010-04-06

We derive the theory of the quantum (zero temperature) superconductor to metal transition in disordered materials when the resistance of the normal metal near criticality is small compared to the quantum of resistivity. This can occur most readily in situations in which 'Anderson's theorem' does not apply. We explicitly study the transition in superconductor-metal composites, in an swave superconducting film in the presence of a magnetic field, and in a low temperature disordered d-wave superconductor. Near the point of the transition, the distribution of the superconducting order parameter is highly inhomogeneous. To describe this situation we employ a procedure which is similar to that introduced by Mott for description of the temperature dependence of the variable range hopping conduction. As the system approaches the point of the transition from the metal to the superconductor, the conductivity of the system diverges, and the Wiedemann-Franz law is violated. In the case of d-wave (or other exotic) superconductors we predict the existence of (at least) two sequential transitions as a function of increasing disorder: a d-wave to s-wave, and then an s-wave to metal transition.

Transiting planetary system WASP-17 (Southworth+, 2012)

DEFF Research Database (Denmark)

Southworth, J.; Hinse, T. C.; Dominik, M.

2013-01-01

A light curve of four transits of the extrasolar planetary system WASP-17 is presented. The data were obtained using the Danish 1.5m telescope and DFOSC camera at ESO La Silla in 2012, with substantial telescope defocussing in order to improve the photometric precision of the observations...

Hyperchaos-chaos-hyperchaos transition in modified Roessler systems

International Nuclear Information System (INIS)

Nikolov, Svetoslav; Clodong, Sebastien

2006-01-01

We consider in this paper a family of modified hyperchaotic Roessler systems and investigate both problems of understanding hyperchaos-chaos-hyperchaos transition and computing the prediction time. These systems were obtained and numerically investigated by Nikolov and Clodong [Nikolov S, Clodong S. Occurrence of regular, chaotic and hyperchaotic behavior in a family of modified Rossler hyperchaotic systems. Chaos, Solitons and Fractals 2004;22:407-31]. Our studies confirm that transition hyperchaos-chaos-hyperchaos (i) depends on the change of the sign of the corresponding characteristic equation roots or (ii) can be obtained as a result of the absorption/repulsion of the repeller originally located out of the attractor by the growing attractor. It is also shown that the prediction time is a more reliable predictor of the evolution than the information dimension. We conclude that the prediction time in hyperchaotic regimes is at least one order of magnitude smaller than those in chaotic zones

Risk Assessment on the Transition Program for Air Traffic Control Automation System Upgrade

Directory of Open Access Journals (Sweden)

Li Dong Bin

2016-01-01

Full Text Available We analyzed the safety risks of the transition program for Air Traffic Control (ATC automation system upgrade by using the event tree analysis method in this paper. We decomposed the occurrence progress of the three transition phase and built the event trees corresponding to the three stages, and then we determined the probability of success of each factor and calculated probability of success of the air traffic control automation system upgrade transition. In the conclusion, we illustrate the transition program safety risk according to the results.

Three Transits for the Price of One: Super-Earth Transits of the Nearest Planetary System Discovered By Kepler/K2

Science.gov (United States)

Redfield, Seth; Niraula, Prajwal; Hedges, Christina; Crossfield, Ian; Kreidberg, Laura; Greene, Tom; Rodriguez, Joey; Vanderburg, Andrew; Laughlin, Gregory; Millholland, Sarah; Wang, Songhu; Cochran, William; Livingston, John; Gandolfi, Davide; Guenther, Eike; Fridlund, Malcolm; Korth, Judith

2018-05-01

We propose primary transit observations of three Super-Earth planets in the newly discovered planetary system around a bright, nearby star, GJ 9827. We recently announced the detection of three super-Earth planets in 1:3:5 commensurability, the inner planet, GJ 9827 b having a period of 1.2 days. This is the nearest planetary system that Kepler or K2 has found, at 30 pc, and given its brightness is one of the top systems for follow-up characterization. This system presents a unique opportunity to acquire three planetary transits for the price of one. There are several opportunities in the Spitzer visibility windows to obtain all three transits in a short period of time. We propose 3.6 micron observations of all three Super-Earth transits in a single 18-hour observation window. The proximity to a 1:3:5 resonance is intriguing from a dynamical standpoint as well. Indeed, anomalous transit timing offsets have been measured for planet d in Hubble observations that suffer from partial phase coverage. The short cadence and extended coverage of Spitzer is essential to provide a firm determination of the ephemerides and characterize any transit timing variations. Constraining these orbital parameters is critical for follow-up observations from space and ground-based telescopes. Due to the brightness of the host star, this planetary system is likely to be extensively observed in the years to come. Indeed, our team has acquired observations of the planets orbiting GJ9827 with Hubble in the ultraviolet and infrared. The proposed observations will provide infrared atmospheric measurements and firm orbital characterization which is critical for planning and designing future observations, in particular atmospheric characterization with JWST.

Planning for Bike Share Connectivity to Rail Transit

Science.gov (United States)

Griffin, Greg Phillip; Sener, Ipek Nese

2016-01-01

Bike sharing can play a role in providing access to transit stations and then to final destinations, but early implementation of these systems in North America has been opportunistic rather than strategic. This study evaluates local intermodal plan goals using trip data and associated infrastructure such as transit stops and bike share station locations in Austin, Texas, and Chicago, Illinois. Bike sharing use data from both cities suggest a weak relationship with existing rail stations that could be strengthened through collaborative, intermodal planning. The study suggests a planning framework and example language that could be tailored to help address the linkage between bike sharing and transit. Rather than an exhaustive study of the practice, this study provides evidence from these two cities that identify opportunities to improve intermodal planning. Cities that are planning or expanding a bike sharing system should consider carefully how to leverage this mode with existing modes of transport. Regardless of a city’s status in implementing a bike sharing system, planners can leverage information on existing transport systems for planning at regional and local levels. PMID:27872554

Heat capacity for systems with excited-state quantum phase transitions

Energy Technology Data Exchange (ETDEWEB)

Cejnar, Pavel; Stránský, Pavel, E-mail: stransky@ipnp.troja.mff.cuni.cz

2017-03-18

Heat capacities of model systems with finite numbers of effective degrees of freedom are evaluated using canonical and microcanonical thermodynamics. Discrepancies between both approaches, which are observed even in the infinite-size limit, are particularly large in systems that exhibit an excited-state quantum phase transition. The corresponding irregularity of the spectrum generates a singularity in the microcanonical heat capacity and affects smoothly the canonical heat capacity. - Highlights: • Thermodynamics of systems with excited-state quantum phase transitions • ESQPT-generated singularities of the microcanonical heat capacity • Non-monotonous dependences of the canonical heat capacity • Discord between canonical and microcanonical pictures in the infinite-size limit.

Pairing symmetry transitions in the even-denominator FQHE system

International Nuclear Information System (INIS)

Nomura, Kentaro; Yoshioka, Daijiro

2001-01-01

Transitions from a paired quantum Hall state to another quantum Hall state in bilayer systems are discussed in the framework of the edge theory. Starting from the edge theory for the Haldane-Rezayi state, it is shown that the charging effect of a bilayer system which breaks the SU (2) symmetry of the pseudospin shifts the central charge and the conformal dimensions of the fermionic fields which describe the pseudospin sector in the edge theory. This corresponds to the transition from the Haldane-Rezayi state to Halperin's 331 state, or from a singlet d-wave to a triplet p-wave ABM type paired state in the composite fermion picture. Considering interlayer tunneling, the tunneling rate-capacitance phase diagram for the ν=5/2 paired bilayer system is discussed. (author)

Pairing Symmetry Transitions in the Even-Denominator FQHE System

Science.gov (United States)

Nomura, Kentaro; Yoshioka, Daijiro

2001-12-01

Transitions from a paired quantum Hall state to another quantum Hall state in bilayer systems are discussed in the framework of the edge theory. Starting from the edge theory for the Haldane Rezayi state, it is shown that the charging effect of a bilayer system which breaks the SU(2) symmetry of the pseudospin shifts the central charge and the conformal dimensions of the fermionic fields which describe the pseudospin sector in the edge theory. This corresponds to the transition from the Haldane Rezayi state to Halperin's 331 state, or from a singlet d-wave to a triplet p-wave ABM type paired state in the composite fermion picture. Considering interlayer tunneling, the tunneling rate-capacitance phase diagram for the ν=5/2 paired bilayer system is discussed.

An assessment method for system innovation and transition (AMSIT)

NARCIS (Netherlands)

Bos, Marc W.; Hofman, Erwin; Kuhlmann, Stefan

2016-01-01

To address comprehensive system innovations that may occur in a future transition, a suitable ex ante assessment method is required. The technological innovation system approach is useful for the retrospective study of the conditions for success or failure of innovation trajectories, and the

Examinations in the Final Year of Transition to Mathematical Methods Computer Algebra System (CAS)

Science.gov (United States)

Leigh-Lancaster, David; Les, Magdalena; Evans, Michael

2010-01-01

2009 was the final year of parallel implementation for Mathematical Methods Units 3 and 4 and Mathematical Methods (CAS) Units 3 and 4. From 2006-2009 there was a common technology-free short answer examination that covered the same function, algebra, calculus and probability content for both studies with corresponding expectations for key…

The stabilisation of final focus system

Indian Academy of Sciences (India)

The StaFF (stabilisation of final focus) system will use interferometers to monitor the relative ... quadrupole magnets will be the most demanding application, where mutual and beam- ... interferometers to measure lines of a geodetic network to record relative motion between two beam ... coupled interferometer design.

Transit Timing Observations from Kepler: III. Confirmation of 4 Multiple Planet Systems by a Fourier-Domain Study of Anti-correlated Transit Timing Variations

Energy Technology Data Exchange (ETDEWEB)

Steffen, Jason H.; /Fermilab; Fabrycky, Daniel C.; /Lick Observ.; Ford, Eric B.; /Florida U.; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Rowe, Jason F.; /SETI Inst., Mtn. View /NASA, Ames; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Welsh, William F.; /Caltech; Borucki, William J.; /NASA, Ames /UC, Santa Barbara

2012-01-01

We present a method to confirm the planetary nature of objects in systems with multiple transiting exoplanet candidates. This method involves a Fourier-domain analysis of the deviations in the transit times from a constant period that result from dynamical interactions within the system. The combination of observed anticorrelations in the transit times and mass constraints from dynamical stability allow us to claim the discovery of four planetary systems, Kepler-25, Kepler-26, Kepler-27 and Kepler-28, containing eight planets and one additional planet candidate.

Transitions of social-ecological subsistence systems in the Arctic

Directory of Open Access Journals (Sweden)

Per Fauchald

2017-04-01

Full Text Available Transitions of social-ecological systems (SES expose governance systems to new challenges. This is particularly so in the Arctic where resource systems are increasingly subjected to global warming, industrial development and globalization which subsequently alter the local SES dynamics. Based on common-pool resource theory, we developed a dynamic conceptual model explaining how exogenous drivers might alter a traditional subsistence system from a provisioning to an appropriation actions situation. In a provisioning action situation the resource users do not control the resource level but adapt to the fluctuating availability of resources, and the collective challenge revolve around securing the subsistence in the community. An increased harvest pressure enabled by exogenous drivers could transform the SES to an appropriation action situation where the collective challenge has changed to avoid overuse of a common-pool resource. The model was used as a focal lens to investigate the premises for broad-scale transitions of subsistence-oriented SESs in Arctic Alaska, Canada and Greenland. We synthesized data from documents, official statistics and grey and scientific literature to explore the different components of our model. Our synthesis suggests that the traditional Arctic subsistence SESs mostly comply with a provisioning action situation. Despite population growth and available technology; urbanization, increased wage labor and importation of food have reduced the resource demand, and we find no evidence for a broad-scale transition to an appropriation action situation throughout the Western Arctic. However, appropriation ­challenges have emerged in some cases either as a consequence of commercialization of the resource or by severely reduced resource stocks due to various exogenous drivers. Future transitions of SESs could be triggered by the emergence of commercial local food markets and Arctic warming. In particular, Arctic warming is an

Strongly correlated electron systems and neutron scattering. Magnetism, superconductivity, structural phase transition

Energy Technology Data Exchange (ETDEWEB)

Katano, Susumu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-03-01

Neutron scattering experiments in our group on strongly correlated electron systems are reviewed Metal-insulator transitions caused by structural phase transitions in (La{sub 1-x}Sr{sub x}) MnO{sub 3}, a novel magnetic transition in the CeP compound, correlations between antiferromagnetism and superconductivity in UPd{sub 2}Al{sub 3} and so forth are discussed. Here, in this note, the phase transition of Mn-oxides was mainly described. (author)

Quantum phase transitions in multi-impurity and lattice Kondo systems

International Nuclear Information System (INIS)

Nejati, Ammar

2017-01-01

The main purpose of this dissertation is to provide a detailed development of a self-consistent perturbative renormalization group (RG) method to investigate the quantum phases and quantum phase transitions of multi-impurity Kondo systems (e.g., two impurities or a lattice of impurities). The essence of the RG method is an extension of the standard ''poor man's scaling'' by including the dynamical effects of the magnetic fluctuations in the Kondo vertex. Such magnetic fluctuations arise due to the indirect carrier-mediated exchange interaction (RKKY interaction) between the impurities and compete with the Kondo effect to determine the ground-state. The aim is to take the most 'economic' route and avoid intensive numerical computations as far as possible. In general, it is shown in detail how a relatively small amount of such magnetic fluctuations can suppress and ultimately, destroy the Kondo-screened phase in a universal manner, and without incurring a magnetic instability in the system. The renormalization group method and its extensions are further applied to several distinct experimental realization of the multi-impurity Kondo effect; namely, Kondo adatoms studied via scanning tunneling spectroscopy, a highly-tunable double-quantum-dot system based on semiconducting heterostructures, and finally, the heavy fermionic compounds as Kondo lattices. We demonstrate the qualitative and quantitative agreement of the RG theory with the experimental findings, which supports the validity of the method. In the case of Kondo lattices, we further include the possibility of a magnetic ordering in the lattice to see whether a magnetic ordering can happen simultaneously with or before the Kondo breakdown (or even prevent it altogether). In the last chapter, we consider the fate of the local moments in the absence of full Kondo screening while Kondo fluctuations are still present. This partially-screened phase needs itself an extensive study

Quantum phase transitions in multi-impurity and lattice Kondo systems

Energy Technology Data Exchange (ETDEWEB)

Nejati, Ammar

2017-01-16

The main purpose of this dissertation is to provide a detailed development of a self-consistent perturbative renormalization group (RG) method to investigate the quantum phases and quantum phase transitions of multi-impurity Kondo systems (e.g., two impurities or a lattice of impurities). The essence of the RG method is an extension of the standard ''poor man's scaling'' by including the dynamical effects of the magnetic fluctuations in the Kondo vertex. Such magnetic fluctuations arise due to the indirect carrier-mediated exchange interaction (RKKY interaction) between the impurities and compete with the Kondo effect to determine the ground-state. The aim is to take the most 'economic' route and avoid intensive numerical computations as far as possible. In general, it is shown in detail how a relatively small amount of such magnetic fluctuations can suppress and ultimately, destroy the Kondo-screened phase in a universal manner, and without incurring a magnetic instability in the system. The renormalization group method and its extensions are further applied to several distinct experimental realization of the multi-impurity Kondo effect; namely, Kondo adatoms studied via scanning tunneling spectroscopy, a highly-tunable double-quantum-dot system based on semiconducting heterostructures, and finally, the heavy fermionic compounds as Kondo lattices. We demonstrate the qualitative and quantitative agreement of the RG theory with the experimental findings, which supports the validity of the method. In the case of Kondo lattices, we further include the possibility of a magnetic ordering in the lattice to see whether a magnetic ordering can happen simultaneously with or before the Kondo breakdown (or even prevent it altogether). In the last chapter, we consider the fate of the local moments in the absence of full Kondo screening while Kondo fluctuations are still present. This partially-screened phase needs itself an extensive study

Phase transition and computational complexity in a stochastic prime number generator

Energy Technology Data Exchange (ETDEWEB)

Lacasa, L; Luque, B [Departamento de Matematica Aplicada y EstadIstica, ETSI Aeronauticos, Universidad Politecnica de Madrid, Plaza Cardenal Cisneros 3, Madrid 28040 (Spain); Miramontes, O [Departamento de Sistemas Complejos, Instituto de FIsica, Universidad Nacional Autonoma de Mexico, Mexico 01415 DF (Mexico)], E-mail: lucas@dmae.upm.es

2008-02-15

We introduce a prime number generator in the form of a stochastic algorithm. The character of this algorithm gives rise to a continuous phase transition which distinguishes a phase where the algorithm is able to reduce the whole system of numbers into primes and a phase where the system reaches a frozen state with low prime density. In this paper, we firstly present a broader characterization of this phase transition, both in analytical and numerical terms. Critical exponents are calculated, and data collapse is provided. Further on, we redefine the model as a search problem, fitting it in the hallmark of computational complexity theory. We suggest that the system belongs to the class NP. The computational cost is maximal around the threshold, as is common in many algorithmic phase transitions, revealing the presence of an easy-hard-easy pattern. We finally relate the nature of the phase transition to an average-case classification of the problem.

State transition storyboards: A tool for designing the Goldstone solar system radar data acquisition system user interface software

Science.gov (United States)

Howard, S. D.

1987-01-01

Effective user interface design in software systems is a complex task that takes place without adequate modeling tools. By combining state transition diagrams and the storyboard technique of filmmakers, State Transition Storyboards were developed to provide a detailed modeling technique for the Goldstone Solar System Radar Data Acquisition System human-machine interface. Illustrations are included with a description of the modeling technique.

A universal indicator of critical state transitions in noisy complex networked systems.

Science.gov (United States)

Liang, Junhao; Hu, Yanqing; Chen, Guanrong; Zhou, Tianshou

2017-02-23

Critical transition, a phenomenon that a system shifts suddenly from one state to another, occurs in many real-world complex networks. We propose an analytical framework for exactly predicting the critical transition in a complex networked system subjected to noise effects. Our prediction is based on the characteristic return time of a simple one-dimensional system derived from the original higher-dimensional system. This characteristic time, which can be easily calculated using network data, allows us to systematically separate the respective roles of dynamics, noise and topology of the underlying networked system. We find that the noise can either prevent or enhance critical transitions, playing a key role in compensating the network structural defect which suffers from either internal failures or environmental changes, or both. Our analysis of realistic or artificial examples reveals that the characteristic return time is an effective indicator for forecasting the sudden deterioration of complex networks.

Dissipation-driven quantum phase transitions in collective spin systems

International Nuclear Information System (INIS)

Morrison, S; Parkins, A S

2008-01-01

We consider two different collective spin systems subjected to strong dissipation-on the same scale as interaction strengths and external fields-and show that either continuous or discontinuous dissipative quantum phase transitions can occur as the dissipation strength is varied. First, we consider a well-known model of cooperative resonance fluorescence that can exhibit a second-order quantum phase transition, and analyse the entanglement properties near the critical point. Next, we examine a dissipative version of the Lipkin-Meshkov-Glick interacting collective spin model, where we find that either first- or second-order quantum phase transitions can occur, depending only on the ratio of the interaction and external field parameters. We give detailed results and interpretation for the steady-state entanglement in the vicinity of the critical point, where it reaches a maximum. For the first-order transition we find that the semiclassical steady states exhibit a region of bistability. (fast track communication)

Shear-induced transitions in a ternary polymeric system

NARCIS (Netherlands)

Zvelindovsky, AV; Sevink, GJA; Fraaije, JGEM

The first three-dimensional simulation of shear-induced phase transitions in a polymeric system has been performed. The method is based on dynamic density-functional theory. The pathways between a bicontinuous phase with developing gyroid mesostructure and a lamellar/cylinder phase coexistence are

TRANSIT TIMING VARIATIONS FOR INCLINED AND RETROGRADE EXOPLANETARY SYSTEMS

International Nuclear Information System (INIS)

Payne, Matthew J.; Ford, Eric B.; Veras, Dimitri

2010-01-01

We perform numerical calculations of the expected transit timing variations (TTVs) induced on a hot-Jupiter by an Earth-mass perturber. Motivated by the recent discoveries of retrograde transiting planets, we concentrate on an investigation of the effect of varying relative planetary inclinations, up to and including completely retrograde systems. We find that planets in low-order (e.g., 2:1) mean-motion resonances (MMRs) retain approximately constant TTV amplitudes for 0 deg. 170 deg. Systems in higher order MMRs (e.g., 5:1) increase in TTV amplitude as inclinations increase toward 45 deg., becoming approximately constant for 45 deg. 135 deg. Planets away from resonance slowly decrease in TTV amplitude as inclinations increase from 0 deg. to 180 deg., whereas planets adjacent to resonances can exhibit a huge range of variability in TTV amplitude as a function of both eccentricity and inclination. For highly retrograde systems (135 deg. < i ≤ 180 deg.), TTV signals will be undetectable across almost the entirety of parameter space, with the exceptions occurring when the perturber has high eccentricity or is very close to an MMR. This high inclination decrease in TTV amplitude (on and away from resonance) is important for the analysis of the known retrograde and multi-planet transiting systems, as inclination effects need to be considered if TTVs are to be used to exclude the presence of any putative planetary companions: absence of evidence is not evidence of absence.

Explosive transitions to synchronization in networks of phase oscillators.

Science.gov (United States)

Leyva, I; Navas, A; Sendiña-Nadal, I; Almendral, J A; Buldú, J M; Zanin, M; Papo, D; Boccaletti, S

2013-01-01

The emergence of dynamical abrupt transitions in the macroscopic state of a system is currently a subject of the utmost interest. The occurrence of a first-order phase transition to synchronization of an ensemble of networked phase oscillators was reported, so far, for very particular network architectures. Here, we show how a sharp, discontinuous transition can occur, instead, as a generic feature of networks of phase oscillators. Precisely, we set conditions for the transition from unsynchronized to synchronized states to be first-order, and demonstrate how these conditions can be attained in a very wide spectrum of situations. We then show how the occurrence of such transitions is always accompanied by the spontaneous setting of frequency-degree correlation features. Third, we show that the conditions for abrupt transitions can be even softened in several cases. Finally, we discuss, as a possible application, the use of this phenomenon to express magnetic-like states of synchronization.

36 CFR 1192.173 - Automated guideway transit vehicles and systems.

Science.gov (United States)

2010-07-01

.... Vertical alignment may be accomplished by vehicle air suspension or other suitable means of meeting the... vehicles and systems. 1192.173 Section 1192.173 Parks, Forests, and Public Property ARCHITECTURAL AND... TRANSPORTATION VEHICLES Other Vehicles and Systems § 1192.173 Automated guideway transit vehicles and systems. (a...

Assessing Sustainability Transition in the US Electrical Power System

Directory of Open Access Journals (Sweden)

Stephen McCauley

2010-02-01

Full Text Available This paper examines sustainability transition dynamics in the US electricity system, drawing on the socio-technical systems approach. We view system change as unfolding along several critical dimensions and geographical scales, including dynamics in the environment, science, civil society, discourse, and state regulatory institutions, as well as in capital and technology formations. A particular emphasis is given to the interaction of discourses, policy networks, and institutions. We trace four distinct regimes which have characterized the evolution of this discourse-network-institutional nexus over the last century. The research examines dynamics that present a challenge to the incumbent energy regime based on fossil fuels, nuclear and hydropower, and demonstrates how the actor-network supporting renewables and energy efficiency has grown stronger and more capable of moving toward a sustainability transition than at any time since the sustainable energy movement began a generation ago.

Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System.

Science.gov (United States)

Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent; Gronbaek, Henning; Krogh, Klaus

2015-07-30

The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the performance of 3D-Transit in patients with carcinoid diarrhea and to compare the patients' regional gastrointestinal transit times (GITT) and colonic motility patterns with those of healthy subjects. Fifteen healthy volunteers and seven patients with neuroendocrine tumor and at least 3 bowel movements per day were inves-tigated with 3D-Transit and standard radiopaque markers. Total GITT assessed with 3D-Transit and radiopaque markers were well correlated (Spearman's rho = 0.64, P = 0.002). Median total GITT was 12.5 (range: 8.5-47.2) hours in patients versus 25.1 (range: 13.1-142.3) hours in healthy (P = 0.007). There was no difference in gastric emptying (P = 0.778). Median small intestinal transit time was 3.8 (range: 1.4-5.5) hours in patients versus 4.4 (range: 1.8-7.2) hours in healthy subjects (P = 0.044). Median colorectal transit time was 5.2 (range: 2.9-40.1) hours in patients versus 18.1 (range: 5.0-134.0) hours in healthy subjects (P = 0.012). Median frequency of pansegmental co-lonic movements was 0.45 (range: 0.03-1.02) per hour in patients and 0.07 (range: 0-0.61) per hour in healthy subjects (P = 0.045). Three-dimensional Transit allows assessment of regional GITT in patients with diarrhea. Patients with carcinoid diarrhea have faster than normal gastrointestinal transit due to faster small intestinal and colorectal transit times. The latter is caused by an increased frequency of pansegmental colonic movements.

Dynamical Detection of Topological Phase Transitions in Short-Lived Atomic Systems

Science.gov (United States)

Setiawan, F.; Sengupta, K.; Spielman, I. B.; Sau, Jay D.

2015-11-01

We demonstrate that dynamical probes provide direct means of detecting the topological phase transition (TPT) between conventional and topological phases, which would otherwise be difficult to access because of loss or heating processes. We propose to avoid such heating by rapidly quenching in and out of the short-lived topological phase across the transition that supports gapless excitations. Following the quench, the distribution of excitations in the final conventional phase carries signatures of the TPT. We apply this strategy to study the TPT into a Majorana-carrying topological phase predicted in one-dimensional spin-orbit-coupled Fermi gases with attractive interactions. The resulting spin-resolved momentum distribution, computed by self-consistently solving the time-dependent Bogoliubov-de Gennes equations, exhibits Kibble-Zurek scaling and Stückelberg oscillations characteristic of the TPT. We discuss parameter regimes where the TPT is experimentally accessible.

Valuing real estate externality-based option in development of transit system projects.

Science.gov (United States)

2010-03-01

Capital-intensive transit projects rely on strong public support and availability of funds. While the general : public has become a strong advocate for transit systems, budget shortfalls and financial constraints are still : resulting in delays in pr...

Energy transition and phasing out nuclear

International Nuclear Information System (INIS)

Laponche, Bernard

2013-05-01

In the first part of this report, the author outlines and comments the need of an energy transition in the world: overview of world challenges (world energy consumption and its constraints, a necessary energy transition, new actors and new responsibilities), and describes the German example of an energy transition policy. In the second part, he presents and discusses the main reasons for phasing out nuclear: description of a nuclear plant operation (fission and chain reaction, heat production, production of radioactive elements, how to stop a nuclear reactor), safety and risk issues (protection arrangements, risk and consequence of a nuclear accident), issue of radioactive wastes, relationship between civil techniques and proliferation of nuclear weapons. In a third part, the author proposes an overview of the energy issue in France: final energy consumption, electricity production and consumption, primary energy consumption, characteristics of the French energy system (oil dependency, electricity consumption, and high share of nuclear energy in electricity production). In a last part, the author addresses the issue of energy transition in a perspective of phasing out nuclear: presentation of the Negawatt scenario, assessments made by Global Chance, main programmes of energy transition

High rate gamma spectroscopy system for activation analysis of short-lived isomeric transitions

Energy Technology Data Exchange (ETDEWEB)

Westphall, G P [Atominstitut der Oesterreichischen Hochschulen, Vienna

1976-07-15

A high rate spectroscopy system specially suited for measurement of short-lived isomeric transitions is described, which, as part of a fast activation analysis facility at the TRIGA Mark II reactor, provides for automatic recording and immediate evaluation of gamma spectra taken from nuclides activated at stationary or pulsed reactor power. The system consists of a commercial de-coupled Ge(Li)-detector of 70 cm/sup 3/ modified for recycling operation for input rates in excess of 500000 c/s /sup 60/Co, a time variant trapezoidal shaping section and a fast constant dead-time ADC coupled to a programmed multichannel analyzer. Novel circuits for efficient pile-up rejection and time variant base line restoration extend the concept of gated integration up to count rates of more than 200000 c/s /sup 60/Co. Time-sequenced recording of spectra is performed by a minicomputer operated as a front-end processor of a larger laboratory computer, where final data processing takes place. New concepts for very simple and cost-effective implementation of multichannel analyzers by means of general purpose small computers are described.

Structural transitions and hysteresis in clump- and stripe-forming systems under dynamic compression

International Nuclear Information System (INIS)

McDermott, Danielle; Reichhardt, Charles

2016-01-01

In using numerical simulations, we study the dynamical evolution of particles interacting via competing long-range repulsion and short-range attraction in two dimensions. The particles are compressed using a time-dependent quasi-one dimensional trough potential that controls the local density, causing the system to undergo a series of structural phase transitions from a low density clump lattice to stripes, voids, and a high density uniform state. The compression proceeds via slow elastic motion that is interrupted with avalanche-like bursts of activity as the system collapses to progressively higher densities via plastic rearrangements. The plastic events vary in magnitude from small rearrangements of particles, including the formation of quadrupole-like defects, to large-scale vorticity and structural phase transitions. In the dense uniform phase, the system compresses through row reduction transitions mediated by a disorder-order process. We also characterize the rearrangement events by measuring changes in the potential energy, the fraction of sixfold coordinated particles, the local density, and the velocity distribution. At high confinements, we find power law scaling of the velocity distribution during row reduction transitions. We observe hysteresis under a reversal of the compression when relatively few plastic rearrangements occur. The decompressing system exhibits distinct phase morphologies, and the phase transitions occur at lower compression forces as the system expands compared to when it is compressed.

Flexible fuel cycle system for the transition from LWR to FBR

International Nuclear Information System (INIS)

Fukasawa, Tetsuo; Yamashita, Junichi; Hoshino, Kuniyoshi; Sasahira, Akira; Inoue, Tadashi; Minato, Kazuo; Sato, Seichi

2009-01-01

Japan will deploy commercial fast breeder reactor (FBR) from around 2050 under the suitable conditions for the replacement of light water reactor (LWR) with FBR. The transition scenario from LWR to FBR is investigated in detail and the flexible fuel cycle initiative (FFCI) system has been proposed as a optimum transition system. The FFCI removes ∼95% uranium from LWR spent fuel (SF) in LWR reprocessing and residual material named Recycle Material (RM), which is ∼1/10 volume of original SF and contains ∼50% U, ∼10% Pu and ∼40% other nuclides, is treated in FBR reprocessing to recover Pu and U. If the FBR deployment speed becomes lower, the RM will be stored until the higher speed again. The FFCI has some merits compared with ordinary system that consists of full reprocessing facilities for both LWR and FBR SF during the transition period. The economy is better for FFCI due to the smaller LWR reprocessing facility (no Pu/U recovery and fabrication). The FFCI can supply high Pu concentration RM, which has high proliferation resistance and flexibly respond to FBR introduction rate changes. Volume minimization of LWR SF is possible for FFCI by its conversion to RM. Several features of FFCI were quantitatively evaluated such as Pu mass balance, reprocessing capacities, LWR SF amounts, RM amounts, and proliferation resistance to compare the effectiveness of the FFCI system with other systems. The calculated Pu balance revealed that the FFCI could supply enough but no excess Pu to FBR. These evaluations demonstrated the applicability of FFCI system to the transition period from LWR to FBR cycles. (author)

Transiting Exoplanet Monitoring Project (TEMP). II. Refined System Parameters and Transit Timing Analysis of HAT-P-33b

Science.gov (United States)

Wang, Yong-Hao; Wang, Songhu; Liu, Hui-Gen; Hinse, Tobias C.; Laughlin, Gregory; Wu, Dong-Hong; Zhang, Xiaojia; Zhou, Xu; Wu, Zhenyu; Zhou, Ji-Lin; Wittenmyer, R. A.; Eastman, Jason; Zhang, Hui; Hori, Yasunori; Narita, Norio; Chen, Yuanyuan; Ma, Jun; Peng, Xiyan; Zhang, Tian-Meng; Zou, Hu; Nie, Jun-Dan; Zhou, Zhi-Min

2017-08-01

We present 10 R-band photometric observations of eight different transits of the hot Jupiter HAT-P-33b, which has been targeted by our Transiting Exoplanet Monitoring Project. The data were obtained by two telescopes at the Xinglong Station of National Astronomical Observatories of China (NAOC) from 2013 December through 2016 January, and exhibit photometric scatter of 1.6{--}3.0 {mmag}. After jointly analyzing the previously published photometric data, radial-velocity (RV) measurements, and our new light curves, we revisit the system parameters and orbital ephemeris for the HAT-P-33b system. Our results are consistent with the published values except for the planet to star radius ratio ({R}{{P}}/{R}* ), the ingress/egress duration (τ) and the total duration (T 14), which together indicate a slightly shallower and shorter transit shape. Our results are based on more complete light curves, whereas the previously published work had only one complete transit light curve. No significant anomalies in Transit Timing Variations (TTVs) are found, and we place upper mass limits on potential perturbers, largely supplanting the loose constraints provided by the extant RV data. The TTV limits are stronger near mean-motion resonances, especially for the low-order commensurabilities. We can exclude the existence of a perturber with mass larger than 0.6, 0.3, 0.5, 0.5, and 0.3 {M}\\oplus near the 1:3, 1:2, 2:3, 3:2, and 2:1 resonances, respectively.

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

Science.gov (United States)

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

Sampling Transition Pathways in Highly Correlated Complex Systems

Energy Technology Data Exchange (ETDEWEB)

Chandler, David

2004-10-20

This research grant supported my group's efforts to apply and extend the method of transition path sampling that we invented during the late 1990s. This methodology is based upon a statistical mechanics of trajectory space. Traditional statistical mechanics focuses on state space, and with it, one can use Monte Carlo methods to facilitate importance sampling of states. With our formulation of a statistical mechanics of trajectory space, we have succeeded at creating algorithms by which importance sampling can be done for dynamical processes. In particular, we are able to study rare but important events without prior knowledge of transition states or mechanisms. In perhaps the most impressive application of transition path sampling, my group combined forces with Michele Parrinello and his coworkers to unravel the dynamics of auto ionization of water [5]. This dynamics is the fundamental kinetic step of pH. Other applications concern nature of dynamics far from equilibrium [1, 7], nucleation processes [2], cluster isomerization, melting and dissociation [3, 6], and molecular motors [10]. Research groups throughout the world are adopting transition path sampling. In part this has been the result of our efforts to provide pedagogical presentations of the technique [4, 8, 9], as well as providing new procedures for interpreting trajectories of complex systems [11].

FINAL TECHNICAL REPORT Synthetic, Structural and Mechanistic Investigations of Olefin Polymerization Catalyzed by Early Transition Metal Compounds

Energy Technology Data Exchange (ETDEWEB)

Bercaw, John E. [California Institute of Technology

2014-05-23

The goal of this project is to develop new catalysts and provide understanding of ligand effects on catalyst composition in order to guide development of superior catalyst systems for polymerization of olefins. Our group is designing and synthesizing new “LX2”,“pincer” type ligands and complexing early transition metals to afford precatalysts. In a collaboration with Hans Brintzinger from the University of Konstanz, we are also examining the structures of the components of catalyst systems obtained from reaction of zirconocene dichlorides with aluminum alkyls and aluminum hydrides. Such systems are currently used commercially to produce polyolefins, but the nature of the active and dormant species as well as the mechanisms of their interconversions are not understood. New information on catalyst design and performance may lead to new types of polymers and/or new chemical transformations between hydrocarbons and transition metal centers, ultimately contributing to the development of catalytic reactions for the production of fuels, commodity and polymeric materials.

Phase transitions in glassy systems via convolutional neural networks

Science.gov (United States)

Fang, Chao

Machine learning is a powerful approach commonplace in industry to tackle large data sets. Most recently, it has found its way into condensed matter physics, allowing for the first time the study of, e.g., topological phase transitions and strongly-correlated electron systems. The study of spin glasses is plagued by finite-size effects due to the long thermalization times needed. Here we use convolutional neural networks in an attempt to detect a phase transition in three-dimensional Ising spin glasses. Our results are compared to traditional approaches.

The roles of users in shaping transitions to new energy systems

Science.gov (United States)

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.

Weyl Semimetal to Metal Phase Transitions Driven by Quasiperiodic Potentials

Science.gov (United States)

Pixley, J. H.; Wilson, Justin H.; Huse, David A.; Gopalakrishnan, Sarang

2018-05-01

We explore the stability of three-dimensional Weyl and Dirac semimetals subject to quasiperiodic potentials. We present numerical evidence that the semimetal is stable for weak quasiperiodic potentials, despite being unstable for weak random potentials. As the quasiperiodic potential strength increases, the semimetal transitions to a metal, then to an "inverted" semimetal, and then finally to a metal again. The semimetal and metal are distinguished by the density of states at the Weyl point, as well as by level statistics, transport, and the momentum-space structure of eigenstates near the Weyl point. The critical properties of the transitions in quasiperiodic systems differ from those in random systems: we do not find a clear critical scaling regime in energy; instead, at the quasiperiodic transitions, the density of states appears to jump abruptly (and discontinuously to within our resolution).

Energy study of rail passenger transportation. Volume 2. Description of operating systems. Final report

Energy Technology Data Exchange (ETDEWEB)

Henderson, C.; Ellis, H. T.; Wilhelm, J. P.

1979-08-01

The rail passenger systems of the US are described in terms of selected physical, operating, and economic characteristics, and relates services rendered to energy usage and costs. Rail passenger transportation exists in 4 distinct forms: intercity railroads, suburban railroads, heavy-rail transit, and light-rail transit. Each form varies in technical equipment, design of facilities, operating practices, size of systems. Specific data for the national rail passenger network and the Boston, Chicago, Cleveland, New York, Philadelphia, Pittsburgh, and San Francisco regions and the Washington Metropolitan area transit authority are presented.

ARCHITECTURE AND DYNAMICS OF KEPLER'S CANDIDATE MULTIPLE TRANSITING PLANET SYSTEMS

Energy Technology Data Exchange (ETDEWEB)

Lissauer, Jack J.; Jenkins, Jon M.; Borucki, William J.; Bryson, Stephen T.; Howell, Steve B. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Ragozzine, Darin; Holman, Matthew J.; Carter, Joshua A. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Fabrycky, Daniel C.; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, Batavia, IL 60510 (United States); Ford, Eric B. [211 Bryant Space Science Center, University of Florida, Gainesville, FL 32611 (United States); Shporer, Avi [Las Cumbres Observatory Global Telescope Network, Santa Barbara, CA 93117 (United States); Rowe, Jason F.; Quintana, Elisa V.; Caldwell, Douglas A. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Ciardi, David [Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Dunham, Edward W. [Lowell Observatory, Flagstaff, AZ 86001 (United States); Gautier, Thomas N. III, E-mail: Jack.Lissauer@nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); and others

2011-11-01

About one-third of the {approx}1200 transiting planet candidates detected in the first four months of Kepler data are members of multiple candidate systems. There are 115 target stars with two candidate transiting planets, 45 with three, 8 with four, and 1 each with five and six. We characterize the dynamical properties of these candidate multi-planet systems. The distribution of observed period ratios shows that the vast majority of candidate pairs are neither in nor near low-order mean-motion resonances. Nonetheless, there are small but statistically significant excesses of candidate pairs both in resonance and spaced slightly too far apart to be in resonance, particularly near the 2:1 resonance. We find that virtually all candidate systems are stable, as tested by numerical integrations that assume a nominal mass-radius relationship. Several considerations strongly suggest that the vast majority of these multi-candidate systems are true planetary systems. Using the observed multiplicity frequencies, we find that a single population of planetary systems that matches the higher multiplicities underpredicts the number of singly transiting systems. We provide constraints on the true multiplicity and mutual inclination distribution of the multi-candidate systems, revealing a population of systems with multiple super-Earth-size and Neptune-size planets with low to moderate mutual inclinations.

78 FR 50313 - Physical Protection of Irradiated Reactor Fuel in Transit

Science.gov (United States)

2013-08-19

... Irradiated Reactor Fuel in Transit AGENCY: Nuclear Regulatory Commission. ACTION: Orders; rescission. SUMMARY... the NRC published a final rule, ``Physical Protection of Irradiated Fuel in Transit,'' on May 20, 2013... of Irradiated Reactor Fuel in Transit'' (RIN 3150-AI64; NRC-2009-0163). The final rule incorporates...

TRANSIT TIMING OBSERVATIONS FROM KEPLER. VI. POTENTIALLY INTERESTING CANDIDATE SYSTEMS FROM FOURIER-BASED STATISTICAL TESTS

International Nuclear Information System (INIS)

Steffen, Jason H.; Ford, Eric B.; Rowe, Jason F.; Borucki, William J.; Bryson, Steve; Caldwell, Douglas A.; Jenkins, Jon M.; Koch, David G.; Sanderfer, Dwight T.; Seader, Shawn; Twicken, Joseph D.; Fabrycky, Daniel C.; Holman, Matthew J.; Welsh, William F.; Batalha, Natalie M.; Ciardi, David R.; Kjeldsen, Hans; Prša, Andrej

2012-01-01

We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies.

Transit timing observations from Kepler. VI. Potentially interesting candidate systems from fourier-based statistical tests

DEFF Research Database (Denmark)

Steffen, J.H.; Ford, E.B.; Rowe, J.F.

2012-01-01

We analyze the deviations of transit times from a linear ephemeris for the Kepler Objects of Interest (KOI) through quarter six of science data. We conduct two statistical tests for all KOIs and a related statistical test for all pairs of KOIs in multi-transiting systems. These tests identify...... several systems which show potentially interesting transit timing variations (TTVs). Strong TTV systems have been valuable for the confirmation of planets and their mass measurements. Many of the systems identified in this study should prove fruitful for detailed TTV studies....

Assessing transition trajectories towards a sustainable energy system: A case study on the Dutch transition to climate-neutral transport fuel chains

NARCIS (Netherlands)

Suurs, R.A.A.; Hekkert, M.P.; Meeus, M.T.H.; Nieuwlaar, E.

2004-01-01

This paper proposes a method for the ex ante evaluation of technological trajectories. As a case we study the Dutch transport energy system and its transition to climate neutrality. Two technological trajectories are proposed: (i) a sequence of transition steps based on radical infrastructural

Multifragmentation of heavy systems: partitions and phase transition signals; Multifragmentation de systemes lourds: partitions et signaux de transition de phases

Energy Technology Data Exchange (ETDEWEB)

Bonnet, E

2006-09-15

This work studies mononuclear systems produced in heavy ion collisions with large (peripheral: Au+Au) and small (central: Xe+Sn et Gd+U) impact parameters. These two classes of collisions need specific selections in order to isolate sources in thermal equilibrium (quasi-projectiles and quasi-fusion sources). We perform analyses on the statistical ensembles of events obtained after those selections to evidence phase transition signatures. First, a bimodal behaviour of the biggest fragment (Z{sub 1}) distribution, in peripheral collisions, is related to an order parameter using a renormalisation with an equiprobable excitation energy (E{sup *}) distribution constraint. A comparison with a canonical ensemble gives us information on the coexistence region location. Then, we compare static and dynamical properties of fragments produced by these sources in peripheral and central collisions. Differences on fragment multiplicities and charge asymmetry of partitions are observed. They find their origins in the presence or not of a velocity field mostly related to collective radial expansion during fragment formation. Analyses of the signal related to abnormal fluctuations of configurational energies and of the fossil signal related to spinodal decomposition for Au quasi-projectiles are performed to establish a link with the same signals already observed for central collisions. Finally, the location of events of the two types of sources in the E{sup *} - Z{sub 1} plane, are compared with a phase diagram, particularly the boundaries of the coexistence region deduced from the previous signals. (author)

Plutonium Finishing Plant Transition Project mission analysis report

International Nuclear Information System (INIS)

Courson, D.B.

1994-01-01

This report defines the mission for the Plutonium Finishing Plant Transition Project (PFPTP) using a systems engineering approach. This mission analysis will be the basis for the functional analysis which will further define and break down the mission statement into all of the detailed functions required to accomplish the mission. The functional analysis is then used to develop requirements, allocate those requirements to functions, and eventually be used to design the system. This report: presents the problem which will be addressed, defines PFP Transition Project, defines the overall mission statement, describes the existing, initial conditions, defines the desired, final conditions, identifies the mission boundaries and external interfaces, identifies the resources required to carry out the mission, describes the uncertainties and risks, and discusses the measures which will be used to determine success

49 CFR 38.173 - Automated guideway transit vehicles and systems.

Science.gov (United States)

2010-10-01

... accomplished by vehicle air suspension or other suitable means of meeting the requirement. (c) In stations... 49 Transportation 1 2010-10-01 2010-10-01 false Automated guideway transit vehicles and systems... DISABILITIES ACT (ADA) ACCESSIBILITY SPECIFICATIONS FOR TRANSPORTATION VEHICLES Other Vehicles and Systems § 38...

Polydispersity effect on solid-fluid transition in hard sphere systems

KAUST Repository

Nogawa, T.

2010-02-01

The solid-fluid transition of the hard elastic particle system with size polydispersity is studied by molecular dynamics simulations. Using nonequilibrium relaxation from the mixed initial condition we determines the melting point where the first order transition between the solid, fcc crystal, and fluid states occurs. It is found that the density gap between the bistable states decreases with increasing the strength of the polydispersity and continuously approaches to zero at the critical point. © 2010.

Hysteresis, phase transitions, and dangerous transients in electrical power distribution systems.

Science.gov (United States)

Duclut, Charlie; Backhaus, Scott; Chertkov, Michael

2013-06-01

The majority of dynamical studies in power systems focus on the high-voltage transmission grids where models consider large generators interacting with crude aggregations of individual small loads. However, new phenomena have been observed indicating that the spatial distribution of collective, nonlinear contribution of these small loads in the low-voltage distribution grid is crucial to the outcome of these dynamical transients. To elucidate the phenomenon, we study the dynamics of voltage and power flows in a spatially extended distribution feeder (circuit) connecting many asynchronous induction motors and discover that this relatively simple 1+1 (space+time) dimensional system exhibits a plethora of nontrivial spatiotemporal effects, some of which may be dangerous for power system stability. Long-range motor-motor interactions mediated by circuit voltage and electrical power flows result in coexistence and segregation of spatially extended phases defined by individual motor states, a "normal" state where the motors' mechanical (rotation) frequency is slightly smaller than the nominal frequency of the basic ac flows and a "stalled" state where the mechanical frequency is small. Transitions between the two states can be initiated by a perturbation of the voltage or base frequency at the head of the distribution feeder. Such behavior is typical of first-order phase transitions in physics, and this 1+1 dimensional model shows many other properties of a first-order phase transition with the spatial distribution of the motors' mechanical frequency playing the role of the order parameter. In particular, we observe (a) propagation of the phase-transition front with the constant speed (in very long feeders) and (b) hysteresis in transitions between the normal and stalled (or partially stalled) phases.

Land use impacts of rapid transit: implications of recent experience. Final report

Energy Technology Data Exchange (ETDEWEB)

Knight, R.L.; Trygg, L.L.

1977-08-01

Evidence of land use impacts of recent major rapid transit improvements are reviewed and conclusions drawn concerning the extent and nature of such impacts and the conditions under which they have occurred. Transit improvements studied are primarily post-World War II in origin. American and Canadian examples are stressed, although European experience is teated briefly. Virtually all major modern American and Canadian rapid transit investments are included, covering conventional rapid rail, commuter rail, light rail and bus/busway. In addition to conclusions on general patterns of land use impact and causes, research recommendations and Federal policy implications are drawn.

Transition from closed system to Internet of Things: A study in standardizing building lighting systems

NARCIS (Netherlands)

Mathews, E.; Muller, G.

2016-01-01

Internet of Things (IoT) is triggering changes in lighting industry from the traditional closed and propriety systems to flexible, interoperable and service oriented systems. To address the challenges of this transition and catering the specific requirements of lighting networks, an Open

An Intelligent System Proposal for Improving the Safety and Accessibility of Public Transit by Highway

Directory of Open Access Journals (Sweden)

Carmelo R. García

2015-08-01

Full Text Available The development of public transit systems that are accessible and safe for everyone, including people with special needs, is an objective that is justified from the civic and economic points of view. Unfortunately, public transit services are conceived for people who do not have reduced physical or cognitive abilities. In this paper, we present an intelligent public transit system by highway with the goal of facilitating access and improving the safety of public transit for persons with special needs. The system is deployed using components that are commonly available in transport infrastructure, e.g., sensors, mobile communications systems, and positioning systems. In addition, the system can operate in non-urban transport contexts, e.g., isolated rural areas, where the availability of basic infrastructure, such as electricity and communications infrastructures, is not always guaranteed. To construct the system, the principles and techniques of Ubiquitous Computing and Ambient Intelligence have been employed. To illustrate the utility of the system, two cases of services rendered by the system are described: the first case involves a surveillance system to guarantee accessibility at bus stops; the second case involves a route assistant for blind people.

Variational Transition State Theory

Energy Technology Data Exchange (ETDEWEB)

Truhlar, Donald G. [Univ. of Minnesota, Minneapolis, MN (United States)

2016-09-29

This is the final report on a project involving the development and applications of variational transition state theory. This project involved the development of variational transition state theory for gas-phase reactions, including optimized multidimensional tunneling contributions and the application of this theory to gas-phase reactions with a special emphasis on developing reaction rate theory in directions that are important for applications to combustion. The development of variational transition state theory with optimized multidimensional tunneling as a useful computational tool for combustion kinetics involved eight objectives.

Nuclear quantum shape-phase transitions in odd-mass systems

Science.gov (United States)

Quan, S.; Li, Z. P.; Vretenar, D.; Meng, J.

2018-03-01

Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and E 2 reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number N =90 compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

FINAL IMPLEMENTATION AND PERFORMANCE OF THE LHC COLLIMATOR CONTROL SYSTEM

CERN Document Server

Redaelli, S; Masi, A; Losito, R

2009-01-01

The 2008 collimation system of the CERN Large Hadron Collider (LHC) included 80 movable collimators for a total of 316 degrees of freedom. Before beam operation, the final controls implementation was deployed and commissioned. The control system enabled remote control and appropriate diagnostics of the relevant parameters. The collimator motion is driven with time-functions, synchronized with other accelerator systems, which allows controlling the collimator jaw positions with a micrometer accuracy during all machine phases. The machine protection functionality of the system, which also relies on function-based tolerance windows, was also fully validated. The collimator control challenges are reviewed and the final system architecture is presented. The results of the remote system commissioning and the overall performance are discussed.

FOCUS: a fire management planning system -- final report

Science.gov (United States)

Frederick W. Bratten; James B. Davis; George T. Flatman; Jerold W. Keith; Stanley R. Rapp; Theodore G. Storey

1981-01-01

FOCUS (Fire Operational Characteristics Using Simulation) is a computer simulation model for evaluating alternative fire management plans. This final report provides a broad overview of the FOCUS system, describes two major modules-fire suppression and cost, explains the role in the system of gaming large fires, and outlines the support programs and ways of...

Deep learning the quantum phase transitions in random two-dimensional electron systems

International Nuclear Information System (INIS)

Ohtsuki, Tomoki; Ohtsuki, Tomi

2016-01-01

Random electron systems show rich phases such as Anderson insulator, diffusive metal, quantum Hall and quantum anomalous Hall insulators, Weyl semimetal, as well as strong/weak topological insulators. Eigenfunctions of each matter phase have specific features, but owing to the random nature of systems, determining the matter phase from eigenfunctions is difficult. Here, we propose the deep learning algorithm to capture the features of eigenfunctions. Localization-delocalization transition, as well as disordered Chern insulator-Anderson insulator transition, is discussed. (author)

A complex systems methodology to transition management

NARCIS (Netherlands)

Alkemade, F.; Frenken, K.; Hekkert, M.P.; Schwoon, M.

2009-01-01

There is a general sense of urgency that major technological transitions are required for sustainable development. Such transitions are best perceived as involving multiple transition steps along a transition path. Due to the path dependent and irreversible nature of innovation in complex

Unconventional Topological Phase Transition in Two-Dimensional Systems with Space-Time Inversion Symmetry

Science.gov (United States)

Ahn, Junyeong; Yang, Bohm-Jung

2017-04-01

We study a topological phase transition between a normal insulator and a quantum spin Hall insulator in two-dimensional (2D) systems with time-reversal and twofold rotation symmetries. Contrary to the case of ordinary time-reversal invariant systems, where a direct transition between two insulators is generally predicted, we find that the topological phase transition in systems with an additional twofold rotation symmetry is mediated by an emergent stable 2D Weyl semimetal phase between two insulators. Here the central role is played by the so-called space-time inversion symmetry, the combination of time-reversal and twofold rotation symmetries, which guarantees the quantization of the Berry phase around a 2D Weyl point even in the presence of strong spin-orbit coupling. Pair creation and pair annihilation of Weyl points accompanying partner exchange between different pairs induces a jump of a 2D Z2 topological invariant leading to a topological phase transition. According to our theory, the topological phase transition in HgTe /CdTe quantum well structure is mediated by a stable 2D Weyl semimetal phase because the quantum well, lacking inversion symmetry intrinsically, has twofold rotation about the growth direction. Namely, the HgTe /CdTe quantum well can show 2D Weyl semimetallic behavior within a small but finite interval in the thickness of HgTe layers between a normal insulator and a quantum spin Hall insulator. We also propose that few-layer black phosphorus under perpendicular electric field is another candidate system to observe the unconventional topological phase transition mechanism accompanied by the emerging 2D Weyl semimetal phase protected by space-time inversion symmetry.

Sustainable transition of socio-technological systems: How can Governance Network Research and Transition Theory contribute to the transition to biofuel for transportation?

DEFF Research Database (Denmark)

Hansen, Ole Erik; Stærdahl, Jens; Søndergård, Bent

-technological systems, calling attention to how such governance structures emerge, stabilize and become dominant, which functions governance structures have to serve to become efficient, and how they can be made subject to deliberate and purposeful shaping and transition. Taking this approach, research in planning...

Dynamics of process at the final stage of nuclear fission

International Nuclear Information System (INIS)

Koljari, I.G.; Mavlitov, N.D.

2005-01-01

Numerous experimental data show, that the final stage of nuclear fission near to a scission point plays an essential role at formation of characteristics of fission products. At the description of a final stage of fission there is a number of problems: Definition of the form of the nuclear near the scission point and definition forms of a fission fragments; The account of dynamic processes in compound nuclear directly before of fission. The condition of the quasistatic al adiabatic process - dS/dt=0 - is applied in a point of transition from the uniform compound nuclei to several forms for definition of generalized coordinates and speeds. Calculation of dependence of post neutrons from nuclear mass of fission fragments for reactions is α+ 83 Bi 209 → 85 At 213 (E lab = 45 MeV); α+ 92 U 242 → 94 Pu 242 (E lab = 45 MeV); 8 O 18 + 79 Au 197 → 97 Fr 215 (E lab = 159 MeV). System of equations, which describes behaviour of system in a point of nuclear fission-transition from the uniform form to system of a two (and, probably more) fission fragments is given. The system of the equations allows in a fission point to define the generalized coordinates, and the generalized speeds for each of the generalized coordinates of collective deformation variables

Phase transition in a spatial Lotka-Volterra model

International Nuclear Information System (INIS)

Szabo, Gyorgy; Czaran, Tamas

2001-01-01

Spatial evolution is investigated in a simulated system of nine competing and mutating bacterium strains, which mimics the biochemical war among bacteria capable of producing two different bacteriocins (toxins) at most. Random sequential dynamics on a square lattice is governed by very symmetrical transition rules for neighborhood invasions of sensitive strains by killers, killers by resistants, and resistants by sensitives. The community of the nine possible toxicity/resistance types undergoes a critical phase transition as the uniform transmutation rates between the types decreases below a critical value P c above that all the nine types of strains coexist with equal frequencies. Passing the critical mutation rate from above, the system collapses into one of three topologically identical (degenerated) states, each consisting of three strain types. Of the three possible final states each accrues with equal probability and all three maintain themselves in a self-organizing polydomain structure via cyclic invasions. Our Monte Carlo simulations support that this symmetry-breaking transition belongs to the universality class of the three-state Potts model

Detecting critical state before phase transition of complex biological systems by hidden Markov model.

Science.gov (United States)

Chen, Pei; Liu, Rui; Li, Yongjun; Chen, Luonan

2016-07-15

Identifying the critical state or pre-transition state just before the occurrence of a phase transition is a challenging task, because the state of the system may show little apparent change before this critical transition during the gradual parameter variations. Such dynamics of phase transition is generally composed of three stages, i.e. before-transition state, pre-transition state and after-transition state, which can be considered as three different Markov processes. By exploring the rich dynamical information provided by high-throughput data, we present a novel computational method, i.e. hidden Markov model (HMM) based approach, to detect the switching point of the two Markov processes from the before-transition state (a stationary Markov process) to the pre-transition state (a time-varying Markov process), thereby identifying the pre-transition state or early-warning signals of the phase transition. To validate the effectiveness, we apply this method to detect the signals of the imminent phase transitions of complex systems based on the simulated datasets, and further identify the pre-transition states as well as their critical modules for three real datasets, i.e. the acute lung injury triggered by phosgene inhalation, MCF-7 human breast cancer caused by heregulin and HCV-induced dysplasia and hepatocellular carcinoma. Both functional and pathway enrichment analyses validate the computational results. The source code and some supporting files are available at https://github.com/rabbitpei/HMM_based-method lnchen@sibs.ac.cn or liyj@scut.edu.cn Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The Homogeneity Research of Urban Rail Transit Network Performance

Directory of Open Access Journals (Sweden)

Wang Fu-jian

2016-01-01

Full Text Available Urban Rail Transit is an important part of the public transit, it is necessary to carry out the corresponding network function analysis. Previous studies mainly about network performance analysis of a single city rail transit, lacking of horizontal comparison between the multi-city, it is difficult to find inner unity of different Urban Rail Transit network functions. Taking into account the Urban Rail Transit network is a typical complex networks, so this paper proposes the application of complex network theory to research the homogeneity of Urban Rail Transit network performance. This paper selects rail networks of Beijing, Shanghai, Guangzhou as calculation case, gave them a complex network mapping through the L, P Space method and had a static topological analysis using complex network theory, Network characteristics in three cities were calculated and analyzed form node degree distribution and node connection preference. Finally, this paper studied the network efficiency changes of Urban Rail Transit system under different attack mode. The results showed that, although rail transport network size, model construction and construction planning of the three cities are different, but their network performance in many aspects showed high homogeneity.

Agent Based Model in SAS Environment for Rail Transit System Alignment Determination

Directory of Open Access Journals (Sweden)

I Made Indradjaja Brunner

2018-04-01

Full Text Available Transit system had been proposed for the urban area of Honolulu. One consideration to be determined is the alignment of the transit system. Decision to set the transit alignment will have influences on which areas will be served, who will be benefiting, as well as who will be impacted. Inputs for the decision usually conducted through public meetings, where community members are shown numbers of maps with pre-set routes. That approach could lead to a rather subjective decision by the community members. This paper attempts to discuss the utilization of grid map in determining the best alignment for rail transit system in Honolulu, Hawaii. It tries to use a more objective approach using various data derived from thematic maps. Overlaid maps are aggregated into a uniform 0.1-square mile vector based grid map system in GIS environment. The large dataset in the GIS environment is analyzed and manipulated using SAS software. The SAS procedure is applied to select the location of the alignment using a rational and deterministic approach. Grid cells that are superior compared to the others are selected based on several predefined criteria. Location of the dominant cells indicates possible transit alignment. The SAS procedure is designed to allow a transient vector called the GUIDE (Grid Unit with Intelligent Directional Expertise agent to analyze several cells at its vicinity and to move towards a cell with the highest value. Each time the agent landed on a cell, it left a mark. The chain of those marks shows location for the transit alignment. This study shows that the combination of ArcGIS and SAS allows a robust analysis of spatial data and manipulation of its datasets, which can be used to run a simulation mimicking the Agent-Based Modelling. This study also opens up further study possibilities by increasing number of factors analyzed by the agent, as well as creating a composite value of multi-factors.

Phase transitions

CERN Document Server

Sole, Ricard V; Solé, Ricard V; Solé, Ricard V; Sol, Ricard V; Solé, Ricard V

2011-01-01

Phase transitions--changes between different states of organization in a complex system--have long helped to explain physics concepts, such as why water freezes into a solid or boils to become a gas. How might phase transitions shed light on important problems in biological and ecological complex systems? Exploring the origins and implications of sudden changes in nature and society, Phase Transitions examines different dynamical behaviors in a broad range of complex systems. Using a compelling set of examples, from gene networks and ant colonies to human language and the degradation of diverse ecosystems, the book illustrates the power of simple models to reveal how phase transitions occur. Introductory chapters provide the critical concepts and the simplest mathematical techniques required to study phase transitions. In a series of example-driven chapters, Ricard Solé shows how such concepts and techniques can be applied to the analysis and prediction of complex system behavior, including the origins of ...

Optical excitations of transition-metal oxides under the orbital multiplicity effects

International Nuclear Information System (INIS)

Lee, J S; Kim, M W; Noh, T W

2005-01-01

We investigated optical excitations of transition-metal (TM) oxides with metal oxygen octahedra taking account of the orbital multiplicity effects. We predicted excitation energies of intersite d-d transitions and p-d transitions of TM oxides. We compared the evaluated excitation energies with reported experimental data, and found that they are in good agreement with each other. Moreover, we could demonstrate possible answers for a few long-standing problems of the low-frequency spectral features in some early 3d TM oxides: (i) the broad and multi-peak structures of the d-d transitions (ii) the low values (around 2 eV) of the d-d transition energies for some t 2g 1 and t 2g 2 systems, and (iii) the lack of the d-d transition below 4.0 eV region for LaCrO 3 , one of the t 2g 3 systems. These indicate that our approach considering the orbital multiplicity effects could provide good explanations of intriguing features in the optical spectra of some early TM oxides. In addition, we showed that optical spectroscopy can be useful as a powerful tool to investigate spin and/or orbital correlations in the TM ions. Finally, we discussed the implications of the orbital multiplicity in the Zannen-Sawatzky-Allen scheme, which has been used successfully to classify correlated electron systems

Homogeneous Photodynamical Analysis of Kepler's Multiply-Transiting Systems

Science.gov (United States)

Ragozzine, Darin

To search for planets more like our own, NASA s Kepler Space Telescope ( Kepler ) discovered thousands of exoplanet candidates that cross in front of ( transit ) their parent stars (e.g., Twicken et al. 2016). The Kepler exoplanet data represent an incredible observational leap forward as evidenced by hundreds of papers with thousands of citations. In particular, systems with multiple transiting planets combine the determination of physical properties of exoplanets (e.g., radii), the context provided by the system architecture, and insights from orbital dynamics. Such systems are the most information-rich exoplanetary systems (Ragozzine & Holman 2010). Thanks to Kepler s revolutionary dataset, understanding these Multi-Transiting Systems (MTSs) enables a wide variety of major science questions. In conclusion, existing analyses of MTSs are incomplete and suboptimal and our efficient and timely proposal will provide significant scientific gains ( 100 new mass measurements and 100 updated mass measurements). Furthermore, our homogeneous analysis enables future statistical analyses, including those necessary to characterize the small planet mass-radius relation with implications for understanding the formation, evolution, and habitability of planets. The overarching goal of this proposal is a complete homogeneous investigation of Kepler MTSs to provide detailed measurements (or constraints) on exoplanetary physical and orbital properties. Current investigations do not exploit the full power of the Kepler data; here we propose to use better data (Short Cadence observations), better methods (photodynamical modeling), and a better statistical method (Bayesian Differential Evolution Markov Chain Monte Carlo) in a homogenous analysis of all 700 Kepler MTSs. These techniques are particularly valuable for understanding small terrestrial planets. We propose to extract the near-maximum amount of information from these systems through a series of three research objectives

Deconfinement phase transition and finite-size scaling in SU(2) lattice gauge theory

International Nuclear Information System (INIS)

Mogilevskij, O.A.

1988-01-01

Calculation technique for deconfinement phase transition parameters based on application of finite-size scaling theory is suggested. The essence of the technique lies in plotting of universal scaling function on the basis of numerical data obtained at different-size final lattices and discrimination of phase transition parameters for infinite lattice system. Finite-size scaling technique was developed as applied to spin system theory. β critical index for Polyakov loop and SU(2) deconfinement temperature of lattice gauge theory are calculated on the basis of finite-size scaling technique. The obtained value agrees with critical index of magnetization in Ising three-dimensional model

Magnetic phase transitions in low dimension quantum spin systems

International Nuclear Information System (INIS)

Canevet, Emmanuel

2010-01-01

In this PhD thesis, three low dimensional spin systems are studied by means of elastic and inelastic neutron scattering. Macroscopic measurements in the DMACuCl 3 compound indicate the coexistence of two kinds of dimers: antiferromagnetic and ferromagnetic. The magnetic structure determined by our neutron diffraction survey at H = 0 shows irrevocably the existence of these two kinds of dimers. It has been shown that the Ising-like compound BaCo 2 V 2 O 8 should be the first realization of a system in which a longitudinal spin density wave (LSDW) magnetic order occurs when a magnetic field is applied. In a first time, we have determined the magnetic structure in zero magnetic field. Then, we focused on the effect of a magnetic field on the propagation vector, showing an entrance in the LSDW phase at H c = 3.9 T. The magnetic structure refined above this critical field confirms that BaCo 2 V 2 O 8 is the first compound in which occurs a LSDW phase. In the organic compound DF 5 PNN, it has been shown that this compound is well described at low temperature by spin chains with alternating couplings. However, the crystallographic structure determined at room temperature implies that the interactions are uniform. By means of neutron diffraction, we characterized a structural transition at low temperature (T c = 450 mK) making the system evolve from C2/c space group to Pc. This transition explains the alternating behavior of the interactions. We have also evidenced a field-induced structural transition (H c = 1.1 T). Above this field, the system is back to the C2/c space group, implying that the interactions are back to uniform. We have confirmed this by studying the magnetic excitations. (author) [fr

Unintended greenhouse gas consequences of lowering level of service in urban transit systems

International Nuclear Information System (INIS)

Griswold, Julia B; Cheng, Han; Madanat, Samer; Horvath, Arpad

2014-01-01

Public transit is often touted as a ‘green’ transportation option and a way for users to reduce their environmental footprint by avoiding automobile emissions, but that may not be the case when systems run well below passenger capacity. In previous work, we explored an approach to optimizing the design and operations of transit systems for both costs and emissions, using continuum approximation models and assuming fixed demand. In this letter, we expand upon our previous work to explore how the level of service for users impacts emissions. We incorporate travel time elasticities into the optimization to account for demand shifts from transit to cars, resulting from increases in transit travel time. We find that emissions reductions are moderated, but not eliminated, for relatively inelastic users. We consider two scenarios: the first is where only the agency faces an emissions budget; the second is where the entire city faces an emissions budget. In the latter scenario, the emissions reductions resulting from reductions in transit level of service are mitigated as users switch to automobile. (letter)

Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System

DEFF Research Database (Denmark)

Gregersen, Tine; Haase, Anne-Mette; Schlageter, Vincent

2015-01-01

BACKGROUND/AIMS: The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea re-stricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not ...

A New Approach for Determining Onset of Transition

Science.gov (United States)

Hassan, H. A.; Warren, E. S.

1997-01-01

The final report consists of three papers which outline and demonstrate the new method for determining transition onset. The procedure developed under this grant requires specification of the instability mechanism, i.e., Tollmien-Schlichting or crossflow, that leads to transition. The attached papers are entitled: 'An Alternative to the e(sup n) Method for Determining Onset of Transition', 'Transition Model for Swept Wing Flows', and 'A Transition Closure Model for Predicting Transition Onset'.

High-Density Quantum Sensing with Dissipative First Order Transitions

Science.gov (United States)

Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik

2018-04-01

The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to √{N }. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T2 coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.

High-Density Quantum Sensing with Dissipative First Order Transitions.

Science.gov (United States)

Raghunandan, Meghana; Wrachtrup, Jörg; Weimer, Hendrik

2018-04-13

The sensing of external fields using quantum systems is a prime example of an emergent quantum technology. Generically, the sensitivity of a quantum sensor consisting of N independent particles is proportional to sqrt[N]. However, interactions invariably occurring at high densities lead to a breakdown of the assumption of independence between the particles, posing a severe challenge for quantum sensors operating at the nanoscale. Here, we show that interactions in quantum sensors can be transformed from a nuisance into an advantage when strong interactions trigger a dissipative phase transition in an open quantum system. We demonstrate this behavior by analyzing dissipative quantum sensors based upon nitrogen-vacancy defect centers in diamond. Using both a variational method and a numerical simulation of the master equation describing the open quantum many-body system, we establish the existence of a dissipative first order transition that can be used for quantum sensing. We investigate the properties of this phase transition for two- and three-dimensional setups, demonstrating that the transition can be observed using current experimental technology. Finally, we show that quantum sensors based on dissipative phase transitions are particularly robust against imperfections such as disorder or decoherence, with the sensitivity of the sensor not being limited by the T_{2} coherence time of the device. Our results can readily be applied to other applications in quantum sensing and quantum metrology where interactions are currently a limiting factor.

Gas Transit Tariffs in Selected ECT Countries

International Nuclear Information System (INIS)

2006-01-01

One of the strategic aims of the Energy Charter process is to promote and facilitate efficient and uninhibited transit of energy materials and products across the ECT constituency. The Energy Charter process has recently been focusing its attention on the issues related to the transit of natural gas due to the increasing reliance on gas imports into Europe and other regions from more distant sources and across more borders. The transit tariffs (including their levels, structures and associated conditions) are, in addition to the terms of access to the transit infrastructure, one of the key factors affecting the cross-border gas flows. The main objectives of this study are to: review transit tariff methodologies for existing and new gas transit pipeline systems across selected ECT countries; compare transit tariff regimes for gas with those for domestic gas transport in the same countries; and assess the overall consistency of these transit tariffs with main provisions of ECT and draft Transit Protocol. The scope of this study is limited to transit tariffs for natural gas. Furthermore the study does not address the issue of access to gas pipelines which sometimes is a more important hurdle for gas flows than the levels of transit tariffs. Geographically, the study covers the following key gas transit countries: EU-25 plus Switzerland, and Non-EU: Belarus, Bulgaria, Georgia, Morocco, Tunisia, the Russian Federation, and Ukraine. Chapter 3 describes the existing flows of gas trade and transit across the ECT countries and points out potential deviations between physical and contractual flows. Chapter 4 reviews the theoretical approaches used for setting transit tariffs, including: Typical costs for new gas pipelines: construction costs, financing, operation and maintenance costs, country/project risks and their impact on costs; Valuation approaches for existing pipelines; and Treatment of system expansion. Chapter 5 compares the theory and the practice by describing

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

Science.gov (United States)

Kiyokawa, Shuji

2018-05-01

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

Demystifying governance and its role for transitions in urban social–ecological systems

Science.gov (United States)

T.A. Muñoz-Erickson; L.K. Campbell; D.L. Childers; J.M. Grove; D.M. Iwaniec; S.T.A. Pickett; Michelle Romolini; Erika S. Svendsen

2016-01-01

Governance is key to sustainable urban transitions. Governance is a system of social, power, and decision-making processes that acts as a key driver of resource allocation and use, yet ecologists even urban ecologists–seldom consider governance concepts in their work. Transitions to more sustainable futures are becoming increasingly important to the management of many...

Adlayer Core-Level Shifts of Random Metal Overlayers on Transition-Metal Substrates

DEFF Research Database (Denmark)

Ganduglia-Pirovano, M. V.; Kudrnovský, J.; Scheffler, M.

1997-01-01

and the screening effects induced by the core hole, and study the influence of the alloy composition for a number of noble metal-transition metal systems. Our analysis clearly indicates the importance of final-state screening effects for the interpretation of measured core-level shifts. Calculated deviations from...

19 CFR 123.22 - In-transit manifest.

Science.gov (United States)

2010-04-01

... CUSTOMS RELATIONS WITH CANADA AND MEXICO Shipments in Transit Through Canada or Mexico § 123.22 In-transit... cars or other overland carriers transiting Mexico a manifest on Customs Form 7512-B or 7533-C shall be... enter and reenter Canada in a continuing movement en route to a final destination in the United States...

Research for the energy turnaround. Phase transitions actively shape. Contributions

International Nuclear Information System (INIS)

Szczepanski, Petra; Wunschick, Franziska; Martin, Niklas

2015-01-01

The Annual Conference 2014 of the Renewable Energy Research Association was held in Berlin on 6 and 7 November 2014. This book documents the contributions of the conference on research for the energy turnaround, phase transitions actively shape. After an introduction and two contributions to the political framework, the contributions to the economic phases of the energy transition, the phase of the current turn, the phases of social energy revolution, the stages of heat turnaround (Waermewende), and the stages of the mobility turn deal with the stages of development of the energy system. Finally, the Research Association Renewable Energy is briefly presented. [de

Transitions induced by speed in self-propelled particles system with attractive interactions

Science.gov (United States)

Cambui, Dorilson. S.; Rosas, Alexandre

2018-05-01

In this work, we consider a system of self-propelled particles with attractive interactions in two dimensions. The model presents an order-disorder transition with the speed playing the role of the control parameter. In order to characterize the transition, we investigate the behavior of the order parameter and the Binder cumulant as a function of the speed. Our main finding is that the transition can be either continuous or discontinuous depending on two parameter of the model: the strength of the noise and the radius of attraction.

Insulator–metal transition in a conservative system: An evidence for ...

Indian Academy of Sciences (India)

substrate, suggest that the mobility coalescence is responsible for the aging in island metal films. ... esting transition observed in a conservative system – after the stoppage of ... Oxidation of islands model and mobility coalescence model.

Polydispersity effect on solid-fluid transition in hard sphere systems

KAUST Repository

Nogawa, T.; Watanabe, H.; Ito, N.

2010-01-01

The solid-fluid transition of the hard elastic particle system with size polydispersity is studied by molecular dynamics simulations. Using nonequilibrium relaxation from the mixed initial condition we determines the melting point where the first

Specification, construction, and exact reduction of state transition system models of biochemical processes.

Science.gov (United States)

Bugenhagen, Scott M; Beard, Daniel A

2012-10-21

Biochemical reaction systems may be viewed as discrete event processes characterized by a number of states and state transitions. These systems may be modeled as state transition systems with transitions representing individual reaction events. Since they often involve a large number of interactions, it can be difficult to construct such a model for a system, and since the resulting state-level model can involve a huge number of states, model analysis can be difficult or impossible. Here, we describe methods for the high-level specification of a system using hypergraphs, for the automated generation of a state-level model from a high-level model, and for the exact reduction of a state-level model using information from the high-level model. Exact reduction is achieved through the automated application to the high-level model of the symmetry reduction technique and reduction by decomposition by independent subsystems, allowing potentially significant reductions without the need to generate a full model. The application of the method to biochemical reaction systems is illustrated by models describing a hypothetical ion-channel at several levels of complexity. The method allows for the reduction of the otherwise intractable example models to a manageable size.

Endothelial to mesenchymal transition in the cardiovascular system.

Science.gov (United States)

Gong, Hui; Lyu, Xing; Wang, Qiong; Hu, Min; Zhang, Xiangyu

2017-09-01

Endothelial to mesenchymal transition (EndMT) is a special type of epithelial to mesenchymal transition. It is a process that is characterized by the loss of features of endothelial cells and acquisition of specific markers of mesenchymal cells. A variety of stimuli, such as inflammation, growth factors, and hypoxia, regulate EndMT through various signaling pathways and intracellular transcription factors. It has been demonstrated that epigenetic modifications are also involved in this process. Recent studies have identified the essential role of EndMT in the cardiovascular system. EndMT contributes to steps in cardiovascular development, such as cardiac valve formation and septation, as well as the pathogenesis of various cardiovascular disorders, such as congenital heart disease, myocardial fibrosis, myocardial infarction and pulmonary arterial hypertension. Thus, comprehensive understanding of the underlying mechanisms of EndMT will provide novel therapeutic strategies to overcome congenital heart disease due to abnormal development and other cardiovascular diseases. This review will focus on summarizing the currently understood signaling pathways and epigenetic modifications involved in the regulation of EndMT and the role of EndMT in pathophysiological conditions of the cardiovascular system. Copyright © 2017. Published by Elsevier Inc.

Phase transitions and equation of state of CsI under high pressure and the development of a focusing system for x-rays

Energy Technology Data Exchange (ETDEWEB)

Wu, Yan.

1990-11-01

The phase transitions and equation of state of ionic solid cesium iodide were studied under high pressure and room temperature in a diamond anvil cell. The studies were carried out using both energy dispersive and angular dispersive diffraction methods on synchrotron radiation sources over the pressure range from atmospheric pressure to over 300 gigapascals (3 million atmospheres). CsI undergoes a distinct phase transition at about 40 GPa, a pressure that is much lower than the reported insulator-metal transition at 110 GPa, from the atmospheric pressure B2(CsCl) structure to an orthorhombic structure. At higher pressures, a continuous distortion in the structure was observed with a final structure similar to a hcp lattice under ultra high pressure. No volume discontinuity was observed at the insulator-metal transition. The newly found transition sequence is different from the result of previous static compression studies. The current structure has a smaller unit cell volume than the previous assignment. This has resolved a long existing controversy among the previous static compression studies, the dynamic compression studies, and the theoretical studies. The current results also explain the apparent discrepancy between the present study and the previous static studies. We also present the development of a focusing system for high energy x-rays (> 12 keV) that is particularly suited for high pressure diffraction studies. This system uses a pair of multilayer coated spherical mirrors in a Kirkpatrick-Baez geometry. A focused beam size less than 10 micron in diameter can be readily achieved with sufficient intensity to perform diffraction studies. 93 refs., 46 figs., 15 tabs.

Phase transitions and equation of state of CsI under high pressure and the development of a focusing system for x-rays

International Nuclear Information System (INIS)

Wu, Yan.

1990-11-01

The phase transitions and equation of state of ionic solid cesium iodide were studied under high pressure and room temperature in a diamond anvil cell. The studies were carried out using both energy dispersive and angular dispersive diffraction methods on synchrotron radiation sources over the pressure range from atmospheric pressure to over 300 gigapascals (3 million atmospheres). CsI undergoes a distinct phase transition at about 40 GPa, a pressure that is much lower than the reported insulator-metal transition at 110 GPa, from the atmospheric pressure B2(CsCl) structure to an orthorhombic structure. At higher pressures, a continuous distortion in the structure was observed with a final structure similar to a hcp lattice under ultra high pressure. No volume discontinuity was observed at the insulator-metal transition. The newly found transition sequence is different from the result of previous static compression studies. The current structure has a smaller unit cell volume than the previous assignment. This has resolved a long existing controversy among the previous static compression studies, the dynamic compression studies, and the theoretical studies. The current results also explain the apparent discrepancy between the present study and the previous static studies. We also present the development of a focusing system for high energy x-rays (> 12 keV) that is particularly suited for high pressure diffraction studies. This system uses a pair of multilayer coated spherical mirrors in a Kirkpatrick-Baez geometry. A focused beam size less than 10 micron in diameter can be readily achieved with sufficient intensity to perform diffraction studies. 93 refs., 46 figs., 15 tabs

Glass transitions in one-, two-, three-, and four-dimensional binary Lennard-Jones systems

Energy Technology Data Exchange (ETDEWEB)

Bruening, Ralf; St-Onge, Denis A; Patterson, Steve [Physics Department, Mount Allison University, Sackville, NB, E4L 1E6 (Canada); Kob, Walter [Laboratoire des Colloides, Verres et Nanomateriaux, UMR5587, Universite Montpellier II and CNRS, 34095 Montpellier Cedex (France)], E-mail: rbruening@mta.ca

2009-01-21

We investigate the calorimetric liquid-glass transition by performing simulations of a binary Lennard-Jones mixture in one through four dimensions. Starting at a high temperature, the systems are cooled to T = 0 and heated back to the ergodic liquid state at constant rates. Glass transitions are observed in two, three and four dimensions as a hysteresis between the cooling and heating curves. This hysteresis appears in the energy and pressure diagrams, and the scanning rate dependence of the area and height of the hysteresis can be described using power laws. The one-dimensional system does not experience a glass transition but its specific heat curve resembles the shape of the D{>=}2 results in the supercooled liquid regime above the glass transition. As D increases, the radial distribution functions reflect reduced geometric constraints. Nearest neighbor distances become smaller with increasing D due to interactions between nearest and next-nearest neighbors. Simulation data for the glasses are compared with crystal and melting data obtained with a Lennard-Jones system with only one type of particle and we find that with increasing D crystallization becomes increasingly more difficult.

SatisFactory Final System Evaluation Report

OpenAIRE

Sunlight SA

2018-01-01

The present document is a deliverable of the SatisFactory project, funded by the European Commission’s Directorate-General for Research and Innovation (DG RTD), under its Horizon 2020 Research and innovation programme (H2020). The main objective of this deliverable is to report on the SatisFactory Final System Evaluation, with regards to the industrial pilots at COMAU and SUNLIGHT. The evaluation of SatisFactory platform is based on the implementation of the business scenarios where each tool...

The future of transportation in sustainable energy systems: Opportunities and barriers in a clean energy transition

DEFF Research Database (Denmark)

Dominkovic, Dominik Franjo; Bačeković, Ivan; Pedersen, Allan Schrøder

2017-01-01

Energy demand of a transport sector has constantly been increasing in the recent years, consuming one third of the total final energy demand in the European Union (EU) over the last decade. A transition of this sector towards sustainable one is facing many challenges in terms of suitable technolo...

Glass transition of repulsive charged rods (fd-viruses).

Science.gov (United States)

Kang, Kyongok

2014-05-14

It has recently been shown that suspensions of long and thin charged fibrous viruses (fd) form a glass at low ionic strengths. The corresponding thick electric double layers give rise to long-ranged repulsive electrostatic interactions, which lead to caging and structural arrest at concentrations far above the isotropic-nematic coexistence region. Structural arrest and freezing of the orientational texture are found to occur at the same concentration. In addition, various types of orientational textures are equilibrated below the glass transition concentration, ranging from a chiral-nematic texture with a large pitch (of about 100 μm), an X-pattern, and a tightly packed domain texture, consisting of helical domains with a relatively small pitch (of about 10 μm) and twisted boundaries. The dynamics of both particles as well as the texture are discussed, below and above the glass transition. Dynamic light scattering correlation functions exhibit two dynamical modes, where the slow mode is attributed to the elasticity of helical domains. On approach of the glass-transition concentration, the slow mode increases in amplitude, while as the amplitudes of the fast and slow mode become equal at the glass transition. Finally, interesting features of the "transient" behaviors of charged fd-rod glass are shown as the initial caging due to structural arrest, the propagation of flow originating from stress release, and the transition to the final metastable glass state. In addition to the intensity correlation function, power spectra are presented as a function of the waiting time, at the zero-frequency limit that may access to the thermal anomalities in a charged system.

Quantum phase transition in strongly correlated many-body system

Science.gov (United States)

You, Wenlong

The past decade has seen a substantial rejuvenation of interest in the study of quantum phase transitions (QPTs), driven by experimental advance on the cuprate superconductors, the heavy fermion materials, organic conductors, Quantum Hall effect, Fe-As based superconductors and other related compounds. It is clear that strong electronic interactions play a crucial role in the systems of current interest, and simple paradigms for the behavior of such systems near quantum critical points remain unclear. Furthermore, the rapid progress in Feshbach resonance and optical lattice provides a flexible platform to study QPT. Quantum Phase Transition (QPT) describes the non-analytic behaviors of the ground-state properties in a many-body system by varying a physical parameter at absolute zero temperature - such as magnetic field or pressure, driven by quantum fluctuations. Such quantum phase transitions can be first-order phase transition or continuous. The phase transition is usually accompanied by a qualitative change in the nature of the correlations in the ground state, and describing this change shall clearly be one of our major interests. We address this issue from three prospects in a few strong correlated many-body systems in this thesis, i.e., identifying the ordered phases, studying the properties of different phases, characterizing the QPT points. In chapter 1, we give an introduction to QPT, and take one-dimensional XXZ model as an example to illustrate the QPT therein. Through this simple example, we would show that when the tunable parameter is varied, the system evolves into different phases, across two quantum QPT points. The distinct phases exhibit very different behaviors. Also a schematic phase diagram is appended. In chapter 2, we are engaged in research on ordered phases. Originating in the work of Landau and Ginzburg on second-order phase transition, the spontaneous symmetry breaking induces nonzero expectation of field operator, e.g., magnetization M

Transit Timing Observations from Kepler: II. Confirmation of Two Multiplanet Systems via a Non-parametric Correlation Analysis

Energy Technology Data Exchange (ETDEWEB)

Ford, Eric B.; /Florida U.; Fabrycky, Daniel C.; /Lick Observ.; Steffen, Jason H.; /Fermilab; Carter, Joshua A.; /Harvard-Smithsonian Ctr. Astrophys.; Fressin, Francois; /Harvard-Smithsonian Ctr. Astrophys.; Holman, Matthew J.; /Harvard-Smithsonian Ctr. Astrophys.; Lissauer, Jack J.; /NASA, Ames; Moorhead, Althea V.; /Florida U.; Morehead, Robert C.; /Florida U.; Ragozzine, Darin; /Harvard-Smithsonian Ctr. Astrophys.; Rowe, Jason F.; /NASA, Ames /SETI Inst., Mtn. View /San Diego State U., Astron. Dept.

2012-01-01

We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies are in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the transit timing variations of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

An Analysis of Public Transit Connectivity Index in Tehran. The Case Study: Tehran Multi-Modal Transit Network

Directory of Open Access Journals (Sweden)

Amir Reza Mamdoohi

2016-10-01

Full Text Available Public transit is a major priority in modern management of large cities and metropolitan areas in particular. Public transit systems in such cities consist of a large number of nodes and lines which are represented by a complex network. A station for public transit is a bridge between the people and public transit network, based on which, the concept of input and output power for each station can be defined. The objective of this study is the application of the transit connectivity indices to the multimodal transit network in the city of Tehran. The public transit network data employed in this study is taken from Tehran Traffic Control Company, and Tehran Urban and Suburban Railway Operation Company. The methodology for measuring transit connectivity consists of three measures: Node connectivity, Line connectivity and Regional connectivity, where activity density is applied to these measures. The results of node connectivity analysis shows that most of the node connectivity in concentrated in the city center with many nodes in the center along routes going north and south. The line connectivity analysis shows that there is a concentration of highly connected lines that are near Tehran municipality region 12 and 16. Finally, we find that areas with more metro and bus facilities with respect to the other areas, have a better regional connectivity. One of these areas includes Sadeghiyeh Metro Station which is the junction of Tehran Metro Line 2 and Tehran Metro Line 5 which have a high connectivity power. Results of this study can be used to suggest some ideas on how future investments in rail and bus should be prioritized. Particularly in Transit Oriented Development (TOD and sustainble development projects, urban planners can design transit stations with high performance to access the crucial services in poor areas.

Grid-connected integrated community energy system. Phase II, Stage 2, final report. Executive summary

Energy Technology Data Exchange (ETDEWEB)

1978-03-22

The University of Minnesota Grid-ICES was divided into four identifiable programs in order to study the feasibility of each of the parts of the ICES independently. The total program involves cogeneration, fuel conversion, fuel substitution, and energy conservation by system change. This Phase II report substantiates the theory that the Basic Grid ICES is not only energy-effective, but it will become cost effective as unit operating costs adjust to supply and demand in the 1980's. The Basic Program involves the cogeneration of steam and electricity. The University of Minnesota has been following an orderly process of converting its Central Heating Plant from gas-oil to 100% coal since 1973. The first step in the transition is complete. The University is presently 100% on coal, and will begin the second step, the test burning of low Btu Western coal during the spring, summer, and fall, and high Btu Eastern coal during the high thermal winter period. The final step to 100% Western coal is planned to be completed by 1980. In conjunction with the final step a retired Northern States Power generating plant has been purchased and is in the process of being retrofitted for topping the existing plant steam output during the winter months. The Basic Plan of ICES involves the add-on work and expense of installing additional boiler capacity at Southeast Steam and non-condensing electric generating capability. This will permit the simultaneous generation of electricity and heat dependent upon the thermal requirements of the heating and cooling system in University buildings. This volume presents an overview of the Community and the ICES. (MCW)

Resilience, Regime Shifts, and Guided Transition under Climate Change: Examining the Practical Difficulties of Managing Continually Changing Systems

Directory of Open Access Journals (Sweden)

Brenda B. Lin

2013-03-01

Full Text Available Managing terrestrial systems has become increasingly difficult under climate change as unidirectional shifts in climate conditions challenge the resilience of ecosystems to maintain their compositional structure and function. Despite the increased attention of resilience management to guide transformational change, questions remain as to how to apply resilience to manage transitions. Rather than pushing systems across thresholds into alternative states, climate change may create a stepwise progression of unknown transitional states that track changing climate conditions. Because of this uncertainty, we must find ways to guide transitioning systems across climate boundaries towards states that are socially and environmentally desirable. We propose to ease the uncertainty of managing shifting systems by providing an approach to adaptive management that we call guided transition, where socially and environmentally important ecosystem functions are preserved through transitions by considering and maintaining the species and structures needed for the desired functions. Scientifically, it will require a better understanding of the relationships between structure, species composition, and function for specific systems. Managers will also need to identify important functions at the local, regional, and national scale, and to determine how best to transition systems to a desired state based on existing scientific knowledge. Guided transition, therefore, helps guide the process of adaptive management by specifying a function-based management pathway that guides transitions through climatic changes.

Synchrotron X-ray diffraction studies of phase transitions in physisorbed monolayers of rare gases on graphite

International Nuclear Information System (INIS)

Bohr, J.

1984-01-01

This study is an investigation of phase transition in monoatomic layers adsorbed on graphite. Such effects can be considered physical realizations of two-dimensional systems. The experimental technique used is synchrotron X-ray diffraction. Systems which have been investigated include the commensurate-incommensurate phase transition in krypton monolayer. By adjusting the spreading pressure in the krypton layer by means of a coadsorbent deuterium gas it has been unambiguously demonstrated that at low temperatures the phase transition is of first order. A melting study of incommensurate argon monolayers demonstrates an experimental verification of the possibility for having a continuous melting transition in two-dimensions. Mixtures of two-components have been investigated for their phases. No (chemical) order-disorder transition is seen. A discussion is given on this lack of a chemical order. This lack is utilized to study the commensurate-incommensurate phase transition driven by average particle size. Finally, a special low-temperature phase is identified in a xenon monlayer which is diluted with freon. (Auth.)

Mirror Fusion Test Facility-B (MFTF-B) axicell configuration: NbTi magnet system. Manufacturing/producibility final report. Volume 2

International Nuclear Information System (INIS)

Ritschel, A.J.; White, W.L.

1985-05-01

This Final MFTF-B Manufacturing/Producibility Report covers facilities, tooling plan, manufacturing sequence, schedule and performance, producibility, and lessons learned for the solenoid, axicell, and transition coils, as well as a deactivation plan, conclusions, references, and appendices

Transition of Future Energy System Infrastructure; through Power-to-Gas Pathways

Directory of Open Access Journals (Sweden)

Azadeh Maroufmashat

2017-07-01

Full Text Available Power-to-gas is a promising option for storing interment renewables, nuclear baseload power, and distributed energy and it is a novel concept for the transition to increased renewable content of current fuels with an ultimate goal of transition to a sustainable low-carbon future energy system that interconnects power, transportation sectors and thermal energy demand all together. The aim of this paper is to introduce different Power-to-gas “pathways”, including Power to Hydrogen, Power to Natural Gas End-users, Power to Renewable Content in Petroleum Fuel, Power to Power, Seasonal Energy Storage to Electricity, Power to Zero Emission Transportation, Power to Seasonal Storage for Transportation, Power to Micro grid, Power to Renewable Natural Gas (RNG to Pipeline (“Methanation”, and Power to Renewable Natural Gas (RNG to Seasonal Storage. In order to compare the different pathways, the review of key technologies of Power-to-gas systems are studied and the qualitative efficiency and benefits of each pathway is investigated from the technical points of view. Moreover, different Power-to-gas pathways are discussed as an energy policy option that can be implemented to transition towards a lower carbon economy for Ontario’s energy systems.

Smart Energy Systems and Energy Transition

International Nuclear Information System (INIS)

Duic, N.

2016-01-01

Transition to decarbonized energy systems is becoming more attractive with fall of investment costs of renewables and volatile prices and political insecurity of fossil fuels. Improving energy efficiency, especially of buildings and transport, is important, but due to long life of buildings, it will be a slow way of decarbonization. The renewable energy resources are bountiful, especially wind and solar, while integrating them into current energy systems is proving to be a challenge. Solar has reached grid parity making it cheapest electricity source for retail customers in most of the World, creating new prosumer markets. It has started to reach cost parity in sunny countries, and soon solar energy will be cheapest everywhere. The limit of cheap and easy integration for wind is around 20% of yearly electricity generation, while a combined wind and solar may reach 30%. Going any further asks for implementation of completely free energy markets (involving day ahead, intraday and various reserve and ancillary services markets), demand response, coupling of wholesale and retail energy prices, and it involves integration between electricity, heat, water and transport systems. The cheapest and simplest way of increasing further the penetration of renewables is integrating power and heating/cooling systems through the use of district heating and cooling (which may be centrally controlled and may have significant heat storage capacity), since power to heat technologies are excellent for demand response. District cooling is of particular importance to historic cities that want to remove split systems from their facades. In countries with low heat demand water supply system may be used to increase the penetration of renewables, by using water at higher potential energy as storage media, or in dry climates desalination and stored water may be used for those purposes, and reversible hydro may be used as balancing technology. Electrification of personal car transport allows

Transition state structures in solution

International Nuclear Information System (INIS)

Bertran, J.; Lluch, J. M.; Gonzalez-Lafont, A.; Dillet, V.; Perez, V.

1995-01-01

In the present paper the location of transition state structures for reactions in solution has been studied. Continuum model calculations have been carried out on the Friedel-Crafts alkylation reaction and a proton transfer through a water molecule between two oxygen atoms in formic acid. In this model the separation between the chemical system and the solvent has been introduced. On the other hand, the discrete Monte Carlo methodology has also been used to simulate the solvent effect on dissociative electron transfer processes. In this model, the hypothesis of separability is not assumed. Finally, the validity of both approaches is discussed

Strict rules for easy transition

International Nuclear Information System (INIS)

Roggen, M.

2003-01-01

The energy companies soon start tests to assess whether their information systems are ready to enable easy transition of retail clients from one energy supplier to another starting early next year. Having learnt a great deal from its experience with the liberalisation of the market for medium-sized business clients, power trade organisation EnergieNed has decided to run a support program named Spoed. (Dutch for Speed) to support the final stage of the liberalisation process. A Reference model has been prepared, on the basis of which energy companies can now test the mutual exchange of switch data [nl

Subsequence automata with default transitions

DEFF Research Database (Denmark)

Bille, Philip; Gørtz, Inge Li; Skjoldjensen, Frederik Rye

2017-01-01

of states and transitions) of the subsequence automaton is O(nσ) and that this bound is asymptotically optimal. In this paper, we consider subsequence automata with default transitions, that is, special transitions to be taken only if none of the regular transitions match the current character, and which do...... not consume the current character. We show that with default transitions, much smaller subsequence automata are possible, and provide a full trade-off between the size of the automaton and the delay, i.e., the maximum number of consecutive default transitions followed before consuming a character......(1), thus matching the bound for the standard subsequence automaton construction. Finally, we generalize the result to multiple strings. The key component of our result is a novel hierarchical automata construction of independent interest....

Operations-oriented performance measures for freeway management systems : final report.

Science.gov (United States)

2008-12-01

This report describes the second and final year activities of the project titled Using Operations-Oriented Performance Measures to Support Freeway Management Systems. Work activities included developing a prototype system architecture for testi...

Phase transitions and dynamic entropy in small two-dimensional systems: Experiment and numerical simulation

Energy Technology Data Exchange (ETDEWEB)

Koss, K. G.; Petrov, O. F.; Myasnikov, M. I., E-mail: miasnikovmi@mail.ru; Statsenko, K. B.; Vasiliev, M. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2016-07-15

The results of experimental and numerical analysis are presented for phase transitions in strongly nonequilibrium small systems of strongly interacting Brownian particles. The dynamic entropy method is applied to analysis of the state of these systems. Experiments are carried out with kinetic heating of the structures of micron-size particles in a laboratory rf discharge plasma. Three phase states of these small systems are observed: crystalline, liquid, and transient. The mechanism of phase transitions in cluster structures of strongly interacting particles is described.

Effect of Parametric Dichotomic Markov Noise on the Properties of Chaotic Transitions in Dynamical Systems

Science.gov (United States)

Gac, J. M.; Żebrowski, J. J.

A chaotic transition occurs when a continuous change of one of the parameters of the system causes a discontinuous change in the properties of the chaotic attractor of the system. Such phenomena are present in many dynamical systems, in which a chaotic behavior occurs. The best known of these transitions are: the period-doubling bifurcation cascade, intermittency and crises. The effect of dichotomous Markov noise (DMN) on the properties of systems with chaotic transitions is discussed. DMN is a very simple two-valued stochastic process, with constant transition rates between the two states. In spite of its simplicity, this kind of noise is a very powerful tool to describe various phenomena present in many physical, chemical or biological systems. Many interesting phenomena induced by DMN are known. However, there is no research on the effect of this kind of noise on intermittency or crises. We present the change of the mean laminar phase length and of laminar phase length distribution caused by DMN modulating the parameters of a system with intermittency and the modification of the mean life time on the pre-crisis attractor in the case of a boundary crisis. The results obtained analytically are compared with numerical simulations for several simple dynamical systems.

Congestion transition in air traffic networks.

Directory of Open Access Journals (Sweden)

Bernardo Monechi

Full Text Available Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios.

Congestion transition in air traffic networks.

Science.gov (United States)

Monechi, Bernardo; Servedio, Vito D P; Loreto, Vittorio

2015-01-01

Air Transportation represents a very interesting example of a complex techno-social system whose importance has considerably grown in time and whose management requires a careful understanding of the subtle interplay between technological infrastructure and human behavior. Despite the competition with other transportation systems, a growth of air traffic is still foreseen in Europe for the next years. The increase of traffic load could bring the current Air Traffic Network above its capacity limits so that safety standards and performances might not be guaranteed anymore. Lacking the possibility of a direct investigation of this scenario, we resort to computer simulations in order to quantify the disruptive potential of an increase in traffic load. To this end we model the Air Transportation system as a complex dynamical network of flights controlled by humans who have to solve potentially dangerous conflicts by redirecting aircraft trajectories. The model is driven and validated through historical data of flight schedules in a European national airspace. While correctly reproducing actual statistics of the Air Transportation system, e.g., the distribution of delays, the model allows for theoretical predictions. Upon an increase of the traffic load injected in the system, the model predicts a transition from a phase in which all conflicts can be successfully resolved, to a phase in which many conflicts cannot be resolved anymore. We highlight how the current flight density of the Air Transportation system is well below the transition, provided that controllers make use of a special re-routing procedure. While the congestion transition displays a universal scaling behavior, its threshold depends on the conflict solving strategy adopted. Finally, the generality of the modeling scheme introduced makes it a flexible general tool to simulate and control Air Transportation systems in realistic and synthetic scenarios.

Transition to Postgraduate Study: Postgraduate Ecological Systems and Identity

Science.gov (United States)

Tobbell, Jane; O'Donnell, Victoria L.

2013-01-01

This paper explores and examines the distal and proximal systems which construct social science postgraduate study in the UK and analyses the emergent identities of postgraduate students as they negotiate the multiple and interacting practices in their transition to study. The data represent part of a one-year research project, funded by the…

ASBESTOS PIPE-INSULATION REMOVAL ROBOT SYSTEM; FINAL

International Nuclear Information System (INIS)

Unknown

2000-01-01

This final topical report details the development, experimentation and field-testing activities for a robotic asbestos pipe-insulation removal robot system developed for use within the DOE's weapon complex as part of their ER and WM program, as well as in industrial abatement. The engineering development, regulatory compliance, cost-benefit and field-trial experiences gathered through this program are summarized

Plant systems/components modularization study. Final report

International Nuclear Information System (INIS)

1977-07-01

The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort

The Final Focus Test Beam laser referene system

International Nuclear Information System (INIS)

Bressler, V.E.; Ruland, R.E.

1993-05-01

The original design for the SLAC linac included an alignment reference system with 270 diffraction gratings situated along the 3000 meter linac. These gratings have provided SLAC with a global reference line repeatable to within 200 micro meters. For the Final Focus Test Beam, this laser system has been extended and 13 new diffraction gratings have been installed. Improvements targets and the availability of new instruments allows us to evaluate the performance of the laser reference system at the 510 micro meter level. An explanation of the system and the results of our evaluation are presented

Field-induced phase transitions in antiferromagnetic systems

International Nuclear Information System (INIS)

Smeets, J.P.M.

1984-05-01

Neutron scattering experiments and magnetization measurements are carried out on cobalt bromide hexahydrate, of which 48% of the water molecules are replaced by deuterium oxide molecules. Results were compared with data obtained from non-deuterated cobalt bromide hexahydrate. Neutron scattering experiments showed the importance of the deuterium fraction. Interplay exists between the crystallographic system and the magnetic system, which is influenced by changing the deuterium fraction. Neutron scattering and magnetization experiments on partially deuterated RbFeCl 3 .2H 2 O and CsFeCl 3 .2H 2 O were performed to study the magnetic phase transitions in these quasi one-dimensional Ising compounds. The observed behaviour in the various phases can be described by the nucleation theory of chain reversals. (Auth.)

Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

Energy Technology Data Exchange (ETDEWEB)

Qiao, Qin, E-mail: qqiao@ust.hk; Zhang, Hou-Dao [Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Huang, Xuhui, E-mail: xuhuihuang@ust.hk [Department of Chemistry, Division of Biomedical Engineering, Center of Systems Biology and Human Health, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); The HKUST Shenzhen Research Institute, Shenzhen (China)

2016-04-21

Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

Science.gov (United States)

Qiao, Qin; Zhang, Hou-Dao; Huang, Xuhui

2016-04-01

Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

Enhancing pairwise state-transition weights: A new weighting scheme in simulated tempering that can minimize transition time between a pair of conformational states

International Nuclear Information System (INIS)

Qiao, Qin; Zhang, Hou-Dao; Huang, Xuhui

2016-01-01

Simulated tempering (ST) is a widely used enhancing sampling method for Molecular Dynamics simulations. As one expanded ensemble method, ST is a combination of canonical ensembles at different temperatures and the acceptance probability of cross-temperature transitions is determined by both the temperature difference and the weights of each temperature. One popular way to obtain the weights is to adopt the free energy of each canonical ensemble, which achieves uniform sampling among temperature space. However, this uniform distribution in temperature space may not be optimal since high temperatures do not always speed up the conformational transitions of interest, as anti-Arrhenius kinetics are prevalent in protein and RNA folding. Here, we propose a new method: Enhancing Pairwise State-transition Weights (EPSW), to obtain the optimal weights by minimizing the round-trip time for transitions among different metastable states at the temperature of interest in ST. The novelty of the EPSW algorithm lies in explicitly considering the kinetics of conformation transitions when optimizing the weights of different temperatures. We further demonstrate the power of EPSW in three different systems: a simple two-temperature model, a two-dimensional model for protein folding with anti-Arrhenius kinetics, and the alanine dipeptide. The results from these three systems showed that the new algorithm can substantially accelerate the transitions between conformational states of interest in the ST expanded ensemble and further facilitate the convergence of thermodynamics compared to the widely used free energy weights. We anticipate that this algorithm is particularly useful for studying functional conformational changes of biological systems where the initial and final states are often known from structural biology experiments.

Few electron transitions in atomic collisions. Final report, September 1, 1992--December 31, 1995

Energy Technology Data Exchange (ETDEWEB)

McGuire, J.

1997-04-01

During the past three years we have evaluated probabilities and cross sections for few and multiple electron transitions in atomic collisions. Our studies included interactions of atoms and molecules with incident protons, bare ions, electrons, positrons, anti-protons, ions carrying electrons and photons. We also: studied the inter-relation between collisions with charged particles and collisions involving various processes with photons. This work has complemented various studies of collisions of atoms with charged particles and with photons as well as more general efforts to understand the nature of multi-electron systems. Our aim has been to begin with relatively simple two electron systems and to focus on fast processes in which there is too little time for complicated processes to occur. We have used a variety of computational techniques, but we emphasize those appropriate for fast collisions in which we hope to obtain insight into the physical nature of the process itself. We generally considered systems in which experimental data was available.

Critical transitions in chronic disease: transferring concepts from ecology to systems medicine.

Science.gov (United States)

Trefois, Christophe; Antony, Paul M A; Goncalves, Jorge; Skupin, Alexander; Balling, Rudi

2015-08-01

Ecosystems and biological systems are known to be inherently complex and to exhibit nonlinear dynamics. Diseases such as microbiome dysregulation or depression can be seen as complex systems as well and were shown to exhibit patterns of nonlinearity in their response to perturbations. These nonlinearities can be revealed by a sudden shift in system states, for instance from health to disease. The identification and characterization of early warning signals which could predict upcoming critical transitions is of primordial interest as prevention of disease onset is a major aim in health care. In this review, we focus on recent evidence for critical transitions in diseases and discuss the potential of such studies for therapeutic applications. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Gastrointestinal transit in patients with systemic sclerosis.

Science.gov (United States)

Fynne, Lotte; Worsøe, Jonas; Gregersen, Tine; Schlageter, Vincent; Laurberg, Søren; Krogh, Klaus

2011-10-01

Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis and collagen deposits. Gastrointestinal symptoms of SSc, including abdominal pain, bloating and discomfort, are common but diffuse and their pathophysiology remains obscure. To investigate the pathophysiology of abdominal pain and discomfort in individuals with SSc. A total of 15 individuals with SSc (13 women, median age 58 years), all suffering from diffuse abdominal symptoms, and 17 healthy volunteers (12 women, median age 52 years) were evaluated with the Motility Tracking System, MTS-1, measuring gastric emptying (GE) and velocity through the small intestine. SSc patients were also examined for bacterial overgrowth using the hydrogen breath test and with radiopaque markers to determine the total gastrointestinal transit time (GITT). Assessed with the MTS-1, the velocity through the proximal small intestine was significantly reduced in SSc patients (median 0.525 m/h, range 0.11-1.15) when compared to healthy subjects (median 0.91 m/h, range 0.51-1.74) (p = 0.02). Prolonged GE was found in 4 SSc patients (27%) but in none of the healthy volunteers (p = 0.04). Only 3 SSc patients (21%) had positive breath tests for small intestinal bacterial overgrowth. GITT was >3 days in 8 patients (53%). Slow small intestinal transit was associated with a prolonged GITT (p < 0.05). Velocity through the small intestine is significantly reduced in SSc patients with diffuse abdominal symptoms.

Evaluating Post-School Transition of Secondary Students with Moderate to Severe Handicaps. Final Report.

Science.gov (United States)

Bruininks, Robert H.; Thurlow, Martha L.

The final report describes a 3-year project which had four primary objectives: (1) development of a followup system feasible for schools to use to obtain information on individuals with handicaps who leave school; (2) data collection on three special education samples; (3) data analysis to evaluate long-term effects of secondary programs and…

A high rate gamma spectroscopy system for activation analysis of short lived isomeric transitions

Energy Technology Data Exchange (ETDEWEB)

Westphal, G P [Atominstitut, Vienna (Austria)

1976-07-01

A high rate spectroscopy system specially suited for measurement of short-lived isomeric transitions is described, which, as part of a fast activation analysis facility at the TRIGA Mark II reactor, provides for automatic recording and immediate evaluation of gamma spectra taken from nuclides activated at stationary or pulsed reactor power. The system consists of a commercial DC-coupled Ge(Li)-detector of 70 cm{sup 3} modified for recycling operation for input rates in excess of 500,000 c/s Co-60, a time variant trapezoidal shaping section and a fast constant dead-time ADC coupled to a programmed multi-channel analyzer. Novel circuits for efficient pile-up rejection and time variant base line restoration extend the concept of gated integration up to count rates of more than 300,000 c/s Co-60. Time-sequenced recording of spectra is performed by a mini computer operated as a front-end processor of a larger laboratory computer, where final data processing takes place. New concepts for very simple and cost-effective implementation of multi-channel analyzers by means of general purpose small computers are described. (author)

Mean Transit Time and Mean Residence Time for Linear Diffusion–Convection–Reaction Transport System

Directory of Open Access Journals (Sweden)

Jacek Waniewski

2007-01-01

Full Text Available Characteristic times for transport processes in biological systems may be evaluated as mean transit times (MTTs (for transit states or mean residence times (MRT (for steady states. It is shown in a general framework of a (linear reaction–diffusion–convection equation that these two times are related. Analytical formulas are also derived to calculate moments of exit time distribution using solutions for a stationary state of the system.

TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

International Nuclear Information System (INIS)

Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C.; Fabrycky, Daniel C.; Steffen, Jason H.; Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David; Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A.; Welsh, William F.; Allen, Christopher; Batalha, Natalie M.; Buchhave, Lars A.

2012-01-01

We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

TRANSIT TIMING OBSERVATIONS FROM KEPLER. II. CONFIRMATION OF TWO MULTIPLANET SYSTEMS VIA A NON-PARAMETRIC CORRELATION ANALYSIS

Energy Technology Data Exchange (ETDEWEB)

Ford, Eric B.; Moorhead, Althea V.; Morehead, Robert C. [Astronomy Department, University of Florida, 211 Bryant Space Sciences Center, Gainesville, FL 32611 (United States); Fabrycky, Daniel C. [UCO/Lick Observatory, University of California, Santa Cruz, CA 95064 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, MS 127, Batavia, IL 60510 (United States); Carter, Joshua A.; Fressin, Francois; Holman, Matthew J.; Ragozzine, Darin; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Lissauer, Jack J.; Rowe, Jason F.; Borucki, William J.; Bryson, Stephen T.; Burke, Christopher J.; Caldwell, Douglas A. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Welsh, William F. [Astronomy Department, San Diego State University, San Diego, CA 92182-1221 (United States); Allen, Christopher [Orbital Sciences Corporation/NASA Ames Research Center, Moffett Field, CA 94035 (United States); Batalha, Natalie M. [Department of Physics and Astronomy, San Jose State University, San Jose, CA 95192 (United States); Buchhave, Lars A., E-mail: eford@astro.ufl.edu [Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen (Denmark); Collaboration: Kepler Science Team; and others

2012-05-10

We present a new method for confirming transiting planets based on the combination of transit timing variations (TTVs) and dynamical stability. Correlated TTVs provide evidence that the pair of bodies is in the same physical system. Orbital stability provides upper limits for the masses of the transiting companions that are in the planetary regime. This paper describes a non-parametric technique for quantifying the statistical significance of TTVs based on the correlation of two TTV data sets. We apply this method to an analysis of the TTVs of two stars with multiple transiting planet candidates identified by Kepler. We confirm four transiting planets in two multiple-planet systems based on their TTVs and the constraints imposed by dynamical stability. An additional three candidates in these same systems are not confirmed as planets, but are likely to be validated as real planets once further observations and analyses are possible. If all were confirmed, these systems would be near 4:6:9 and 2:4:6:9 period commensurabilities. Our results demonstrate that TTVs provide a powerful tool for confirming transiting planets, including low-mass planets and planets around faint stars for which Doppler follow-up is not practical with existing facilities. Continued Kepler observations will dramatically improve the constraints on the planet masses and orbits and provide sensitivity for detecting additional non-transiting planets. If Kepler observations were extended to eight years, then a similar analysis could likely confirm systems with multiple closely spaced, small transiting planets in or near the habitable zone of solar-type stars.

The Transiting Exocomets in the HD 172555 System

Science.gov (United States)

Grady, C. A.; Brown, A.; Kamp, I.; Roberge, A.; Riviere-Marichalar, P.; Welsh, B.

2017-01-01

The Earth is thought to have formed dry, in a part of the Solar Nebula deficient in organic material, and to have acquired its organics and water through bombardment by minor bodies. Observations of this process in well-dated systems can provide insight into the probable origin and composition of the bombarding parent bodies. Transiting cometary activity has previously been reported in Ca II for the late-A member of the 241 Myr old Pictoris Moving Group member, HD 172555(Kiefer et al. 2014). We present HST STIS and COS spectra of HD 172555 demonstrating that the star has chromospheric emission and variable in falling gas features in transitions of silicon and carbon ions at times when no Fe II absorption is seen in the UV data, and no Ca II absorption is seen in contemporary optical spectra. The lack of CO absorption and stable gas absorption at the system velocity is consistent with the absence of a cold Kuiper belt analog (Riviere-Marichalar et al. 2012) in this system. The presence of infall in some species at one epoch and others at different epochs suggests that, like Pictoris, there may be more than one family of exocomets. If perturbed into star-grazing orbits by the same mechanism as for Pic, these data suggest that the wide planet frequency among A-early F stars in the PMG is at least 37.5, well above the frequency estimated for young moving groups independent of host star spectral type.

Cosmological Final Focus Systems

International Nuclear Information System (INIS)

Irwin, J

2004-01-01

We develop the many striking parallels between the dynamics of light streams from distant galaxies and particle beams in accelerator final focus systems. Notably the deflections of light by mass clumps are identical to the kicks arising from the long-range beam-beam interactions of two counter-rotating particle beams (known as parasitic crossings). These deflections have sextupolar as well as quadrupolar components. We estimate the strength of such distortions for a variety of circumstances and argue that the sextupolar distortions from clumping within clusters may be observable. This possibility is enhanced by the facts that (1) the sextupolar distortions of background galaxies is a factor of 5 smaller than the quadrupolar distortion, (2) the angular orientation of the sextupolar and quadrupolar distortions from a mass distribution would be correlated, appearing as a slightly curved image, (3) these effects should be spatially clumped on the sky

Waveguide transition with vacuum window for multiband dynamic nuclear polarization systems

Energy Technology Data Exchange (ETDEWEB)

Rybalko, Oleksandr; Bowen, Sean; Zhurbenko, Vitaliy [Technical University of Denmark, Ørsteds Plads 349, 2800 Kgs. Lyngby (Denmark); Ardenkjær-Larsen, Jan Henrik, E-mail: jhar@elektro.dtu.dk [Technical University of Denmark, Ørsteds Plads 349, 2800 Kgs. Lyngby (Denmark); GE Healthcare, Park Alle 295, Brøndby (Denmark)

2016-05-15

A low loss waveguide transition section and oversized microwave vacuum window covering several frequency bands (94 GHz, 140 GHz, 188 GHz) is presented. The transition is compact and was optimized for multiband Dynamic Nuclear Polarization (DNP) systems in a full-wave simulator. The window is more broadband than commercially available windows, which are usually optimized for single band operation. It is demonstrated that high-density polyethylene with urethane adhesive can be used as a low loss microwave vacuum window in multiband DNP systems. The overall assembly performance and dimensions are found using full-wave simulations. The practical aspects of the window implementation in the waveguide are discussed. To verify the design and simulation results, the window is tested experimentally at the three frequencies of interest.

Participating to the Transition Towards New Energy Technology Systems

International Nuclear Information System (INIS)

Tosato, G.

2008-01-01

The paper analyses possible implications for Croatia of a global transition towards new energy technology systems, as depicted by the recent report on scenarios and strategies to 2050 of the International Energy Agency [ETP2008]. The analysis is based upon the present Croatian energy balance. It takes into account some draft results of the USAID-supported Regional Energy Demand Planning (REDP) study under the South East Europe Regional Energy Market Support (SEE REMS) Project. The paper then presents ongoing EC-funded energy research projects, such as RES2020 (Monitoring and Evaluation of the Renewable Energy Sources directives implementation in EU27 and policy recommendations for 2020), REACCESS (Risk of Energy Availability: Common Corridors for Europe Supply Security) and REALISEGRID (REseArch, methodoLogIes and technologieS for the effective development of pan-European key GRID infrastructures to support the achievement of a reliable, competitive and sustainable electricity supply). The participation of Croatian research organizations to EC-funded research projects could make the transition towards new energy system an opportunity for economic development.(author)

HIGH-RESOLUTION SATELLITE IMAGING OF THE 2004 TRANSIT OF VENUS AND ASYMMETRIES IN THE CYTHEREAN ATMOSPHERE

International Nuclear Information System (INIS)

Pasachoff, Jay M.; Schneider, Glenn; Widemann, Thomas

2011-01-01

This paper presents the only space-borne optical-imaging observations of the 2004 June 8 transit of Venus, the first such transit visible from Earth since AD 1882. The high-resolution, high-cadence satellite images we arranged from NASA's Transition Region and Coronal Explorer (TRACE) reveal the onset of visibility of Venus's atmosphere and give further information about the black-drop effect, whose causes we previously demonstrated from TRACE observations of a transit of Mercury. The atmosphere is gradually revealed before second contact and after third contact, resulting from the changing depth of atmospheric layers refracting the photospheric surface into the observer's direction. We use Venus Express observations to relate the atmospheric arcs seen during the transit to the atmospheric structure of Venus. Finally, we relate the transit images to current and future exoplanet observations, providing a sort of ground truth showing an analog in our solar system to effects observable only with light curves in other solar systems with the Kepler and CoRoT missions and ground-based exoplanet-transit observations.

Heliopause Electrostatic Rapid Transit System (HERTS)

Science.gov (United States)

Wiegmann, Bruce M.

2015-01-01

A recent six month investigation focused on: "Determining the benefits of propelling a scientific spacecraft by an 'Electric Sail' propulsion system to the edge of our solar system (the Heliopause), a distance of 100 to 120 AU, in ten years or less" has recently been completed by the Advance Concepts Office at NASA's MSFC. The concept investigated has been named the Heliopause Electrostatic Rapid Transit System (HERTS) by the MSFC team. The HERTS is a revolutionary propellant-less propulsion concept that is ideal for deep space missions to the Outer Planets, Heliopause, and beyond. It is unique in that it uses momentum exchange from naturally occurring solar wind protons to propel a spacecraft within the heliosphere. The propulsion system consists of an array of electrically positively-biased wires that extend outward 20 km from a rotating (one revolution per hour) spacecraft. It was determined that the HERTS system can accelerate a spacecraft to velocities as much as two to three times that possible by any realistic extrapolation of current state-of-the-art propulsion technologies- including solar electric and solar sail propulsion systems. The data produced show that a scientific spacecraft could reach distances of 100AU in less than 10 years. Moreover, it can be reasonably expected that this system could be developed within a decade and provide meaningful Heliophysics Science and Outer Planetary Science returns in the 2025-2035 timeframe.

Potential development of an intercity passenger transit system in Texas : final project report.

Science.gov (United States)

2010-05-01

This report describes the findings of a research study of the potential for development of an intercity rail and : express bus system in the state of Texas. Rather than focus on regional commuter or light rail systems : radiating from urban areas, th...

A Transitive Recommendation System for Information Technology Communities

Directory of Open Access Journals (Sweden)

Hesham Ali

2013-06-01

Full Text Available Social networks have become a new trend for research among computer scientist around the world. Social network had an impact on users' way of life. One of social network usages is recommendation systems. The need of recommendation systems is arising when users try to know best choice for them in many items types (books, experts, locations, technologies...etc. The problem is that a single person can't try all alternatives in all possibles life goals to compare. Thus, a person has to use his friends' expertise to select better option in any item category. This process is the main idea of “Recommendation Systems”. Recommendation systems usually depend on users-to-items ratings in a network (graph. Two main challenges for recommendation systems are accuracy of recommendation and computation size. The main objective of this paper is to introduce a suggested technique for transitive recommendation system based on users' collaborative ratings, and also to balance loading of computation. All this has to be applied on a special type of social network. Our work studied the transitivity usage in connections to get a relation (path as a recommendation for nodes not directly connected. The target social network has eight types of nodes. So, there are techniques that are not suitable to this complex type of network. Those we can present a new support for recommending items of several types to users with several types. We believe that this functionality hasn't been fully provided elsewhere. We have suggested using single source shortest path algorithm combined with Map Reduce technique, and mathematically deduced that we have a speeding up of algorithm by 10% approximately. Our testing results shows an accuracy of 89% and false rejection of 99% compared to traditional algorithms with less configuration parameters and more steady count of recommendations.

Facilitating energy transition through energy commons : An application of socio-ecological systems framework for integrated community energy systems

NARCIS (Netherlands)

Acosta, Cristina; Ortega, Mariana; Bunsen, Till; Koirala, B.P.; Ghorbani, A.

2018-01-01

Integrated Community Energy Systems (ICES) are an emerging local energy system focusing on the collective use of distributed energy resources (DER). These socio-technical systems (STSs) have a high potential to advance the transition towards socially inclusive, environmentally-friendly energy

Facilitating energy transition through energy commons : An application of socio-ecological systems framework for integrated community energy systems

NARCIS (Netherlands)

Acosta, Cristina; Ortega, Mariana; Bunsen, Till; Koirala, Binod Prasad; Ghorbani, Amineh

2018-01-01

Integrated Community Energy Systems (ICES) are an emerging local energy system focusing on the collective use of distributed energy resources (DER). These socio-technical systems (STSs) have a high potential to advance the transition towards socially inclusive, environmentally-friendly energy

Quantum phase transitions

International Nuclear Information System (INIS)

Sachdev, S.

1999-01-01

Phase transitions are normally associated with changes of temperature but a new type of transition - caused by quantum fluctuations near absolute zero - is possible, and can tell us more about the properties of a wide range of systems in condensed-matter physics. Nature abounds with phase transitions. The boiling and freezing of water are everyday examples of phase transitions, as are more exotic processes such as superconductivity and superfluidity. The universe itself is thought to have passed through several phase transitions as the high-temperature plasma formed by the big bang cooled to form the world as we know it today. Phase transitions are traditionally classified as first or second order. In first-order transitions the two phases co-exist at the transition temperature - e.g. ice and water at 0 deg., or water and steam at 100 deg. In second-order transitions the two phases do not co-exist. In the last decade, attention has focused on phase transitions that are qualitatively different from the examples noted above: these are quantum phase transitions and they occur only at the absolute zero of temperature. The transition takes place at the ''quantum critical'' value of some other parameter such as pressure, composition or magnetic field strength. A quantum phase transition takes place when co-operative ordering of the system disappears, but this loss of order is driven solely by the quantum fluctuations demanded by Heisenberg's uncertainty principle. The physical properties of these quantum fluctuations are quite distinct from those of the thermal fluctuations responsible for traditional, finite-temperature phase transitions. In particular, the quantum system is described by a complex-valued wavefunction, and the dynamics of its phase near the quantum critical point requires novel theories that have no analogue in the traditional framework of phase transitions. In this article the author describes the history of quantum phase transitions. (UK)

Universal scheme to generate metal–insulator transition in disordered systems

International Nuclear Information System (INIS)

Guo, Ai-Min; Xiong, Shi-Jie; Xie, X C; Sun, Qing-feng

2013-01-01

We propose a scheme to generate metal–insulator transition in the random binary layer (RBL) model, which is constructed by randomly assigning two types of layers along the longitudinal direction. Based on a tight-binding Hamiltonian, the localization length is calculated for a variety of RBLs with different cross section geometries by using the transfer-matrix method. Both analytical and numerical results show that a band of extended states could appear in the quasi-one-dimensional RBLs and the systems behave as metals by properly tuning the model parameters, due to the existence of a completely ordered subband, leading to a metal–insulator transition in parameter space. Furthermore, the extended states are irrespective of the diagonal and off-diagonal disorder strengths. Our results can be generalized to two- and three-dimensional disordered systems with arbitrary layer structures, and may be realized in Bose–Einstein condensates. (paper)

Merger transitions in brane-black-hole systems: Criticality, scaling, and self-similarity

International Nuclear Information System (INIS)

Frolov, Valeri P.

2006-01-01

We propose a toy model for studying merger transitions in a curved spacetime with an arbitrary number of dimensions. This model includes a bulk N-dimensional static spherically symmetric black hole and a test D-dimensional brane (D≤N-1) interacting with the black hole. The brane is asymptotically flat and allows a O(D-1) group of symmetry. Such a brane-black-hole (BBH) system has two different phases. The first one is formed by solutions describing a brane crossing the horizon of the bulk black hole. In this case the internal induced geometry of the brane describes a D-dimensional black hole. The other phase consists of solutions for branes which do not intersect the horizon, and the induced geometry does not have a horizon. We study a critical solution at the threshold of the brane-black-hole formation, and the solutions which are close to it. In particular, we demonstrate that there exists a striking similarity of the merger transition, during which the phase of the BBH system is changed, both with the Choptuik critical collapse and with the merger transitions in the higher dimensional caged black-hole-black-string system

Nuclear safeguards - a system in transition

International Nuclear Information System (INIS)

Carlson, J.

1999-01-01

'Classical' safeguards have a strong emphasis on nuclear materials accountancy, and are primarily concerned with verifying nuclear activities as declared by the State - what has been termed the correctness of States' declarations. Following the Gulf War, failure to adequately address the possibility of undeclared nuclear activities - the issue of the completeness of States' declarations - has been recognised as a major shortcoming in the classical safeguards system, and major changes are in progress to strengthen the IAEA's capabilities in this regard. Agreement has been reached on a Model Protocol substantially extending the IAEA's authority, and there has been good progress in developing the new approaches and technologies required to ensure this authority is used effectively. IAEA safeguards are undergoing a major transition, towards greater emphasis on information collection and analysis, diversity of verification methods, incorporation of more qualitative judgments, and improved efficiency. These changes present major challenges to the IAEA and to the international community, but the end result will be a more effective safeguards system

Transition of International System and China’s Strategic Choice

Institute of Scientific and Technical Information of China (English)

TANG YONGSHENG

2016-01-01

At present,the international situation is at change.The international system undergoes profound transition.Great changes are happening to structure of power pattern,essence of international relations and norms of global governance.Major events of overall and strategic bearings such as the Ukraine Crisis,the Chaos of the Middle East,the proliferation of terrorism and the slowdown in economic

Brane-antibrane systems at finite temperature and phase transition near the Hagedorn temperature

International Nuclear Information System (INIS)

Hotta, Kenji

2002-01-01

In order to study the thermodynamic properties of brane-antibrane systems, we compute the finite temperature effective potential of tachyon T in this system on the basis of boundary string field theory. At low temperature, the minimum of the potential shifts towards T=0 as the temperature increases. In the D9-anti-D9 case, the sign of the coefficient of vertical bar T vertical bar 2 term of the potential changes slightly below the Hagedorn temperature. This means that a phase transition occurs near the Hagedorn temperature. On the other hand, the coefficient is kept negative in the Dp-anti-Dp case with p≤8, and thus a phase transition does not occur. This leads us to the conclusion that only a D9-anti-D9 pair and no other (lower dimensional) brane-antibrane pairs are created near the Hagedorn temperature. We also discuss a phase transition in NS9B-anti-NS9B case as a model of the Hagedorn transition of closed strings. (author)

Comprehensive Final Report for the Marine Seismic System Program

Science.gov (United States)

1985-08-01

serve as a principal reference for transitioning marine seismic system techniques and results from the research and development arena to the...vM . .’ .■ .» .%■■.•. - Viaj ^."-;/-.■■ *• -’•’■■’■ ■ ■ - ■ • ■ -. . -. • ^;-■:■:-:•:> •■•."--.--.v. ’-• V ’.■ *.- ".i • ■ - ■ ■ v V

Development and evaluation of the process for final placement application: a review of the new student led allocation system

OpenAIRE

Mason, Rachael; Brackenbury, Debra; Broady, Sophie

2016-01-01

Background A process to facilitate nursing students to have more ownership of their final placement was introduced for this academic year by inviting them to apply for a specific placement they felt most appropriate. Whilst there has been significant research into preparing students for practice (Woods et al, 2015) and to explore the transition from student to graduate nurse (Kumaran and Carney, 2014), there is little to explore the effect of gaining preference for their final placement or...

Dipole transitions and Stark effect in the charge-dyon system

International Nuclear Information System (INIS)

Mardoyan, Levon; Nersessian, Armen; Sarkisyan, Hayk; Yeghikyan, Vahagn

2007-01-01

We consider the dipole transitions and the linear and quadratic Stark effects in the MICZ-Kepler system interpreted as a charge-dyon system. We show that while the linear Stark effect in the ground state is proportional to the azimuth quantum number (and to the sign of the monopole number), the quadratic Stark effect in the ground state is independent of the signs of the azimuth and monopole numbers

Transition? What transition? : Changing energy systems in an increasingly carbon constrained world

NARCIS (Netherlands)

Mc Cahery, J.A.; Lopez de Silanes, Florencio; de Roode, Alexander

2014-01-01

Energy transitions have been taking place continuously since the Industrial Revolution. These transitions primarily involve national energy mixes. In general, countries keep moving up the energy ladder, meaning that they integrate larger and larger proportions of specialized fuels into their energy

75 FR 1632 - Public Housing Assessment System (PHAS): Asset Management Transition Year 2 Information

Science.gov (United States)

2010-01-12

... accounting under asset management, also known as ``Transition Year 2.'' FOR FURTHER INFORMATION CONTACT: The... System (PHAS): Asset Management Transition Year 2 Information AGENCY: Office of the Assistant Secretary... by HUD under the Public Housing Management Assessment Program (PHMAP), the regulations for which are...

From system requirements to source code: transitions in UML and RUP

Directory of Open Access Journals (Sweden)

Stanisław Wrycza

2011-06-01

Full Text Available There are many manuals explaining language specification among UML-related books. Only some of books mentioned concentrate on practical aspects of using the UML language in effective way using CASE tools and RUP. The current paper presents transitions from system requirements specification to structural source code, useful while developing an information system.

Transitional region of phase transitions in nuclear models

Energy Technology Data Exchange (ETDEWEB)

Kotze, A A

1988-01-01

The phase transition in an exactly solvable nuclear model, the Lipkin model, is scrutinised, first using Hartree-Fock methods or the plain mean flield approximation, and then using projected wave functions. It turns out that the plain mean field is not reliable in the transitional region. Although the projection methods give better resutls in the transitional region, it leads to spurious singularities. While the energy of the projection before variation is slightly better than its projection after variation counterpart, the perfomance of the wave function is considerably worse in the transitional region. The model's wave function undergoes dramatic changes in the transitional region. The mechanism that brings about these changes is studied within a model Hamiltonian that can reproduce the Lipkin model mathematically. It turns out that the numerous exceptional points found in the transitional region, bring about the change of the ground state wave function. Exceptional points are associated with level crossings in the complex plane. These level crossings can be seen as level repulsions in the spectrum. Level repulsion and a sensitive dependence of the system on some external parameter are characteristics of chaotic behaviour. These two features are found in the transitional region of the Lipkin model. In order to study chaos, one has to resort to a statistical analysis. A measure of the chaotic behaviour of systems, the ..delta../sub 3/ statistic, is introduced. The results show that the Lipkin model is harmonic, even in the transitional region. For the Lipkin model the exceptional points are regularly distributed in the complex plane. In a total chaotic system the points would be randomly distributed.

MODEL-INDEPENDENT STELLAR AND PLANETARY MASSES FROM MULTI-TRANSITING EXOPLANETARY SYSTEMS

International Nuclear Information System (INIS)

Montet, Benjamin T.; Johnson, John Asher

2013-01-01

Precise exoplanet characterization requires precise classification of exoplanet host stars. The masses of host stars are commonly estimated by comparing their spectra to those predicted by stellar evolution models. However, spectroscopically determined properties are difficult to measure accurately for stars that are substantially different from the Sun, such as M-dwarfs and evolved stars. Here, we propose a new method to dynamically measure the masses of transiting planets near mean-motion resonances and their host stars by combining observations of transit timing variations with radial velocity (RV) measurements. We derive expressions to analytically determine the mass of each member of the system and demonstrate the technique on the Kepler-18 system. We compare these analytic results to numerical simulations and find that the two are consistent. We identify eight systems for which our technique could be applied if follow-up RV measurements are collected. We conclude that this analysis would be optimal for systems discovered by next-generation missions similar to TESS or PLATO, which will target bright stars that are amenable to efficient RV follow-up.

Maltreatment, family environment, and social risk factors: Determinants of the child welfare to juvenile justice transition among maltreated children and adolescents.

Science.gov (United States)

Vidal, Sarah; Prince, Dana; Connell, Christian M; Caron, Colleen M; Kaufman, Joy S; Tebes, Jacob K

2017-01-01

This study prospectively examines the transition from the child welfare system into the juvenile justice system among 10,850 maltreated children and adolescents and explores how patterns of risks, including severity and chronicity of maltreatment, adverse family environment, and social risk factors, affect service systems transition. Almost three percent of maltreated children and adolescents had their first juvenile justice adjudication within an average of approximately six years of their initial child protective services investigation (CPS). Social risk factors, including a child's age at index CPS investigation (older), gender (boys), and race/ethnicity (Black and Hispanic) significantly predicted the risk of transition into the juvenile justice system. Recurrence of maltreatment and experiencing at least one incident of neglect over the course of the study period also increased the risk of transition into the juvenile justice system. However, subtypes of maltreatment, including physical, sexual, and other types of abuse did not significantly predict the risk of juvenile justice system transition. Finally, family environment characterized by poverty also significantly increased the risk of juvenile justice system transition. These findings have important implications for developing and tailoring services for maltreated children, particularly those at-risk for transitioning into the juvenile justice system. Copyright © 2016 Elsevier Ltd. All rights reserved.

Hysteretic transitions in the Kuramoto model with inertia.

Science.gov (United States)

Olmi, Simona; Navas, Adrian; Boccaletti, Stefano; Torcini, Alessandro

2014-10-01

We report finite-size numerical investigations and mean-field analysis of a Kuramoto model with inertia for fully coupled and diluted systems. In particular, we examine, for a gaussian distribution of the frequencies, the transition from incoherence to coherence for increasingly large system size and inertia. For sufficiently large inertia the transition is hysteretic, and within the hysteretic region clusters of locked oscillators of various sizes and different levels of synchronization coexist. A modification of the mean-field theory developed by Tanaka, Lichtenberg, and Oishi [Physica D 100, 279 (1997)] allows us to derive the synchronization curve associated to each of these clusters. We have also investigated numerically the limits of existence of the coherent and of the incoherent solutions. The minimal coupling required to observe the coherent state is largely independent of the system size, and it saturates to a constant value already for moderately large inertia values. The incoherent state is observable up to a critical coupling whose value saturates for large inertia and for finite system sizes, while in the thermodinamic limit this critical value diverges proportionally to the mass. By increasing the inertia the transition becomes more complex, and the synchronization occurs via the emergence of clusters of whirling oscillators. The presence of these groups of coherently drifting oscillators induces oscillations in the order parameter. We have shown that the transition remains hysteretic even for randomly diluted networks up to a level of connectivity corresponding to a few links per oscillator. Finally, an application to the Italian high-voltage power grid is reported, which reveals the emergence of quasiperiodic oscillations in the order parameter due to the simultaneous presence of many competing whirling clusters.

Thermal-hydraulic effects of transition to improved System 80TM fuel

International Nuclear Information System (INIS)

Rodack, T.; Joffre, P.F.; Kapoor, R.K.

2004-01-01

ABB CE's improved System 80 TM PWR fuel design includes GUARDIAN debris-resistant features and laser-welded Zircaloy grids. The GUARDIAN features include an Inconel grid with debris-filtering features located just above the Lower End Fitting, and a solid fuel rod bottom end cap that extends above the filtering features. Tests and analyses were done to establish the impact of these design improvements on fuel assembly hydraulic performance. Further analysis was done to determine the mixed core thermal-hydraulic performance as the transition is made over two fuel cycles to a full core of the improved System 80 TM fuel. Results confirm that the Thermal-Hydraulic (T-H) effects of the reduction in hydraulic resistance between the improved and resident fuel due to the laser-welded Zircaloy grids offsets the effects of the increased resistance GUARDIAN grid. Therefore, the mechanically improved System 80 TM fuel can be implemented with no net impact on Departure from Nucleate Boiling (DNB) margin in transition cores. (author)

Transitions of interaction outcomes in a uni-directional consumer-resource system

Science.gov (United States)

Wang, Y.; DeAngelis, D.L.

2011-01-01

A uni-directional consumer-resource system of two species is analyzed. Our aim is to understand the mechanisms that determine how the interaction outcomes depend on the context of the interaction; that is, on the model parameters. The dynamic behavior of the model is described and, in particular, it is demonstrated that no periodic orbits exist. Then the parameter (factor) space is shown to be divided into four regions, which correspond to the four forms of interaction outcomes; i.e. mutualism, commensalism, parasitism and amensalism. It is shown that the interaction outcomes of the system transition smoothly among these four forms when the parameters of the system are varied continuously. Varying each parameter individually or varying pairs of parameters can also lead to smooth transitions between the interaction outcomes. The analysis leads to both conditions for which each species achieves its maximal density, and situations in which periodic oscillations of the interaction outcomes emerge. ?? 2011 Elsevier Ltd.

Critical behavior and phase transition of dilaton black holes with nonlinear electrodynamics

Energy Technology Data Exchange (ETDEWEB)

Dayyani, Z.; Dehghani, M.H.; Hajkhalili, S. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Sheykhi, A. [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of)

2018-02-15

In this paper, we take into account the dilaton black hole solutions of Einstein gravity in the presence of logarithmic and exponential forms of nonlinear electrodynamics. First of all, we consider the cosmological constant and nonlinear parameter as thermodynamic quantities which can vary. We obtain thermodynamic quantities of the system such as pressure, temperature and Gibbs free energy in an extended phase space. We complete the analogy of the nonlinear dilaton black holes with the Van der Waals liquid-gas system. We work in the canonical ensemble and hence we treat the charge of the black hole as an external fixed parameter. Moreover, we calculate the critical values of temperature, volume and pressure and show that they depend on the dilaton coupling constant as well as on the nonlinear parameter. We also investigate the critical exponents and find that they are universal and independent of the dilaton and nonlinear parameters, which is an expected result. Finally, we explore the phase transition of nonlinear dilaton black holes by studying the Gibbs free energy of the system. We find that in the case of T > T{sub c}, we have no phase transition. When T = T{sub c}, the system admits a second-order phase transition, while for T = T{sub f} < T{sub c} the system experiences a first-order transition. Interestingly, for T{sub f} < T < T{sub c} we observe a zeroth-order phase transition in the presence of a dilaton field. This novel zeroth-order phase transition occurs due to a finite jump in the Gibbs free energy which is generated by the dilaton-electromagnetic coupling constant, α, for a certain range of pressure. (orig.)

Allosteric transitions of supramolecular systems explored by network models: application to chaperonin GroEL.

Directory of Open Access Journals (Sweden)

Zheng Yang

2009-04-01

Full Text Available Identification of pathways involved in the structural transitions of biomolecular systems is often complicated by the transient nature of the conformations visited across energy barriers and the multiplicity of paths accessible in the multidimensional energy landscape. This task becomes even more challenging in exploring molecular systems on the order of megadaltons. Coarse-grained models that lend themselves to analytical solutions appear to be the only possible means of approaching such cases. Motivated by the utility of elastic network models for describing the collective dynamics of biomolecular systems and by the growing theoretical and experimental evidence in support of the intrinsic accessibility of functional substates, we introduce a new method, adaptive anisotropic network model (aANM, for exploring functional transitions. Application to bacterial chaperonin GroEL and comparisons with experimental data, results from action minimization algorithm, and previous simulations support the utility of aANM as a computationally efficient, yet physically plausible, tool for unraveling potential transition pathways sampled by large complexes/assemblies. An important outcome is the assessment of the critical inter-residue interactions formed/broken near the transition state(s, most of which involve conserved residues.

Concavity anomalies, topology of events and phase transitions in finite systems

International Nuclear Information System (INIS)

Gulminelli, F.; Chomaz, P.H.

2001-02-01

We propose a definition of first order phase transitions in finite systems based on topology anomalies of the event distribution in the space of observations. This generalizes the definitions based on the curvature anomalies of thermodynamical potentials, provides a natural definition of order parameters and can be related to the Yang Lee theorem in the thermodynamical limit. It is directly operational from the experimental point of view. It allows to study phase transitions in Gibbs equilibria as well as in other ensembles such as the Tsallis ensemble. (authors)

Transit Duration Variations due to Secular Interactions in Systems with Tightly-packed Inner Planets

Science.gov (United States)

Boley, Aaron; Van Laerhoven, Christa; Granados Contreras, A. Paula

2018-04-01

Secular interactions among planets in multi-planet systems will lead to variations in orbital inclinations and to the precession of orbital nodes. Taking known system architectures at face value, we calculate orbital precession rates for planets in tightly-packed systems using classical second-order secular theory, in which the orientation of the orbits can be described as a vector sum of eigenmodes and the eigenstructure is determined only by the masses and semi-major axes of the planets. Using this framework, we identify systems that have fast precession frequencies, and use those systems to explore the range of transit duration variation that could occur using amplitudes that are consistent with tightly-packed planetary systems. We then further assess how transit duration variations could be used in practice.

Investigation of Ternary Transition-Metal Nitride Systems by Reactive Cosputtering

NARCIS (Netherlands)

Dover, R.B. Van; Hessen, B.; Werder, D.; Chen, C.-H.; Felder, R.J.

1993-01-01

A reactive dc cosputtering technique has been used to evaluate compound formation in bimetallic transition-metal nitride systems. A wide range in M-M’ composition can be studied in a single deposition run, and the method is applicable to nonalloying metal combinations. Using this technique, it was

Optimization of film synthesized rare earth transition metal permanent magnet systems

International Nuclear Information System (INIS)

Cadieu, F.J.

1990-01-01

This report reviews work on the optimization of film synthesized rare earth transition metal permanent magnet systems. Topics include: high coercivity in Sm-Fe-Ti-V, Sm-Fe-V, and two element systems; ThMn 12 type pseudobinary SmFe 12 - X T X ; and sputter process control for the synthesis of precisely textured RE-TM magnetic films. (JL)

Nervous systems and scenarios for the invertebrate-to-vertebrate transition.

Science.gov (United States)

Holland, Nicholas D

2016-01-05

Older evolutionary scenarios for the origin of vertebrates often gave nervous systems top billing in accordance with the notion that a big-brained Homo sapiens crowned a tree of life shaped mainly by progressive evolution. Now, however, tree thinking positions all extant organisms equidistant from the tree's root, and molecular phylogenies indicate that regressive evolution is more common than previously suspected. Even so, contemporary theories of vertebrate origin still focus on the nervous system because of its functional importance, its richness in characters for comparative biology, and its central position in the two currently prominent scenarios for the invertebrate-to-vertebrate transition, which grew out of the markedly neurocentric annelid and enteropneust theories of the nineteenth century. Both these scenarios compare phyla with diverse overall body plans. This diversity, exacerbated by the scarcity of relevant fossil data, makes it challenging to establish plausible homologies between component parts (e.g. nervous system regions). In addition, our current understanding of the relation between genotype and phenotype is too preliminary to permit us to convert gene network data into structural features in any simple way. These issues are discussed here with special reference to the evolution of nervous systems during proposed transitions from invertebrates to vertebrates. © 2015 The Author(s).

Dealing with the Empty Vehicle Movements in Personal Rapid Transit System with Batteries Constraints in a Dynamic Context

Directory of Open Access Journals (Sweden)

Ezzeddine Fatnassi

2017-01-01

Full Text Available The Personal Rapid Transit is a new emergent transportation tool. It relies on using a set of small driverless electric vehicles to transport people on demand. Because of the specific on-demand characteristic of the Personal Rapid Transit system, many Personal Rapid Transit vehicles would move empty which results in a high level of wasted transportation capacity. This is enhanced while using Personal Rapid Transit vehicles with limited electric battery capacity. This paper deals with this problem in a real time context while minimizing the set of empty vehicle movements. First, a mathematical formulation to benchmark waiting time of passengers in Personal Rapid Transit systems is proposed. Then, a simulation model that captures the main features of the Personal Rapid Transit system is developed. A decision support system which integrates several real time solution strategies as well as a simulation module is proposed. Our dispatching strategies are evaluated and compared based on our simulation model. The efficiency of our method is tested through extensive test studies.

Phase transitions in a system of hard Y-shaped particles on the triangular lattice

Science.gov (United States)

Mandal, Dipanjan; Nath, Trisha; Rajesh, R.

2018-03-01

We study the different phases and the phase transitions in a system of Y-shaped particles, examples of which include immunoglobulin-G and trinaphthylene molecules, on a triangular lattice interacting exclusively through excluded volume interactions. Each particle consists of a central site and three of its six nearest neighbors chosen alternately, such that there are two types of particles which are mirror images of each other. We study the equilibrium properties of the system using grand canonical Monte Carlo simulations that implement an algorithm with cluster moves that is able to equilibrate the system at densities close to full packing. We show that, with increasing density, the system undergoes two entropy-driven phase transitions with two broken-symmetry phases. At low densities, the system is in a disordered phase. As intermediate phases, there is a solidlike sublattice phase in which one type of particle is preferred over the other and the particles preferentially occupy one of four sublattices, thus breaking both particle symmetry as well as translational invariance. At even higher densities, the phase is a columnar phase, where the particle symmetry is restored, and the particles preferentially occupy even or odd rows along one of the three directions. This phase has translational order in only one direction, and breaks rotational invariance. From finite-size scaling, we demonstrate that both the transitions are first order in nature. We also show that the simpler system with only one type of particle undergoes a single discontinuous phase transition from a disordered phase to a solidlike sublattice phase with an increasing density of particles.

Beam dynamics in the SLC final focus system

International Nuclear Information System (INIS)

Bambade, P.S.

1987-06-01

The SLC luminosity is reached by colliding beams focused to about 2 μm transverse sizes. The Final Focus System (FFS) must enable, beyond its basic optical design, the detection and correction of errors accumulated in the system. In this paper, after summarizing the design, we review the sensitivity to such errors and the ability to correct them. The overall tuning strategy involves three phases: single beam spot minimization, steering the beams in collision and luminosity optimization with beam-beam effects

Photo-modulation of the spin Hall conductivity of mono-layer transition metal dichalcogenides

Energy Technology Data Exchange (ETDEWEB)

Sengupta, Parijat; Bellotti, Enrico [Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215 (United States)

2016-05-23

We report on a possible optical tuning of the spin Hall conductivity in mono-layer transition metal dichalcogenides. Light beams of frequencies much higher than the energy scale of the system (the off-resonant condition) do not excite electrons but rearrange the band structure. The rearrangement is quantitatively established using the Floquet formalism. For such a system of mono-layer transition metal dichalcogenides, the spin Hall conductivity (calculated with the Kubo expression in presence of disorder) exhibits a drop at higher frequencies and lower intensities. Finally, we compare the spin Hall conductivity of the higher spin-orbit coupled WSe{sub 2} to MoS{sub 2}; the spin Hall conductivity of WSe{sub 2} was found to be larger.

Cystic fibrosis: addressing the transition from pediatric to adult-oriented health care.

Science.gov (United States)

Kreindler, James L; Miller, Victoria A

2013-12-11

Survival for patients with cystic fibrosis (CF) increased to nearly 40 years in 2012 from the early childhood years in the 1940s. Therefore, patients are living long enough to require transition from pediatric CF centers to adult CF centers. The goal of transition is for the young adult to be engaged in the adult health care system in ways that optimize health, maximize potential, and increase quality of life. A successful transition promotes autonomy and responsibility with respect to one's own health. Currently, there is an information gap in the literature with respect to psychological models that can help guide informed transition processes. In this review, we establish the framework in which transition exists in CF; we review some of the published literature from the last 20 years of experience with transition in CF centers around the world; and we discuss psychological models of pediatric illness that can help to explain the current state of transition to adult-oriented care from pediatric-oriented care and help to formulate new models of ascertaining readiness for transition. Finally, we look at our current knowledge gaps and opportunities for future research endeavors.

Quantum scaling in many-body systems an approach to quantum phase transitions

CERN Document Server

Continentino, Mucio

2017-01-01

Quantum phase transitions are strongly relevant in a number of fields, ranging from condensed matter to cold atom physics and quantum field theory. This book, now in its second edition, approaches the problem of quantum phase transitions from a new and unifying perspective. Topics addressed include the concepts of scale and time invariance and their significance for quantum criticality, as well as brand new chapters on superfluid and superconductor quantum critical points, and quantum first order transitions. The renormalisation group in real and momentum space is also established as the proper language to describe the behaviour of systems close to a quantum phase transition. These phenomena introduce a number of theoretical challenges which are of major importance for driving new experiments. Being strongly motivated and oriented towards understanding experimental results, this is an excellent text for graduates, as well as theorists, experimentalists and those with an interest in quantum criticality.

Easing the transition to secondary education for children with autism spectrum disorder: An evaluation of the Systemic Transition in Education Programme for Autism Spectrum Disorder (STEP-ASD)

OpenAIRE

Mandy, William; Murin, Marianna; Baykaner, Ozlem; Staunton, Sara; Cobb, Robert; Hellriegel, Josselyn; Anderson, Seonaid; Skuse, David

2015-01-01

In mainstream education, the transition from primary to secondary school ('school transition') is difficult for children with autism spectrum disorder, being marked by high levels of emotional and behavioural difficulties. The Systemic Transition in Education Programme for Autism Spectrum Disorder (STEP-ASD) is a new, manualised school transition intervention. We investigated its feasibility and efficacy for children diagnosed with autism spectrum disorder (N = 37; mean age = 11.47 years; mea...

Minnesota urban partnership agreement national evaluation : transit system data test plan.

Science.gov (United States)

2009-11-17

This report presents the test plan for collecting and analyzing transit system data for the Minnesota Urban Partnership Agreement (UPA) National Evaluation under the United States Department of Transportation (U.S. DOT) UPA Program. The Minnesota UPA...

Clean energy for Europe in transition

International Nuclear Information System (INIS)

Zaleski, C.P.

1992-01-01

Energy, an important subject, cannot be validly discussed alone. For some time already, most experts agree that is necessary to include the environmental effects if one seeks a valid discussion. It appears now this was especially pointed out by the dramatic changes in Russia and other Eastern and Central European countries that the only efficient way to discuss energy is even more global. That discussion should, of course, include economics and the politico-economic system, but also society-people's motivations, mentality, education and finally a touch of philosophy, notably value systems. The debates of the third MIEC conference were characterized by their interdisciplinary character. The organizers tried to address these different issues by having them discussed together while emphasizing in different sessions specific aspects like economics and political system society, education, and value system and finally scientific and technical aspects of new energy technology. This meeting presents 28 papers of which 15 are in the INIS and Energy database scope. In the first and the second issue, the subject studied is energy policy in transition economy. The third issue describes the relationships between energy, environment and society. In the two last issues, the problems of safety in nuclear industry are studied

Probing LINEAR Collider Final Focus Systems in SuperKEKB

CERN Document Server

Thrane, Paul Conrad Vaagen

2017-01-01

A challenge for future linear collider final focus systems is the large chromaticity produced by the final quadrupoles. SuperKEKB will be correcting high levels of chromaticity using the traditional scheme which has been also proposed for the CLIC FFS. We present early simulation results indicating that lowering β*у in the SuperKEKB Low Energy Ring might be possible given on-axis injection and low bunch current, opening the possibility of testing chromaticity correction beyond FFTB level, similar to ILC and approaching that of CLIC. CLIC – Note – 1077

A RECIPE FOR LINEAR COLLIDER FINAL FOCUS SYSTEM DESIGN

International Nuclear Information System (INIS)

Seryi, Andrei

2003-01-01

The design of Final Focus systems for linear colliders is challenging because of the large demagnifications needed to produce nanometer-sized beams at the interaction point. Simple first- and second-order matrix matching have proven insufficient for this task, and minimization of third- and higher-order aberrations is essential. An appropriate strategy is required for the latter to be successful. A recipe for Final Focus design, and a set of computational tools used to implement this approach, are described herein. An example of the use of this procedure is given

Soil Vapor Extraction System Optimization, Transition, and Closure Guidance

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Becker, Dave; Simon, Michelle A.; Oostrom, Martinus; Rice, Amy K.; Johnson, Christian D.

2013-02-08

Soil vapor extraction (SVE) is a prevalent remediation approach for volatile contaminants in the vadose zone. A diminishing rate of contaminant extraction over time is typically observed due to 1) diminishing contaminant mass, and/or 2) slow rates of removal for contamination in low-permeability zones. After a SVE system begins to show indications of diminishing contaminant removal rate, SVE performance needs to be evaluated to determine whether the system should be optimized, terminated, or transitioned to another technology to replace or augment SVE. This guidance specifically addresses the elements of this type of performance assessment. While not specifically presented, the approach and analyses in this guidance could also be applied at the onset of remediation selection for a site as a way to evaluate current or future impacts to groundwater from vadose zone contamination. The guidance presented here builds from existing guidance for SVE design, operation, optimization, and closure from the U.S. Environmental Protection Agency, U.S. Army Corps of Engineers, and the Air Force Center for Engineering and the Environment. The purpose of the material herein is to clarify and focus on the specific actions and decisions related to SVE optimization, transition, and/or closure.

System Design for Transitional Aircraft Support

Directory of Open Access Journals (Sweden)

John P.T. Mo

2014-01-01

Full Text Available The Australian Defence Force and industry are undergoing significant changes in the way they work together in capability enhancement programs. There are capability gaps in maintaining and supporting current obligations during major asset acquisition, which has migrated into the front line of Royal Air Force Fighter Groups as a new capability. This paper examines a steady state support solution and argues that in order to interchange from one support solution to a new architecture there must be a period for transition, which may need its own interim business model and operational service. A preliminary study of several existing support solutions reveals the generic elements that need to be parameterized and traced through the support system architecture trajectory.

Gaussian dominance and phase transitions in systems with continuous symmetry

International Nuclear Information System (INIS)

Sankovich, D.P.

1989-01-01

In the framework of Froehlich's strategy in the theory of phase transitions in systems with continuous symmetry a condition on the interaction is obtained that leads to the existence of a Bose condensate in the model of a nonideal Bose gas at sufficiently low temperatures. It is shown that this conditions can be satisfied for the Huang-Davis and Huang-Yang-Luttinger models. The technique of majorizing estimates for the correlation functions based on the condition of local Gaussian dominance is used. An equation is obtained for the phase-transition temperature, an upper bound is obtained for the energy of the elementary excitations, and Bogolyubov's 1/q 2 singularity theorem is generalized

Multiple dimensions of transitions in complex socio-ecological systems - A case from China

Science.gov (United States)

Liu, Wei; Yang, Wu; Vina, Andres; Schröter, Dagmar; Liu, Jianguo

2013-04-01

Transitions in complex socio-ecological systems are intermediate phases between two successive and more stable periods or states and involve various societal, ecological, and biophysical changes that are often non-linear and inter-related. Understanding transitions is challenging but important for managing socio-ecological systems for achieving environmental sustainability and improving human well-being. Long-term and intensive research is warranted to disclose common patterns and mechanisms of socio-ecological transitions and to develop ideas and methods for studying and planning sustainable transitions. Based on a long-term research on human-nature relationships in Wolong Nature Reserve in China, we studied multiple concurrent social, economic, and ecological transitions during the last 15 years. As a UNESCO biosphere reserve, Wolong lies within a global biodiversity hotspot and a World Heritage site. It contains the largest populations of the world-famous endangered giant pandas and several thousand other animal and plant species. Like most nature reserves in China and many other developing countries, Wolong is also home to many local residents who undertake a variety of activities that involve interaction with ecosystem. For the majority of the 20th century, local people in Wolong lived under poverty line in a closed subsistence-based agricultural economy. Their demands on for wood (as fuel and raw materials) from the natural forests were high and resulted in severe deforestation, habitat degradation, and landslides. Since late 1990s, a series of major economic (e.g., tourism development) and environmental (e.g., payment for ecosystem services programs) policies have been implemented in the reserve as adaptive strategies to cope with poverty and ecological degradation. Within a decade, we have observed major transitions in land use (i.e., from extractive use to non-consumptive use), economic structure (i.e., from a subsistence-based agricultural economy to an

The order-to-disorder transition behavior of PS-b-P2VP thin film system

Science.gov (United States)

Ahn, Hyungju; Ryu, Du

2013-03-01

We investigated the transition behavior such as the order-to-disorder transition (ODT) for symmetric poly(styrene)-block-poly(2-vinly pridine) (PS-b-P2VP) using SAXS and GISAXS for block copolymer bulks and films. The bulk transition temperature of PS-b-P2VP was significantly influenced by the interfacial interactions in thin films, leading to the different transition temperature. From these results, we will discuss about the interfacial interaction effects on the phase behaviors in bulks and thin films system of PS-b-P2VP.

Research and development on super heat pump energy accumulation system. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-06-01

This is the final report on research and development of super heat pump energy accumulation system, which has been carried out from FY 1985 to 1992. It describes outline of the research and development program, R and D results, final evaluation methodology, evaluation of the R and D, proposals for the commercialization, and so on. The super high performance compression heat pumps are technically evaluated for highly efficient type (for heating, and cooling and heating), high temperature type (utilizing high temperature heat source, and low temperature heat source), working fluids (alcohol-based and nonalcohol-based), stainless steel plate fin type heat exchanger, EHD heat exchanger, and so on. The other techniques evaluated include those for chemical heat storage, combined systems, plant simulation, and systemization. The evaluation works are also directed to the economic and environmental aspects. Finally, the R and D themes are proposed to leap over various hurdles, e.g., reliability and economic viability, for the eventual commercialization of the energy accumulation system. (NEDO)

Fixed-Guideway Transit Lines (National) - National Geospatial Data Asset (NGDA) Transit (Lines)

Data.gov (United States)

Department of Transportation — Version 2004 of the Fixed-Guideway Transit Network is a network database of the nation's fixed-guideway transit systems (NTAD). The data set covers systems in cities...

Fixed-Guideway Transit Stations (National) - National Geospatial Data Asset (NGDA) Transit (Stations)

Data.gov (United States)

Department of Transportation — Version 2004 of the Fixed-Guideway Transit Network is a network database of the nation's fixed-guideway transit systems (NTAD). The data set covers systems in cities...

On the behavior of Bronsted-Evans-Polanyi Relations for Transition Metal Oxides

Energy Technology Data Exchange (ETDEWEB)

Vojvodic, Aleksandra

2011-08-22

Versatile Broensted-Evans-Polanyi (BEP) relations are found from density functional theory for a wide range of transition metal oxides including rutiles and perovskites. For oxides, the relation depends on the type of oxide, the active site and the dissociating molecule. The slope of the BEP relation is strongly coupled to the adsorbate geometry in the transition state. If it is final state-like the dissociative chemisorption energy can be considered as a descriptor for the dissociation. If it is initial state-like, on the other hand, the dissociative chemisorption energy is not suitable as descriptor for the dissociation. Dissociation of molecules with strong intramolecular bonds belong to the former and molecules with weak intramolecular bonds to the latter group. We show, for the prototype system La-perovskites, that there is a 'cyclic' behavior in the transition state characteristics upon change of the active transition metal of the oxide.

Multi-Point Combustion System: Final Report

Science.gov (United States)

Goeke, Jerry; Pack, Spencer; Zink, Gregory; Ryon, Jason

2014-01-01

A low-NOx emission combustor concept has been developed for NASA's Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 lb thrust engine application. These goals include 75 percent reduction of LTO NOx from CAEP6 standards without increasing CO, UHC, or smoke from that of current state of the art. An additional key factor in this work is to improve lean combustion stability over that of previous work performed on similar technology in the early 2000s. The purpose of this paper is to present the final report for the NASA contract. This work included the design, analysis, and test of a multi-point combustion system. All design work was based on the results of Computational Fluid Dynamics modeling with the end results tested on a medium pressure combustion rig at the UC and a medium pressure combustion rig at GRC. The theories behind the designs, results of analysis, and experimental test data will be discussed in this report. The combustion system consists of five radially staged rows of injectors, where ten small scale injectors are used in place of a single traditional nozzle. Major accomplishments of the current work include the design of a Multipoint Lean Direct Injection (MLDI) array and associated air blast and pilot fuel injectors, which is expected to meet or exceed the goal of a 75 percent reduction in LTO NOx from CAEP6 standards. This design incorporates a reduced number of injectors over previous multipoint designs, simplified and lightweight components, and a very compact combustor section. Additional outcomes of the program are validation that the design of these combustion systems can be aided by the use of Computational Fluid Dynamics to predict and reduce emissions. Furthermore, the staging of fuel through the individually controlled radially staged injector rows successfully demonstrated improved low power operability as well as improvements in emissions over previous multipoint designs. Additional comparison

The transitional region of phase transitions in nuclear models

International Nuclear Information System (INIS)

Kotze, A.A.

1988-01-01

The phase transition in an exactly solvable nuclear model, the Lipkin model, is scrutinised, first using Hartree-Fock methods or the plain mean flield approximation, and then using projected wave functions. It turns out that the plain mean field is not reliable in the transitional region. Although the projection methods give better resutls in the transitional region, it leads to spurious singularities. While the energy of the projection before variation is slightly better than its projection after variation counterpart, the perfomance of the wave function is considerably worse in the transitional region. The model's wave function undergoes dramatic changes in the transitional region. The mechanism that brings about these changes is studied within a model Hamiltonian that can reproduce the Lipkin model mathematically. It turns out that the numerous exceptional points found in the transitional region, bring about the change of the ground state wave function. Exceptional points are associated with level crossings in the complex plane. These level crossings can be seen as level repulsions in the spectrum. Level repulsion and a sensitive dependence of the system on some external parameter are characteristics of chaotic behaviour. These two features are found in the transitional region of the Lipkin model. In order to study chaos, one has to resort to a statistical analysis. A measure of the chaotic behaviour of systems, the Δ 3 statistic, is introduced. The results show that the Lipkin model is harmonic, even in the transitional region. For the Lipkin model the exceptional points are regularly distributed in the complex plane. In a total chaotic system the points would be randomly distributed

Thermodynamic phase transition of a black hole in rainbow gravity

Directory of Open Access Journals (Sweden)

Zhong-Wen Feng

2017-09-01

Full Text Available In this letter, using the rainbow functions that were proposed by Magueijo and Smolin, we investigate the thermodynamics and the phase transition of rainbow Schwarzschild black hole. First, we calculate the rainbow gravity corrected Hawking temperature. From this modification, we then derive the local temperature, free energy, and other thermodynamic quantities in an isothermal cavity. Finally, we analyze the critical behavior, thermodynamic stability, and phase transition of the rainbow Schwarzschild black hole. The results show that the rainbow gravity can stop the Hawking radiation in the final stages of black holes' evolution and lead to the remnants of black holes. Furthermore, one can observe that the rainbow Schwarzschild black hole has one first-order phase transition, two second-order phase transitions, and three Hawking–Page-type phase transitions in the framework of rainbow gravity theory.

Turner syndrome: transition from pediatrics to adulthood.

Science.gov (United States)

Rubin, Karen R

2008-09-01

To highlight the importance of an improved, seamless, and effective transition from pediatric to adult care, especially for medically complex conditions such as Turner syndrome (TS). The morbidities in adult patients with TS are reviewed, including features of the metabolic syndrome, congenital and acquired cardiovascular conditions, osteopenia and osteoporosis, autoimmune thyroid disease, and obesity, and psychobehavioral issues are addressed, in terms of promoting the development of independent self-care and autonomy in adolescent patients. An essential component of high-quality health care, transition for adolescents with TS needs to be reengineered as a staged process initiated during early-stage adolescence (about age 12 years), when exogenous estrogen therapy is begun in coordination with the final phase of growth hormone therapy. At this time, the focus of care shifts from the parent to the adolescent and from maximizing final adult height to inducing puberty with gradually increasing doses of estrogen. During this transition, the development of healthful and independent healthcare behaviors should be promoted to prepare patients with TS for the adult responsibility of self-care. During the final phase of transition, an adult care plan should be formulated in collaboration with the adolescent with TS and her providers of adult care to improve the likelihood that she will continue to be carefully monitored in a way that optimizes her adult health and longevity. The transitional period from pediatrics to adulthood is the ideal time for patients with TS to be made aware of their health history and health needs and of the evolving impact of TS into adulthood.

The impact of transit-oriented development on social capital : final report.

Science.gov (United States)

2016-10-01

This paper focuses on the ability of Transit Oriented Development (TOD) to improve social capital and interactions within a community. The expectation is that TOD has a positive impact on the lifestyle and activities of individuals who reside, work, ...

Multi Optical Transition Radiation System for ATF2

International Nuclear Information System (INIS)

Alabau-Gonzalvo, Javier

2012-01-01

In this paper we describe the design, installation and first calibration tests of a Multi Optical Transition Radiation System in the beam diagnostic section of the Extraction (EXT) line of ATF2, close to the multi wire scanner system. This system will be a valuable tool for measuring beam sizes and emittances coming from the ATF Damping Ring. With an optical resolution of about 2 (micro)m an original OTR design (OTR1X) located after the septum at the entrance of the EXT line demonstrated the ability to measure a 5.5 (micro)m beam size in one beam pulse and to take many fast measurements. This gives the OTR the ability to measure the beam emittance with high statistics, giving a low error and a good understanding of emittance jitter. Furthermore the nearby wire scanners will be a definitive test of the OTR as a beam emittance diagnostic device. The multi-OTR system design proposed here is based on the existing OTR1X.

Study of the phase transition in lithium potassium rubidium sulfate system

Science.gov (United States)

Hamed, A. E.; Abd. El-Aziz, Y. M.; Madi, N. K.; Kassem, M. E.

1998-10-01

Specific heat, Cp, measurements have been performed in lithium potassium rubidium sulfate, (Li 0.5- x/2 K 0.5- x/2 Rb x) 2SO 4, system in a wide range of Rb 2SO 4 content ( x) ( x=0 up to x=10%). Measurements were made between 300 and 800 K with special attention paid to the phase transition at 708 K. It is shown that for small contents, ( x), ( x=0.2 up to x=2%) quantitative changes in the temperature dependence of specific heat Cp( T) around the transition point, T1, are observed. A larger content, x, results in essential changes in the critical behavior of Cp( T) and a considerable change in the phase transition accompanied by a progressive decrease in the thermodynamic parameters. The ratios of the Landau expansion coefficients change as the content of Rb 2SO 4 increases.

A conceptual framework for exploring transitions to decarbonised energy systems in the United Kingdom

International Nuclear Information System (INIS)

Shackley, Simon; Green, Ken

2007-01-01

Drawing upon 'transitions theory' and a typology which produces five types of transitions, we describe and analyse the changes that have taken place in the United Kingdom's energy system over the past several decades in terms of three of these transition pathways, namely reproduction (e.g. incremental improvements in energy efficiency), transformation (e.g. more directed efforts towards energy efficiency gains, e.g., through voluntary and compulsory standards-setting processes) and substitution (e.g. the shift from coal to natural gas). Looking into the future, and drawing upon a programme of UK-based research which covered a wide range of potential new supply technologies and changes on the demand side, we identify the key drivers of change, including economic and commercial, technological, policy and regulatory imperatives. This analysis opens up the prospect for two further transition pathways to become manifest. These are: de-alignment/re-alignment (e.g. shift from conventional coal to coal technologies with carbon dioxide capture and storage) and re-configuration (e.g. integrating renewables within buildings and the possible emergence of the 'hydrogen economy'). We conclude with a discussion of the opportunities for policy learning and experimentation consistent with transitions theory to facilitate the deployment of more sustainable energy systems

Geometric structure and information change in phase transitions

Science.gov (United States)

Kim, Eun-jin; Hollerbach, Rainer

2017-06-01

We propose a toy model for a cyclic order-disorder transition and introduce a geometric methodology to understand stochastic processes involved in transitions. Specifically, our model consists of a pair of forward and backward processes (FPs and BPs) for the emergence and disappearance of a structure in a stochastic environment. We calculate time-dependent probability density functions (PDFs) and the information length L , which is the total number of different states that a system undergoes during the transition. Time-dependent PDFs during transient relaxation exhibit strikingly different behavior in FPs and BPs. In particular, FPs driven by instability undergo the broadening of the PDF with a large increase in fluctuations before the transition to the ordered state accompanied by narrowing the PDF width. During this stage, we identify an interesting geodesic solution accompanied by the self-regulation between the growth and nonlinear damping where the time scale τ of information change is constant in time, independent of the strength of the stochastic noise. In comparison, BPs are mainly driven by the macroscopic motion due to the movement of the PDF peak. The total information length L between initial and final states is much larger in BPs than in FPs, increasing linearly with the deviation γ of a control parameter from the critical state in BPs while increasing logarithmically with γ in FPs. L scales as |lnD | and D-1 /2 in FPs and BPs, respectively, where D measures the strength of the stochastic forcing. These differing scalings with γ and D suggest a great utility of L in capturing different underlying processes, specifically, diffusion vs advection in phase transition by geometry. We discuss physical origins of these scalings and comment on implications of our results for bistable systems undergoing repeated order-disorder transitions (e.g., fitness).

Issues on Settlement of Final Expenses and Performance Assessment in the Course of Transition: Evidence from China

OpenAIRE

L¨¹ Wei; LIU Yusheng

2006-01-01

This paper studies the process and the performance of transition with the following logic: transition is an objective process in accordance with the general principles of economic history; the objectivity is embodied in the expected economic and social effects of transition, the profound economic and social changes in the course of transition, and the different problems facing different transitional stages. Transition is, at the same time, a subjective process involving the participation of t...

Nucleic acid-functionalized transition metal nanosheets for biosensing applications.

Science.gov (United States)

Mo, Liuting; Li, Juan; Liu, Qiaoling; Qiu, Liping; Tan, Weihong

2017-03-15

In clinical diagnostics, as well as food and environmental safety practices, biosensors are powerful tools for monitoring biological or biochemical processes. Two-dimensional (2D) transition metal nanomaterials, including transition metal chalcogenides (TMCs) and transition metal oxides (TMOs), are receiving growing interest for their use in biosensing applications based on such unique properties as high surface area and fluorescence quenching abilities. Meanwhile, nucleic acid probes based on Watson-Crick base-pairing rules are also being widely applied in biosensing based on their excellent recognition capability. In particular, the emergence of functional nucleic acids in the 1980s, especially aptamers, has substantially extended the recognition capability of nucleic acids to various targets, ranging from small organic molecules and metal ions to proteins and cells. Based on π-π stacking interaction between transition metal nanosheets and nucleic acids, biosensing systems can be easily assembled. Therefore, the combination of 2D transition metal nanomaterials and nucleic acids brings intriguing opportunities in bioanalysis and biomedicine. In this review, we summarize recent advances of nucleic acid-functionalized transition metal nanosheets in biosensing applications. The structure and properties of 2D transition metal nanomaterials are first discussed, emphasizing the interaction between transition metal nanosheets and nucleic acids. Then, the applications of nucleic acid-functionalized transition metal nanosheet-based biosensors are discussed in the context of different signal transducing mechanisms, including optical and electrochemical approaches. Finally, we provide our perspectives on the current challenges and opportunities in this promising field. Copyright © 2016 Elsevier B.V. All rights reserved.

An effective Hamiltonian approach for Donor-Bridge-Acceptor electronic transitions: Exploring the role of bath memory

Directory of Open Access Journals (Sweden)

E.R. Bittner

2016-03-01

Full Text Available We present here a formally exact model for electronic transitions between an initial (donor and final (acceptor states linked by an intermediate (bridge state. Our model incorporates a common set of vibrational modes that are coupled to the donor, bridge, and acceptor states and serves as a dissipative bath that destroys quantum coherence between the donor and acceptor. Taking the memory time of the bath as a free parameter, we calculate transition rates for a heuristic 3-state/2 mode Hamiltonian system parameterized to represent the energetics and couplings in a typical organic photovoltaic system. Our results indicate that if the memory time of the bath is of the order of 10-100 fs, a two-state kinetic (i.e., incoherent hopping model will grossly underestimate overall transition rate.

Routes to chaos in continuous mechanical systems: Part 2. Modelling transitions from regular to chaotic dynamics

International Nuclear Information System (INIS)

Krysko, A.V.; Awrejcewicz, J.; Papkova, I.V.; Krysko, V.A.

2012-01-01

In second part of the paper both classical and novel scenarios of transition from regular to chaotic dynamics of dissipative continuous mechanical systems are studied. A detailed analysis allowed us to detect the already known classical scenarios of transition from periodic to chaotic dynamics, and in particular the Feigenbaum scenario. The Feigenbaum constant was computed for all continuous mechanical objects studied in the first part of the paper. In addition, we illustrate and discuss different and novel scenarios of transition of the analysed systems from regular to chaotic dynamics, and we show that the type of scenario depends essentially on excitation parameters.

THE HOMOGENEOUS STUDY OF TRANSITING SYSTEMS (HoSTS). I. THE PILOT STUDY OF WASP-13

Energy Technology Data Exchange (ETDEWEB)

Gomez Maqueo Chew, Yilen; Cargile, Phillip; Hebb, Leslie; Stassun, Keivan G. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States); Faedi, Francesca; Pollacco, Don [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Doyle, Amanda P.; Smalley, Barry [Astrophysics Group, Keele University, Staffordshire ST5 5BG (United Kingdom); Ghezzi, Luan; Cunha, Katia; Smith, Verne V. [Observatorio Nacional, Rua Gal. Jose Cristino 77, Rio de Janeiro, RJ 20921-400 (Brazil); Sousa, Sergio; Santos, Nuno C. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Barros, Susana C. C. [LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, Aix Marseille Universite, CNRS, F-13388 Marseille (France); Schuler, Simon C. [Stewart Observatory, University of Arizona, Tucson, AZ 85721 (United States); Collier Cameron, Andrew, E-mail: yilen.gomez@vanderbilt.edu [School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS (United Kingdom)

2013-05-01

We present the fundamental stellar and planetary properties of the transiting planetary system WASP-13 within the framework of the Homogeneous Study of Transiting Systems (HoSTS). HoSTS aims to derive the fundamental stellar (T{sub eff}, [Fe/H], M{sub *}, R{sub *}) and planetary (M{sub pl}, R{sub pl}, T{sub eq}) physical properties of known transiting planets using a consistent methodology and homogeneous high-quality data set. Four spectral analysis techniques are independently applied to a Keck+HIRES spectrum of WASP-13 considering two distinct cases: unconstrained parameters and constrained log g from transit light curves. We check the derived stellar temperature against that from a different temperature diagnostic based on an INT+IDS H{alpha} spectrum. The four unconstrained analyses render results that are in good agreement, and provide an improvement of 50% in the precision of T{sub eff}, and of 85% in [Fe/H] with respect to the WASP-13 discovery paper. The planetary parameters are then derived via the Monte Carlo Markov Chain modeling of the radial velocity and light curves, in iteration with stellar evolutionary models to derive realistic uncertainties. WASP-13 (1.187 {+-} 0.065 M{sub Sun }; 1.574 {+-} 0.048 R{sub Sun }) hosts a Saturn-mass, transiting planet (0.500 {+-} 0.037 M{sub Jup}; 1.407 {+-} 0.052 R{sub Jup}), and is at the end of its main-sequence lifetime (4-5.5 Gyr). Our analysis of WASP-13 showcases that both a detailed stellar characterization and transit modeling are necessary to well determine the fundamental properties of planetary systems, which are paramount in identifying and determining empirical relationships between transiting planets and their hosts.

Drifting between transitions : Lessons from the environmental transition around the river Acheloos Diversion project in Greece

NARCIS (Netherlands)

Frantzeskaki, N.; Thissen, W.; Grin, J.

Systems can experience different types of transitions. The existing literature on transitions distinguishes socio-technological, social-ecological and institutional transitions that each focus on different aspects of real-life systems. For every one of these types of transitions we have identified a

Eigenstate Phase Transitions

Science.gov (United States)

Zhao, Bo

Phase transitions are one of the most exciting physical phenomena ever discovered. The understanding of phase transitions has long been of interest. Recently eigenstate phase transitions have been discovered and studied; they are drastically different from traditional thermal phase transitions. In eigenstate phase transitions, a sharp change is exhibited in properties of the many-body eigenstates of the Hamiltonian of a quantum system, but not the thermal equilibrium properties of the same system. In this thesis, we study two different types of eigenstate phase transitions. The first is the eigenstate phase transition within the ferromagnetic phase of an infinite-range spin model. By studying the interplay of the eigenstate thermalization hypothesis and Ising symmetry breaking, we find two eigenstate phase transitions within the ferromagnetic phase: In the lowest-temperature phase the magnetization can macroscopically oscillate by quantum tunneling between up and down. The relaxation of the magnetization is always overdamped in the remainder of the ferromagnetic phase, which is further divided into phases where the system thermally activates itself over the barrier between the up and down states, and where it quantum tunnels. The second is the many-body localization phase transition. The eigenstates on one side of the transition obey the eigenstate thermalization hypothesis; the eigenstates on the other side are many-body localized, and thus thermal equilibrium need not be achieved for an initial state even after evolving for an arbitrary long time. We study this many-body localization phase transition in the strong disorder renormalization group framework. After setting up a set of coarse-graining rules for a general one dimensional chain, we get a simple "toy model'' and obtain an almost purely analytical solution to the infinite-randomness critical fixed point renormalization group equation. We also get an estimate of the correlation length critical exponent nu

Plant systems/components modularization study. Final report. [PWR

Energy Technology Data Exchange (ETDEWEB)

1977-07-01

The final results are summarized of a Plant Systems/Components Modularization Study based on Stone and Webster's Pressurized Water Reactor Reference Design. The program has been modified to include evaluation of the most promising areas for modular consideration based on the level of the Sundesert Project engineering design completion and the feasibility of their incorporation into the plant construction effort.

Towards Transition Theory

NARCIS (Netherlands)

J. de Haan (Hans)

2010-01-01

textabstractThis thesis is a treatise on a theory for societal transitions: pillar theory. Societal transitions are complex processes taking place in complex systems, large-scale, long-term processes in which societal systems radically change the way they are composed and function. Since we all are

Brayton isotope power system, phase I. Final report

International Nuclear Information System (INIS)

1978-01-01

The Phase I program resulted in the development and ground demonstration of a dynamic power conversion system. The two key contractual objectives of 25% conversion efficiency and 1000 h of endurance testing were successfully met. As a result of the Phase I effort, the BIPS is a viable candidate for further development into a flight system capable of sustained operation in space. It represents the only known dynamic space power system to demonstrate the performance and endurance coupled with the simplicity necessary for reliable operation. This final report follows thirty-five monthly reports. For expediency, it makes liberal use of referenced documents which have been submitted to DOE during the course of the program

Molecular-nuclear transitions

International Nuclear Information System (INIS)

Belyaev, V.B.; Miller, M.B.

2007-01-01

the high-excited levels is necessary for creating a so-called inverse population, or the active medium. The role of the active medium in this case belongs to the initial molecular system in its ground state (which is stable contrary to the case of the active medium in the quantum optics). Now, if we irradiate the system of these molecules by electromagnetic radiation with the energy in keV range, the coherent molecular-nuclear transitions can be induced. Hence, this phenomenon can be observable in coincidence experiments: one should look for the coincidences between keV-range molecular-nuclear radiation and γ-radiation in MeV-energy range in final nuclei. For example, in the process H 2 O → 18 Ne γ-quanta with the energy E γ =4.522 MeV will be emitted, and for the case of 6 LiD→ 8 Be two α-particles with the energy E α =11.2 MeV each are expected. Then one will observe an effect like the 'molecular-nuclear laser', in which the low energy electromagnetic radiation (x-rays or hard UV radiation) is transformed into the high energy radiation: γ-quanta or α-particles, depending on the decay mode of the final nuclei. Later it can in principle be considered as a new way of obtaining the nuclear energy

Relaxation and final-state structure in XPS of atoms, molecules, and metals

International Nuclear Information System (INIS)

Shirley, D.A.; Martin, R.L.; McFeely, F.R.; Kowalczyk, S.P.; Ley, L.

1975-03-01

Photoemission from a many-electron system is a many-electron process, even though the transition operator may affect only one electron directly. Relaxation and ''shake-up'' structure are related by a sum rule. When one is present, the other must be also. Shake-up structure is shown to be accurately predictable in atomic neon and molecular HF if the CI calculations are done carefully. In metals the sum rule also applies but final-state effects usually appear as relaxation energy, which is large even for valence electrons. Finally, in rare-earth metals discrete shake-up structure is observable in the 4p region. (7 figs, 30 refs) (auth)

Phase transitions in distributed control systems with multiplicative noise

Science.gov (United States)

Allegra, Nicolas; Bamieh, Bassam; Mitra, Partha; Sire, Clément

2018-01-01

Contemporary technological challenges often involve many degrees of freedom in a distributed or networked setting. Three aspects are notable: the variables are usually associated with the nodes of a graph with limited communication resources, hindering centralized control; the communication is subject to noise; and the number of variables can be very large. These three aspects make tools and techniques from statistical physics particularly suitable for the performance analysis of such networked systems in the limit of many variables (analogous to the thermodynamic limit in statistical physics). Perhaps not surprisingly, phase-transition like phenomena appear in these systems, where a sharp change in performance can be observed with a smooth parameter variation, with the change becoming discontinuous or singular in the limit of infinite system size. In this paper, we analyze the so called network consensus problem, prototypical of the above considerations, that has previously been analyzed mostly in the context of additive noise. We show that qualitatively new phase-transition like phenomena appear for this problem in the presence of multiplicative noise. Depending on dimensions, and on the presence or absence of a conservation law, the system performance shows a discontinuous change at a threshold value of the multiplicative noise strength. In the absence of the conservation law, and for graph spectral dimension less than two, the multiplicative noise threshold (the stability margin of the control problem) is zero. This is reminiscent of the absence of robust controllers for certain classes of centralized control problems. Although our study involves a ‘toy’ model, we believe that the qualitative features are generic, with implications for the robust stability of distributed control systems, as well as the effect of roundoff errors and communication noise on distributed algorithms.

Shooting the Rapids: Navigating Transitions to Adaptive Governance of Social-Ecological Systems

Directory of Open Access Journals (Sweden)

Per Olsson

2006-06-01

Full Text Available The case studies of Kristianstads Vattenrike, Sweden; the Northern Highlands Lake District and the Everglades in the USA; the Mae Nam Ping Basin, Thailand; and the Goulburn-Broken Catchment, Australia, were compared to assess the outcome of different actions for transforming social-ecological systems (SESs. The transformations consisted of two phases, a preparation phase and a transition phase, linked by a window of opportunity. Key leaders and shadow networks can prepare a system for change by exploring alternative system configurations and developing strategies for choosing from among possible futures. Key leaders can recognize and use or create windows of opportunity and navigate transitions toward adaptive governance. Leadership functions include the ability to span scales of governance, orchestrate networks, integrate and communicate understanding, and reconcile different problem domains. Successful transformations rely on epistemic and shadow networks to provide novel ideas and ways of governing SESs. We conclude by listing some ð"„¬rules of thumb" that can help build leadership and networks for successful transformations toward adaptive governance of social-ecological systems.

Generalized Smooth Transition Map Between Tent and Logistic Maps

Science.gov (United States)

Sayed, Wafaa S.; Fahmy, Hossam A. H.; Rezk, Ahmed A.; Radwan, Ahmed G.

There is a continuous demand on novel chaotic generators to be employed in various modeling and pseudo-random number generation applications. This paper proposes a new chaotic map which is a general form for one-dimensional discrete-time maps employing the power function with the tent and logistic maps as special cases. The proposed map uses extra parameters to provide responses that fit multiple applications for which conventional maps were not enough. The proposed generalization covers also maps whose iterative relations are not based on polynomials, i.e. with fractional powers. We introduce a framework for analyzing the proposed map mathematically and predicting its behavior for various combinations of its parameters. In addition, we present and explain the transition map which results in intermediate responses as the parameters vary from their values corresponding to tent map to those corresponding to logistic map case. We study the properties of the proposed map including graph of the map equation, general bifurcation diagram and its key-points, output sequences, and maximum Lyapunov exponent. We present further explorations such as effects of scaling, system response with respect to the new parameters, and operating ranges other than transition region. Finally, a stream cipher system based on the generalized transition map validates its utility for image encryption applications. The system allows the construction of more efficient encryption keys which enhances its sensitivity and other cryptographic properties.

Transiting Exoplanet Monitoring Project (TEMP). IV. Refined System Parameters, Transit Timing Variations, and Orbital Stability of the Transiting Planetary System HAT-P-25

Science.gov (United States)

Wang, Xian-Yu; Wang, Songhu; Hinse, Tobias C.; Li, Kai; Wang, Yong-Hao; Laughlin, Gregory; Liu, Hui-Gen; Zhang, Hui; Wu, Zhen-Yu; Zhou, Xu; Zhou, Ji-Lin; Hu, Shao-Ming; Wu, Dong-Hong; Peng, Xi-Yan; Chen, Yuan-Yuan

2018-06-01

We present eight new light curves of the transiting extra-solar planet HAT-P-25b obtained from 2013 to 2016 with three telescopes at two observatories. We use the new light curves, along with recent literature material, to estimate the physical and orbital parameters of the transiting planet. Specifically, we determine the mid-transit times (T C ) and update the linear ephemeris, T C[0] = 2456418.80996 ± 0.00025 [BJDTDB] and P = 3.65281572 ± 0.00000095 days. We carry out a search for transit timing variations (TTVs), and find no significant TTV signal at the ΔT = 80 s-level, placing a limit on the possible strength of planet–planet interactions (TTVG). In the course of our analysis, we calculate the upper mass-limits of the potential nearby perturbers. Near the 1:2, 2:1, and 3:1 resonances with HAT-P-25b, perturbers with masses greater than 0.5, 0.3, and 0.5 M ⊕ respectively, can be excluded. Furthermore, based on the analysis of TTVs caused by light travel time effect (LTTE) we also eliminate the possibility that a long-period perturber exists with M p > 3000 MJ within a = 11.2 au of the parent star.

World in transition 3 towards sustainable energy systems

CERN Document Server

2014-01-01

'The publication of World in Transition: Towards Sustainable Energy Systems is timely indeed. The World Summit on Sustainable Development gave great prominence to this challenge, but failed to agree on a quantitative, time-bound target for the introduction of renewable energy sources. The German Advisory Council on Global Change (WBGU) has now produced a report with a global focus, which is essential in view of the global impacts of climate change. The report provides a convincing long-term analysis, which is also essential. Global energy policies have to take a long-term perspective, over the

Electricity tariff design for transition economies. Application to the Libyan power system

Energy Technology Data Exchange (ETDEWEB)

Reneses, Javier; Gomez, Tomas; Rivier, Juan [Universidad Pontificia Comillas, Madrid (Spain); Angarita, Jorge L. [Europraxis Operations, Madrid (Spain)

2011-01-15

This paper presents a general electricity tariff design methodology, especially applicable for transition economies. These countries are trying to modernize their power systems from a centralized environment (with normally, a public vertically integrated electric company) to a liberalized framework (unbundling electricity companies and, eventually, starting a privatization process). Two issues arise as crucial to achieving a successful transition: (1) ensuring cost recovery for all future unbundled activities (generation, transmission, distribution and retailing), and (2) sending the right price signals to electricity customers, avoiding cross-subsidies between customer categories. The design of electricity tariffs plays a pivotal role in achieving both objectives. This paper proposes a new tariff design methodology that, complying with these two aforementioned criteria, requires a low amount of information regarding system data and customer load profiles. This is important since, typically, volume and quality of data are poor in those countries. The presented methodology is applied to computing tariffs for the Libyan power system in 2006, using real data. (author)

Phase transitions and reflection positivity for a class of quantum lattice systems

International Nuclear Information System (INIS)

Perez, J.F.; Wreszinski, W.F.

1980-08-01

A form reflection positivity in planes containing sites is proved for a class of quantum lattice systems. Two apllications to typical models are given: a proof of phase transition of ferromagnetic type by the method of infrared bounds for hhe Fisher-stabilized Ising antiferromagnet in an external magnetic field with parallel and tranverse components, and a proof of a phase transition of antiferromagnetic type for the same model with no stabilization by a suitable version of the Peierls argument. The spherical model is also discussed in an appendix. (Author) [pt

The socio-technical transition of distributed electricity storage into future networks—System value and stakeholder views

International Nuclear Information System (INIS)

Grünewald, Philipp H.; Cockerill, Timothy T.; Contestabile, Marcello; Pearson, Peter J.G.

2012-01-01

Whole system models for the GB electricity system suggest that distributed electricity storage has the potential to significantly reduce the system integration cost for future system scenarios. From a policy perspective, this poses the question why this value should not be realised within existing market structures. Opinion among stakeholders is divided. Some believe that storage deployment constitutes a ‘special case’ in need of policy support. Others insist that markets can provide the necessary platform to negotiate contracts, which reward storage operators for the range of services they could provide. This paper seeks to inform this debate with a process of stakeholder engagement using a perspective informed by socio-technical transition literatures. This approach allows the identification of tensions among actors in the electricity system and of possibilities for co-evolution in the deployment of storage technologies during a transition towards a low carbon electricity system. It also draws attention to policy-related challenges of technology lock-in and path dependency resulting from poor alignment of incumbent regimes with the requirements for distributed electricity storage. - Highlights: ► Electricity storage is poorly aligned with existing regimes in the electricity system. ► Stakeholders perceive electricity storage as “somebody else's problem”. ► Combining stakeholder views and transition theory provides new insight. ► Transition from network to operational benefits poses regulatory challenge. ► Value aggregation made difficult due to institutional barriers.

Mapping the Typology of Transition Systems in a Liberal Market Economy: The Case of Canada

Science.gov (United States)

Arnold, Christine Helen; Wheelahan, Leesa; Moodie, Gavin; Beaulieu, Jacqueline; Taylor-Cline, Jean-Claude

2018-01-01

This research explores links between tertiary education institutions and between tertiary education and the labour market as determinants of provincial and national transition patterns in Canada. The study consists of a provincial analysis that maps the typology of transition systems across Canada's devolved federated tertiary education structure.…

Structural and phase transitions of one and two polymer mushrooms in poor solvent

Science.gov (United States)

Yang, Delian; Wang, Qiang

2014-05-01

Using the recently proposed fast lattice Monte Carlo (FLMC) simulations and the corresponding lattice self-consistent field (LSCF) calculations based on the same model system, where multiple occupancy of lattice sites is allowed [Q. Wang, Soft Matter 5, 4564 (2009); Q. Wang, Soft Matter 5, 6206 (2010)], we studied the coil-globule transition (CGT) of one-mushroom systems and the fused-separated transition (FST) of two-mushroom systems, where a polymer mushroom is formed by a group of n homopolymer chains each of N segments end-grafted at the same point onto a flat substrate and immersed in a poor solvent. With our soft potential that allows complete particle overlapping, LSCF theory neglecting the system fluctuations/correlations becomes exact in the limit of n → ∞, and FLMC results approach LSCF predictions with increasing n. Using LSCF calculations, we systematically constructed the phase diagrams of one- and two-mushroom systems. A second-order symmetric-asymmetric transition (SAT) was found in the globule state of one-mushroom systems, where the rotational symmetry around the substrate normal passing through the grafting point is broken in each individual configuration but preserved by the degeneracy of different orientations of these asymmetric configurations. Three different states were also found in two-mushroom systems: separated coils, separated globules, and fused globule. We further studied the coupling between FST in two-mushroom systems and CGT and SAT of each mushroom. Finally, direct comparisons between our simulation and theoretical results, without any parameter-fitting, unambiguously and quantitatively revealed the fluctuation/correlation effects on these phase transitions.

Adaptable Energy Systems Integration by Modular, Standardized and Scalable System Architectures: Necessities and Prospects of Any Time Transition

Directory of Open Access Journals (Sweden)

Jonas Hinker

2018-03-01

Full Text Available Energy conversion and distribution of heat and electricity is characterized by long planning horizons, investment periods and depreciation times, and it is thus difficult to plan and tell the technology that optimally fits for decades. Uncertainties include future energy prices, applicable subsidies, regulation, and even the evolution of market designs. To achieve higher adaptability to arbitrary transition paths, a technical concept based on integrated energy systems is envisioned and described. The problem of intermediate steps of evolution is tackled by introducing a novel paradigm in urban infrastructure design. It builds on standardization, modularization and economies of scale for underlying conversion units. Building on conceptual arguments for such a platform, it is then argued how actors like (among others municipalities and district heating system operators can use this as a practical starting point for a manageable and smooth transition towards more environmental friendly supply technologies, and to commit to their own pace of transition (bearable investment/risk. Merits are not only supported by technical arguments but also by strategical and societal prospects like technology neutrality and availability of real options.

Discontinuous nature of the repulsive-to-attractive colloidal glass transition.

Science.gov (United States)

van de Laar, T; Higler, R; Schroën, K; Sprakel, J

2016-03-04

In purely repulsive colloidal systems a glass transition can be reached by increasing the particle volume fraction beyond a certain threshold. The resulting glassy state is governed by configurational cages which confine particles and restrict their motion. A colloidal glass may also be formed by inducing attractive interactions between the particles. When attraction is turned on in a repulsive colloidal glass a re-entrant solidification ensues. Initially, the repulsive glass melts as free volume in the system increases. As the attraction strength is increased further, this weakened configurational glass gives way to an attractive glass in which motion is hindered by the formation of physical bonds between neighboring particles. In this paper, we study the transition from repulsive-to-attractive glasses using three-dimensional imaging at the single-particle level. We show how the onset of cage weakening and bond formation is signalled by subtle changes in local structure. We then demonstrate the discontinuous nature of the solid-solid transition, which is marked by a critical onset at a threshold bonding energy. Finally, we highlight how the interplay between bonding and caging leads to complex and heterogeneous dynamics at the microscale.

NPS Transit System Passenger Boardings Study: Converting Ticket Sales to Passenger Boardings.

Science.gov (United States)

2016-01-01

This report examines the reporting of passenger boardings (unlinked passenger trips) by NPS transit systems that use a ticket sales conversion methodology. By studying and validating the park units' passenger boarding methodology from converting tick...

CHARACTERIZATION OF THE K2-19 MULTIPLE-TRANSITING PLANETARY SYSTEM VIA HIGH-DISPERSION SPECTROSCOPY, AO IMAGING, AND TRANSIT TIMING VARIATIONS

Energy Technology Data Exchange (ETDEWEB)

Narita, Norio; Hori, Yasunori; Kusakabe, Nobuhiko; Takeda, Yoichi; Tamura, Motohide [Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan); Hirano, Teruyuki [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Fukui, Akihiko; Yanagisawa, Kenshi [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan); Sanchis-Ojeda, Roberto [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); Winn, Joshua N. [Department of Physics, and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ryu, Tsuguru; Onitsuka, Masahiro [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan); Kudo, Tomoyuki [Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720 (United States); Delrez, Laetitia; Gillon, Michael; Jehin, Emmanuel [Institut d’Astrophysique et de Géophysique, Université de Liège, Allée du 6 Août 17, Bat. B5C, B-4000 Liège (Belgium); McCormac, James [Department of Physics, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL (United Kingdom); Holman, Matthew [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Izumiura, Hideyuki, E-mail: norio.narita@nao.ac.jp [SOKENDAI (The Graduate University for Advanced Studies), 2-21-1 Osawa, Mitaka, Tokyo, 181-8588 (Japan)

2015-12-10

K2-19 (EPIC201505350) is an interesting planetary system in which two transiting planets with radii ∼7 R{sub ⊕} (inner planet b) and ∼4 R{sub ⊕} (outer planet c) have orbits that are nearly in a 3:2 mean-motion resonance. Here, we present results of ground-based follow-up observations for the K2-19 planetary system. We have performed high-dispersion spectroscopy and high-contrast adaptive-optics imaging of the host star with the HDS and HiCIAO on the Subaru 8.2 m telescope. We find that the host star is a relatively old (≥8 Gyr) late G-type star (T{sub eff} ∼ 5350 K, M{sub s} ∼ 0.9 M{sub ⊙}, and R{sub s} ∼ 0.9 R{sub ⊙}). We do not find any contaminating faint objects near the host star that could be responsible for (or dilute) the transit signals. We have also conducted transit follow-up photometry for the inner planet with KeplerCam on the FLWO 1.2 m telescope, TRAPPISTCAM on the TRAPPIST 0.6 m telescope, and MuSCAT on the OAO 1.88 m telescope. We confirm the presence of transit timing variations (TTVs), as previously reported by Armstrong and coworkers. We model the observed TTVs of the inner planet using the synodic chopping formulae given by Deck and Agol. We find two statistically indistinguishable solutions for which the period ratios (P{sub c}/P{sub b}) are located slightly above and below the exact 3:2 commensurability. Despite the degeneracy, we derive the orbital period of the inner planet P{sub b} ∼ 7.921 days and the mass of the outer planet M{sub c} ∼ 20 M{sub ⊕}. Additional transit photometry (especially for the outer planet) as well as precise radial-velocity measurements would be helpful to break the degeneracy and to determine the mass of the inner planet.

LANL environmental restoration site ranking system: System description. Final report

International Nuclear Information System (INIS)

Merkhofer, L.; Kann, A.; Voth, M.

1992-01-01

The basic structure of the LANL Environmental Restoration (ER) Site Ranking System and its use are described in this document. A related document, Instructions for Generating Inputs for the LANL ER Site Ranking System, contains detailed descriptions of the methods by which necessary inputs for the system will be generated. LANL has long recognized the need to provide a consistent basis for comparing the risks and other adverse consequences associated with the various waste problems at the Lab. The LANL ER Site Ranking System is being developed to help address this need. The specific purpose of the system is to help improve, defend, and explain prioritization decisions at the Potential Release Site (PRS) and Operable Unit (OU) level. The precise relationship of the Site Ranking System to the planning and overall budget processes is yet to be determined, as the system is still evolving. Generally speaking, the Site Ranking System will be used as a decision aid. That is, the system will be used to aid in the planning and budgetary decision-making process. It will never be used alone to make decisions. Like all models, the system can provide only a partial and approximate accounting of the factors important to budget and planning decisions. Decision makers at LANL will have to consider factors outside of the formal system when making final choices. Some of these other factors are regulatory requirements, DOE policy, and public concern. The main value of the site ranking system, therefore, is not the precise numbers it generates, but rather the general insights it provides

LANL environmental restoration site ranking system: System description. Final report

Energy Technology Data Exchange (ETDEWEB)

Merkhofer, L.; Kann, A.; Voth, M. [Applied Decision Analysis, Inc., Menlo Park, CA (United States)

1992-10-13

The basic structure of the LANL Environmental Restoration (ER) Site Ranking System and its use are described in this document. A related document, Instructions for Generating Inputs for the LANL ER Site Ranking System, contains detailed descriptions of the methods by which necessary inputs for the system will be generated. LANL has long recognized the need to provide a consistent basis for comparing the risks and other adverse consequences associated with the various waste problems at the Lab. The LANL ER Site Ranking System is being developed to help address this need. The specific purpose of the system is to help improve, defend, and explain prioritization decisions at the Potential Release Site (PRS) and Operable Unit (OU) level. The precise relationship of the Site Ranking System to the planning and overall budget processes is yet to be determined, as the system is still evolving. Generally speaking, the Site Ranking System will be used as a decision aid. That is, the system will be used to aid in the planning and budgetary decision-making process. It will never be used alone to make decisions. Like all models, the system can provide only a partial and approximate accounting of the factors important to budget and planning decisions. Decision makers at LANL will have to consider factors outside of the formal system when making final choices. Some of these other factors are regulatory requirements, DOE policy, and public concern. The main value of the site ranking system, therefore, is not the precise numbers it generates, but rather the general insights it provides.

Systems Biology Approach and Mathematical Modeling for Analyzing Phase-Space Switch During Epithelial-Mesenchymal Transition.

Science.gov (United States)

Simeoni, Chiara; Dinicola, Simona; Cucina, Alessandra; Mascia, Corrado; Bizzarri, Mariano

2018-01-01

In this report, we aim at presenting a viable strategy for the study of Epithelial-Mesenchymal Transition (EMT) and its opposite Mesenchymal-Epithelial Transition (MET) by means of a Systems Biology approach combined with a suitable Mathematical Modeling analysis. Precisely, it is shown how the presence of a metastable state, that is identified at a mesoscopic level of description, is crucial for making possible the appearance of a phase transition mechanism in the framework of fast-slow dynamics for Ordinary Differential Equations (ODEs).

Study of the hard-disk system at high densities: the fluid-hexatic phase transition.

Science.gov (United States)

Mier-Y-Terán, Luis; Machorro-Martínez, Brian Ignacio; Chapela, Gustavo A; Del Río, Fernando

2018-06-21

Integral equations of uniform fluids have been considered unable to predict any characteristic feature of the fluid-solid phase transition, including the shoulder that arises in the second peak of the fluid-phase radial distribution function, RDF, of hard-core systems obtained by computer simulations, at fluid densities very close to the structural two-step phase transition. This reasoning is based on the results of traditional integral approximations, like Percus-Yevick, PY, which does not show such a shoulder in hard-core systems, neither in two nor three dimensions. In this work, we present results of three Ansätze, based on the PY theory, that were proposed to remedy the lack of PY analytical solutions in two dimensions. This comparative study shows that one of those Ansätze does develop a shoulder in the second peak of the RDF at densities very close to the phase transition, qualitatively describing this feature. Since the shoulder grows into a peak at still higher densities, this integral equation approach predicts the appearance of an orientational order characteristic of the hexatic phase in a continuous fluid-hexatic phase transition.

Simulated coal gas MCFC power plant system verification. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-30

The objective of the main project is to identify the current developmental status of MCFC systems and address those technical issues that need to be resolved to move the technology from its current status to the demonstration stage in the shortest possible time. The specific objectives are separated into five major tasks as follows: Stack research; Power plant development; Test facilities development; Manufacturing facilities development; and Commercialization. This Final Report discusses the M-C power Corporation effort which is part of a general program for the development of commercial MCFC systems. This final report covers the entire subject of the Unocal 250-cell stack. Certain project activities have been funded by organizations other than DOE and are included in this report to provide a comprehensive overview of the work accomplished.

THE KEPLER-19 SYSTEM: A TRANSITING 2.2 R{sub Circled-Plus} PLANET AND A SECOND PLANET DETECTED VIA TRANSIT TIMING VARIATIONS

Energy Technology Data Exchange (ETDEWEB)

Ballard, Sarah; Fressin, Francois; Charbonneau, David; Desert, Jean-Michel; Torres, Guillermo; Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fabrycky, Daniel [Department of Astronomy and Astrophysics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Marcy, Geoffrey; Isaacson, Howard [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720 (United States); Burke, Christopher J.; Henze, Christopher; Howell, Steven B.; Bryson, Stephen T.; Rowe, Jason F.; Lissauer, Jack J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Steffen, Jason H. [Fermilab Center for Particle Astrophysics, P.O. Box 500, Batavia, IL 60510 (United States); Ciardi, David R. [NASA Exoplanet Science Institute/Caltech, Pasadena, CA 91125 (United States); Cochran, William D.; Endl, Michael [McDonald Observatory, The University of Texas, Austin, TX 78712 (United States); Jenkins, Jon M., E-mail: sballard@cfa.harvard.edu [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States); and others

2011-12-20

We present the discovery of the Kepler-19 planetary system, which we first identified from a 9.3 day periodic transit signal in the Kepler photometry. From high-resolution spectroscopy of the star, we find a stellar effective temperature T{sub eff} = 5541 {+-} 60 K, a metallicity [Fe/H] = -0.13 {+-} 0.06, and a surface gravity log(g) = 4.59 {+-} 0.10. We combine the estimate of T{sub eff} and [Fe/H] with an estimate of the stellar density derived from the photometric light curve to deduce a stellar mass of M{sub *} = 0.936 {+-} 0.040 M{sub Sun} and a stellar radius of R{sub *} = 0.850 {+-} 0.018 R{sub Sun} (these errors do not include uncertainties in the stellar models). We rule out the possibility that the transits result from an astrophysical false positive by first identifying the subset of stellar blends that reproduce the precise shape of the light curve. Using the additional constraints from the measured color of the system, the absence of a secondary source in the high-resolution spectrum, and the absence of a secondary source in the adaptive optics imaging, we conclude that the planetary scenario is more than three orders of magnitude more likely than a blend. The blend scenario is independently disfavored by the achromaticity of the transit: we measure a transit depth with Spitzer at 4.5 {mu}m of 547{sup +113}{sub -110} ppm, consistent with the depth measured in the Kepler optical bandpass of 567 {+-} 6 ppm (corrected for stellar limb darkening). We determine a physical radius of the planet Kepler-19b of R{sub p} = 2.209 {+-} 0.048 R{sub Circled-Plus }; the uncertainty is dominated by uncertainty in the stellar parameters. From radial velocity observations of the star, we find an upper limit on the planet mass of 20.3 M{sub Circled-Plus }, corresponding to a maximum density of 10.4 g cm{sup -3}. We report a significant sinusoidal deviation of the transit times from a predicted linear ephemeris, which we conclude is due to an additional perturbing body in

What's new with the electroweak phase transition?

CERN Document Server

Laine, M.

1999-01-01

We review the status of non-perturbative lattice studies of the electroweak phase transition. In the Standard Model, the complete phase diagram has been reliably determined, and the conclusion is that there is no phase transition at all for the experimentally allowed Higgs masses. In the Minimal Supersymmetric Standard Model (MSSM), in contrast, there can be a strong first order transition allowing for baryogenesis. Finally, we point out possibilities for future simulations, such as the problem of CP-violation at the MSSM electroweak phase boundary.

Fine structure transition cross sections for several alkali+rare gas systems

International Nuclear Information System (INIS)

Olson, R.E.

1975-01-01

The energy dependence E(cm) 2 P1/2→ 2 P3/2 fine structure transition of the lowest excited states of the alkali are calculated for the following systems: Na, K, Rb+He, Ne, Ar and Cs+He. Encouraging agreement between theory and experiment is obtained [fr

Model validation studies of solar systems, Phase III. Final report

Energy Technology Data Exchange (ETDEWEB)

Lantz, L.J.; Winn, C.B.

1978-12-01

Results obtained from a validation study of the TRNSYS, SIMSHAC, and SOLCOST solar system simulation and design are presented. Also included are comparisons between the FCHART and SOLCOST solar system design programs and some changes that were made to the SOLCOST program. Finally, results obtained from the analysis of several solar radiation models are presented. Separate abstracts were prepared for ten papers.

Towards an energy transition? Which energies for tomorrow and for all, on the territory. Research-action, problematic note - Activity report 2012-2014 - Final report. Citizen recommendations

International Nuclear Information System (INIS)

Aubin, Samuel; Lemoult, Bernard; Allagnat, Bernard; Cohu, Sylvie; Gadoin, Emilie; Crochet, Moise; Dothee, Jean-Luc; Gauduchon, Marie-Veronique; Gendre, Nicolas; Musard, Denis; Retiere, Alain; Vacher, Pierre; Vilbert, Christine; Petillon, Xavier; Damerose, Clotilde

2014-11-01

This document first presents a project launched on the issue of energy choice for tomorrow for the territory, and more particularly on a shared regional diagnosis and principles for action. A second document reports activities of this research-action project which aimed at making citizen recommendations emerge, and at elaborating an operational territorial tool for energy transition. Then comes the final report of this project. After an introduction which outlines that energy transition is a major stake for the territory, a first chapter discusses which are tomorrow's energies by outlining the climatic emergency, the energy situation at the world level, the perspective of smart cities and communities, national energetic stakes, the role given to citizen, and the perspective of a new relationship to the world and to the nature. The second chapter briefly evokes the perspective for 2050. The next part discusses the societal dimension of energy transition, and examines what could be the engines for change. The next chapter identifies and discusses various debates to be held: on climate situation, on energy resource availability, on human development and on the economic model. The last chapter outlines the role of the territorial scale and of collective dynamics to elaborate and implement scenarios of energy transition

Macroeconomic models and energy transition

International Nuclear Information System (INIS)

Douillard, Pierre; Le Hir, Boris; Epaulard, Anne

2016-02-01

As a new policy for energy transition has just been adopted, several questions emerge about the best way to reduce CO 2 emissions, about policies which enable this reduction, and about their costs and opportunities. This note discusses the contribution macro-economic models may have in this respect, notably in the definition of policies which trigger behaviour changes, and those which support energy transition. The authors first discuss the stakes of the assessment of energy transition, and then describe macro-economic models which can be used for such an assessment, give and comment some results of simulations performed for France by using four of these models (Mesange, Numesis, ThreeME, and Imaclim-R France). The authors finally draw lessons about the way to use these models and to interpret their results within the frame of energy transition

Vascular Remodelling and Mesenchymal Transition in Systemic Sclerosis

Directory of Open Access Journals (Sweden)

Pier Andrea Nicolosi

2016-01-01

Full Text Available Fibrosis of the skin and of internal organs, autoimmunity, and vascular inflammation are hallmarks of Systemic Sclerosis (SSc. The injury and activation of endothelial cells, with hyperplasia of the intima and eventual obliteration of the vascular lumen, are early features of SSc. Reduced capillary blood flow coupled with deficient angiogenesis leads to chronic hypoxia and tissue ischemia, enforcing a positive feed-forward loop sustaining vascular remodelling, further exacerbated by extracellular matrix accumulation due to fibrosis. Despite numerous developments and a growing number of controlled clinical trials no treatment has been shown so far to alter SSc natural history, outlining the need of further investigation in the molecular pathways involved in the pathogenesis of the disease. We review some processes potentially involved in SSc vasculopathy, with attention to the possible effect of sustained vascular inflammation on the plasticity of vascular cells. Specifically we focus on mesenchymal transition, a key phenomenon in the cardiac and vascular development as well as in the remodelling of injured vessels. Recent work supports the role of transforming growth factor-beta, Wnt, and Notch signaling in these processes. Importantly, endothelial-mesenchymal transition may be reversible, possibly offering novel cues for treatment.

PHYSICAL PROPERTIES OF THE 0.94-DAY PERIOD TRANSITING PLANETARY SYSTEM WASP-18

International Nuclear Information System (INIS)

Southworth, John; Anderson, D. R.; Maxted, P. F. L.; Hinse, T. C.; Dominik, M.; Mathiasen, M.; Browne, P.; Glitrup, M.; Joergensen, U. G.; Harpsoee, K.; Liebig, C.; Maier, G.; Bozza, V.; Calchi Novati, S.; Mancini, L.; Burgdorf, M.; Dreizler, S.; Hessman, F.; Hundertmark, M.; Finet, F.

2009-01-01

We present high-precision photometry of five consecutive transits of WASP-18, an extrasolar planetary system with one of the shortest orbital periods known. Through the use of telescope defocusing we achieve a photometric precision of 0.47-0.83 mmag per observation over complete transit events. The data are analyzed using the JKTEBOP code and three different sets of stellar evolutionary models. We find the mass and radius of the planet to be M b = 10.43 ± 0.30 ± 0.24 M Jup and R b = 1.165 ± 0.055 ± 0.014 R Jup (statistical and systematic errors), respectively. The systematic errors in the orbital separation and the stellar and planetary masses, arising from the use of theoretical predictions, are of a similar size to the statistical errors and set a limit on our understanding of the WASP-18 system. We point out that seven of the nine known massive transiting planets (M b > 3 M Jup ) have eccentric orbits, whereas significant orbital eccentricity has been detected for only four of the 46 less-massive planets. This may indicate that there are two different populations of transiting planets, but could also be explained by observational biases. Further radial velocity observations of low-mass planets will make it possible to choose between these two scenarios.

Quantum criticality around metal-insulator transitions of strongly correlated electron systems

Science.gov (United States)

Misawa, Takahiro; Imada, Masatoshi

2007-03-01

Quantum criticality of metal-insulator transitions in correlated electron systems is shown to belong to an unconventional universality class with violation of the Ginzburg-Landau-Wilson (GLW) scheme formulated for symmetry breaking transitions. This unconventionality arises from an emergent character of the quantum critical point, which appears at the marginal point between the Ising-type symmetry breaking at nonzero temperatures and the topological transition of the Fermi surface at zero temperature. We show that Hartree-Fock approximations of an extended Hubbard model on square lattices are capable of such metal-insulator transitions with unusual criticality under a preexisting symmetry breaking. The obtained universality is consistent with the scaling theory formulated for Mott transitions and with a number of numerical results beyond the mean-field level, implying that preexisting symmetry breaking is not necessarily required for the emergence of this unconventional universality. Examinations of fluctuation effects indicate that the obtained critical exponents remain essentially exact beyond the mean-field level. It further clarifies the whole structure of singularities by a unified treatment of the bandwidth-control and filling-control transitions. Detailed analyses of the criticality, containing diverging carrier density fluctuations around the marginal quantum critical point, are presented from microscopic calculations and reveal the nature as quantum critical “opalescence.” The mechanism of emerging marginal quantum critical point is ascribed to a positive feedback and interplay between the preexisting gap formation present even in metals and kinetic energy gain (loss) of the metallic carrier. Analyses of crossovers between GLW type at nonzero temperature and topological type at zero temperature show that the critical exponents observed in (V,Cr)2O3 and κ-ET -type organic conductors provide us with evidence for the existence of the present marginal

Urban Transit System Microbial Communities Differ by Surface Type and Interaction with Humans and the Environment.

Science.gov (United States)

Hsu, Tiffany; Joice, Regina; Vallarino, Jose; Abu-Ali, Galeb; Hartmann, Erica M; Shafquat, Afrah; DuLong, Casey; Baranowski, Catherine; Gevers, Dirk; Green, Jessica L; Morgan, Xochitl C; Spengler, John D; Huttenhower, Curtis

2016-01-01

Public transit systems are ideal for studying the urban microbiome and interindividual community transfer. In this study, we used 16S amplicon and shotgun metagenomic sequencing to profile microbial communities on multiple transit surfaces across train lines and stations in the Boston metropolitan transit system. The greatest determinant of microbial community structure was the transit surface type. In contrast, little variation was observed between geographically distinct train lines and stations serving different demographics. All surfaces were dominated by human skin and oral commensals such as Propionibacterium , Corynebacterium , Staphylococcus , and Streptococcus . The detected taxa not associated with humans included generalists from alphaproteobacteria, which were especially abundant on outdoor touchscreens. Shotgun metagenomics further identified viral and eukaryotic microbes, including Propionibacterium phage and Malassezia globosa . Functional profiling showed that Propionibacterium acnes pathways such as propionate production and porphyrin synthesis were enriched on train holding surfaces (holds), while electron transport chain components for aerobic respiration were enriched on touchscreens and seats. Lastly, the transit environment was not found to be a reservoir of antimicrobial resistance and virulence genes. Our results suggest that microbial communities on transit surfaces are maintained from a metapopulation of human skin commensals and environmental generalists, with enrichments corresponding to local interactions with the human body and environmental exposures. IMPORTANCE Mass transit environments, specifically, urban subways, are distinct microbial environments with high occupant densities, diversities, and turnovers, and they are thus especially relevant to public health. Despite this, only three culture-independent subway studies have been performed, all since 2013 and all with widely differing designs and conclusions. In this study, we

Mid-section of a can-annular gas turbine engine with a cooling system for the transition

Science.gov (United States)

Wiebe, David J.; Rodriguez, Jose L.

2015-12-08

A cooling system is provided for a transition (420) of a gas turbine engine (410). The cooling system includes a cowling (460) configured to receive an air flow (111) from an outlet of a compressor section of the gas turbine engine (410). The cowling (460) is positioned adjacent to a region of the transition (420) to cool the transition region upon circulation of the air flow within the cowling (460). The cooling system further includes a manifold (121) to directly couple the air flow (111) from the compressor section outlet to an inlet (462) of the cowling (460). The cowling (460) is configured to circulate the air flow (111) within an interior space (426) of the cowling (460) that extends radially outward from an inner diameter (423) of the cowling to an outer diameter (424) of the cowling at an outer surface.

Relaxation theory of spin-3/2 Ising system near phase transition temperatures

International Nuclear Information System (INIS)

Canko, Osman; Keskin, Mustafa

2010-01-01

Dynamics of a spin-3/2 Ising system Hamiltonian with bilinear and biquadratic nearest-neighbour exchange interactions is studied by a simple method in which the statistical equilibrium theory is combined with the Onsager's theory of irreversible thermodynamics. First, the equilibrium behaviour of the model in the molecular-field approximation is given briefly in order to obtain the phase transition temperatures, i.e. the first- and second-order and the tricritical points. Then, the Onsager theory is applied to the model and the kinetic or rate equations are obtained. By solving these equations three relaxation times are calculated and their behaviours are examined for temperatures near the phase transition points. Moreover, the z dynamic critical exponent is calculated and compared with the z values obtained for different systems experimentally and theoretically, and they are found to be in good agrement. (general)

A systems approach framework for the transition to sustainable development: Potential value based on coastal experiments

DEFF Research Database (Denmark)

Hopkins, Tom S.; Bailly, Denis; Elmgren, Ragnar

2012-01-01

This article explores the value of the Systems Approach Framework (SAF) as a tool for the transition to sustainable development in coastal zone systems, based on 18 study sites in Europe, where the SAF was developed and tested. The knowledge gained from these experiments concerns the practical......-dependent and system-independent problems, and the inclusion of non-market evaluations. It also develops a real partnership among research, management, and stakeholders to establish a quantitative basis for collaborative decision making. Furthermore, the article argues that the transition to sustainable development...

Phase transition in finite systems

Energy Technology Data Exchange (ETDEWEB)

Chomaz, Ph.; Duflot, V. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France); Duflot, V.; Gulminelli, F. [Laboratoire de Physique Corpusculaire, LPC-ISMRa, CNRS-IN2P3, 14 - Caen (France)

2000-07-01

The general problem of the definition of a phase transition without employing the thermodynamical limit is addressed. Different necessary conditions are considered and illustrated with examples from different nuclear and general physics phenomenologies. (authors)

Phase transition in finite systems

International Nuclear Information System (INIS)

Chomaz, Ph.; Duflot, V.; Duflot, V.; Gulminelli, F.

2000-01-01

The general problem of the definition of a phase transition without employing the thermodynamical limit is addressed. Different necessary conditions are considered and illustrated with examples from different nuclear and general physics phenomenologies. (authors)

The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation

DEFF Research Database (Denmark)

Harpsøe, Kennet Bomann West; Hardis, S.; Hinse, T. C.

2012-01-01

Aims: We present 11 high-precision photometric transit observations of the transiting super-Earth planet GJ1214b. Combining these data with observations from other authors, we investigate the ephemeris for possible signs of transit timing variations (TTVs) using a Bayesian approach. Methods......: The observations were obtained using telescope-defocusing techniques, and achieve a high precision with random errors in the photometry as low as 1mmag per point. To investigate the possibility of TTVs in the light curve, we calculate the overall probability of a TTV signal using Bayesian methods. Results...

A study of topological quantum phase transition and Majorana localization length for the interacting helical liquid system

International Nuclear Information System (INIS)

Dey, Dayasindhu; Saha, Sudip Kumar; Deo, P. Singha; Kumar, Manoranjan; Sarkar, Sujit

2017-01-01

We study the topological quantum phase transition and also the nature of this transition using the density matrix renormalization group method. We observe the existence of topological quantum phase transition for repulsive interaction, however this phase is more stable for the attractive interaction. The length scale dependent study shows many new and important results and we show explicitly that the major contribution to the excitation comes from the edge of the system when the system is in the topological state. We also show the dependence of Majorana localization length for various values of chemical potential. (author)

Cooperative effect of random and time-periodic coupling strength on synchronization transitions in one-way coupled neural system: mean field approach.

Science.gov (United States)

Jiancheng, Shi; Min, Luo; Chusheng, Huang

2017-08-01

The cooperative effect of random coupling strength and time-periodic coupling strengh on synchronization transitions in one-way coupled neural system has been investigated by mean field approach. Results show that cooperative coupling strength (CCS) plays an active role for the enhancement of synchronization transitions. There exist an optimal frequency of CCS which makes the system display the best CCS-induced synchronization transitions, a critical frequency of CCS which can not further affect the CCS-induced synchronization transitions, and a critical amplitude of CCS which can not occur the CCS-induced synchronization transitions. Meanwhile, noise intensity plays a negative role for the CCS-induced synchronization transitions. Furthermore, it is found that the novel CCS amplitude-induced synchronization transitions and CCS frequency-induced synchronization transitions are found.

European Transition into a Socio-ecological Market Economy

Directory of Open Access Journals (Sweden)

Erich Hoedl

2014-10-01

Full Text Available The European Union has introduced the Europe 2020 Strategy and Horizon 2020, which contain several elements for a transition into a Socio-ecological Market Economy. But their implementations are mainly hampered by the unduly large financial sector and the political striving for high economic growth. A turn into low growth equilibrium needs a reduction of total capital inputs, which are composed of financial, man-made and natural capital. Whereas the reduction of financial capital needs a strong, but actually lacking political will, the reduction of man-made and natural capital depends on a real capital saving innovation system, which should partly be financed by a transfer of financial capital to the real productive sector. Beyond a strong reduction of financial capital and depending on existing ecological, social and economic problems, the innovation system should save man-made and natural capital accordingly. In all cases these innovations need higher qualification by means of a human-centered educational system. Higher educational investments, i.e. augmented “human capital,” are decisive for a transition into a Socio-ecological Market Economy for two reasons: First, higher qualification will augment the wage-profit relation and second, capital saving innovations will reduce productive capital inputs without reducing the profit rate on the reduced real capital stock. Increasing “human capital” intensity will accelerate the transition into low growth equilibrium with a higher consumption-investment relation, which creates more domestic final demand and needs lower export surpluses. Starting from existing high productive and financial capital intensity, during the transition saving surpluses in Europe will decline only step by step; they should not be allocated in financial markets, but for a considerably more human-centered education and real investments in Europe and the Third World.

Livestock in a changing climate: production system transitions as an adaptation strategy for agriculture

International Nuclear Information System (INIS)

Weindl, Isabelle; Lotze-Campen, Hermann; Popp, Alexander; Müller, Christoph; Schmitz, Christoph; Rolinski, Susanne; Havlík, Petr; Herrero, Mario

2015-01-01

Livestock farming is the world’s largest land use sector and utilizes around 60% of the global biomass harvest. Over the coming decades, climate change will affect the natural resource base of livestock production, especially the productivity of rangeland and feed crops. Based on a comprehensive impact modeling chain, we assess implications of different climate projections for agricultural production costs and land use change and explore the effectiveness of livestock system transitions as an adaptation strategy. Simulated climate impacts on crop yields and rangeland productivity generate adaptation costs amounting to 3% of total agricultural production costs in 2045 (i.e. 145 billion US$). Shifts in livestock production towards mixed crop-livestock systems represent a resource- and cost-efficient adaptation option, reducing agricultural adaptation costs to 0.3% of total production costs and simultaneously abating deforestation by about 76 million ha globally. The relatively positive climate impacts on grass yields compared with crop yields favor grazing systems inter alia in South Asia and North America. Incomplete transitions in production systems already have a strong adaptive and cost reducing effect: a 50% shift to mixed systems lowers agricultural adaptation costs to 0.8%. General responses of production costs to system transitions are robust across different global climate and crop models as well as regarding assumptions on CO 2 fertilization, but simulated values show a large variation. In the face of these uncertainties, public policy support for transforming livestock production systems provides an important lever to improve agricultural resource management and lower adaptation costs, possibly even contributing to emission reduction. (letter)

Characterization of a quantum phase transition in Dirac systems by means of the wave-packet dynamics

Directory of Open Access Journals (Sweden)

E. Romera

2012-12-01

Full Text Available We study the signatures of phase transitions in the time evolution of wave-packets by analyzing two simple model systems: a graphene quantum dot model in a magnetic field and a Dirac oscillator in a magnetic field. We have characterized the phase transitions using the autocorrelation function. Our work also reveals that the description in terms of Shannon entropy of the autocorrelation function is a clear phase transition indicator.

Pattern transition between periodic Liesegang pattern and crystal growth regime in reaction-diffusion systems

Science.gov (United States)

Lagzi, István; Ueyama, Daishin

2009-01-01

The pattern transition between periodic precipitation pattern formation (Liesegang phenomenon) and pure crystal growth regimes is investigated in silver nitrate and potassium dichromate system in mixed agarose-gelatin gel. Morphologically different patterns were found depending on the quality of the gel, and transition between these typical patterns can be controlled by the concentration of gelatin in mixed gel. Effect of temperature and hydrodynamic force on precipitation pattern structure was also investigated.

Hybrid phase transition into an absorbing state: Percolation and avalanches

Science.gov (United States)

Lee, Deokjae; Choi, S.; Stippinger, M.; Kertész, J.; Kahng, B.

2016-04-01

Interdependent networks are more fragile under random attacks than simplex networks, because interlayer dependencies lead to cascading failures and finally to a sudden collapse. This is a hybrid phase transition (HPT), meaning that at the transition point the order parameter has a jump but there are also critical phenomena related to it. Here we study these phenomena on the Erdős-Rényi and the two-dimensional interdependent networks and show that the hybrid percolation transition exhibits two kinds of critical behaviors: divergence of the fluctuations of the order parameter and power-law size distribution of finite avalanches at a transition point. At the transition point global or "infinite" avalanches occur, while the finite ones have a power law size distribution; thus the avalanche statistics also has the nature of a HPT. The exponent βm of the order parameter is 1 /2 under general conditions, while the value of the exponent γm characterizing the fluctuations of the order parameter depends on the system. The critical behavior of the finite avalanches can be described by another set of exponents, βa and γa. These two critical behaviors are coupled by a scaling law: 1 -βm=γa .

Development of the Model of Decision Support for Alternative Choice in the Transportation Transit System

Directory of Open Access Journals (Sweden)

Kabashkin Igor

2015-02-01

Full Text Available The decision support system is one of the instruments for choosing the most effective decision for cargo owner in constant fluctuated business environment. The objective of this Paper is to suggest the multiple-criteria approach for evaluation and choice the alternatives of cargo transportation in the large scale transportation transit system for the decision makers - cargo owners. The large scale transportation transit system is presented by directed finite graph. Each of 57 alternatives is represented by the set of key performance indicators Kvi and set of parameters Paj. There has been developed a two-level hierarchy system of criteria with ranging expert evaluations based on Analytic Hierarchy Process Method. The best alternatives were suggested according to this method.

Complex Systems Engineering : Designing in sociotechnical systems for the energy transition

NARCIS (Netherlands)

Moncada Escudero, J.A.; Nava Guerrero, G.D.C.; Park Lee, H.; Okur, Ö.; Chakraborty, S.T.; Lukszo, Z.

2017-01-01

The EU has set ambitious targets for an energy transition. While research often focuses on technology, institutions or actors, a transition requires complex coordination and comprehensive analysis and design. We propose a framework accounting for technology, institutions and actors' perspective

TRANSIT OBSERVATIONS OF THE WASP-10 SYSTEM

International Nuclear Information System (INIS)

Dittmann, J. A.; Close, L. M.; Scuderi, L. J.; Morris, M. D.

2010-01-01

We present here observations of the transit of WASP-10b on 2009 October 14 UT taken from the University of Arizona's 1.55 m Kuiper telescope on Mount Bigelow. Conditions were photometric and accuracies of 2.0 mmag rms were obtained throughout the transit. We have found that the ratio of the planet to host star radii is in agreement with the measurements of Christian et al. instead of the refinements of Johnson et al., suggesting that WASP-10b is indeed inflated beyond what is expected from theoretical modeling. We find no evidence for large (>20 s) transit timing variations in WASP-10b's orbit from the ephemeris of Christian et al. and Johnson et al.

IT security standards for the digitalization of the energy transition

International Nuclear Information System (INIS)

Laupichler, Dennis

2016-01-01

Intelligent measuring systems are important components in the intelligent net and require security and privacy by design in this critical infrastructure. The smart meter gateway as secure communication platform makes the digital sector coupling possible and becomes the driver for innovations of the digitalization. The protection profiles and the technical rules of the BSI as essential part of the law for the digitalization of the energy transition guarantee a great amount of data protection and data security and provide a unique security standard in the future energy supply system. The data -protection concept of the intelligent measuring system regards a calibration-law conformal data processing and star-shaped data dispatch of the gateway. By this both a traceability and a transparency for the final user is guaranteed and the handling of the data in the sense of the data sovereignty is also technically enforced. For the evidences of compliance of the protection profiles and the technical rules correponding tests in approved test centers with final certification by the BSI are performed. The law for the digitalization of the energy transition makes the first important step to an innovative, digital infrastructure of the intelligent net. By the legal framework additionally a base is created, in order to perform a progressive development of the security targets of the BSI both for intelligent measuring systems as for further important system components of the intelligent energy net via a roadmap for the digitalization. In connection with the technical standards of the BSI the law creates the necessary legal certainty and realizes the aim pursued in the coalition treaty to regulate binding framework conditions for the secure and data-protection conformal application of intelligent measuring systems for diversified application cases in the intelligent net.

Unbinding Transition of Probes in Single-File Systems

Science.gov (United States)

Bénichou, Olivier; Démery, Vincent; Poncet, Alexis

2018-02-01

Single-file transport, arising in quasi-one-dimensional geometries where particles cannot pass each other, is characterized by the anomalous dynamics of a probe, notably its response to an external force. In these systems, the motion of several probes submitted to different external forces, although relevant to mixtures of charged and neutral or active and passive objects, remains unexplored. Here, we determine how several probes respond to external forces. We rely on a hydrodynamic description of the symmetric exclusion process to obtain exact analytical results at long times. We show that the probes can either move as a whole, or separate into two groups moving away from each other. In between the two regimes, they separate with a different dynamical exponent, as t1 /4. This unbinding transition also occurs in several continuous single-file systems and is expected to be observable.

Phase transitions in thin films of Sn-Sb-Se system

International Nuclear Information System (INIS)

Samsudi Sakrani; Abdalla Belal Adam; Yussof Wahab

1998-01-01

The preparation and formation of covalent ternary Sn-Sb-Se system were investigated. A solid state reaction technique was employed whereby the evaporated multilayers of Sn/Se/Sb/Sn reacted chemically at a fixed temperature of 240 o C and were allowed to a room temperature slow-cooling. X-ray diffraction analysis showed that phase changes occurred in the system, with indication of amorphization for the predicted Sn 9 .3Sb 8 .1Se 4 4.9 and Sn 1 3.2Sb 4 3.4Se 4 3.4 compositions. These enabled the preliminary topological phase transitions of Sn-Sb-Se system according to the Gibb's triangle in which the areas of crystalline-amorphous were located. (Author)

The unsustainable directionality of innovation – The example of the broadband transition

DEFF Research Database (Denmark)

Røpke, Inge

2012-01-01

Information and communication technology (ICT) can be seen as a general-purpose technology with wide-ranging socio-economic and environmental implications across sectors. ICTs also constitute a system of technologies with stronger internal links since the emergence of the Internet and broadband...... as a new information infrastructure. The new infrastructure has co-evolved with widespread integration of ICTs in everyday life, and consumer demand has been decisive for ICT innovation. This article explores the environmental directionality of ICT innovation and the broadband transition, focusing mainly...... more prominently in the broadband transition. Finally, it is discussed how the direction of ICT innovation could be influenced in order to realize more of the positive sustainability potential....

Milestoning with transition memory

Science.gov (United States)

Hawk, Alexander T.; Makarov, Dmitrii E.

2011-12-01

Milestoning is a method used to calculate the kinetics and thermodynamics of molecular processes occurring on time scales that are not accessible to brute force molecular dynamics (MD). In milestoning, the conformation space of the system is sectioned by hypersurfaces (milestones), an ensemble of trajectories is initialized on each milestone, and MD simulations are performed to calculate transitions between milestones. The transition probabilities and transition time distributions are then used to model the dynamics of the system with a Markov renewal process, wherein a long trajectory of the system is approximated as a succession of independent transitions between milestones. This approximation is justified if the transition probabilities and transition times are statistically independent. In practice, this amounts to a requirement that milestones are spaced such that trajectories lose position and velocity memory between subsequent transitions. Unfortunately, limiting the number of milestones limits both the resolution at which a system's properties can be analyzed, and the computational speedup achieved by the method. We propose a generalized milestoning procedure, milestoning with transition memory (MTM), which accounts for memory of previous transitions made by the system. When a reaction coordinate is used to define the milestones, the MTM procedure can be carried out at no significant additional expense as compared to conventional milestoning. To test MTM, we have applied its version that allows for the memory of the previous step to the toy model of a polymer chain undergoing Langevin dynamics in solution. We have computed the mean first passage time for the chain to attain a cyclic conformation and found that the number of milestones that can be used, without incurring significant errors in the first passage time is at least 8 times that permitted by conventional milestoning. We further demonstrate that, unlike conventional milestoning, MTM permits

Chaotic transitions in deterministic and stochastic dynamical systems applications of Melnikov processes in engineering, physics, and neuroscience

CERN Document Server

Simiu, Emil

2002-01-01

The classical Melnikov method provides information on the behavior of deterministic planar systems that may exhibit transitions, i.e. escapes from and captures into preferred regions of phase space. This book develops a unified treatment of deterministic and stochastic systems that extends the applicability of the Melnikov method to physically realizable stochastic planar systems with additive, state-dependent, white, colored, or dichotomous noise. The extended Melnikov method yields the novel result that motions with transitions are chaotic regardless of whether the excitation is deterministic or stochastic. It explains the role in the occurrence of transitions of the characteristics of the system and its deterministic or stochastic excitation, and is a powerful modeling and identification tool. The book is designed primarily for readers interested in applications. The level of preparation required corresponds to the equivalent of a first-year graduate course in applied mathematics. No previous exposure to d...

Transition to turbulence

International Nuclear Information System (INIS)

Pomeau, Y.

1981-07-01

In this work it is reviewed a few known types of transition to turbulence, as the cascade of period doubling and the intermittent transition. This happens in dynamical systems with a few degrees of freedom, as modelled by the iteration of non linear maps. Then it is presented specific transitions for systems with many degrees of freedom. It is condidered first the occurence of a low frequency broadband noise in large cells at the onset of Rayleigh-Benard convection; then the transition by intermittent bursts in parallel flows. In this last case, one is concerned with localized and finite amplitude perturbations. Simple geometric arguments show that these fluctuations, when they are isolated and with a well definite relative speed, exist for a single value of the Reynolds number only [fr

Political symbols and political transitions