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Sample records for thermal challenge problem

  1. Hydrodynamics challenge problem

    Energy Technology Data Exchange (ETDEWEB)

    Hornung, R. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Keasler, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gokhale, M. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2011-06-09

    The hydrodynamics challenge problem represents a classical HPC physics problem, namely high deformation event modeling via Lagrangian shock hydrodynamics. This challenge problem solves the Sedov blast wave problem for one material in three dimensions. The problem has an analytic solution, and can be scaled to arbitrarily large problem sizes. The reference code is drawn from a production LLNL hydrodynamics code.

  2. Grand Challenge Problem 10

    DEFF Research Database (Denmark)

    Dirckinck-Holmfeld, Lone; Balacheff, Nicolas; Bottino, Rosa Maria

    2016-01-01

    Small and medium sized research labs (SMLs) are dominating European TEL research. This is justified by the great numbers of countries and regions in Europe needing to develop a research and innovation competence to facilitate the diverse educational systems contextualized in various institutional...... settings across Europe. However, to strengthen the various research practices and to develop a common scientific language on TEL research the Grand Challenge Problem is to establish a vivid network and a community of practice among the research labs. TELEARC (Technology Enhanced Learning European Advanced...

  3. Challenging problems in algebra

    CERN Document Server

    Posamentier, Alfred S

    1996-01-01

    Over 300 unusual problems, ranging from easy to difficult, involving equations and inequalities, Diophantine equations, number theory, quadratic equations, logarithms, more. Detailed solutions, as well as brief answers, for all problems are provided.

  4. Challenging problems in geometry

    CERN Document Server

    Posamentier, Alfred S

    1996-01-01

    Collection of nearly 200 unusual problems dealing with congruence and parallelism, the Pythagorean theorem, circles, area relationships, Ptolemy and the cyclic quadrilateral, collinearity and concurrency and more. Arranged in order of difficulty. Detailed solutions.

  5. Aleph Field Solver Challenge Problem Results Summary

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, Stan Gerald [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Aleph models continuum electrostatic and steady and transient thermal fields using a finite-element method. Much work has gone into expanding the core solver capability to support enriched modeling consisting of multiple interacting fields, special boundary conditions and two-way interfacial coupling with particles modeled using Aleph's complementary particle-in-cell capability. This report provides quantitative evidence for correct implementation of Aleph's field solver via order- of-convergence assessments on a collection of problems of increasing complexity. It is intended to provide Aleph with a pedigree and to establish a basis for confidence in results for more challenging problems important to Sandia's mission that Aleph was specifically designed to address.

  6. Challenging the assumptions for thermal sensation scales

    DEFF Research Database (Denmark)

    Schweiker, Marcel; Fuchs, Xaver; Becker, Susanne

    2016-01-01

    extensively, which is suitable for describing a one-dimensional relationship between physical parameters of indoor environments and subjective thermal sensation. However, human thermal comfort is not merely a physiological but also a psychological phenomenon. Thus, it should be investigated how scales for its...... assessment could benefit from a multidimensional conceptualization. The common assumptions related to the usage of thermal sensation scales are challenged, empirically supported by two analyses. These analyses show that the relationship between temperature and subjective thermal sensation is non......-linear and depends on the type of scale used. Moreover, the results signify that most people do not perceive the categories of the thermal sensation scale as equidistant and that the range of sensations regarded as ‘comfortable’ varies largely. Therefore, challenges known from experimental psychology (describing...

  7. Two problems in thermal field theory

    Indian Academy of Sciences (India)

    In this talk, I review recent progress made in two areas of thermal field theory. In par- ticular, I discuss various approaches for the calculation of the quark gluon plasma thermodynamical properties, and the problem of its photon production rate. Keywords. Thermal field theory; quark-gluon plasma. PACS Nos 11.10.Wx; 12.38.

  8. Challenging mathematical problems with elementary solutions

    CERN Document Server

    Yaglom, A M

    1987-01-01

    Volume I of a two-part series, this book features a broad spectrum of 100 challenging problems related to probability theory and combinatorial analysis. The problems, most of which can be solved with elementary mathematics, range from relatively simple to extremely difficult. Suitable for students, teachers, and any lover of mathematics. Complete solutions.

  9. Two problems in thermal field theory

    Indian Academy of Sciences (India)

    Abstract. In this talk, I review recent progress made in two areas of thermal field theory. In particular, I discuss various approaches for the calculation of the quark gluon plasma thermodynamical properties, and the problem of its photon production rate.

  10. Computer Simulation in Problems of Thermal Strength

    Directory of Open Access Journals (Sweden)

    Olga I. Chelyapina

    2012-05-01

    Full Text Available This article discusses informative technology of using graphical programming environment LabVIEW 2009 when calculating and predicting the thermal strength of materials with an inhomogeneous structure. Algorithm for processing the experimental data was developed as part of the problem.

  11. Crowdsourcing for Challenging Technical Problems - It Works!

    Science.gov (United States)

    Davis, Jeffrey R.

    2011-01-01

    The NASA Johnson Space Center Space Life Sciences Directorate (SLSD) and Wyle Integrated Science and Engineering (Wyle) will conduct a one-day business cluster at the 62nd IAC so that IAC attendees will understand the benefits of open innovation (crowdsourcing), review successful results of conducting technical challenges in various open innovation projects, and learn how an organization can effectively deploy these new problem solving tools to innovate more efficiently and effectively. Results from both the SLSD open innovation pilot program and the open innovation workshop conducted by the NASA Human Health and Performance Center will be discussed. NHHPC members will be recruited to participate in the business cluster (see membership http://nhhpc.nasa.gov) and as IAF members. Crowdsourcing may be defined as the act of outsourcing tasks that are traditionally performed by an employee or contractor to an undefined, generally large group of people or community (a crowd) in the form of an open call. The open call may be issued by the organization wishing to find a solution to a particular problem or complete a task, or by an open innovation service provider on behalf of that organization. In 2008, the SLSD, with the support of Wyle, established and implemented pilot projects in open innovation (crowdsourcing) to determine if these new internet-based platforms could indeed find solutions to difficult technical challenges. These unsolved technical problems were converted to problem statements, called Challenges by some open innovation service providers, and were then posted externally to seek solutions to these problems. In addition, an open call was issued internally to NASA employees Agency wide (11 Field Centers and NASA HQ) using an open innovation service provider crowdsourcing platform to post NASA challenges from each Center for the others to propose solutions). From 2008 to 2010, the SLSD issued 34 challenges, 14 externally and 20 internally. The 14 external

  12. Challenging problems and solutions in intelligent systems

    CERN Document Server

    Grzegorzewski, Przemysław; Kacprzyk, Janusz; Owsiński, Jan; Penczek, Wojciech; Zadrożny, Sławomir

    2016-01-01

    This volume presents recent research, challenging problems and solutions in Intelligent Systems– covering the following disciplines: artificial and computational intelligence, fuzzy logic and other non-classic logics, intelligent database systems, information retrieval, information fusion, intelligent search (engines), data mining, cluster analysis, unsupervised learning, machine learning, intelligent data analysis, (group) decision support systems, intelligent agents and multi-agent systems, knowledge-based systems, imprecision and uncertainty handling, electronic commerce, distributed systems, etc. The book defines a common ground for sometimes seemingly disparate problems and addresses them by using the paradigm of broadly perceived intelligent systems. It presents a broad panorama of a multitude of theoretical and practical problems which have been successfully dealt with using the paradigm of intelligent computing.

  13. Problems and challenges in social marketing.

    Science.gov (United States)

    Bloom, P N; Novelli, W D

    1981-01-01

    This article reviews the problems that arise when general marketing principles are applied to social programs. Social marketing is conceptualized as the design, implementation, and control of programs seeking to increase the acceptability of a social ideal or practice in a target group. These problems can occur in 8 basic decision-making areas: market analysis, market segmentation, product strategy development, pricing strategy development, channel strategy development, communications strategy development, organizational design and planning, and evaluation. Social marketers find that they have less good secondary data about their consumers, more problems obtaining valid and reliable measures of relevant variables, more difficulty sorting out the relative influence of determinants of consumer behavior, and more problems getting consumer research funded than marketers in the commercial sector. They tend to have less flexibility in shaping their products and more difficulty formulating product concepts. Problems associated with establishing, utilizing, and controlling distribution channels comprise another major difference between social and more conventional forms of marketing. Social marketers also find that their communications options are somewhat limited as a result of problems associated with use of paid advertisements, pressures not to use certain types of appeals in their messages, and the need to communicate large amounts of information in their messages. Moreover, social marketers must function in organizations where marketing activities are poorly understood, underappreciated, and inappropriately located. Finally, they face problems trying to define effectiveness measures or estimating the contribution their program has made toward the achievement of certain objectives. If all these problems are anticipated and handled creatively, social marketing efforts can succeed.

  14. Decommissioning: a problem or a challenge?

    OpenAIRE

    Mele Irena

    2004-01-01

    With the ageing of nuclear facilities or the reduced interest in their further operation, a new set of problems, related to the decommissioning of these facilities, has come into forefront. In many cases it turns out that the preparations for decommissioning have come too late, and that financial resources for covering decommissioning activities have not been provided. To avoid such problems, future liailities should be thoroughly estimated in drawing up the decommissioning and waste manageme...

  15. Decommissioning: a problem or a challenge?

    Directory of Open Access Journals (Sweden)

    Mele Irena

    2004-01-01

    Full Text Available With the ageing of nuclear facilities or the reduced interest in their further operation, a new set of problems, related to the decommissioning of these facilities, has come into forefront. In many cases it turns out that the preparations for decommissioning have come too late, and that financial resources for covering decommissioning activities have not been provided. To avoid such problems, future liailities should be thoroughly estimated in drawing up the decommissioning and waste management programme for each nuclear facility in time, and financial provisions for implementing such programme should be provided. In this paper a presentation of current decommissioning experience in Slovenia is given. The main problems and difficulties in decommissioning of the Žirovski Vrh Uranium Mine are exposed and the lesson learned from this case is presented. The preparation of the decommissioning programme for the Nuclear Power Plant Krško is also described, and the situation at the TRIGA research reactor is briefly discussed.

  16. Fifty challenging problems in probability with solutions

    CERN Document Server

    Mosteller, Frederick

    1987-01-01

    Can you solve the problem of ""The Unfair Subway""? Marvin gets off work at random times between 3 and 5 p.m. His mother lives uptown, his girlfriend downtown. He takes the first subway that comes in either direction and eats dinner with the one he is delivered to. His mother complains that he never comes to see her, but he says she has a 50-50 chance. He has had dinner with her twice in the last 20 working days. Explain. Marvin's adventures in probability are one of the fifty intriguing puzzles that illustrate both elementary ad advanced aspects of probability, each problem designed to chall

  17. An inverse heat transfer problem for optimization of the thermal ...

    Indian Academy of Sciences (India)

    It is evident that machining process causes development of large quantities of thermal energy within a relatively narrow area of the cutting zone. The generated thermal energy and the problems of its evacuation from the cutting zone account for high temperatures in machining. These increased temperatures exert a ...

  18. An inverse heat transfer problem for optimization of the thermal ...

    Indian Academy of Sciences (India)

    Abstract. It is evident that machining process causes development of large quan- tities of thermal energy within a relatively narrow area of the cutting zone. The generated thermal energy and the problems of its evacuation from the cutting zone account for high temperatures in machining. These increased temperatures exert ...

  19. Religious Tolerance in Malaysia: Problems and Challenges

    Directory of Open Access Journals (Sweden)

    Nur Farhana Abdul Rahman

    2013-06-01

    Full Text Available Every religion is normally perceived from their own religion to tend toward exclusiveness by claiming that their religion is the only true religion, offering the true revelation and the true way of salvation. This exclusiveness started with desire to know the religious status or truth position among other religions. The question on which religion is the ideal religion and ultimately the truest one has always been raised and debated among people of religions. This polemic can be a seed of many conflicts and disagreements between religions in many parts of the world, including Malaysia as a multi-religious country. This is a preliminary study which attempts to explore issues and challenges pertaining to religious tolerance as practiced in Malaysia. This research is a qualitative research which data are gathered from various sources including books, journals, magazines, newspapers, articles and internet sources related to the topic as well as in depth interview with qualified persons. The data will then be analysed using document analysis method. The result shows that religious tolerance in this country is seen working under various and distinctive understanding. The main challenges to practising religious tolerance in Malaysia emerged from none guidance module to practising religious tolerance especially which stated the limitation and the rule in religious tolerance applicable in Malaysia context and lack of understanding of religious tolerance needed within adherents of religion which cause prejudices against the adherents of religions.

  20. A multiscale problem in thermal science

    Directory of Open Access Journals (Sweden)

    Casenave Fabien

    2013-01-01

    Full Text Available We consider a multiscale heat problem in civil aviation: determine the temperature field in a plane in flying conditions, with air conditioning. Ventilated electronic components in the bay bring a heat source, introducing a second scale in the problem. First, we present three levels of modelling for the physical phenomena, which are applied to the two sub-problems: the plane and the electronic component. Then, having reduced the complexity of the problem to a linear non-symmetric coercive PDE, we will use the reduced basis method for the electronic component problem. Nous considérons un problème multi-échelle d’aérothermie en aviation civile. Nous souhai- tons déterminer le champ de température dans un avion en conditions de vol, avec présence d’une climatisation. Des composants électroniques ventilés sont présents dans la soute, et constituent une source de chaleur, introduisant une deuxième échelle dans notre problème. Dans un premier temps, nous présentons trois niveaux de modélisation pour le phénomène d’aérothermie, que nous appliquerons aux deux sous-problèmes : l’avion et le composant électronique. Ensuite, nous appliquons la méthode des bases réduites au problème du composant électronique, en considérant des simplifications de modélisation amenant à la résolution numérique d’une EDP elliptique linéaire coercive non-symétrique.

  1. A suite of benchmark and challenge problems for enhanced geothermal systems

    Energy Technology Data Exchange (ETDEWEB)

    White, Mark; Fu, Pengcheng; McClure, Mark; Danko, George; Elsworth, Derek; Sonnenthal, Eric; Kelkar, Sharad; Podgorney, Robert

    2017-11-06

    A diverse suite of numerical simulators is currently being applied to predict or understand the performance of enhanced geothermal systems (EGS). To build confidence and identify critical development needs for these analytical tools, the United States Department of Energy, Geothermal Technologies Office sponsored a Code Comparison Study (GTO-CCS), with participants from universities, industry, and national laboratories. A principal objective for the study was to create a community forum for improvement and verification of numerical simulators for EGS modeling. Teams participating in the study were those representing U.S. national laboratories, universities, and industries, and each team brought unique numerical simulation capabilities to bear on the problems. Two classes of problems were developed during the study, benchmark problems and challenge problems. The benchmark problems were structured to test the ability of the collection of numerical simulators to solve various combinations of coupled thermal, hydrologic, geomechanical, and geochemical processes. This class of problems was strictly defined in terms of properties, driving forces, initial conditions, and boundary conditions. The challenge problems were based on the enhanced geothermal systems research conducted at Fenton Hill, near Los Alamos, New Mexico, between 1974 and 1995. The problems involved two phases of research, stimulation, development, and circulation in two separate reservoirs. The challenge problems had specific questions to be answered via numerical simulation in three topical areas: 1) reservoir creation/stimulation, 2) reactive and passive transport, and 3) thermal recovery. Whereas the benchmark class of problems were designed to test capabilities for modeling coupled processes under strictly specified conditions, the stated objective for the challenge class of problems was to demonstrate what new understanding of the Fenton Hill experiments could be realized via the application of

  2. Thermal problems on high flux beam lines

    Science.gov (United States)

    Avery, Robert T.

    1984-05-01

    Wiggler and undulator magnets can provide very intense photon flux densities to beam line components. This paper addresses some thermal/materials consequences due to such impingement. The LBL/Exxon/SSRL hybrid-wiggler beam line VI [1] now nearing operation will be able to provide up to ˜ 7 kW of total photon power at planned SPEAR operating conditions. The first masks are located at 6.5 m from the source and may receive a peak power density (transverse to the beam) exceeding 20 kW/cm 2. Significantly, this heat transfer rate exceeds that radiated from the sun's surface (7 kW/cm 2) and is comparable to that if welding torches. Clearly, cooling and configuration are of critical importance. Configurations for the first mask, the movable mask and the pivot mask on this beam line are presented together with considerations of thermal stress fatigue and of heat transfer by conduction to water-cooling circuits. Some preliminary information on the heating of crystals and mirrors is also presented. For the future, many additional intense wiggler/undulator beam lines are contemplated at several storage rings. The design of these beamlines would be enhanced by faster and more accurate computational techniques. LBL is developing a computer code which will be capable of giving photon power densities onto impinged surfaces for a wide range of source and beam line parameters. These include electron beam energy, current, emittance and orbit deviations; wiggler/undulator length, period and magnetic field; photon energy and angular distribution; reflection/absorption at intermediate impinged surfaces; defining apertures and focusing by mirrors. Three-dimensional computer programs for temperature, stress and strain have been available for some years, but "user friendly" versions are being sought. Other items to pursue are also suggested.

  3. Endoscopic solutions to challenging enteral feeding problems.

    Science.gov (United States)

    Paski, Shirley C; Dominitz, Jason A

    2012-09-01

    Enteral nutrition support is often required in patients who are unable to meet their own nutritional requirements. Endoscopists play a key role in the placement of enteral feeding catheters. This review focuses on the recently published solutions to common problems encountered during endoscopic placement of enteral feeding devices. Case reports and case series describe solutions for overcoming common problems encountered during the placement of enteral feeding devices. Transnasal techniques can simplify nasojejunal tube placement, whereas deep enteroscopy techniques provide more reliable jejunostomy placement. Endoscopic ultrasound can help when transillumination is not possible or in the setting of postsurgical anatomy like Roux-en-Y. Laparoscopic-assisted procedures are useful when endoscopic techniques have failed in adults or in select high-risk pediatric patients. The American Society for Gastrointestinal Endoscopy and the American Gastroenterology Association both published comprehensive guidelines that outline the indications, contraindications, technical aspects of feeding catheter placement, and complications. Advances in endoscopic techniques, including deep enteroscopy, endoscopic ultrasound, ultra-slim transnasal endoscopes and laparoscopic-assisted procedures, have enabled endoscopists to successfully place enteral feeding tubes in patients who previously required open procedures.

  4. Survival tactics within thermally-challenging roosts: heat tolerance ...

    African Journals Online (AJOL)

    Survival tactics within thermally-challenging roosts: heat tolerance and cold sensitivity in the Angolan free-tailed bat, Mops condylurus. ... This presumably allowed them to minimize energy costs of thermoregulation without compromising reproductive activity or their ability to avoid predators. Bats displayed pronounced heat ...

  5. An inverse heat conduction problem of estimating thermal conductivity

    CERN Document Server

    Shidfar, S

    2002-01-01

    In this paper we consider an inverse heat conduction problem. We define the inverse and direct problem and solve the direct problem by method of Lines. We estimated the thermal conductivity k(u) which is assumed k(u)=k sub o +k sub 1 u+...+k sub N u sup N and contiguously in the direction normal to the surface of a sample plate.

  6. Islamic World: International and Internal Political Problems and Challenges

    Directory of Open Access Journals (Sweden)

    - Ahmad Bashir

    2011-06-01

    Full Text Available The article envisages principle international and internal political problems and challenges that are faced by the Islamic world in the context of contemporary world politics. Particular attention is being paid to specific internal processes within the Islamic world and countries included thereto. The article revises the experience of Iran and Turkey in modernization and reforming which are in turn considered as main strategic ways to overcome problems and challenges typical for the Islamic world including the international component.

  7. The vehicle routing problem latest advances and new challenges

    CERN Document Server

    Golden, Bruce L; Wasil, Edward A

    2008-01-01

    The Vehicle Routing Problem (VRP) has been an especially active and fertile area of research. Over the past five to seven years, there have been numerous technological advances and exciting challenges that are of considerable interest to students, teachers, and researchers. The Vehicle Routing Problem: Latest Advances and New Challenges will focus on a host of significant technical advances that have evolved over the past few years for modeling and solving vehicle routing problems and variants. New approaches for solving VRPs have been developed from important methodological advances. These developments have resulted in faster solution algorithms, more accurate techniques, and an improvement in the ability to solve large-scale, complex problems. The book will systematically examine these recent developments in the VRP and provide the following in a unified and carefully developed presentation: Present novel problems that have arisen in the vehicle routing domain and highlight new challenges for the field; Pre...

  8. Theory of elasticity and thermal stresses explanations, problems and solutions

    CERN Document Server

    Eslami, M Reza; Ignaczak, Józef; Noda, Naotake; Sumi, Naobumi; Tanigawa, Yoshinobu

    2013-01-01

    This book contains the elements of the theory and the problems of Elasticity and Thermal Stresses with full solutions. The emphasis is placed on problems and solutions and the book consists of  four parts: one part is on The Mathematical Theory of Elasticity, two parts are on Thermal Stresses and one part is on Numerical Methods. The book is addressed to higher level undergraduate students, graduate students and engineers and it is an indispensable companion to all who study any of the books published earlier by the authors. This book links the three previously published books by the authors into one comprehensive entity.

  9. Transdisciplinary weed research: new leverage on challenging weed problems?

    Science.gov (United States)

    Transdisciplinary Weed Research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social aspec...

  10. Odera Oruka™s Philosophic Sagacity: Problems and Challenges of ...

    African Journals Online (AJOL)

    Reginald M. J. Oduor

    Odera Oruka's Philosophic Sagacity: Problems and Challenges of Conversation Method 83 or sages, just like Plato did to Socrates. Then it becomes difficult to draw the line. The problem here, according to Bodunrin, then becomes that of authorship. Who owns the new idea or product - the sage or the philosopher? But then ...

  11. Transdisciplinary weed research: new leverage on challenging weed problems?

    NARCIS (Netherlands)

    Jordan, N.; Schut, M.; Graham, S.; Barney, J.N.; Childs, D.Z.; Christensen, S.B.; Cousens, R.D.; Davis, A.S.; Eizenberg, H.; Ervin, D.E.; Fernandez-Quintanilla, C.; Harrison, L.J.; Harsch, M.A.; Heijting, S.; Liebman, M.; Loddo, D.; Mirsky, S.B.; Riemens, M.; Neve, P.; Peltzer, D.A.; Renton, M.; Williams, M.; Recasens, J.; Sønderskov, M.

    2016-01-01

    Transdisciplinary weed research (TWR) is a promising path to more effective management of challenging weed problems. We define TWR as an integrated process of inquiry and action that addresses complex weed problems in the context of broader efforts to improve economic, environmental and social

  12. Teaching introductory thermal physics through problem based learning

    OpenAIRE

    Tracey, Rebecca

    2005-01-01

    The development and delivery of an introductory thermal physics module taught through Problem Based Learning (PBL) in a lecture-based curriculum is reported on. The development and implementation of the module is illustrated through discussion of the problems and students responses. The PBL methodology is compared with traditional lecture style teaching and the educational theories that the methodologies stem from are discussed. Examples of how PBL has been used to teach physics, along wi...

  13. Crowd Sourcing for Challenging Technical Problems and Business Model

    Science.gov (United States)

    Davis, Jeffrey R.; Richard, Elizabeth

    2011-01-01

    Crowd sourcing may be defined as the act of outsourcing tasks that are traditionally performed by an employee or contractor to an undefined, generally large group of people or community (a crowd) in the form of an open call. The open call may be issued by an organization wishing to find a solution to a particular problem or complete a task, or by an open innovation service provider on behalf of that organization. In 2008, the Space Life Sciences Directorate (SLSD), with the support of Wyle Integrated Science and Engineering, established and implemented pilot projects in open innovation (crowd sourcing) to determine if these new internet-based platforms could indeed find solutions to difficult technical challenges. These unsolved technical problems were converted to problem statements, also called "Challenges" or "Technical Needs" by the various open innovation service providers, and were then posted externally to seek solutions. In addition, an open call was issued internally to NASA employees Agency wide (10 Field Centers and NASA HQ) using an open innovation service provider crowd sourcing platform to post NASA challenges from each Center for the others to propose solutions). From 2008 to 2010, the SLSD issued 34 challenges, 14 externally and 20 internally. The 14 external problems or challenges were posted through three different vendors: InnoCentive, Yet2.com and TopCoder. The 20 internal challenges were conducted using the InnoCentive crowd sourcing platform designed for internal use by an organization. This platform was customized for NASA use and promoted as NASA@Work. The results were significant. Of the seven InnoCentive external challenges, two full and five partial awards were made in complex technical areas such as predicting solar flares and long-duration food packaging. Similarly, the TopCoder challenge yielded an optimization algorithm for designing a lunar medical kit. The Yet2.com challenges yielded many new industry and academic contacts in bone

  14. Tennessee Eastman Plant-wide Industrial Process Challenge Problem

    DEFF Research Database (Denmark)

    Sales-Cruz, Mauricio; Cameron, Ian; Gani, Rafiqul

    2011-01-01

    This chapter presents a comprehensive analysis and modelling of the Tennessee Eastman challenge problem. Both a simplified model of the system as well as a full process model that includes the energy balances is given. In each case a full model analysis is carried out to establish the degrees...... problem data are given and initial conditions for dynamic runs are stated to enable readers to replicate the model performance....

  15. A finite difference Taylor series method applied to thermal problems

    Science.gov (United States)

    Collins, R. L.

    1988-06-01

    A new technique has been developed for solving finite difference equations that approximate parabolic (transient) and elliptic (steady) partial differential equations for heat transfer problems. The approach utilizes a Taylor series method and a variable-weighted implicit finite difference approximation. The weighting function for each difference equation is determined from the power-law suggested by S. Patankar and B. Baliga. An automatic-time-step selection process has been incorporated to enhance the transient solution scheme. Both the transient and steady-state equation sets are solved iteratively. The Aitken extrapolation process is used to accelerate convergence to steady state. Although this solution process was developed for the SINDA thermal analyzer, application to other finite difference thermal analysis codes should be fairly straightforward. The potential of this new scheme is demonstrated by solving three transient and two steady-state heat transfer problems that involve conduction and radiation.

  16. Thermally assisted quantum annealing of a 16-qubit problem

    Science.gov (United States)

    Dickson, N. G.; Johnson, M. W.; Amin, M. H.; Harris, R.; Altomare, F.; Berkley, A. J.; Bunyk, P.; Cai, J.; Chapple, E. M.; Chavez, P.; Cioata, F.; Cirip, T.; Debuen, P.; Drew-Brook, M.; Enderud, C.; Gildert, S.; Hamze, F.; Hilton, J. P.; Hoskinson, E.; Karimi, K.; Ladizinsky, E.; Ladizinsky, N.; Lanting, T.; Mahon, T.; Neufeld, R.; Oh, T.; Perminov, I.; Petroff, C.; Przybysz, A.; Rich, C.; Spear, P.; Tcaciuc, A.; Thom, M. C.; Tolkacheva, E.; Uchaikin, S.; Wang, J.; Wilson, A. B.; Merali, Z.; Rose, G.

    2013-05-01

    Efforts to develop useful quantum computers have been blocked primarily by environmental noise. Quantum annealing is a scheme of quantum computation that is predicted to be more robust against noise, because despite the thermal environment mixing the system's state in the energy basis, the system partially retains coherence in the computational basis, and hence is able to establish well-defined eigenstates. Here we examine the environment's effect on quantum annealing using 16 qubits of a superconducting quantum processor. For a problem instance with an isolated small-gap anticrossing between the lowest two energy levels, we experimentally demonstrate that, even with annealing times eight orders of magnitude longer than the predicted single-qubit decoherence time, the probabilities of performing a successful computation are similar to those expected for a fully coherent system. Moreover, for the problem studied, we show that quantum annealing can take advantage of a thermal environment to achieve a speedup factor of up to 1,000 over a closed system.

  17. Thermally assisted quantum annealing of a 16-qubit problem.

    Science.gov (United States)

    Dickson, N G; Johnson, M W; Amin, M H; Harris, R; Altomare, F; Berkley, A J; Bunyk, P; Cai, J; Chapple, E M; Chavez, P; Cioata, F; Cirip, T; Debuen, P; Drew-Brook, M; Enderud, C; Gildert, S; Hamze, F; Hilton, J P; Hoskinson, E; Karimi, K; Ladizinsky, E; Ladizinsky, N; Lanting, T; Mahon, T; Neufeld, R; Oh, T; Perminov, I; Petroff, C; Przybysz, A; Rich, C; Spear, P; Tcaciuc, A; Thom, M C; Tolkacheva, E; Uchaikin, S; Wang, J; Wilson, A B; Merali, Z; Rose, G

    2013-01-01

    Efforts to develop useful quantum computers have been blocked primarily by environmental noise. Quantum annealing is a scheme of quantum computation that is predicted to be more robust against noise, because despite the thermal environment mixing the system's state in the energy basis, the system partially retains coherence in the computational basis, and hence is able to establish well-defined eigenstates. Here we examine the environment's effect on quantum annealing using 16 qubits of a superconducting quantum processor. For a problem instance with an isolated small-gap anticrossing between the lowest two energy levels, we experimentally demonstrate that, even with annealing times eight orders of magnitude longer than the predicted single-qubit decoherence time, the probabilities of performing a successful computation are similar to those expected for a fully coherent system. Moreover, for the problem studied, we show that quantum annealing can take advantage of a thermal environment to achieve a speedup factor of up to 1,000 over a closed system.

  18. Sensitivity theory applied to a transient thermal-hydraulics problem

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.F.; Oblow, E.M.

    1979-10-01

    A new method for sensitivity analysis of transient nonlinear problems is developed and applied to a reactor thermal-hydraulics problem. The method resembles the differential sensitivity methods currently used in the linear problems of reactor physics, but it is applicable to nonlinear systems as well. The equations governing heat transfer and fluid flow in a fuel pin and surrounding coolant are given and used to derive a second set of equations (commonly known as the adjoint equations) used in the sensitivity analysis. Both systems contain one second-order parabolic and one first-order hyperbolic partial differential equation. Difference equations are derived to approximate both systems and the convergence properties of these discrete systems are evaluated, yielding a useful analysis of the numerical solution. The solution functions are used to derive sensitivity coefficients for any desired integral response. These sensitivity coefficients are used in a first-order perturbation theory to predict changes in a response resulting from changes in parameter values. The results of a test problem are shown, verifying that this procedure is indeed useful for a wide variety of sensitivity calculations.

  19. Reentry challenges facing women with mental health problems.

    Science.gov (United States)

    Visher, Christy A; Bakken, Nicholas W

    2014-01-01

    Women entering the correctional system represent a population at high risk for mental health and the body of research on the mental health needs of women offenders is growing. These mental health problems pose challenges for women at every stage of the criminal justice process, from arrest to incarceration to community reentry and reintegration. In this article, we examined mental health status among a sample of 142 women leaving confinement and the role that mental health problems played in shaping their reentry outcomes using data collected between 2002 and 2005 in Houston, Texas. In the year after leaving prison, women with mental health problems reported poorer health, more hospitalizations, more suicidal thoughts, greater difficulties securing housing and employment, more involvement in criminal behavior, and less financial support from family than women with no indication of mental health problems. However, mental health status did not increase the likelihood of substance use relapse or reincarceration. The article concludes with a discussion of recommendations for improved policy and practice.

  20. Ability evaluation by binary tests: Problems, challenges & recent advances

    Science.gov (United States)

    Bashkansky, E.; Turetsky, V.

    2016-11-01

    Binary tests designed to measure abilities of objects under test (OUTs) are widely used in different fields of measurement theory and practice. The number of test items in such tests is usually very limited. The response to each test item provides only one bit of information per OUT. The problem of correct ability assessment is even more complicated, when the levels of difficulty of the test items are unknown beforehand. This fact makes the search for effective ways of planning and processing the results of such tests highly relevant. In recent years, there has been some progress in this direction, generated by both the development of computational tools and the emergence of new ideas. The latter are associated with the use of so-called “scale invariant item response models”. Together with maximum likelihood estimation (MLE) approach, they helped to solve some problems of engineering and proficiency testing. However, several issues related to the assessment of uncertainties, replications scheduling, the use of placebo, as well as evaluation of multidimensional abilities still present a challenge for researchers. The authors attempt to outline the ways to solve the above problems.

  1. Modelling of hydrogen thermal desorption spectrum in nonlinear dynamical boundary-value problem

    Science.gov (United States)

    Kostikova, E. K.; Zaika, Yu V.

    2016-11-01

    One of the technological challenges for hydrogen materials science (including the ITER project) is the currently active search for structural materials with various potential applications that will have predetermined limits of hydrogen permeability. One of the experimental methods is thermal desorption spectrometry (TDS). A hydrogen-saturated sample is degassed under vacuum and monotone heating. The desorption flux is measured by mass spectrometer to determine the character of interactions of hydrogen isotopes with the solid. We are interested in such transfer parameters as the coefficients of diffusion, dissolution, desorption. The paper presents a distributed boundary-value problem of thermal desorption and a numerical method for TDS spectrum simulation, where only integration of a nonlinear system of low order (compared with, e.g., the method of lines) ordinary differential equations (ODE) is required. This work is supported by the Russian Foundation for Basic Research (project 15-01-00744).

  2. Engineering Risk Assessment of Space Thruster Challenge Problem

    Science.gov (United States)

    Mathias, Donovan L.; Mattenberger, Christopher J.; Go, Susie

    2014-01-01

    The Engineering Risk Assessment (ERA) team at NASA Ames Research Center utilizes dynamic models with linked physics-of-failure analyses to produce quantitative risk assessments of space exploration missions. This paper applies the ERA approach to the baseline and extended versions of the PSAM Space Thruster Challenge Problem, which investigates mission risk for a deep space ion propulsion system with time-varying thruster requirements and operations schedules. The dynamic mission is modeled using a combination of discrete and continuous-time reliability elements within the commercially available GoldSim software. Loss-of-mission (LOM) probability results are generated via Monte Carlo sampling performed by the integrated model. Model convergence studies are presented to illustrate the sensitivity of integrated LOM results to the number of Monte Carlo trials. A deterministic risk model was also built for the three baseline and extended missions using the Ames Reliability Tool (ART), and results are compared to the simulation results to evaluate the relative importance of mission dynamics. The ART model did a reasonable job of matching the simulation models for the baseline case, while a hybrid approach using offline dynamic models was required for the extended missions. This study highlighted that state-of-the-art techniques can adequately adapt to a range of dynamic problems.

  3. Approximate solution to a singular perturbed boundary value problem of thermal shielding

    Science.gov (United States)

    Latypov, I. I.

    2017-11-01

    The paper aims to investigate the problem of distribution of a non-regular, non-steady-state thermal field in the porous thermal shield material irradiated by a high flow of energy. A mathematical model of the original problem is stated in the form of a singular perturbed boundary value problem of a thermal conductivity equation with the nonlinear boundary conditions on moving boundaries. Its solution is obtained as asymptotic Poincare-type expansions in powers of small parameters.

  4. Thermal sensors to control polymer forming. Challenge and solutions

    Science.gov (United States)

    Lemeunier, F.; Boyard, N.; Sarda, A.; Plot, C.; Lefèvre, N.; Petit, I.; Colomines, G.; Allanic, N.; Bailleul, J. L.

    2017-10-01

    Many thermal sensors are already used, for many years, to better understand and control material forming processes, especially polymer processing. Due to technical constraints (high pressure, sealing, sensor dimensions…) the thermal measurement is often performed in the tool or close its surface. Thus, it only gives partial and disturbed information. Having reliable information about the heat flux exchanges between the tool and the material during the process would be very helpful to improve the control of the process and to favor the development of new materials. In this work, we present several sensors developed in labs to study the molding steps in forming processes. The analysis of the obtained thermal measurements (temperature, heat flux) shows the required sensitivity threshold of sensitivity of thermal sensors to be able to detect on-line the rate of thermal reaction. Based on these data, we will present new sensor designs which have been patented.

  5. Managing Radioactive Waste. Problems and Challenges in a Globalizing World

    Energy Technology Data Exchange (ETDEWEB)

    2010-09-15

    Many countries are at a crossroads in terms of maintaining their energy supply. The existing resources of fossil fuels are dwindling, and global warming makes their use increasingly problematic. Nuclear power is now often regarded inevitable for future sustainability, energy security, and economic prosperity. There are, however, still unsolved problems regarding nuclear power. The fact that no country has established a final waste repository for spent nuclear fuel throws fundamental doubt on nuclear energy expansion. Also, the processes of globalization have transformed the nuclear industry towards increased privatization, concentration, and internationalization. This leads to uncertainties regarding the responsibility for nuclear waste management. In these circumstances is it of greatest importance that scholars from different disciplines, as well as policy makers and practitioners within the field, meet to share experiences. This conference had the general objective of producing knowledge about the challenges caused by global developmental trends, and what the management of nuclear waste implies for contemporary and future social development. Over 100 persons attended the conferences. Papers available at the conference site have been separately indexed. Several contributions were also made as PP-presentation, which are available at the site, among others the Keynote Speeches: Waiting for the Nuclear Renaissance: Exploring the Nexus of Expansion and Disposal in Europe (Jane Dawson); Applying the Risk Governance Framework: Institutional Requirements for Dealing with Nuclear Waste (Ortwin Renn); Learning to Listen: The Long Road to Legitimating Radioactive Waste Management Policies (Frans Berkhout); The Nuclear Waste Debate is Irrational but We Need Not Panic (Frank von Hippel). The conference was divided into the following sessions: Session A: Political characteristics matters; Session B: Radioactivity, geology, society. On a problem definition of HLW

  6. A computational domain decomposition approach for solving coupled flow-structure-thermal interaction problems

    Directory of Open Access Journals (Sweden)

    Eugenio Aulisa

    2009-04-01

    Full Text Available Solving complex coupled processes involving fluid-structure-thermal interactions is a challenging problem in computational sciences and engineering. Currently there exist numerous public-domain and commercial codes available in the area of Computational Fluid Dynamics (CFD, Computational Structural Dynamics (CSD and Computational Thermodynamics (CTD. Different groups specializing in modelling individual process such as CSD, CFD, CTD often come together to solve a complex coupled application. Direct numerical simulation of the non-linear equations for even the most simplified fluid-structure-thermal interaction (FSTI model depends on the convergence of iterative solvers which in turn rely heavily on the properties of the coupled system. The purpose of this paper is to introduce a flexible multilevel algorithm with finite elements that can be used to study a coupled FSTI. The method relies on decomposing the complex global domain, into several local sub-domains, solving smaller problems over these sub-domains and then gluing back the local solution in an efficient and accurate fashion to yield the global solution. Our numerical results suggest that the proposed solution methodology is robust and reliable.

  7. Survival tactics within thermally-challenging roosts: heat tolerance ...

    African Journals Online (AJOL)

    We studied roost microclimates, thermal preferences and temperature-related variation in body tem- peratures and flight abilities of M. condylurus from three roosts in man-made structures in South. Africa. Roosts were characterized by marked spatio-temporal variability in ambient temperature and relative humidity on a ...

  8. International Field Reversible Thermal Connector (RevCon) Challenge

    Science.gov (United States)

    2016-07-01

    load/unload experience. Comments and Suggestions • 2 almost identical prototypes. • Soldering edges slightly thicker than the Al slot. • Got...the competition. Comments and Suggestions • New prototype leaves less clearance, compared with the previous prototype. • Solder at the wedge...utilizing the available test measurements, adequate material selection , and a large clamping force usually resulted in lower thermal resistances. Of

  9. Challenges of thermal nociceptive threshold testing in the donkey.

    Science.gov (United States)

    Grint, Nicola J; Whay, Helen R; Beths, Thierry; Yvorchuk, Kathy; Murrell, Joanna C

    2015-03-01

    To evaluate a thermal nociceptive threshold (TNT) testing device in the donkey, and the influence of potential confounding factors on TNTs. Two groups (Group 1 and Group 2) of eight castrated male donkeys aged 4-9 years, weighing 105-170 kg. TNTs were measured by heating a thermal probe on skin until an end-point behaviour (threshold temperature) or a cut-out temperature (51 °C) was reached. The withers and the dorsal aspect of the distal limb were used as sites for TNT testing. The effects on TNT of different confounding factors: the limb tested; rate of heating; and ambient temperature were evaluated. Data were analyzed using general linear models, and Mann-Whitney tests, p < 0.05 was considered significant. End-point behaviours (skin twitch or donkey looking at test device) when the thermal probe heated the withers were observed in approximately half of tests. TNT was (mean ± SD) 46.8 ± 2.85 °C. Subsequently the limb was evaluated as the test site in Group 1 followed by Group 2 donkeys; end-point behaviour being a foot-lift. In Group 1, 72% of tests ended in an end-point behaviour but the response rate was lower in Group 2 (20%), although TNTs were similar [(47.6 ± 3.3) and (47.3 ± 3.0) °C respectively] for responding animals. Rate of heating, ambient temperature and laterality (right or left) did not affect thresholds, but mean TNT was significantly higher in the forelimb (48.5 ± 2.8 °C) than the hind limb (47.4 ± 2.8 °C) (p = 0.012). When a thermal probe cut-out temperature of 51 °C was used in TNT testing in the donkey a high proportion of tests did not produce an identifiable end point behaviour. Higher cut-out temperatures damaged the skin. Under these conditions, thermal nociceptive threshold testing appears not be an appropriate analgesiometry technique in the donkey. TNT testing under these conditions is not suitable form of analgesiometry for donkeys. © 2014 Association of Veterinary Anaesthetists and the American

  10. Challenges to quantitative applications of Landsat observations for the urban thermal environment.

    Science.gov (United States)

    Chen, Feng; Yang, Song; Yin, Kai; Chan, Paul

    2017-09-01

    Since the launch of its first satellite in 1972, the Landsat program has operated continuously for more than forty years. A large data archive collected by the Landsat program significantly benefits both the academic community and society. Thermal imagery from Landsat sensors, provided with relatively high spatial resolution, is suitable for monitoring urban thermal environment. Growing use of Landsat data in monitoring urban thermal environment is demonstrated by increasing publications on this subject, especially over the last decade. Urban thermal environment is usually delineated by land surface temperature (LST). However, the quantitative and accurate estimation of LST from Landsat data is still a challenge, especially for urban areas. This paper will discuss the main challenges for urban LST retrieval, including urban surface emissivity, atmospheric correction, radiometric calibration, and validation. In addition, we will discuss general challenges confronting the continuity of quantitative applications of Landsat observations. These challenges arise mainly from the scan line corrector failure of the Landsat 7 ETM+ and channel differences among sensors. Based on these investigations, the concerns are to: (1) show general users the limitation and possible uncertainty of the retrieved urban LST from the single thermal channel of Landsat sensors; (2) emphasize efforts which should be done for the quantitative applications of Landsat data; and (3) understand the potential challenges for the continuity of Landsat observation (i.e., thermal infrared) for global change monitoring, while several climate data record programs being in progress. Copyright © 2017. Published by Elsevier B.V.

  11. Problem reporting and tracking system: a systems engineering challenge

    Science.gov (United States)

    Cortez, Vasco; Lopez, Bernhard; Whyborn, Nicholas; Price, Roberto; Hernandez, Octavio; Gairing, Stefan; Barrios, Emilio; Alarcon, Hector

    2016-08-01

    The problem reporting and tracking system (PRTS) is the ALMA system to register operational problems, track unplanned corrective operational maintenance activities and follow the investigations of all problems or possible issues arisen in operation activities. After the PRTS implementation appeared several issues that finally produced a lack in the management of the investigations, problems to produce KPIs, loss of information, among others. In order to improve PRTS, we carried out a process to review the status of system, define a set of modifications and implement a solution; all according to the stakeholder requirements. In this work, we shall present the methodology applied to define a set of concrete actions at the basis of understanding the complexity of the problem, which finally got to improve the interactions between different subsystems and enhance the communication at different levels.

  12. The use of indigenous knowledge in development: problems and challenges

    OpenAIRE

    Briggs, J.

    2005-01-01

    The use of indigenous knowledge has been seen by many as an alternative way of promoting development in poor rural communities in many parts of the world. By reviewing much of the recent work on indigenous knowledge, the paper suggests that a number of problems and tensions has resulted in indigenous knowledge not being as useful as hoped for or supposed. These include problems emanating from a focus on the (arte)factual; binary tensions between western science and indigenous knowledge system...

  13. Odera Oruka's Philosophic Sagacity: Problems and Challenges of ...

    African Journals Online (AJOL)

    This paper examines the implications and challenges of Odera Oruka's conversation approach to the study of contemporary African philosophy as enunciated in his “Philosophic sagacity”. In Oruka's method, African philosophy is conceived as a joint venture and product of both the ancient (traditional) and modern African

  14. Improving Mathematics Problem Solving Skills for Students with Challenging Behavior

    Science.gov (United States)

    Alter, Peter J.; Wyrick, Amanda; Brown, E. Todd; Lingo, Amy

    2008-01-01

    Research indicates that there is a reciprocal relationship between challenging behavior and poor academic performance and that this relationship will have a lifelong negative impact on individuals caught in this detrimental cycle. New interventions continue to be reported in the literature describing more effective ways to implement academic…

  15. Mixed boundary-value problems for quantum hydrodynamic models with semiconductors in thermal equilibrium

    Directory of Open Access Journals (Sweden)

    Jianwei Dong

    2005-11-01

    Full Text Available We show the existence of solutions for mixed boundary-value problems that model quantum hydrodynamics in thermal equilibrium. Also we find the semi-classical limit of the solutions.

  16. Sleep medicine in Saudi Arabia: Current problems and future challenges

    Science.gov (United States)

    BaHammam, Ahmed S.

    2011-01-01

    Sleep medicine is a relatively new specialty in the medical community. The practice of sleep medicine in Saudi Arabia (KSA) began in the mid to late nineties. Since its inception, the specialty has grown, and the number of specialists has increased. Nevertheless, sleep medicine is still underdeveloped in the KSA, particularly in the areas of clinical service, education, training and research. Based on available data, it appears that sleep disorders are prevalent among Saudis, and the demand for sleep medicine service is expected to rise significantly in the near future. A number of obstacles have been defined that hinder the progress of the specialty, including a lack of trained technicians, specialists and funding. Awareness about sleep disorders and their serious consequences is low among health care workers, health care authorities, insurance companies and the general public. A major challenge for the future is penetrating the educational system at all levels to demonstrate the high prevalence and serious consequences of sleep disorders. To attain adequate numbers of staff and facilities, the education and training of health care professionals at the level of sleep medicine specialists and sleep technologists is another important challenge that faces the specialty. This review discusses the current position of sleep medicine as a specialty in the KSA and the expected challenges of the future. In addition, it will guide clinicians interested in setting up new sleep medicine services in the KSA or other developing countries through the potential obstacles that may face them in this endeavor. PMID:21264164

  17. Sleep medicine in Saudi Arabia: Current problems and future challenges

    Directory of Open Access Journals (Sweden)

    BaHammam Ahmed

    2011-01-01

    Full Text Available Sleep medicine is a relatively new specialty in the medical community. The practice of sleep medicine in Saudi Arabia (KSA began in the mid to late nineties. Since its inception, the specialty has grown, and the number of specialists has increased. Nevertheless, sleep medicine is still underdeveloped in the KSA, particularly in the areas of clinical service, education, training and research. Based on available data, it appears that sleep disorders are prevalent among Saudis, and the demand for sleep medicine service is expected to rise significantly in the near future. A number of obstacles have been defined that hinder the progress of the specialty, including a lack of trained technicians, specialists and funding. Awareness about sleep disorders and their serious consequences is low among health care workers, health care authorities, insurance companies and the general public. A major challenge for the future is penetrating the educational system at all levels to demonstrate the high prevalence and serious consequences of sleep disorders. To attain adequate numbers of staff and facilities, the education and training of health care professionals at the level of sleep medicine specialists and sleep technologists is another important challenge that faces the specialty. This review discusses the current position of sleep medicine as a specialty in the KSA and the expected challenges of the future. In addition, it will guide clinicians interested in setting up new sleep medicine services in the KSA or other developing countries through the potential obstacles that may face them in this endeavor.

  18. Problems, challenges and promises: perspectives on precision medicine.

    Science.gov (United States)

    Duffy, David J

    2016-05-01

    The 'precision medicine (systems medicine)' concept promises to achieve a shift to future healthcare systems with a more proactive and predictive approach to medicine, where the emphasis is on disease prevention rather than the treatment of symptoms. The individualization of treatment for each patient will be at the centre of this approach, with all of a patient's medical data being computationally integrated and accessible. Precision medicine is being rapidly embraced by biomedical researchers, pioneering clinicians and scientific funding programmes in both the European Union (EU) and USA. Precision medicine is a key component of both Horizon 2020 (the EU Framework Programme for Research and Innovation) and the White House's Precision Medicine Initiative. Precision medicine promises to revolutionize patient care and treatment decisions. However, the participants in precision medicine are faced with a considerable central challenge. Greater volumes of data from a wider variety of sources are being generated and analysed than ever before; yet, this heterogeneous information must be integrated and incorporated into personalized predictive models, the output of which must be intelligible to non-computationally trained clinicians. Drawing primarily from the field of 'oncology', this article will introduce key concepts and challenges of precision medicine and some of the approaches currently being implemented to overcome these challenges. Finally, this article also covers the criticisms of precision medicine overpromising on its potential to transform patient care. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  19. Keynote Lecture: The Problems and Challenges in Biomedical Sciences

    Directory of Open Access Journals (Sweden)

    Bruce Albert

    2015-08-01

    Full Text Available Distressed by the perverse incentives that have generated the current hyper-competitive biomedical research environment in the United States, four of us published an open-access article in April 2014 entitled: Rescuing US biomedical research from its systemic flaws (Alberts, B., Kirschner, Marc W., Tilghman, Shirley, and  Varmus, H.; Proc. Natl. Acad. Sci. USA 111, 5773-5777 (2014. As announced in our follow-up piece, Opinion: Addressing systemic problems in the biomedical research enterprise (Proc. Natl. Acad. Sci. USA 112, 1912-1913 (2015, we have formed a 16-member steering committee to oversee a new website that is designed to collect suggestions for actions that can ameliorate the identified problems, as well as to highlight promising changes that are either underway or proposed (see http://rescuingbiomedicalresearch.org.  Despite widespread agreement concerning the problems, any substantial change in the system is bound to be controversial. Experiments are therefore needed. In my talk, I will outline some possible ideas for overcoming the inertia that prevents moving forward.We are encouraging both national and international contributions to this effort, since the problems that we have described are by no means unique to the United States.

  20. Psychological Problems and Challenge In EFL Speaking Classroom

    Directory of Open Access Journals (Sweden)

    Win Listyaningrum Arifin

    2017-07-01

    Full Text Available Psychological aspect regarding to learning attitudes plays in determining learning achievement. Psychological problems also involve not only to the students but also teacher. Less-confidence, speech anxiety, and low self-esteem are almost common problem in classroom, and occur on both teachers and students. Students who have low of self-confidence are often hardly able to control themselves for public speaking in the classroom, like, Governing his/ her behavior on that his/her peers think, lose belief on self, thinking that his/her friends dis-appraising, afraid of getting mistakes, etc. However, teachers which are low self-esteem and confidence also lose their performance and ability to manage their classroom optimally. Low self-esteem may caused by teacher’s poor understanding on subject matter. Both of psychological problems impact on dis-effectiveness of classroom activities. This paper takes accounts of some psychological problems of students and teachers in English speaking classroom, and some guidelines to overcome. At the last discus, this paper also provides some keys of how to make good classroom atmosphere.

  1. Challenges of Environmental Problems to the Philosophy of Education

    Science.gov (United States)

    Kato, Moricmichi

    2015-01-01

    We live in an age in which the destruction of the environment has become a major concern. However, until recently, environmental problems have not become a major issue for the philosophy of education. The reason for this is that for a very long time the philosophy of education was intimately related to the concept of nature as the foundation and…

  2. Problems and Challenges of Automating Cataloguing Process at ...

    African Journals Online (AJOL)

    This paper discusses the problems faced by Kenneth Dike Library in automating its cataloguing process since 1992. It further attempts to identify some of the constraints inhibiting the success of the process: inadequate funding, dearth of systems analysts, absence of dedicated commitment to automation on the part of the ...

  3. A Professional Challenge: Working with Multi-Problem Families.

    Science.gov (United States)

    Carson, Ann Taylor

    The manual for professionals working with multi-problem families was developed by Project IINTACT which provided home-based services to families with young children who were developmentally delayed or at risk of developmental delay. Three groups of high risk families were served: those in which one or more parents is mentally retarded, those…

  4. Uniqueness for a boundary identification problem in thermal imaging

    Directory of Open Access Journals (Sweden)

    Kurt Bryan

    1998-11-01

    Full Text Available An inverse problem for an initial-boundary value problem is considered. The goal is to determine an unknown portion of the boundary of a region in ${mathbb R}^n$ from measurements of Cauchy data on a known portion of the boundary. The dynamics in the interior of the region are governed by a differential operator of parabolic type. Utilizing a unique continuation result for evolution operators, along with the method of eigenfunction expansions, it is shown that uniqueness holds for a large and physically reasonable class of Cauchy data pairs.

  5. Response of turkey muscle satellite cells to thermal challenge. I. transcriptome effects in proliferating cells

    OpenAIRE

    Reed, Kent M.; Kristelle M Mendoza; Abrahante, Juan E.; Barnes, Natalie E.; Velleman, Sandra G.; Strasburg, Gale M.

    2017-01-01

    Background Climate change poses a multi-dimensional threat to food and agricultural systems as a result of increased risk to animal growth, development, health, and food product quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells cultured under cold or hot thermal challenge to better define molecular mechanisms by which thermal stress alters breast muscle ultrastructure. Results Satellite cells isolated from the pectoralis major mu...

  6. Drug problems in China: recent trends, countermeasures, and challenges.

    Science.gov (United States)

    Chen, Zhonglin; Huang, Kaicheng

    2007-02-01

    Drug crime in China is on an overall rising trend. Major drug crime cases are becoming more common, the types of drugs being trafficked are more diverse, and the smuggling and trafficking of drugs into the country and the smuggling of precursor chemicals out of the country have formed a bidirectional cycle. Drug crimes in China have also begun to show a conspicuous trend of internationalization. China's main countermeasures against drug crimes have been to pass new laws and regulations against drugs, to increase the efforts to eradicate cultivation, to establish and expand "drug-free communities" programs, and to strengthen international cooperation in antidrug campaigns. The existing problems demand prompt solutions, which include a shortage of funding and lack of accurate knowledge about prevalence of drug abuse and related data for scientifically studying the drug problems.

  7. Keynote Lecture: The Problems and Challenges in Biomedical Sciences

    OpenAIRE

    Bruce Albert

    2015-01-01

    Distressed by the perverse incentives that have generated the current hyper-competitive biomedical research environment in the United States, four of us published an open-access article in April 2014 entitled: Rescuing US biomedical research from its systemic flaws (Alberts, B., Kirschner, Marc W., Tilghman, Shirley, and  Varmus, H.; Proc. Natl. Acad. Sci. USA 111, 5773-5777 (2014)). As announced in our follow-up piece, Opinion: Addressing systemic problems in the biomedical research enterpri...

  8. What is the policy problem? : Methodological challenges in policy evaluation

    OpenAIRE

    Hanberger, Anders

    2001-01-01

    Because when a policy process starts, nobody knows what line of action will eventually be implemented, policy evaluation has to continuously examine the content of different policy components. In order to understand and explain public policy, different stakeholders’ perceptions of the policy problem need to be scrutinized. A policy evaluation should also facilitate the interpretation of policy in a broader context. What values and order does the policy or programme promote? Using an open eval...

  9. Prevalence of challenging nutritional problems among adolescents in Sri Lanka.

    Science.gov (United States)

    Jayatissa, Renuka; Ranbanda, R M

    2006-06-01

    Although 21% of the population of Sri Lanka consists of adolescents, studies of nutritional status among this group are limited. To assess nutritional problems and dietary and activity patterns among adolescents in Sri Lanka. A nationally representative cross-sectional study was conducted on 6,264 adolescents 10 to 15 years of age. All subjects were clinically examined for Bitot's spots, and their weights and heights were measured. The subjects were interviewed during regular class time. Hemoglobin concentration and dietary and activity patterns were assessed among a subsample (n = 787) of 1,521 adolescents. The World Health Organization age- and sex-specific references for body-mass index and height-for-age were used to estimate the prevalence of underweight and stunting, respectively. The International Obesity Task Force age- and sex-specific reference for body-mass index was used to estimate the prevalence of overweight. Age-specific WHO-defined cut off points were used to estimate the prevalence of anemia. The prevalence rates of underweight, stunting, and overweight were 47.2%, 28.5%, and 2.2%, respectively. The prevalence rates of anemia and vitamin A deficiency were 11.1% and 0.4%, respectively. During the previous 6 months, 10.4% of the subjects had usually not eaten breakfast before going to school. During the week before the interview, 24.4% of the children had not consumed green leafy vegetables, 26.6% had not consumed fruit, 19.0% had not participated in physical activities, and 27.5% had watched television for more than 2 hours per day. The nutritional problems of adolescents aged 10 to 15 years should be addressed through the schools. Specific policies should be developed in collaboration with the Ministry of Health and Education to control nutritional problems among adolescents.

  10. Medical Libraries and Problem Based Learning: New Challenges and Opportunities

    Directory of Open Access Journals (Sweden)

    Kuan-nien Chen

    2004-06-01

    Full Text Available This article explores the changing role of the medical library and librarians in the context of problem-based learning in terms of fives aspects - impacts on medical libraries, library instruction, technology, the collection, and the new role of the librarians. For the libraries, the role change process is ongoing rather than a single event. The medical school and the library must collaborate and interact in the areas of curriculum design, communications, and library user education. In addition, administrative supports such as budgets, staffing, and the building space of the library are always in demand. [Article content in Chinese

  11. Profile of men's health in Malaysia: problems and challenges

    Science.gov (United States)

    Tong, Seng Fah; Low, Wah Yun; Ng, Chirk Jenn

    2011-01-01

    Men's health concerns have evolved from the traditional andrology and male sexual health to a more holistic approach that encompasses male psychological, social and physical health. The poor state of health in men compared to their female counterparts is well documented. A review of the epidemiological data from Malaysia noted a similar trend in which men die at higher rates in under 1 and above 15 years old groups and most disease categories compared to women. In Malaysia, the main causes of death in men are non-communicable diseases and injuries. Risk factors, such as risk-taking behaviour, smoking and hypertension, are prevalent and amenable to early interventions. Erectile dysfunction, premature ejaculation and prostate disorders are also prevalent. However, many of these morbidities go unreported and are not diagnosed early; therefore, opportunities for early intervention are missed. This reflects poor health knowledge and inadequate health-care utilisation among Malaysian men. Their health-seeking behaviour has been shown to be strongly influenced by family members and friends. However, more research is needed to identify men's unmet health-care needs and to develop optimal strategies for addressing them. Because the Malaysian population is aging and there is an increase in sedentary lifestyles, optimizing men's health will remain a challenge unless effective measures are implemented. The existing male-unfriendly health-care system and the negative influence of masculinity on men's health behaviour must be addressed. A national men's health policy based on a male-friendly approach to health-care delivery is urgently needed to provide a framework for addressing these challenges. PMID:21358664

  12. Challenge problem and milestones for : Nuclear Energy Advanced Modeling and Simulation (NEAMS) waste Integrated Performance and Safety Codes (IPSC).

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Geoffrey A.; Wang, Yifeng; Howard, Robert; McNeish, Jerry A.; Schultz, Peter Andrew; Arguello, Jose Guadalupe, Jr.

    2010-09-01

    This report describes the specification of a challenge problem and associated challenge milestones for the Waste Integrated Performance and Safety Codes (IPSC) supporting the U.S. Department of Energy (DOE) Office of Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign. The NEAMS challenge problems are designed to demonstrate proof of concept and progress towards IPSC goals. The goal of the Waste IPSC is to develop an integrated suite of modeling and simulation capabilities to quantitatively assess the long-term performance of waste forms in the engineered and geologic environments of a radioactive waste storage or disposal system. The Waste IPSC will provide this simulation capability (1) for a range of disposal concepts, waste form types, engineered repository designs, and geologic settings, (2) for a range of time scales and distances, (3) with appropriate consideration of the inherent uncertainties, and (4) in accordance with robust verification, validation, and software quality requirements. To demonstrate proof of concept and progress towards these goals and requirements, a Waste IPSC challenge problem is specified that includes coupled thermal-hydrologic-chemical-mechanical (THCM) processes that describe (1) the degradation of a borosilicate glass waste form and the corresponding mobilization of radionuclides (i.e., the processes that produce the radionuclide source term), (2) the associated near-field physical and chemical environment for waste emplacement within a salt formation, and (3) radionuclide transport in the near field (i.e., through the engineered components - waste form, waste package, and backfill - and the immediately adjacent salt). The initial details of a set of challenge milestones that collectively comprise the full challenge problem are also specified.

  13. Thermal Challenges in LED-Driven Display Technologies: The Early Days

    OpenAIRE

    Yazawa, Kazuaki

    2014-01-01

    This section discusses a variety of thermal challenges in LED-driven displays, especially in early development phase of the LED displays. The unique fundamentals of the displays are their wide screen size, flat and thin envelop, light weight for a wall mount, and the requirements of bright and high contrast on screens. A historical background in the introduction is followed by the technological challenges of the system primarily based on a passive air convection cooling for LED displays. Even...

  14. Nanomaterials in consumer products: a challenging analytical problem

    Science.gov (United States)

    Contado, Catia

    2015-08-01

    Many products used in everyday life are made with the assistance of nanotechnologies. Cosmetic, pharmaceuticals, sunscreen, powdered food are only few examples of end products containing nano-sized particles (NPs), generally added to improve the product quality. To evaluate correctly benefits versus risks of engineered nanomaterials and consequently to legislate in favor of consumer’s protection, it is necessary to know the hazards connected with the exposure levels. This information implies transversal studies and a number of different competences. On analytical point of view the identification, quantification and characterization of NPs in food matrices and in cosmetic or personal care products pose significant challenges, because NPs are usually present at low concentration levels and the matrices, in which they are dispersed, are complexes and often incompatible with analytical instruments that would be required for their detection and characterization. This paper focused on some analytical techniques suitable for the detection, characterization and quantification of NPs in food and cosmetics products, reports their recent application in characterizing specific metal and metal-oxide NPs in these two important industrial and market sectors. The need of a characterization of the NPs as much as possible complete, matching complementary information about different metrics, possible achieved through validate procedures, is what clearly emerges from this research. More work should be done to produce standardized materials and to set-up methodologies to determine number-based size distributions and to get quantitative date about the NPs in such a complex matrices.

  15. Nanomaterials in consumer products: a challenging analytical problem

    Directory of Open Access Journals (Sweden)

    Catia eContado

    2015-08-01

    Full Text Available Many products used in everyday life are made with the assistance of nanotechnologies. Cosmetic, pharmaceuticals, sunscreen, powdered food are only few examples of end products containing nano-sized particles (NPs, generally added to improve the product quality. To evaluate correctly benefits versus risks of engineered nanomaterials and consequently to legislate in favor of consumer’s protection, it is necessary to know the hazards connected with the exposure levels. This information implies transversal studies and a number of different competences.On analytical point of view the identification, quantification and characterization of NPs in food matrices and in cosmetic or personal care products pose significant challenges, because NPs are usually present at low concentration levels and the matrices, in which they are dispersed, are complexes and often incompatible with analytical instruments that would be required for their detection and characterization.This paper focused on some analytical techniques suitable for the detection, characterization and quantification of NPs in food and cosmetics products, reports their recent application in characterizing specific metal and metal-oxide NPs in these two important industrial and market sectors.The need of a characterization of the NPs as much as possible complete, matching complementary information about different metrics, possible achieved through validate procedures, is what clearly emerges from this research. More work should be done to produce standardized materials and to set-up methodologies to determine number-based size distributions and to get quantitative date about the NPs in such a complex matrices.

  16. Problems and challenges in relation to treatment of patients with multimorbidity

    DEFF Research Database (Denmark)

    Søndergaard, Elisabeth; Willadsen, Tora Grauers; Guassora, Ann Dorrit Kristiane

    2015-01-01

    Objective. To explore views and attitudes among general practitioners (GPs) and researchers in the field of general practicetowards problems and challenges related to treatment of patients with multimorbidity. Setting. A workshop entitled Patientswith multimorbidity in general practice held during...

  17. Determination of the thermal conductivity and specific heat capacity of neem seeds by inverse problem method

    Directory of Open Access Journals (Sweden)

    S.N. Nnamchi

    2010-01-01

    Full Text Available Determination of the thermal conductivity and the specific heat capacity of neem seeds (Azadirachta indica A. Juss usingthe inverse method is the main subject of this work. One-dimensional formulation of heat conduction problem in a spherewas used. Finite difference method was adopted for the solution of the heat conduction problem. The thermal conductivityand the specific heat capacity were determined by least square method in conjunction with Levenberg-Marquardt algorithm.The results obtained compare favourably with those obtained experimentally. These results are useful in the analysis ofneem seeds drying and leaching processes.

  18. Chaotic living conditions and sleep problems associated with children's responses to academic challenge.

    Science.gov (United States)

    Brown, Eleanor D; Low, Christine M

    2008-12-01

    The ecology of economic disadvantage includes chaotic living conditions that may disrupt children's regulatory functioning and undermine mastery oriented responses to challenge. The present study examined chaotic living conditions, sleep problems, and responses to academic challenge for 96 economically disadvantaged children enrolled in a Head Start preschool. Caregiver interviews provided information regarding chaotic living conditions of residential crowding, noise, and family instability, as well as child sleep problems. Tasks individually administered to children provided measures of responses to academic challenge. Chaotic living conditions statistically predicted helpless/hopeless responses to academic challenge, and sleep problems partially mediated this relationship. Implications concern pathways of ecological risk and diversity in the school functioning of economically disadvantaged children. Copyright 2008 APA, all rights reserved.

  19. Thermal Energy for Lunar In Situ Resource Utilization: Technical Challenges and Technology Opportunities

    Science.gov (United States)

    Gordon, Pierce E. C.; Colozza, Anthony J.; Hepp, Aloysius F.; Heller, Richard S.; Gustafson, Robert; Stern, Ted; Nakamura, Takashi

    2011-01-01

    Oxygen production from lunar raw materials is critical for sustaining a manned lunar base but is very power intensive. Solar concentrators are a well-developed technology for harnessing the Sun s energy to heat regolith to high temperatures (over 1375 K). The high temperature and potential material incompatibilities present numerous technical challenges. This study compares and contrasts different solar concentrator designs that have been developed, such as Cassegrains, offset parabolas, compound parabolic concentrators, and secondary concentrators. Differences between concentrators made from lenses and mirrors, and between rigid and flexible concentrators are also discussed. Possible substrate elements for a rigid mirror concentrator are selected and then compared, using the following (target) criteria: (low) coefficient of thermal expansion, (high) modulus of elasticity, and (low) density. Several potential lunar locations for solar concentrators are compared; environmental and processing-related challenges related to dust and optical surfaces are addressed. This brief technology survey examines various sources of thermal energy that can be utilized for materials processing on the lunar surface. These include heat from nuclear or electric sources and solar concentrators. Options for collecting and transporting thermal energy to processing reactors for each source are examined. Overall system requirements for each thermal source are compared and system limitations, such as maximum achievable temperature are discussed.

  20. Feasible Modified Subgradient Method for Solving the Thermal Unit Commitment Problem as a New Approach

    Directory of Open Access Journals (Sweden)

    Ummuhan Basaran Filik

    2010-01-01

    Full Text Available The Lagrangian relaxation- (LR- based methods are commonly used to solve the thermal unit commitment (UC problem which is an important subject in power system engineering. The main drawback of this group of methods is the difference between the dual and the primal solutions which gives some significant problems on the quality of the feasible solutions. In this paper, a new approach, feasible modified subgradient (F-MSG method which does not require finding an unconstrained global minimum of the Lagrangian function and knowing an optimal value of the problem under consideration in order to update dual variables at the each iteration, is firstly used for solving the thermal UC problem. The major advantage of the proposed approach is that it guarantees the zero duality gap and convergence independently from the size of the problem. In order to discuss the advantages of this method, the four-unit Tuncbilek thermal plant, which is located in Kutahya region in Turkey, is chosen as a small test system. The numerical results show that F-MSG gives better solutions as compared to the standard LR method.

  1. Application of the SHARP Toolkit to Sodium-Cooled Fast Reactor Challenge Problems

    Energy Technology Data Exchange (ETDEWEB)

    Shemon, E. R. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Yu, Y. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division; Kim, T. K. [Argonne National Lab. (ANL), Argonne, IL (United States). Nuclear Engineering Division

    2017-09-30

    The Simulation-based High-efficiency Advanced Reactor Prototyping (SHARP) toolkit is under development by the Nuclear Energy Advanced Modeling and Simulation (NEAMS) Campaign of the U.S. Department of Energy, Office of Nuclear Energy. To better understand and exploit the benefits of advanced modeling simulations, the NEAMS Campaign initiated the “Sodium-Cooled Fast Reactor (SFR) Challenge Problems” task, which include the assessment of hot channel factors (HCFs) and the demonstration of zooming capability using the SHARP toolkit. If both challenge problems are resolved through advanced modeling and simulation using the SHARP toolkit, the economic competitiveness of a SFR can be significantly improved. The efforts in the first year of this project focused on the development of computational models, meshes, and coupling procedures for multi-physics calculations using the neutronics (PROTEUS) and thermal-hydraulic (Nek5000) components of the SHARP toolkit, as well as demonstration of the HCF calculation capability for the 100 MWe Advanced Fast Reactor (AFR-100) design. Testing the feasibility of the SHARP zooming capability is planned in FY 2018. The HCFs developed for the earlier SFRs (FFTF, CRBR, and EBR-II) were reviewed, and a subset of these were identified as potential candidates for reduction or elimination through high-fidelity simulations. A one-way offline coupling method was used to evaluate the HCFs where the neutronics solver PROTEUS computes the power profile based on an assumed temperature, and the computational fluid dynamics solver Nek5000 evaluates the peak temperatures using the neutronics power profile. If the initial temperature profile used in the neutronics calculation is reasonably accurate, the one-way offline method is valid because the neutronics power profile has weak dependence on small temperature variation. In order to get more precise results, the proper temperature profile for initial neutronics calculations was obtained from the

  2. Prediction of the thermal conductivity of metal hydrides - The inverse problem

    Energy Technology Data Exchange (ETDEWEB)

    Ghafir, Mohd Fahmi Abdul; Batcha, Mohd Faizal Mohideen [Faculty of Mechanical Engineering, University Tun Hussein Onn Malaysia, 86400 Parit Raja, Johor (Malaysia); Raghavan, Vijay R. [Department of Mechanical Engineering, University Technology Petronas, Bandar Seri Iskander, 31750 Tronoh, Perak (Malaysia)

    2009-08-15

    With sustainability as an important and driving theme, not merely of research, but that of our existence itself, the effort in developing sustainable systems takes many directions. One of these directions is in the transport sector, particularly personal transport using hydrogen as fuel, which logically leads on to the problem of hydrogen storage. This paper deals with the prediction of the effective conductivity of beds of metal hydride for hydrogen storage. To enable modeling of the effective thermal conductivity of these systems, it is necessary to arrive at the functional dependence of the thermal conductivity of the solid hydride on its hydrogen concentration or content. This is the inverse problem in thermal conductivity of multiphase materials. Inverse methods in general are those where we start from known consequences in order to find unknown causes. Using published and known data of the effective thermal conductivity of the hydride-hydrogen assemblage, we arrive at the unknown hydride conductivity by analysis. Among the models available in the literature for determination of the effective conductivity of the bed from the properties of the constituent phases, the model of Raghavan and Martin is chosen for the analysis as it combines simplicity and physical rigor. The result is expected to be useful for predicting the thermal conductivity of hydride particles and determining the optimum heat transfer rates governing the absorption and desorption rates of hydrogen in the storage system. (author)

  3. Problem-Based Learning in Biomechanics: Advantages, Challenges, and Implementation Strategies.

    Science.gov (United States)

    Clyne, Alisa Morss; Billiar, Kristen L

    2016-07-01

    Problem-based learning (PBL) has been shown to be effective in biomedical engineering education, particularly in motivating student learning, increasing knowledge retention, and developing problem solving, communication, and teamwork skills. However, PBL adoption remains limited by real challenges in effective implementation. In this paper, we review the literature on advantages and challenges of PBL and present our own experiences. We also provide practical guidelines for implementing PBL, including two examples of PBL modules from biomechanics courses at two different institutions. Overall, we conclude that the benefits for both professors and students support the use of PBL in biomedical engineering education.

  4. Grand challenge problems in environmental modeling and remediation: Groundwater contaminant transport. Final project report 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997.

  5. Benefits and Challenges when Performing Robust Topology Optimization for Interior Acoustic Problems

    DEFF Research Database (Denmark)

    Christiansen, Rasmus Ellebæk; Jensen, Jakob Søndergaard; Lazarov, Boyan Stefanov

    The objective of this work is to present benets and challenges of using robust topology optimization techniques for minimizing the sound pressure in interior acoustic problems. The focus is on creating designs which maintain high performance under uniform spatial variations. This work takes offset...... in previous work considering topology optimization for interior acoustic problems, [1]. However in the previous work the robustness of the designs was not considered....

  6. Grand challenge problems in environmental modeling and remediation: groundwater contaminant transport

    Energy Technology Data Exchange (ETDEWEB)

    Todd Arbogast; Steve Bryant; Clint N. Dawson; Mary F. Wheeler

    1998-08-31

    This report describes briefly the work of the Center for Subsurface Modeling (CSM) of the University of Texas at Austin (and Rice University prior to September 1995) on the Partnership in Computational Sciences Consortium (PICS) project entitled Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport.

  7. Transforming Traditional Lectures into Problem-Based Blended Learning: Challenges and Experiences

    Science.gov (United States)

    Dalsgaard, Christian; Godsk, Mikkel

    2007-01-01

    This paper presents our experiences and the challenges identified in transforming traditional lecture-based modules at a university into problem-based blended learning within a social constructivist approach. Our experiment was, among other factors, motivated by an urgent need to meet new curriculum requirements by reducing the lecturing time in a…

  8. Fourth-Grade Primary School Students' Thought Processes and Challenges Encountered during the Butter Beans Problem

    Science.gov (United States)

    Sahin, Neslihan; Eraslan, Ali

    2017-01-01

    In parallel with mathematical modeling studies that have gradually drawn interest in recent years, the aim of this study is to investigate the thought processes of fourth-grade students in the Butter Beans Problem and to identify possible challenges in this process. For this purpose, a qualitative study was conducted at a university-foundation…

  9. Graded meshes in bio-thermal problems with transmission-line modeling method.

    Science.gov (United States)

    Milan, Hugo F M; Carvalho, Carlos A T; Maia, Alex S C; Gebremedhin, Kifle G

    2014-10-01

    In this study, the transmission-line modeling (TLM) applied to bio-thermal problems was improved by incorporating several novel computational techniques, which include application of graded meshes which resulted in 9 times faster in computational time and uses only a fraction (16%) of the computational resources used by regular meshes in analyzing heat flow through heterogeneous media. Graded meshes, unlike regular meshes, allow heat sources to be modeled in all segments of the mesh. A new boundary condition that considers thermal properties and thus resulting in a more realistic modeling of complex problems is introduced. Also, a new way of calculating an error parameter is introduced. The calculated temperatures between nodes were compared against the results obtained from the literature and agreed within less than 1% difference. It is reasonable, therefore, to conclude that the improved TLM model described herein has great potential in heat transfer of biological systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. A scope of the problem: Post-deployment reintegration challenges in a National Guard Unit.

    Science.gov (United States)

    Wilcox, Sherrie L; Oh, Hyunsung; Redmond, Sarah A; Chicas, Joseph; Hassan, Anthony M; Lee, Pey-Jiuan; Ell, Kathleen

    2015-01-01

    More Reserve and Guard members have been activated in the past few years than in any other time in history. In addition to the high rates of psychological and behavioral challenges among military personnel, there are other equally important post-deployment reintegration challenges. Post-deployment reintegration challenges are particularly important to Reserve and Guard members, who transition rapidly from civilian-military-civilian. This study aims to describe the scope of challenges that a battalion of National Guard members (NGM) report experiencing after returning from a one-year deployment to Iraq. This article reports data from a sample of 126 NGM who recently returned from a one-year deployment to Iraq. The scope of post-deployment problems at baseline, 3- and 6-month post-deployment are presented. Overall, the rates of post-deployment psychological and behavioral problems were elevated upon returning from deployment and remained fairly constant for up to 6 months post-deployment. Approximately 30% of respondents were unsatisfied with their relationship and upwards of 30% reported family reintegration challenges. Comparisons with similar research and implications for prevention and improvement of post-deployment quality of life are addressed.

  11. Response of turkey muscle satellite cells to thermal challenge. I. transcriptome effects in proliferating cells.

    Science.gov (United States)

    Reed, Kent M; Mendoza, Kristelle M; Abrahante, Juan E; Barnes, Natalie E; Velleman, Sandra G; Strasburg, Gale M

    2017-05-06

    Climate change poses a multi-dimensional threat to food and agricultural systems as a result of increased risk to animal growth, development, health, and food product quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells cultured under cold or hot thermal challenge to better define molecular mechanisms by which thermal stress alters breast muscle ultrastructure. Satellite cells isolated from the pectoralis major muscle of 7-weeks-old male turkeys from two breeding lines (16 weeks body weight-selected and it's randombred control) were proliferated in culture at 33 °C, 38 °C or 43 °C for 72 h. Total RNA was isolated and 12 libraries subjected to RNAseq analysis. Statistically significant differences in gene expression were observed among treatments and between turkey lines with a greater number of genes altered by cold treatment than by hot and fewer differences observed between lines than between temperatures. Pathway analysis found that cold treatment resulted in an overrepresentation of genes involved in cell signaling/signal transduction and cell communication/cell signaling as compared to control (38 °C). Heat-treated muscle satellite cells showed greater tendency towards expression of genes related to muscle system development and differentiation. This study demonstrates significant transcriptome effects on turkey skeletal muscle satellite cells exposed to thermal challenge. Additional effects on gene expression could be attributed to genetic selection for 16 weeks body weight (muscle mass). New targets are identified for further research on the differential control of satellite cell proliferation in poultry.

  12. Technological Solutions to Social and Citizen Problems. The Case of Civic and Public Challenges in Mexico

    Directory of Open Access Journals (Sweden)

    Martin Adalberto TENA-ESPINOZA-DE-LOS-MONTEROS

    2017-04-01

    Full Text Available This paper describes the process of civic innovation that, based on technological solutions and open initiatives, the civic society’s organization Codeando México suggests for the attention and solution of social and civic problems in Mexico. The Retos Cívicos (Civic Challenges and Retos Públicos (Public Challenges initiatives are addressed and described as experiences of innovation in the implementation of technological strategies for the solution of social and civic problems. A reflection is made on the civic appropriation of the ICTs and its irruption in the processes of innovation, as well as on the impact that the ICTs have in the conformation of a new civic ecosystem. Last, the strategies of Hacking cívico (Civic Hacking and Comunidades Cívicas (Civic Communities that the Codeando México organization promotes as a model for the linkage and civic participation within the frame of civic innovation, are mentioned.

  13. ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) solutions to developmental assessment problems

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, K.E.; Ransom, V.H.; Roth, P.A.

    1987-03-01

    The ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) code has been developed to perform transient simulation of the thermal hydraulic systems that may be found in fusion reactors, space reactors, and other advanced systems. As an assessment of current capability the code was applied to a number of physical problems, both conceptual and actual experiments. Results indicate that the numerical solution to the basic conservation equations is technically sound, and that generally good agreement can be obtained when modeling relevant hydrodynamic experiments. The assessment also demonstrates basic fusion system modeling capability and verifies compatibility of the code with both CDC and CRAY mainframes. Areas where improvements could be made include constitutive modeling, which describes the interfacial exchange term. 13 refs., 84 figs.

  14. Health Futures Lab -Transdisciplinary development of T shaped professionals through wicked problem challenges

    OpenAIRE

    De Eyto, Adam; Ryan, Annmarie; McMahon, Muireann; Hassett, Grainne; Flynn, Morgan

    2015-01-01

    non-peer-reviewed It is clear that significant differences in approach and enquiry are apparent between the established disciplines of Design, Engineering, Business and Health Sciences. The attempt to tackle Wicked Problems (Rittel and Webber 1973) has become a challenge for universities and policy makers throughout the world yet we are only beginning to appreciate the impact that transdisciplinary collaboration can have. This paper outlines a case study in transdisci...

  15. Problems of reliability and economy work of thermal power plants water treatment based on baromembrane technologies

    Science.gov (United States)

    Chichirova, N. D.; Chichirov, A. A.; Saitov, S. R.

    2017-11-01

    The introduction of baromembrane water treatment technologies for water desalination at Russian thermal power plants was beganed more than 25 years ago. These technologies have demonstrated their definite advantage over the traditional technologies of additional water treatment for steam boilers. However, there are problems associated with the reliability and economy of their work. The first problem is a large volume of waste water (up to 60% of the initial water). The second problem a expensive and unique chemical reagents complex (biocides, antiscalants, washing compositions) is required for units stable and troublefree operation. Each manufacturer develops his own chemical composition for a certain membrane type. This leads to a significant increase in reagents cost, as well as creates dependence of the technology consumer on the certain supplier. The third problem is that the reliability of the baromembrane units depends directly on the water preliminary treatment. The popular pre-cleaning technology with coagulation of aluminum oxychloride proves to be unacceptable during seasonal changes in the quality of the source water at a number of stations. As a result, pollution, poisoning and lesion of the membrane structure or deterioration of their mechanical properties are observed. The report presents ways to solve these problems.

  16. Extensive transcriptional variation poses a challenge to thermal stress biomarker development for endangered corals.

    Science.gov (United States)

    Parkinson, John Everett; Bartels, Erich; Devlin-Durante, Meghann K; Lustic, Caitlin; Nedimyer, Ken; Schopmeyer, Stephanie; Lirman, Diego; LaJeunesse, Todd C; Baums, Iliana B

    2018-02-07

    As climate changes, sea surface temperature anomalies that negatively impact coral reef organisms continue to increase in frequency and intensity. Yet, despite widespread coral mortality, genetic diversity remains high even in those coral species listed as threatened. While this is good news in many ways it presents a challenge for the development of biomarkers that can identify resilient or vulnerable genotypes. Taking advantage of three coral restoration nurseries in Florida that serve as long-term common garden experiments, we exposed over thirty genetically distinct Acropora cervicornis colonies to hot and cold temperature shocks seasonally and measured pooled gene expression responses using RNAseq. Targeting a subset of twenty genes, we designed a high-throughput qPCR array to quantify expression in all individuals separately under each treatment with the goal of identifying predictive and/or diagnostic thermal stress biomarkers. We observed extensive transcriptional variation in the population, suggesting abundant raw material is available for adaptation via natural selection. However, this high variation made it difficult to correlate gene expression changes with colony performance metrics such as growth, mortality, and bleaching susceptibility. Nevertheless, we identified several promising diagnostic biomarkers for acute thermal stress that may improve coral restoration and climate change mitigation efforts in the future. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  17. Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens.

    Science.gov (United States)

    LeBlanc, Stephanie; Tobalske, Bret; Quinton, Margaret; Springthorpe, Dwight; Szkotnicki, Bill; Wuerbel, Hanno; Harlander-Matauschek, Alexandra

    2016-01-01

    With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad dermatitis, keel damage, poor wing feather cover; n = 15) using a series of environmental challenges and compared such abilities with those of healthy birds (n = 5). Environmental challenges consisted of visual and spatial constraints, created using a head mask, perch obstacles, and static and swaying perch states. We hypothesized that perch movement, environmental challenges, and diminished physical health would negatively impact perching performance demonstrated as balance (as measured by time spent on perch and by number of falls of the perch) and would require more exaggerated correctional movements. We measured perching stability whereby each bird underwent eight 30-second trials on a static and swaying perch: with and without disrupted vision (head mask), with and without space limitations (obstacles) and combinations thereof. Video recordings (600 Hz) and a three-axis accelerometer/gyroscope (100 Hz) were used to measure the number of jumps/falls, latencies to leave the perch, as well as magnitude and direction of both linear and rotational balance-correcting movements. Laying hens with and without physical health problems, in both challenged and unchallenged environments, managed to perch and remain off the ground. We attribute this capacity to our training of the birds. Environmental challenges and physical state had an effect on the use of accelerations and rotations to stabilize themselves on a perch. Birds with physical health problems performed a higher frequency of rotational corrections to keep the body centered over the perch, whereas, for both health categories

  18. Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens

    Science.gov (United States)

    LeBlanc, Stephanie; Tobalske, Bret; Quinton, Margaret; Springthorpe, Dwight; Szkotnicki, Bill; Wuerbel, Hanno; Harlander-Matauschek, Alexandra

    2016-01-01

    With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad dermatitis, keel damage, poor wing feather cover; n = 15) using a series of environmental challenges and compared such abilities with those of healthy birds (n = 5). Environmental challenges consisted of visual and spatial constraints, created using a head mask, perch obstacles, and static and swaying perch states. We hypothesized that perch movement, environmental challenges, and diminished physical health would negatively impact perching performance demonstrated as balance (as measured by time spent on perch and by number of falls of the perch) and would require more exaggerated correctional movements. We measured perching stability whereby each bird underwent eight 30-second trials on a static and swaying perch: with and without disrupted vision (head mask), with and without space limitations (obstacles) and combinations thereof. Video recordings (600 Hz) and a three-axis accelerometer/gyroscope (100 Hz) were used to measure the number of jumps/falls, latencies to leave the perch, as well as magnitude and direction of both linear and rotational balance-correcting movements. Laying hens with and without physical health problems, in both challenged and unchallenged environments, managed to perch and remain off the ground. We attribute this capacity to our training of the birds. Environmental challenges and physical state had an effect on the use of accelerations and rotations to stabilize themselves on a perch. Birds with physical health problems performed a higher frequency of rotational corrections to keep the body centered over the perch, whereas, for both health categories

  19. Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens.

    Directory of Open Access Journals (Sweden)

    Stephanie LeBlanc

    Full Text Available With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad dermatitis, keel damage, poor wing feather cover; n = 15 using a series of environmental challenges and compared such abilities with those of healthy birds (n = 5. Environmental challenges consisted of visual and spatial constraints, created using a head mask, perch obstacles, and static and swaying perch states. We hypothesized that perch movement, environmental challenges, and diminished physical health would negatively impact perching performance demonstrated as balance (as measured by time spent on perch and by number of falls of the perch and would require more exaggerated correctional movements. We measured perching stability whereby each bird underwent eight 30-second trials on a static and swaying perch: with and without disrupted vision (head mask, with and without space limitations (obstacles and combinations thereof. Video recordings (600 Hz and a three-axis accelerometer/gyroscope (100 Hz were used to measure the number of jumps/falls, latencies to leave the perch, as well as magnitude and direction of both linear and rotational balance-correcting movements. Laying hens with and without physical health problems, in both challenged and unchallenged environments, managed to perch and remain off the ground. We attribute this capacity to our training of the birds. Environmental challenges and physical state had an effect on the use of accelerations and rotations to stabilize themselves on a perch. Birds with physical health problems performed a higher frequency of rotational corrections to keep the body centered over the perch, whereas, for both

  20. Response of Turkey Muscle Satellite Cells to Thermal Challenge. II. Transcriptome Effects in Differentiating Cells

    Directory of Open Access Journals (Sweden)

    Kent M. Reed

    2017-11-01

    Full Text Available Background: Exposure of poultry to extreme temperatures during the critical period of post-hatch growth can seriously affect muscle development and thus compromise subsequent meat quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells by thermal challenge during differentiation. Our goal is to better define how thermal stress alters breast muscle ultrastructure and subsequent development.Results: Skeletal muscle satellite cells previously isolated from the Pectoralis major muscle of 7-wk-old male turkeys (Meleagris gallopavo from two breeding lines: the F-line (16 wk body weight-selected and RBC2 (randombred control line were used in this study. Cultured cells were induced to differentiate at 38°C (control or thermal challenge temperatures of 33 or 43°C. After 48 h of differentiation, cells were harvested and total RNA was isolated for RNAseq analysis. Analysis of 39.9 Gb of sequence found 89% mapped to the turkey genome (UMD5.0, annotation 101 with average expression of 18,917 genes per library. In the cultured satellite cells, slow/cardiac muscle isoforms are generally present in greater abundance than fast skeletal isoforms. Statistically significant differences in gene expression were observed among treatments and between turkey lines, with a greater number of genes affected in the F-line cells following cold treatment whereas more differentially expressed (DE genes were observed in the RBC2 cells following heat treatment. Many of the most significant pathways involved signaling, consistent with ongoing cellular differentiation. Regulation of Ca2+ homeostasis appears to be significantly affected by temperature treatment, particularly cold treatment.Conclusions: Satellite cell differentiation is directly influenced by temperature at the level of gene transcription with greater effects attributed to selection for fast growth. At lower temperature, muscle-associated genes in the

  1. Medicines counterfeiting is a complex problem: a review of key challenges across the supply chain.

    Science.gov (United States)

    Tremblay, Michael

    2013-02-01

    The paper begins by asking why there is a market for counterfeit medicines, which in effect creates the problem of counterfeiting itself. Contributing factors include supply chain complexity and the lack of whole-systems thinking. These two underpin the author's view that counterfeiting is a complex (i.e. wicked) problem, and that corporate, public policy and regulatory actions need to be mindful of how their actions may be causal. The paper offers a problem-based review of key components of this complexity, viz., the knowledge end-users/consumers have of medicines; whether restrictive information policies may hamper information provision to patients; the internet's direct access to consumers; internet-enabled distribution of unsafe and counterfeit medicines; whether the internet is a parallel and competitive supply chain to legitimate routes; organised crime as an emerging medicines manufacturer and supplier and whether substandard medicines is really the bigger problem. Solutions respect the perceived complexity of the supply chain challenges. The paper identifies the need to avoid technologically-driven solutions, calling for 'technological agnosticism'. Both regulation and public policy need to reflect the dynamic nature of the problem and avoid creating perverse incentives; it may be, for instance, that medicines pricing and reimbursement policies, which affect consumer/patient access may act as market signals to counterfeiters, since this creates a cash market in cheaper drugs.

  2. Metaheuristic Algorithms Applied to Bioenergy Supply Chain Problems: Theory, Review, Challenges, and Future

    Directory of Open Access Journals (Sweden)

    Krystel K. Castillo-Villar

    2014-11-01

    Full Text Available Bioenergy is a new source of energy that accounts for a substantial portion of the renewable energy production in many countries. The production of bioenergy is expected to increase due to its unique advantages, such as no harmful emissions and abundance. Supply-related problems are the main obstacles precluding the increase of use of biomass (which is bulky and has low energy density to produce bioenergy. To overcome this challenge, large-scale optimization models are needed to be solved to enable decision makers to plan, design, and manage bioenergy supply chains. Therefore, the use of effective optimization approaches is of great importance. The traditional mathematical methods (such as linear, integer, and mixed-integer programming frequently fail to find optimal solutions for non-convex and/or large-scale models whereas metaheuristics are efficient approaches for finding near-optimal solutions that use less computational resources. This paper presents a comprehensive review by studying and analyzing the application of metaheuristics to solve bioenergy supply chain models as well as the exclusive challenges of the mathematical problems applied in the bioenergy supply chain field. The reviewed metaheuristics include: (1 population approaches, such as ant colony optimization (ACO, the genetic algorithm (GA, particle swarm optimization (PSO, and bee colony algorithm (BCA; and (2 trajectory approaches, such as the tabu search (TS and simulated annealing (SA. Based on the outcomes of this literature review, the integrated design and planning of bioenergy supply chains problem has been solved primarily by implementing the GA. The production process optimization was addressed primarily by using both the GA and PSO. The supply chain network design problem was treated by utilizing the GA and ACO. The truck and task scheduling problem was solved using the SA and the TS, where the trajectory-based methods proved to outperform the population

  3. Thermal Comfort and HVAC Systems Operation Challenges in a Modern Office Building - Case Study

    Science.gov (United States)

    Nemethova, Ema; Stutterecker, Werner; Schoberer, Thomas

    2016-12-01

    The aim of the study is to evaluate the indoor environment conditions in the new-built office building, Energetikum, and consequently suggest the control strategies, which can lead to determination of critical areas and elimination of thermal discomfort. Representative offices have been selected and equipped with portable sensor groups for monitoring of the indoor environment parameters. Contribution is presenting the data obtained from 6 selected rooms during 3 reference weeks - heating, transition and cooling period. The measured results indicate overheating of the rooms, particularly in the ones with the large glazed areas with higher solar gains. The values of indoor air temperature during heating and transition period could not meet the normative criteria according to standard EN 15251:2007 (the cat. II.) during 13 % - 49 % of evaluated time intervals. Consequently, the simulation model of the selected office was created and is pointing to the possibilities of the control system improvement, which can lead to an elimination of the problem with overheating.

  4. Dental health - a challenging problem for a patient with autism spectrum disorder.

    Science.gov (United States)

    Lu, Yuan-Yuan; Wei, I-Hua; Huang, Chih-Chia

    2013-01-01

    Patients with autism spectrum disorders (ASDs) are at an increased risk for many diseases. However, little has been published about the dental health of patients with ASDs. Here, we describe the clinical presentations in a 28-year-old woman with autistic disorder. The most striking finding was the severe dental problems which had been neglected for several years. Our patient exhibited a combination of several factors that may have increased the risk of development of severe dental problem. The early recognition is still challenging to managing this unusual condition in patients with ASDs. From the experience of caring for this patient, a team of parents or caregivers, psychiatrist and dentist should be involved in maintaining oral health care of such patients with early intervention and long-term follow-up. Evidence-based behavioral management approaches for patients with ASD need to be developed to improve compliance with oral care procedures. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. The Problems and Challenges of Managing Crowd Sourced Audio-Visual Evidence

    Directory of Open Access Journals (Sweden)

    Harjinder Singh Lallie

    2014-04-01

    Full Text Available A number of recent incidents, such as the Stanley Cup Riots, the uprisings in the Middle East and the London riots have demonstrated the value of crowd sourced audio-visual evidence wherein citizens submit audio-visual footage captured on mobile phones and other devices to aid governmental institutions, responder agencies and law enforcement authorities to confirm the authenticity of incidents and, in the case of criminal activity, to identify perpetrators. The use of such evidence can present a significant logistical challenge to investigators, particularly because of the potential size of data gathered through such mechanisms and the added problems of time-lining disparate sources of evidence and, subsequently, investigating the incident(s. In this paper we explore this problem and, in particular, outline the pressure points for an investigator. We identify and explore a number of particular problems related to the secure receipt of the evidence, imaging, tagging and then time-lining the evidence, and the problem of identifying duplicate and near duplicate items of audio-visual evidence.

  6. Review of concentrating solar thermal power industry in China: Status quo, problems, trend and countermeasures

    Science.gov (United States)

    Zou, Jiajun

    2018-01-01

    Concentrating solar thermal power (CSP) industry is a strategic emerging industry in China. Its further development is of great significance for promoting the energy revolution, achieving energy saving and emission reduction. In this paper, China’s CSP industry is systematically analysed. First of all, the status quo is elaborated from the perspectives of relevant policies and regulations, market and generation technology development. Secondly, the problems and the underlying reasons of China’s CSP industry are deeply studied. On this basis, the future trends of CSP are expounded on the three levels of policy, market and power generation technology. Finally, a series of feasible countermeasures are put forward, designed to promote the development of CSP industry and the transformation of energy structure.

  7. The NTF Inlet Guide Vanes Thermal Gradient Problem and Its Mitigation

    Science.gov (United States)

    Venkat, Venki S.; Paryz, Roman W.; Bissett, Owen W.; Kilgore, W.

    2013-01-01

    The National Transonic Facility (NTF) utilizes Inlet Guide Vanes (IGV) to provide precise, quick response Mach number control for the tunnel. During cryogenic operations, the massive IGV structure can experience large thermal gradients, measured as "Delta T or (Delta)T", between the IGV ring and its support structure called the transfer case. If these temperature gradients are too large, the IGV structure can be stressed beyond its safety limit and cease operation. In recent years, (Delta)T readings exceeding the prescribed safety limits were observed frequently during cryogenic operations, particularly during model access. The tactical operation methods of the tunnel to minimize (Delta)T did not always succeed. One obvious option to remedy this condition is to warm up the IGV structure by disabling the main drive operation, but this "natural" warm up method can takes days in some cases, resulting in productivity loss. This paper documents the thermal gradient problem associated with the IGV structure during cryogenic operation and how the facility has recently achieved an acceptable mitigation which has resulted in improved efficiency of operations.

  8. Simulation of Thermal Flow Problems via a Hybrid Immersed Boundary-Lattice Boltzmann Method

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    J. Wu

    2012-01-01

    Full Text Available A hybrid immersed boundary-lattice Boltzmann method (IB-LBM is presented in this work to simulate the thermal flow problems. In current approach, the flow field is resolved by using our recently developed boundary condition-enforced IB-LBM (Wu and Shu, (2009. The nonslip boundary condition on the solid boundary is enforced in simulation. At the same time, to capture the temperature development, the conventional energy equation is resolved. To model the effect of immersed boundary on temperature field, the heat source term is introduced. Different from previous studies, the heat source term is set as unknown rather than predetermined. Inspired by the idea in (Wu and Shu, (2009, the unknown is calculated in such a way that the temperature at the boundary interpolated from the corrected temperature field accurately satisfies the thermal boundary condition. In addition, based on the resolved temperature correction, an efficient way to compute the local and average Nusselt numbers is also proposed in this work. As compared with traditional implementation, no approximation for temperature gradients is required. To validate the present method, the numerical simulations of forced convection are carried out. The obtained results show good agreement with data in the literature.

  9. mathematical model of thermal explosion, the dual variational formulation of nonlinear problem, alternative functional

    Directory of Open Access Journals (Sweden)

    V. S. Zarubin

    2016-01-01

    in its plane, and in the circular cylinder unlimited in length.An approximate numerical solution of the differential equation that is included in a nonlinear mathematical model of the thermal explosion enables us to obtain quantitative estimates of combination of determining parameters at which the limit state occurs in areas of not only canonical form. A capability to study of the thermal explosion state can be extended in the context of development of mathematical modeling methods, including methods of model analysis to describe the thermal state of solids.To analyse a mathematical model of the thermal explosion in a homogeneous solid the paper uses a variational approach based on the dual variational formulation of the appropriate nonlinear stationary problem of heat conduction in such a body. This formulation contains two alternative functional reaching the matching values in their stationary points corresponding to the true temperature distribution. This functional feature allows you to not only get an approximate quantitative estimate of the combination of parameters that determine the thermal explosion state, but also to find the greatest possible error in such estimation.

  10. Rethinking the globalisation of problem-based learning: how culture challenges self-directed learning.

    Science.gov (United States)

    Frambach, Janneke M; Driessen, Erik W; Chan, Li-Chong; van der Vleuten, Cees P M

    2012-08-01

    Medical schools worldwide are increasingly switching to student-centred methods such as problem-based learning (PBL) to foster lifelong self-directed learning (SDL). The cross-cultural applicability of these methods has been questioned because of their Western origins and because education contexts and learning approaches differ across cultures. This study evaluated PBL's cross-cultural applicability by investigating how it is applied in three medical schools in regions with different cultures in, respectively, East Asia, the Middle East and Western Europe. Specifically, it investigated how students' cultural backgrounds impact on SDL in PBL and how this impact affects students. A qualitative, cross-cultural, comparative case study was conducted in three medical schools. Data were collected through 88 semi-structured, in-depth interviews with Year 1 and 3 students, tutors and key persons involved in PBL, 32 observations of Year 1 and 3 PBL tutorials, document analysis, and contextual information. The data were thematically analysed using the template analysis method. Comparisons were made among the three medical schools and between Year 1 and 3 students across and within the schools. The cultural factors of uncertainty and tradition posed a challenge to Middle Eastern students' SDL. Hierarchy posed a challenge to Asian students and achievement impacted on both sets of non-Western students. These factors were less applicable to European students, although the latter did experience some challenges. Several contextual factors inhibited or enhanced SDL across the cases. As students grew used to PBL, SDL skills increased across the cases, albeit to different degrees. Although cultural factors can pose a challenge to the application of PBL in non-Western settings, it appears that PBL can be applied in different cultural contexts. However, its globalisation does not postulate uniform processes and outcomes, and culturally sensitive alternatives might be developed.

  11. Interpreting the Bible in the 'new' South Africa: Remarks on some problems and challenges

    Directory of Open Access Journals (Sweden)

    D. J. Human

    1997-12-01

    Full Text Available Interpreting the Bible in the 'new' South Africa DJ Human Department of Biblical Studies (Sec B University of Pretoria The Bible plays an important role in South African society. The interpretation of this book within or outside the Christian community has become an increaslingly major source of debate. It has been used and misused in several spheres of society. This article does not intend providing an extensive and composite picture of the problems and character of biblical hermeneutics. Nor will it attempt to elaborate on or explain the origins, development and influences of all the different her-meneutical approaches. Rather, it poses to be an introduction to a few of the problem(s encountered in the attempt to understand the Bible, especially in terms of the 'new' South Africa. Within the framework of this scope, remarks will be made regarding the challenges involved in interpreting the Bible, the role of the interpreter in the interpretation process, the varied forms of literature to be found in Scripture, and in the last instance, to take cognisance of a few methodological approaches to the text analysis of the Bible.

  12. Interpreting the Bible in the 'new' South Africa: Remarks on some problems and challenges

    Directory of Open Access Journals (Sweden)

    D. J. Human

    1997-01-01

    Full Text Available Interpreting the Bible in the 'new' South Africa DJ Human Department of Biblical Studies (Sec B University of Pretoria The Bible plays an important role in South African society. The interpretation of this book within or outside the Christian community has become an increaslingly major source of debate. It has been used and misused in several spheres of society. This article does not intend providing an extensive and composite picture of the problems and character of biblical hermeneutics. Nor will it attempt to elaborate on or explain the origins, development and influences of all the different her-meneutical approaches. Rather, it poses to be an introduction to a few of the problem(s encountered in the attempt to understand the Bible, especially in terms of the 'new' South Africa. Within the framework of this scope, remarks will be made regarding the challenges involved in interpreting the Bible, the role of the interpreter in the interpretation process, the varied forms of literature to be found in Scripture, and in the last instance, to take cognisance of a few methodological approaches to the text analysis of the Bible.

  13. Three-dimensional potentials for a telegrapher's equation and their application to boundary problems of thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, I.A.

    1979-01-01

    A mathematical solution is worked out for solving direct and inverse linear boundary problems on thermal conductivity where the heat transfer process is assumed to occur at a finite velocity. Three-dimensional potentials for a simple and binary layers and volume are introduced for the telegrapher's equation. Within the limiting cases of a parabolic and wave equation, they transfer to the corresponding heat and wave potentials. The introduced potentials make it possible to reduce the internal boundary problems of thermal conductivity to second order integral-differential equations. In addition, the potentials of the telegrapher's equation are used to reduce a linear three-dimensional boundary inverse problem on thermal conductivity to a system composed of integral-differential equations of the second order and a certain integral condition for two coordinate and time functions. 9 references.

  14. SU-E-J-161: Inverse Problems for Optical Parameters in Laser Induced Thermal Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Fahrenholtz, SJ; Stafford, RJ; Fuentes, DT [UT MD Anderson Cancer Center, Houston, TX (United States); UT Graduate School of Biomedical Sciences, Houston, TX (United States)

    2014-06-01

    Purpose: Magnetic resonance-guided laser-induced thermal therapy (MRgLITT) is investigated as a neurosurgical intervention for oncological applications throughout the body by active post market studies. Real-time MR temperature imaging is used to monitor ablative thermal delivery in the clinic. Additionally, brain MRgLITT could improve through effective planning for laser fiber's placement. Mathematical bioheat models have been extensively investigated but require reliable patient specific physical parameter data, e.g. optical parameters. This abstract applies an inverse problem algorithm to characterize optical parameter data obtained from previous MRgLITT interventions. Methods: The implemented inverse problem has three primary components: a parameter-space search algorithm, a physics model, and training data. First, the parameter-space search algorithm uses a gradient-based quasi-Newton method to optimize the effective optical attenuation coefficient, μ-eff. A parameter reduction reduces the amount of optical parameter-space the algorithm must search. Second, the physics model is a simplified bioheat model for homogeneous tissue where closed-form Green's functions represent the exact solution. Third, the training data was temperature imaging data from 23 MRgLITT oncological brain ablations (980 nm wavelength) from seven different patients. Results: To three significant figures, the descriptive statistics for μ-eff were 1470 m{sup −1} mean, 1360 m{sup −1} median, 369 m{sup −1} standard deviation, 933 m{sup −1} minimum and 2260 m{sup −1} maximum. The standard deviation normalized by the mean was 25.0%. The inverse problem took <30 minutes to optimize all 23 datasets. Conclusion: As expected, the inferred average is biased by underlying physics model. However, the standard deviation normalized by the mean is smaller than literature values and indicates an increased precision in the characterization of the optical parameters needed to plan MRg

  15. On benchmark problems, challenges, and competitions in electrokinetics-A review.

    Science.gov (United States)

    Hurák, Zdeněk; Foret, František

    2015-07-01

    In this critical review, we comment on the absence of widely shared benchmark problems and relevant challenges or even attractive competitions in the field of electrokinetics. We argue that in some other scientific domains that are, similarly as electrokinetics, strongly multidisciplinary, the existence of these tools is very beneficial because it stimulates the discussion about what constitutes the bottleneck of further progress, allows easier exploitation of results provided by other scientific and engineering disciplines, and, last but not least, makes the research domain attractive and visible to a broader public, including students. The goal of this review is to provoke some discussion that might perhaps lead to compensating for these shortcomings. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. PENINGKATAN KEMAMPUAN CREATIVE PROBLEM SOLVING MATEMATIS SISWA SMP DENGAN PENDEKATAN CHALLENGE BASED LEARNING

    Directory of Open Access Journals (Sweden)

    Selviana Junita

    2016-11-01

    Penelitian ini bertujuan untuk menelaah pencapaian dan peningkatan kemampuan creative problem solving (CPS matematis siswa ditinjau secara keseluruhan maupun gender. Sampel penelitian adalah siswa kelas VIII di salah satu sekolah menengah pertama di Kabupaten Bandung. Kelas eksperimen belajar dengan pendekatan challenge based learning (CBL dan kelas kontrol belajar dengan pendekatan saintifik. Instrumen yang digunakan adalah tes kemampuan CPS matematis. Data yang diperoleh kemudian dianalisis secara statistik. Hasil penelitian menunjukkan bahwa pencapaian dan peningkatan kemampuan CPS matematis siswa yang belajar dengan pendekatan CBL lebih baik daripada siswa yang belajar dengan pendekatan saintifik baik siswa laki-laki ( p= 0,001; p< 0,05 ataupun siswa perempuan (p= 0,0015; p< 0,05. Dalam hal aspek CPS matematis, aspek terkuat yang dimiliki siswa adalah aspek fact finding sedangkan aspek CPS matematis ter-lemah adalah aspek acceptance finding.

  17. Methods for analysis and synthesis of technological schemes of thermal power plants based on solving auxiliary problems of linear programming

    Science.gov (United States)

    Kler, A. M.; Maximov, A. S.; Epishkin, N. O.

    2017-09-01

    The paper describes the developed method for analyzing technological schemes of thermal power plants based on solving problems of auxiliary linear programming. This method involves solving the linear programming problems to evaluate the effect of supply and removal of heat or material flows of various sizes at different points of the technological scheme of a thermal power plant (TPP). The method effectiveness is demonstrated by the example of the coaldust steam turbine unit with nominal electrical output of 660 MW. As a result of its application, the change of the technological scheme of the unit was found to provide reduction in electricity cost by 0.3%.

  18. Current challenges for confronting the public health problem of snakebite envenoming in Central America

    Science.gov (United States)

    2014-01-01

    Snakebite envenoming is a serious public health problem in Central America, where approximately 5,500 cases occur every year. Panama has the highest incidence and El Salvador the lowest. The majority, and most severe, cases are inflicted by the pit viper Bothrops asper (family Viperidae), locally known as ‘terciopelo’, ‘barba amarilla’ or ‘equis’. About 1% of the bites are caused by coral snakes of the genus Micrurus (family Elapidae). Despite significant and successful efforts in Central America regarding snakebite envenomings in the areas of research, antivenom manufacture and quality control, training of health professionals in the diagnosis and clinical management of bites, and prevention of snakebites, much remains to be done in order to further reduce the impact of this medical condition. This essay presents seven challenges for improving the confrontation of snakebite envenoming in Central America. Overcoming these challenges demands a coordinated partnership of highly diverse stakeholders though inter-sectorial and inter-programmatic interventions. PMID:24602234

  19. Celiac disease in the developing countries: A new and challenging public health problem

    Science.gov (United States)

    Cataldo, Francesco; Montalto, Giuseppe

    2007-01-01

    In the past, celiac disease was believed to be a chronic enteropathy, almost exclusively affecting people of European origin. The availability of new, simple, very sensitive and specific serological tests (anti-gliadin, anti-endomysium and anti-transglutaminase antibody assays) have shown that celiac disease is common not only in Europe and in people of European ancestry but also in the developing countries where the major staple diet is wheat (Southern Asia, the Middle East, North West and East Africa, South America), both in the general population and in the groups at risk. Gluten intolerance thus appears to be a widespread public health problem and an increased level of awareness and clinical suspicion are needed in the New World where physicians must learn to recognize the variable clinical presentations (classical, atypical and silent forms) of celiac disease. In the developing countries, both serological screening in the general population and serological testing in groups at risk are necessary for an early identification of celiac patients. The gluten-free diet poses a challenging public health problem in the developing countries, especially since commercial gluten-free products are not available. PMID:17465493

  20. National Qualifications Framework For Higher Education in Turkey, and Architectural Education: Problems and Challenges of Implementation

    Directory of Open Access Journals (Sweden)

    Emel AKÖZER

    2013-01-01

    Full Text Available The Council of Higher Education (CoHE adopted the National Qualifications Framework for Higher Education in Turkey (NQF-HETR in May 2009, as part of the Bologna reforms. In January 2010, the CoHE decided full implementation of the NQF-HETR at institutional and program levels and in this decision, it was foreseen that the process would be completed by the end of December 2012. The NQFHETR has been aligned both to the overarching Framework for Qualifications in the European Higher Education Area (QF-EHEA, 2005 and to the European Qualifications Framework for lifelong learning (EQF-LLL, 2008. The latter was introduced to facilitate the European cooperation in education and training, in line with the goals of the European Union's (EU Lisbon Strategy. This paper focuses on some of the problems that have become apparent during the NQF-HETR's implementation at the levels of “narrow fields of education” and architecture programs, and the challenges ahead. Following a discussion of the significance of the two European frameworks in light of the goals of the EHEA, the Education and Training 2010 work programme (ET 2010 and the strategic framework for European cooperation in Education and Training (ET 2020, it covers two problem areas concerning qualifications in architecture: i terminological and classificatory problems entailed by the NQF-HETR; ii the lack of alignment between the European qualifications frameworks and the EU Directive on the Recognition of Professional Qualifications (Directive EC/2005/36 that covers seven “sectoral professions” including architecture. The paper also reviews the latest developments for the modernization of the EU Directive in order to provide progression in forming an integrated European Higher Education Area.

  1. The "Diagnostic Guideline for Anxiety and Challenging Behaviour" for Persons with Intellectual Disabilities: Preliminary Outcomes on Internalizing Problems, Challenging Behaviours, Quality of Life and Clients' Satisfaction

    Science.gov (United States)

    Pruijssers, Addy; Meijel, Berno; Maaskant, Marian; Teerenstra, Steven; van Achterberg, Theo

    2017-01-01

    Background: People with intellectual disabilities are vulnerable to develop psychopathology (in particular anxiety) and related challenging behaviour. Method: A comparative multiple case study with an experimental and a control condition. Results: The application of the guideline showed a trend of decreases of internalizing problems (P = 0.07) and…

  2. Stabilized FE simulation of prototype thermal-hydraulics problems with integrated adjoint-based capabilities

    Science.gov (United States)

    Shadid, J. N.; Smith, T. M.; Cyr, E. C.; Wildey, T. M.; Pawlowski, R. P.

    2016-09-01

    A critical aspect of applying modern computational solution methods to complex multiphysics systems of relevance to nuclear reactor modeling, is the assessment of the predictive capability of specific proposed mathematical models. In this respect the understanding of numerical error, the sensitivity of the solution to parameters associated with input data, boundary condition uncertainty, and mathematical models is critical. Additionally, the ability to evaluate and or approximate the model efficiently, to allow development of a reasonable level of statistical diagnostics of the mathematical model and the physical system, is of central importance. In this study we report on initial efforts to apply integrated adjoint-based computational analysis and automatic differentiation tools to begin to address these issues. The study is carried out in the context of a Reynolds averaged Navier-Stokes approximation to turbulent fluid flow and heat transfer using a particular spatial discretization based on implicit fully-coupled stabilized FE methods. Initial results are presented that show the promise of these computational techniques in the context of nuclear reactor relevant prototype thermal-hydraulics problems.

  3. Potential and Challenges of Web-based Collective Intelligence to Tackle Societal Problems

    Directory of Open Access Journals (Sweden)

    Birutė Pitrėnaitė-Žilėnienė

    2014-03-01

    Full Text Available Purpose – to research what are conditions and challenges for collective intelligence (hereinafter – CI, i.e., emerging applying social technologies, to tackle societal problems. Several objectives were set in order to achieve the goal: to analyze the scientific concepts of CI and its contents; to summarize possibilities and challenges of application of CI in largescale online argumentation; following theoretical attitudes towards CI, to analyze Lithuanian praxis of application of CI technologies in large-scale online argumentation.Methodology – the methods of document analysis and content analysis of virtual community projects were applied. Theoretical analysis enabled recognition of CI phenomena and the variety of interpretations on CI as well as preconditions and difficulties to be tackled in order to ensure effective application of CI technologies in the processes of different policies design and/or societal problem solving. Having theoretical analysis as a base, the authors researched how the theoretical frameworks correspond to practices of Lithuanian virtual community projects, which are oriented to identification and analysis of relevant problems that communities are facing.Findings – scientific documents analysis demonstrates the variety of possible interpretations of CI. Such interpretations depend on the researcher’s attitudes towards this phenomenon: some authors explain CI in a very broad sense not including the aspects of social technologies. However, in the last decades, with the emergence of the Internet, social technologies have become concurrent dimension of CI. The main principles of Web-based CI are geographically spread users and a big number of them. Materialization of these principles ensures variety of elements needed for emerging of CI. There are diverse web-based mediums, where CI is being developed. However, not all of them ensure collective action, which is obligatory for CI. Researchers have analyzed

  4. Thermal Protection for Mars Sample Return Earth Entry Vehicle: A Grand Challenge for Design Methodology and Reliability Verification

    Science.gov (United States)

    Venkatapathy, Ethiraj; Gage, Peter; Wright, Michael J.

    2017-01-01

    Mars Sample Return is our Grand Challenge for the coming decade. TPS (Thermal Protection System) nominal performance is not the key challenge. The main difficulty for designers is the need to verify unprecedented reliability for the entry system: current guidelines for prevention of backward contamination require that the probability of spores larger than 1 micron diameter escaping into the Earth environment be lower than 1 million for the entire system, and the allocation to TPS would be more stringent than that. For reference, the reliability allocation for Orion TPS is closer to 11000, and the demonstrated reliability for previous human Earth return systems was closer to 1100. Improving reliability by more than 3 orders of magnitude is a grand challenge indeed. The TPS community must embrace the possibility of new architectures that are focused on reliability above thermal performance and mass efficiency. MSR (Mars Sample Return) EEV (Earth Entry Vehicle) will be hit with MMOD (Micrometeoroid and Orbital Debris) prior to reentry. A chute-less aero-shell design which allows for self-righting shape was baselined in prior MSR studies, with the assumption that a passive system will maximize EEV robustness. Hence the aero-shell along with the TPS has to take ground impact and not break apart. System verification will require testing to establish ablative performance and thermal failure but also testing of damage from MMOD, and structural performance at ground impact. Mission requirements will demand analysis, testing and verification that are focused on establishing reliability of the design. In this proposed talk, we will focus on the grand challenge of MSR EEV TPS and the need for innovative approaches to address challenges in modeling, testing, manufacturing and verification.

  5. New challenges and old problems: end of life care and the dilemma of prognostic accuracy.

    Science.gov (United States)

    Tanneberger, K S; Pannuti, F; Malavasi, I; Mariano, P; Strocchi, E

    2002-01-01

    Dignity of the natural end of life for everybody is one of the new great challenges of medicine and social care for the beginning 21st century. However, many end of life care providing doctors are confused about how to categorize the help they give. One of the central problems is predicting the life expectancy of an individual patient. Difficulties in this field can become ethical dilemmas when physicians are obliged to predict accurately a patient's prognosis as the basis for a certain care strategy. Clinical estimation of the duration of life for patients with end of life cancer needs experience and training. Education programmes in the field should include this topic much more until now. Prognosis should be based more on proven indices and less on intuition. However, there is no doubt that daily clinical practice limits the use of highly sophisticated computer-based score models. Even maximal accuracy of prognosis will not exclude the risk of errors in a great part of patients. This limits their classification in care categories too strictly defined. Health care systems should avoid models for care with standards and budgets based on prognostic estimates and the medical community should avoid claim by disciplines of certain categories of patients defined by their prognoses. What we need is a network of assistance for incurable patients with single parts defined by patients needs and not by predicted life expectancy. Separating palliative and terminal care is artificial and often in contrast to the needs of the patients.

  6. Changes, Problems, and Challenges in Swedish Spatial Planning—An Analysis of Power Dynamics

    Directory of Open Access Journals (Sweden)

    Till Koglin

    2017-10-01

    Full Text Available During the past few decades, the Swedish spatial planning system has experienced numerous problems and challenges. In particular, there have been changes in legislation and an increased neoliberalisation of planning that gives private actors a larger influence over the planning processes in Sweden. In this article, we analyse these changes through the lenses of collaborative and neoliberal planning in order to illuminate the shifting power relations within spatial planning in Sweden. We analyse the changes of power relations from three dimensions of power based on interviews with different kinds of planners throughout Sweden. We show that power relations in the Swedish spatial planning system have shifted and that neoliberalisation and an increased focus on collaborative planning approaches have made spatial planning more complex in recent decades. This has led to a change of role for planners form actual planners to collaborators. We conclude that market-oriented planning (neoliberal planning and collaborative planning have made it more difficult for spatial planners in Sweden to work towards sustainable urban futures.

  7. Contribution to the study of thermal-hydraulic problems in nuclear reactors; Contribution a l`etude de problemes de thermohydraulique dans les reacteurs nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cognet, G

    1998-07-07

    In nuclear reactors, whatever the type considered, Pressurized Water Water Reactors (PWRs), Fast Breeder reactors (FBRs)..., thermal-hydraulics, the science of fluid mechanics and thermal behaviour, plays an essential role, both in nominal operating and accidental conditions. Fluid can either be the primary fluid (liquid or gas) or a very specific fluid called corium, which, in case of severe accident, could result from core and environning structure melting. The work reported here represents a 20-year contribution to thermal-hydraulic issues which could occur in FBRs and PWRs. Working on these two types of reactors, both in nominal and severe accident situations, has allowed me to compare the problems and to realize the importance of communication between research teams. The evolution in the complexity of studied problems, unavoidable in order to reduce costs and significantly improve safety, has led me from numerical modelling of single-phase flow turbulence to high temperature real melt experiments. The difficulties encountered in understanding the observed phenomena and in increasing experimental databases for computer code qualification have often entailed my participation in specific measurement device developments or adaptations, in particular non-intrusive devices generally based on optical techniques. Being concerned about the end-use of this research work, I actively participated in `in-situ` thermalhydraulic experiments in the FBRs: Phenix and Super-Phenix, of which I appreciated their undeniable scientific contribution. In my opinion, the thermal-hydraulic questions related to severe accidents are the most complex as they are at the cross-roads of several scientific specialities. Consequently, they require a multi-disciplinary approach and a continuous see-saw motion between experimentalists and modelling teams. After a brief description of the various problems encountered, the main ones are reported. Finally, the importance for research teams to

  8. New option for solving the climatic problems with non-thermal laser driven boron fusion and ultrahigh magnetic fields

    CERN Document Server

    Hora, Heinrich

    2014-01-01

    In contrast to the broad stream of sustainable developments on fusion energy, new aspects are developed now by applying ultra-short, ultra-powerful laser pulses in a plasma-block ignition scheme by avoiding the well known difficulties of thermal-pressure instabilities and losses through using electro-dynamic non-thermal energy conversion. A further advantage is given by the new 10 kilo-Tesla magnetic fields for fusion of uncompressed proton-boron fuel which avoids problems of dangerous nuclear radiation.

  9. Enhancing Cross-functional Collaboration and Effective Problem Solving Through an Innovation Challenge for Point-of-Care Providers.

    Science.gov (United States)

    Bakallbashi, Eni; Vyas, Anjali; Vaswani, Nikita; Rosales, David; Russell, David; Dowding, Dawn; Bernstein, Michael; Abdelaal, Hany; Hawkey, Regina

    2015-01-01

    An internal employee challenge competition is a way to promote staff engagement and generate innovative business solutions. This Spotlight on Leadership focuses on the approach that a large not-for-profit healthcare organization, the Visiting Nurse Service of New York, took in designing and executing an innovation challenge. The challenge leveraged internal staff expertise and promoted wide participation. This model is 1 that can be replicated by organizations as leaders work to engage employees at the point of service in organization-wide problem solving.

  10. Problems With Self-Regulation, Family Conflict, and Glycemic Control in Adolescents Experiencing Challenges With Managing Type 1 Diabetes.

    Science.gov (United States)

    Vaid, Esha; Lansing, Amy Hughes; Stanger, Catherine

    2017-10-25

    This study explored the associations between problems with self-regulation and glycemic control (HbA1c) in teens experiencing challenges with managing type 1 diabetes by examining greater diabetes-related family conflict and poorer adherence as serial mediators of the link between greater problems with self-regulation and higher HbA1c. Teens experiencing challenges with managing type 1 diabetes (n = 93, HbA1c ≥8%, 96% White, 57% male) completed an HbA1c test, and their parents completed assessments including measures of adherence and family conflict related to diabetes management during an intake for a larger Web-based intervention study or fMRI study. Teen problems with self-regulation were indexed the Child Behavior Checklist using the dysregulation profile. Bivariate correlations found significant associations between greater problems with self-regulation, greater family conflict about diabetes management, poorer adherence, and higher HbA1c. However, only greater family conflict, and not adherence, significantly explained the association between greater self-regulation problems and higher HbA1c. These findings suggest that among teens experiencing challenges with managing type 1 diabetes, interventions that decrease family conflict may be critical to promoting optimal glycemic control in those teens with greater problems with self-regulation.

  11. Problems, Challenges and Benefits of Implementing E-learning in Nigerian Universities: An Empirical Study

    Directory of Open Access Journals (Sweden)

    Manir Abdullahi Kamba

    2009-03-01

    Full Text Available This paper tries to examine and discuss the problems, challenges and Benefits of implementing E-Learning in Nigeria by reviewing the consciousness and willingness of the selected Universities. This study also identifies the enabling factors, the traffic-jam and, forecasts the future growth of E-learning in Nigeria. Survey research method was adopted for the study, and questionnaire was the only instrument used for the data collection. The findings of the study show that out of the 18 universities selected from different specialization areas, i.e three universities from each Geopolitical zone, only 12 responded with usable answers. The response rate was 67%, which is an expected rate for such surveys. Awareness of e-learning among the Universities is very high but investment and commitment to develop an e-learning application is very poor and below expectation according to the study. Most of the staff and students in the universities only use Internet related e- learning site just for the sake of finding related information for their researches, since their libraries cannot afford to provide them with adequate and current materials but not for the sake of real online learning. The study also found out that some of the universities have web page and others are in the trend of creating a web page, which is usually for advertisement of the universities but not for the e-leaning activities. Furthermore, the findings also reveal that staff and the students have also been using e-mail and Internet in addition to developing web pages for transaction of students. The Universities are planning to invest number of funds in future in the selected areas of the e-learning application. The Statistical analysis result shows that there are significant differences across both forms of e-learning activities and type of universities in Nigeria.

  12. Software-engineering challenges of building and deploying reusable problem solvers.

    Science.gov (United States)

    O'Connor, Martin J; Nyulas, Csongor; Tu, Samson; Buckeridge, David L; Okhmatovskaia, Anna; Musen, Mark A

    2009-11-01

    Problem solving methods (PSMs) are software components that represent and encode reusable algorithms. They can be combined with representations of domain knowledge to produce intelligent application systems. A goal of research on PSMs is to provide principled methods and tools for composing and reusing algorithms in knowledge-based systems. The ultimate objective is to produce libraries of methods that can be easily adapted for use in these systems. Despite the intuitive appeal of PSMs as conceptual building blocks, in practice, these goals are largely unmet. There are no widely available tools for building applications using PSMs and no public libraries of PSMs available for reuse. This paper analyzes some of the reasons for the lack of widespread adoptions of PSM techniques and illustrate our analysis by describing our experiences developing a complex, high-throughput software system based on PSM principles. We conclude that many fundamental principles in PSM research are useful for building knowledge-based systems. In particular, the task-method decomposition process, which provides a means for structuring knowledge-based tasks, is a powerful abstraction for building systems of analytic methods. However, despite the power of PSMs in the conceptual modeling of knowledge-based systems, software engineering challenges have been seriously underestimated. The complexity of integrating control knowledge modeled by developers using PSMs with the domain knowledge that they model using ontologies creates a barrier to widespread use of PSM-based systems. Nevertheless, the surge of recent interest in ontologies has led to the production of comprehensive domain ontologies and of robust ontology-authoring tools. These developments present new opportunities to leverage the PSM approach.

  13. Challenges in thermal design of industrial single-phase power inverter

    Directory of Open Access Journals (Sweden)

    Ninković Predrag

    2016-01-01

    Full Text Available This paper presents the influence of thermal aspects in design process of an industrial single-phase inverter, choice of its topology and components. Stringent design inputs like very high overload level, demand for natural cooling and very wide input voltage range have made conventional circuit topology inappropriate therefore asking for alternative solution. Different power losses calculations in semiconductors are performed and compared, outlining the guidelines how to choose the final topology. Some recommendations in power magnetic components design are given. Based on the final project, a 20kVA single-phase inverter for thermal power plant supervisory and control system is designed and commissioned.

  14. Contextual Challenges of Implementing Learner-Centred Pedagogy: The Case of the Problem-Solving Approach in Uganda

    Science.gov (United States)

    Sikoyo, Leah

    2010-01-01

    This article explores teachers' experiences of implementing the problem-solving approach; a learner centred pedagogic innovation prescribed by a centrally mandated curriculum in Uganda. It presents teachers' interpretations of the pedagogic principles suggested by the innovation as well as their accounts of challenges of implementing the pedagogic…

  15. Challenges of Conducting Problem-Based Learning in a Large Class: A Study at Shantou University Medical College in China

    Science.gov (United States)

    Long, Ting; Qin, Danian

    2014-01-01

    One major challenge of developing problem-based learning (PBL) curricula in medical schools in China is to meet the requirements of sufficient qualified PBL tutors. Since 2011, we have developed a modified group teaching approach where an experienced faculty tutor facilitates several small PBL student groups in a large class. Although our study…

  16. The Challenge of Assessing Creative Problem Solving in Client-Based Marketing Development Projects: A SOLO Taxonomy Approach

    Science.gov (United States)

    Jaskari, Minna-Maarit

    2013-01-01

    Creativity and marketing imagination are essential core competencies for marketers. Therefore, higher marketing education emphasizes creativity in several ways. However, assessing creativity and creative problem solving is challenging and tools for this purpose have not been developed in the context of marketing education. To address this gap, we…

  17. Comments on an Analytical Thermal Agglomeration for Problems with Surface Growth

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-22

    Up until Dec 2016, the thermal agglomeration was very heuristic, and as such, difficult to define. The lack of predictability became problematic, and the current notes represent the first real attempt to systematize the specification of the agglomerated process parameters.

  18. Nurses working in primary and community care settings in England: problems and challenges in identifying numbers.

    Science.gov (United States)

    Storey, Claire; Ford, Jackie; Cheater, Francine; Hurst, Keith; Leese, Brenda

    2007-11-01

    One third of the primary care nursing workforce is aged 50 years and over. Workforce planning is essential if primary care is to ensure that there are appropriate numbers of nurses available to replace the loss of experienced nurses as they approach retirement. As part of an ongoing study to explore the factors influencing retention of female nurses over the age of 50 years in the primary care nursing workforce, a questionnaire survey targeting all community nurses employed in five Primary Care Trusts was undertaken. Accurate statistics on the number and type of community nurse employed in the five Primary Care Trusts were sought to: (i) identify a denominator to accurately identify the response rates to questionnaires in the survey of Primary Care Trusts; and (ii) to compare the Primary Care Trust data with Department of Health statistics to investigate the accuracy of workforce data. A number of problems with locating accurate primary care nursing workforce statistics were identified. The purpose of this paper is to highlight the difficulties inherent in collating workforce data and the implications for future workforce planning, both locally and nationally. The impact on research is also highlighted. An ageing nursing workforce indicates that primary care nursing will experience significant reductions in its workforce. Local and National workforce statistics for primary care are flawed. There are significant gaps in primary care data for school and practice nurses. There needs to be clarification and a consensus for the term 'community nurse'. The expansion of the public health role for school nurses is seriously challenged because of limited availability of appropriately qualified nurses and an urgent need for an investigation into school nursing statistics. Future workforce planning and development needs to be based on accurate and reliable statistics, to plan for an ageing nursing workforce. The quality of research in primary care is compromised because of

  19. On The Cusp of the New Spatial Challenges – The Thermal Waste Processing Plant as an Element of Urban Space

    Science.gov (United States)

    Wójtowicz-Wróbel, Agnieszka

    2017-10-01

    The goal of this paper is to answer the question about the current importance of structures associated with the thermal processing of waste within the space of Polish cities and what status can they have in the functional and spatial structure of Polish cities in the future. The construction of thermal waste processing plants in Poland is currently a new and important problem, with numerous structures of this type being built due to increasing care for the natural environment, with the introduction of legal regulations, as well as due to the possibility of obtaining large external funding for the purposes of undertaking pro-environmental spatial initiatives, etc. For this reason, the paper contains research on the increase in the number of thermal waste processing plants in Poland in recent years. The abovementioned data was compared with similar information from other European Union member states. In the group containing Polish thermal waste processing plants, research was performed regarding the stage of the construction of a plant (operating plant, plant under construction, design in a construction phase, etc.). The paper also contains a listing of the functions other than the basic form of use, which is the incineration of waste - similarly to numerous foreign examples - that the environmentally friendly waste incineration plants fulfil in Poland, dividing the additional forms of use into "hard" elements (at the design level, requiring the expansion of a building featuring new elements that are not directly associated with the basic purpose of waste processing) and soft (social, educational, promotional actions, as well as other endeavours that require human involvement, but that do not entail significant design work on the buildings itself, expanding its form of use, etc.) as well as mixed activity, which required design work, but on a relatively small scale. Research was also conducted regarding the placement of thermal waste processing plants within the

  20. Evolution, opportunity and challenges of transboundary water and energy problems in Central Asia

    National Research Council Canada - National Science Library

    Guo, Lidan; Zhou, Haiwei; Xia, Ziqiang; Huang, Feng

    2016-01-01

    .... It is now facing imbalanced supply—demand relations of water and energy resources. These issues in Northwest China and Central Asia pose severe challenges in the implementation of the Silk Road Economic Belt strategy...

  1. Understanding wicked problems and organized irresponsibility: challenges for governing the sustainable intensification of chicken meat production

    NARCIS (Netherlands)

    Bueren, E.M.; Lammerts Van Bueren, E.; Zijpp, van der A.J.

    2014-01-01

    Framing sustainable intensification as a wicked problem reveals how inherent trade-offs and resulting uncertainty and ambiguity block integrated problem solving as promoted by sustainable chain management approaches to production and consumption. The fragmented institutional set-up of the chains

  2. Responding to Educational Challenges with Problem-Based Learning and Information Technology.

    Science.gov (United States)

    Tedesco, Lisa A.

    1990-01-01

    The paper addresses application of new educational technologies to dental education. Noted is technology's ability to create an electronic curriculum that uses images and text to advance problem-solving and problem-based learning. Information technology provides a risk-free (i.e., patient-free) environment for dental students to test decisions.…

  3. Social Issues and Problem-Based Learning in Sociology: Opportunities and Challenges in the Undergraduate Classroom

    Science.gov (United States)

    Eglitis, Daina S.; Buntman, Fran L.; Alexander, Dameon V.

    2016-01-01

    This article discusses the use of problem-based learning (PBL) in the undergraduate sociology classroom. PBL shifts students from the role of passive listeners and learners to active knowledge builders and communicators through the use of concise and engaging social problem cases. PBL creates opportunities for building substantive area knowledge,…

  4. Organic propagation of seed and planting material: an overview of problems and challenges for research

    NARCIS (Netherlands)

    Lammerts Van Bueren, E.; Struik, P.C.; Jacobsen, E.

    2003-01-01

    By 1 January 2004, as a result of EU-regulation 2092/91 for organic farming, the organic sector needs to have developed efficient schemes to be able to use adequate quantities of organically produced seed and planting material. Market problems and agronomic problems that are related to obtaining

  5. A Problem-Solving Approach to Addressing Current Global Challenges in Education

    Science.gov (United States)

    Chapman, Judith D.; Aspin, David N.

    2013-01-01

    This paper begins with an analysis of global problems shaping education, particularly as they impact upon learning and life chances. In addressing these problems a range of philosophical positions and controversies are considered, including: traditional romantic and institutional views of schooling; and more recent maximalist, neo-liberal,…

  6. Solving algebraic computational problems in geodesy and geoinformatics the answer to modern challenges

    CERN Document Server

    Awange, Joseph L

    2004-01-01

    While preparing and teaching 'Introduction to Geodesy I and II' to - dergraduate students at Stuttgart University, we noticed a gap which motivated the writing of the present book: Almost every topic that we taughtrequiredsomeskillsinalgebra,andinparticular,computeral- bra! From positioning to transformation problems inherent in geodesy and geoinformatics, knowledge of algebra and application of computer algebra software were required. In preparing this book therefore, we haveattemptedtoputtogetherbasicconceptsofabstractalgebra which underpin the techniques for solving algebraic problems. Algebraic c- putational algorithms useful for solving problems which require exact solutions to nonlinear systems of equations are presented and tested on various problems. Though the present book focuses mainly on the two ?elds,theconceptsand techniquespresented hereinarenonetheless- plicable to other ?elds where algebraic computational problems might be encountered. In Engineering for example, network densi?cation and robo...

  7. Bringing Fenton Hill into the Digital Age: Data Conversion in Support of the Geothermal Technologies Office Code Comparison Study Challenge Problems

    Energy Technology Data Exchange (ETDEWEB)

    White, Signe K.; Kelkar, Sharad M.; Brown, Don W.

    2016-03-01

    The Geothermal Technologies Office Code Comparison Study (GTO-CCS) was established by the U.S. Department of Energy to facilitate collaboration among members of the geothermal modeling community and to evaluate and improve upon the ability of existing codes to simulate thermal, hydrological, mechanical, and chemical processes associated with complex enhanced geothermal systems (EGS). The first stage of the project, which has been completed, involved comparing simulations for seven benchmark problems that were primarily designed using well-prescribed, simplified data sets. In the second stage, the participating teams are tackling two challenge problems based on the EGS research conducted in hot dry rock (HDR) at Fenton Hill, near Los Alamos, New Mexico. The Fenton Hill project, conducted by Los Alamos National Laboratory (LANL) from 1970 to 1995, was the world’s first HDR demonstration project. One of the criteria for selecting this experiment as the basis for the challenge problems was the amount and availability of data for generating model inputs. The Fenton Hill HDR system consisted of two reservoirs – an earlier Phase I reservoir tested from 1974 to 1981 and a deeper Phase II reservoir tested from 1980 to 1995. Detailed accounts of both phases of the HDR project have been presented in a number of books and reports, including a recently published summary of the lessons learned and a final report with a chronological description of the Fenton Hill project, prepared by LANL. Project documents and records have been archived and made public through the National Geothermal Data System (NGDS). Some of the data acquired from Phase II are available in electronic format readable on modern computers. These include the microseismic data from some of the important experiments (e.g. the massive hydraulic fracturing test conducted in 1983) and the injection/production wellhead data from the circulation tests conducted between 1992-1995. However, much of the data collected

  8. Aging and corrosion problems of plane thermal solar collectors: literature and field investigations

    Energy Technology Data Exchange (ETDEWEB)

    Wennerholm, H.; Lagerkvist, K.U.

    1979-01-01

    The literature and field investigation will be the basis of a project concerning the development of standardized methods for the test of solar collectors which are used in heating and cooling systems. The literature and field investigations include the study of the construction of plane thermal solar collectors as well as atmospheric degradation processes on different construction materials.

  9. Challenge.

    Directory of Open Access Journals (Sweden)

    René-Éric Dagorn

    2004-04-01

    Full Text Available Sous le titre « The Hispanic Challenge », Samuel P. Huntington propose dans le numéro de Foreign Policy de mars-avril 2004 une nouvelle démonstration du danger de sa pseudo-théorie du « choc des civilisations ». Quel est donc ce «  challenge  » auquel, d'après Huntington, la société américaine serait aujourd'hui confrontée ? C'est celui de l'immigration « hispanique » qui « menace l'identité américaine, ses valeurs et son mode de vie » ...

  10. Scientific and Technical Challenges in Thermal Transport and Thermoelectric Materials and Devices

    KAUST Repository

    O'Dwyer, Colm

    2017-01-19

    This paper considers the state-of-the-art and open scientific and technological questions in thermoelectric materials and devices, from phonon engineering and scattering methods, to new and complex materials and their thermoelectric behavior. The paper also describes recent approaches to create structural and compositional material systems designed to enhance the thermoelectric figure of merit and power factors. We also summarize and contextualize recent advances in the use of superlattice structures and porosity or roughness to influence phonon scattering mechanisms and detail some advances in integrated thermoelectric materials for generators and coolers for thermally stable photonic devices.

  11. Medialogy – An Interdisciplinary Education Challenge in a Problem Based Learning Environment

    DEFF Research Database (Denmark)

    Nordahl, Rolf; Kofoed, Lise B.

    2012-01-01

    Different new educations in the field of media and technology are constantly developing worldwide. Searching on the Internet almost every university has programs in both media and communication. Several universities are discussing the challenges to offer double degrees, so the students can combine...... an individual education according to their interests. Other universities are offering interdisciplinary educations in the field of media technology. Having worked with those interdisciplinary engineering and science educations for several years, it seems to be a challenge to define the students’ key competences......, and the ability of such educations to provide new scientific paradigms and disciplines. This paper investigates the challenges connected to a new interdisciplinary science and engineering program: Medialogy at Aalborg University. The program includes Bachelor and Master level educations and combines humanistic...

  12. Rural and Urban Manufacturing Workers: Similar Problems, Similar Challenges: Results of the ERS Rural Manufacturing Survey

    OpenAIRE

    Teixeira, Ruy

    1998-01-01

    Low skill levels among rural workers put rural manufacturing at a competitive disadvantage, according to the "skills shortage" theory. Data from the ERS Rural Manufacturing Survey, conducted in 1996, suggest that is not happening. Skill requirements are rising, but manufacturers who reported major problems finding workers with specific skills were relatively rare, among both rural and urban firms. Moreover, the most common problem was in finding reliable workers with an acceptable work attitu...

  13. The effect of daily challenges in children with autism on parents' couple problem-solving interactions.

    Science.gov (United States)

    Hartley, Sigan L; Papp, Lauren M; Blumenstock, Shari M; Floyd, Frank; Goetz, Greta L

    2016-09-01

    The vulnerability-stress-adaptation model guided this examination of the impact of daily fluctuations in the symptoms and co-occurring behavior problems of children with autism spectrum disorder (ASD) on parents' couple problem-solving interactions in natural settings and as these interactions spontaneously occur. A 14-day daily diary was completed by mothers and fathers in 176 families who had a child with ASD. On each day of the diary, parents separately reported on the child with ASD's daily level of symptoms and co-occurring behavior problems and the topic and level of negative affect in their most meaningful or important daily couple problem-solving interaction. Multilevel modeling was used to account for the within-person, within-couple nested structure of the data. Results indicated that many parents are resilient to experiencing a day with a high level of child ASD symptoms and co-occurring behavior problems and do not report more negative couple problem-solving interactions. However, household income, level of parental broader autism phenotype, and presence of multiple children with special care needs served as vulnerability factors in that they were related to a higher overall rating of negative affect in couple interactions and moderated the impact of reporting a day with a high level of child ASD symptoms and co-occurring behavior problems on next-day ratings of negative couple problem-solving interactions. The magnitude of these effects was small. Understanding mechanisms that support adaptive couple interactions in parents of children with ASD is critical for promoting best outcomes. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  14. School Students and Part-Time Work: Workplace Problems and Challenges

    Science.gov (United States)

    Smith, Erica; Patton, Wendy

    2009-01-01

    The findings of a large national project on the part-time working careers of full-time students aged 15 to 24 challenge some widely held perceptions of large corporations that employ school students. (Contains 2 tables and 2 notes.)

  15. Rational and Challenges of Competency-Based Education and Training: The "Wickedness" of the Problem

    Science.gov (United States)

    Oyugi, Jacob L.

    2015-01-01

    Our students will continue to be confronted with many environment and sustainability issues during their lifetimes because they are unpredictable, serious and complex by nature. These issues challenge not just our technologies but our universities and educational institutions, values and way of living and interaction. Competency-based education…

  16. Challenges Experienced by Korean Medical Students and Tutors during Problem-Based Learning: A Cultural Perspective

    Science.gov (United States)

    Ju, Hyunjung; Choi, Ikseon; Rhee, Byoung Doo; Tae-Lee, Jong

    2016-01-01

    How people learn is influenced by the cultural contexts in which their learning occurs. This qualitative case study explored challenges Korean medical students and tutors experienced during their PBL sessions from a cultural perspective using Hofstede's cultural dimensions. Twelve preclinical medical students and nine tutors from a large Korean…

  17. Are project managers ready for the 21th challenges? A review of problem structuring methods for decision support

    Directory of Open Access Journals (Sweden)

    José Mateo

    2017-01-01

    Full Text Available Numerous contemporary problems that project managers face today can be considered as unstructured decision problems characterized by multiple actors and perspectives, incommensurable and/or conflicting objectives, and important intangibles. This work environment demands that project managers possess not only hard skills but also soft skills with the ability to take a management perspective and, above all, develop real leadership capabilities. In this paper, a family of problem structured methods for decision support aimed at assisting project managers in tackling complex problems are presented. Problem structured methods are a family of soft operations research methods for decision support that assist groups of diverse composition to agree a problem focus and make commitments to consequential action. Project management programs are challenged to implement these methodologies in such a way that it is organized around the key competences that a project manager needs in order to be more effective, work efficiently as members of interdisciplinary teams and successfully execute even a small project.

  18. [VI Symposium: Some global health problems with local impact: Great challenges for Public Health].

    Science.gov (United States)

    2015-01-01

    The objective of the symposium was to emphasize the great public health challenges that we are facing today; such is the case of dementia, which is one of the main causes of disability and dependence among older adults. Another important issue is antibiotic resistance; even though it has played a key role in the health of humanity, its indiscriminate use has resulted in increased bacterial resistance. Therefore, health regulations in the rational use of prescribed drugs in our country are part of the actions taken in order to not only control the use of such drugs, but also regulate different areas related to health in order to avoid health risks. Finally, a current challenge is emerging and reemerging diseases that have caused various epidemics such as influenza, Ebola virus disease, binomial tuberculosis and HIV, and Chikungunya that is currently affecting the Region of the Americas.

  19. Space Acquisitions: Some Programs Have Overcome Past Problems, but Challenges and Uncertainty Remain for the Future

    Science.gov (United States)

    2015-04-29

    are being conducted for the SpaceX Falcon 9 v1.1 launch system. In addition, in its fiscal year 2016 President’s Budget request, DOD requested funding...DOD expects SpaceX to be certified by June 2015. Additionally, the department has faced unexpected complications, such as challenges to its...oversight, policy, and funding decisions. GAO’s commitment to good government is reflected in its core values of accountability, integrity, and

  20. Scaling of Thermal Images at Different Spatial Resolution: The Mixed Pixel Problem

    Directory of Open Access Journals (Sweden)

    Hamlyn G. Jones

    2014-07-01

    Full Text Available The consequences of changes in spatial resolution for application of thermal imagery in plant phenotyping in the field are discussed. Where image pixels are significantly smaller than the objects of interest (e.g., leaves, accurate estimates of leaf temperature are possible, but when pixels reach the same scale or larger than the objects of interest, the observed temperatures become significantly biased by the background temperature as a result of the presence of mixed pixels. Approaches to the estimation of the true leaf temperature that apply both at the whole-pixel level and at the sub-pixel level are reviewed and discussed.

  1. Tarzan's Dilemma: A Challenging Problem for Introductory Physics Students

    Science.gov (United States)

    Rave, Matthew; Sayers, Marcus

    2013-01-01

    The following kinematics problem was given to several students as a project in conjunction with a first-semester calculus-based physics course. The students were asked to keep a journal of all their work and were encouraged to keep even their scrap paper. The goal of the project was to expose the students to the process of doing theoretical…

  2. Baccalaureate Student Perceptions of Challenging Family Problems: Building Bridges to Acceptance

    Science.gov (United States)

    Floyd, Melissa; Gruber, Kenneth J.

    2011-01-01

    This study explored the attitudes of 147 undergraduate social work majors to working with difficult families. Students indicated which problems (from a list of 42, including hot topics such as homosexuality, transgender issues, abortion, and substance abuse) they believed they would find most difficult to work with and provided information…

  3. Addressing Bullying Problems in Irish Schools and in Cyberspace: A Challenge for School Management

    Science.gov (United States)

    Corcoran, Lucie; Mc Guckin, Conor

    2014-01-01

    Background: School management, in Ireland and also internationally, are currently faced with the problem of peer aggression among students both in a traditional school context and in a cyber context. Although Irish school principals are obliged to implement policy and procedures to counter bullying among students, there is a need for guidance that…

  4. Rethinking the globalisation of problem-based learning: how culture challenges self-directed learning.

    NARCIS (Netherlands)

    Frambach, J.M.; Driessen, E.W.; Chan, L.C.; Vleuten, C.P.M. van der

    2012-01-01

    Medical Education 2012: 46: 738-747 Context Medical schools worldwide are increasingly switching to student-centred methods such as problem-based learning (PBL) to foster lifelong self-directed learning (SDL). The cross-cultural applicability of these methods has been questioned because of their

  5. Problems and challenges of nursing students’ clinical evaluation: A qualitative study

    Science.gov (United States)

    Rafiee, Ghazanfar; Moattari, Marzieh; Nikbakht, Alireza N; Kojuri, Javad; Mousavinasab, Masoud

    2014-01-01

    Background: The purpose of this qualitative exploratory study was to explore the views of nursing trainers and students about nursing students’ clinical evaluation problems and drawbacks in Shiraz Nursing and Midwifery School. Materials and Methods: A qualitative exploratory approach was used in this study at Shiraz Nursing and Midwifery School in 2012. A purposeful sample of 8 nursing instructors and 40 nursing students was interviewed and the data on their opinions about the problems of the clinical evaluation were collected through semi-structured deep interviews. Initially, four open-ended questions, which were related to the clinical evaluation status, problems, were used to stimulate discussions in the interview sessions. Content analysis was employed in order to analyze the transcribed data. The recorded interviews were initially transcribed, read, and reread on a number of occasions to get an overall feeling of what the participants were saying. Each line or incident was described, and then a code, which reflected the essence of the participants’ comments, was given. Results: The codes were compared for similarity and differences, merged together, and categorized. Finally, five themes emerged: In appropriate clinical evaluation method, problems of clinical evaluation Process, problems related to clinical instructors, unsuitable programming of clinical education, and organizational shortcomings. Conclusion: Besides focusing on upgrading the current clinical evaluation forms, nursing trainers should improve their knowledge about a complete and comprehensive clinical evaluation. They should also apply other appropriate and objective clinical evaluation methods and tools, and perform a formative and summative clinical evaluation. Also, workload adjustment of the nursing trainers needs revision. Therefore, despite using traditional and sometimes limited evaluation methods for assessing nursing students, a co mprehensive and appropriate evaluation of nursing

  6. A frictional contact problem with wear involving elastic-viscoplastic materials with damage and thermal effects

    Directory of Open Access Journals (Sweden)

    Abdelmoumene Djabi

    2015-05-01

    Full Text Available We consider a mathematical problem for quasistatic contact between a thermo-elastic-viscoplastic body with damage and an obstacle. The contact is frictional and bilateral with a moving rigid foundation which results in the wear of the contacting surface. We employ the thermo-elasticviscoplastic with damage constitutive law for the material. The damage of the material caused by elastic deformations. The evolution of the damage is described by an inclusion of parabolic type. The problem is formulated as a coupled system of an elliptic variational inequality for the displacement, a parabolic variational inequality for the damage and the heat equation for the temperature. We establish a variational formulation for the model and we prove the existence of a unique weak solution to the problem. The proof is based on a classical existence and uniqueness result on parabolic inequalities, differential equations and fixed point arguments.

  7. Effects of GnRHa treatment during vitellogenesis on the reproductive physiology of thermally challenged female Atlantic salmon (Salmo salar

    Directory of Open Access Journals (Sweden)

    Kelli Anderson

    2017-10-01

    Full Text Available Tasmanian Atlantic salmon (S. salar broodstock can experience temperatures above 20 °C, which impairs reproductive development and inhibits ovulation. The present study investigated the prolonged use of gonadotropin releasing hormone analogue (GnRHa during vitellogenesis as a means of maintaining endocrine function and promoting egg quality at elevated temperature in maiden and repeat spawning S. salar. GnRHa-treatment during vitellogenesis did not compensate for the negative effects of thermal challenge on the timing of ovulation, egg size, egg fertility or embryo survival in any fish maintained at 22 °C relative to 14 °C. The lack of effectiveness was reflected by the endocrine data, as plasma follicle stimulating hormone and luteinising hormone levels were not different between treated and untreated groups at 22 °C. Furthermore, plasma testosterone and E2 levels were unchanged in GnRHa-treated fish at 22 °C, and plasma levels were generally lower in both groups maintained at 22 °C relative to 14 °C. Transcription of vitellogenin, and zona pellucida B and C was not enhanced in GnRHa-treated fish relative to untreated fish at 22 °C, presumably due to observed suppression of plasma E2. These results indicate that thermal impairment of reproduction is likely to occur on multiple levels, and is difficult to overcome via hormonal manipulation.

  8. Effects of GnRHa treatment during vitellogenesis on the reproductive physiology of thermally challenged female Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Anderson, Kelli; Pankhurst, Ned; King, Harry; Elizur, Abigail

    2017-01-01

    Tasmanian Atlantic salmon (S. salar) broodstock can experience temperatures above 20 °C, which impairs reproductive development and inhibits ovulation. The present study investigated the prolonged use of gonadotropin releasing hormone analogue (GnRHa) during vitellogenesis as a means of maintaining endocrine function and promoting egg quality at elevated temperature in maiden and repeat spawning S. salar. GnRHa-treatment during vitellogenesis did not compensate for the negative effects of thermal challenge on the timing of ovulation, egg size, egg fertility or embryo survival in any fish maintained at 22 °C relative to 14 °C. The lack of effectiveness was reflected by the endocrine data, as plasma follicle stimulating hormone and luteinising hormone levels were not different between treated and untreated groups at 22 °C. Furthermore, plasma testosterone and E2 levels were unchanged in GnRHa-treated fish at 22 °C, and plasma levels were generally lower in both groups maintained at 22 °C relative to 14 °C. Transcription of vitellogenin, and zona pellucida B and C was not enhanced in GnRHa-treated fish relative to untreated fish at 22 °C, presumably due to observed suppression of plasma E2. These results indicate that thermal impairment of reproduction is likely to occur on multiple levels, and is difficult to overcome via hormonal manipulation.

  9. A key problem and challenge for hepatology: Obesity-related metabolic liver diseases.

    Science.gov (United States)

    Balaban, Yasemin Hatice

    2011-06-27

    With the arrival of the new millennium, gastroenterologists have been faced with the problem of metabolic liver diseases associated with obesity. The active role of the liver in metabolism and inflammation make it a key organ in the war against the rapidly-spreading world-wide epidemic of obesity. Many lives and much money could be saved if the work of hepatologists led to the development of effective diagnostic and therapeutic strategies against this growing leader of cirrhosis.

  10. POTENTIALLY GRAVE GASTRO-INTESTINAL TRACT PROBLEMS IN PREGNANCY - A CHALLENGE TO THE OBSTETRICIAN!

    Directory of Open Access Journals (Sweden)

    Chaitra

    2016-02-01

    Full Text Available CONTEXT Acute surgical pathology may be overlooked in pregnancy. Despite advances in medical technology, preoperative diagnosis of potentially grave pathologies of the gastrointestinal tract (GIT is often delayed due to overlap with symptoms of pregnancy non-specific elevation of some laboratory parameters due to pregnancy and a dilemma for obstetricians and surgeons in ordering radiological imaging modalities given the risk associated with fetal exposure to ionizing radiation and contrast. AIMS The aim of this study is to analyse the cases of gastrointestinal tract problems encountered in pregnancy so that increasing awareness can be created among obstetricians. This is important because early diagnosis and timely intervention can significantly improve maternal and fetal outcome in these cases. SETTINGS AND DESIGN There is a retrospective case study of potentially grave GIT problems encountered at Vanivilas hospital, Bangalore, a tertiary referral institute wherein the clinical presentation was confounded by pregnancy. MATERIALS AND METHODS All the included cases were analysed for age of the patient, pre-existing gastrointestinal tract disorders, gestational age at diagnosis, maternal and fetal outcome. RESULTS A total of 8 cases of GIT problems in pregnancy were studied. Though acute appendicitis is the most common cause of GIT emergency in pregnancy as quoted in literature 5, we did not encounter any case of acute appendicitis in pregnancy in the study period. Other conditions which were encountered were small bowel obstruction, stomach and bowel perforation and bleeding oesophageal varices. Whilst few of the conditions could be managed conservatively without harm to the pregnancy, others required a laparotomy and reparative procedures. Delay in diagnosis and intervention proved to be fatal in some of these women. CONCLUSIONS Knowledge about potentially grave gastrointestinal tract problems during pregnancy, high index of clinical suspicion

  11. Visualization of the Geometry Problems in Primary Math Education -Needs and Challenges-

    OpenAIRE

    Atanasova-Pacemska, Tatjana; Gunova, Vesna; Lazarova, Limonka; Pacemska, Sanja

    2016-01-01

    The visualization as an approach in the teaching process is not only limited representation of drawings in order to illustrate certain objects or concepts, but it is used in every step of solving mathematical problems, especially in the geometry. It is thought that mathematics is more "abstract world",which examines objects and concepts quite different from physical phenomena that rely on visualization with all its various forms and levels. In this p...

  12. Conquering a wicked problem: New challenges and opportunities for biogeochemistry and catchment science

    Science.gov (United States)

    Haygarth, P.

    2012-04-01

    Meeting the demands of good water quality such as those of the EU Water Framework Directive is a complicated, wicked problem. On the one hand the directive forces us to consider the catchment as a single functioning unit, a water body where ecological status can be assessed and classified. On the other hand, catchments are most obviously perturbed and managed in spatially and temporally discrete units. This makes assigning the 'cause' and 'response' particularly complicated - the familiar problem of managing diffuse pollution. This talk will explore some of these complexities in understanding the diffuse pollution 'cause' and 'response' in catchment science. Some particular opportunities may lie in cross team consortia style working, with multidisciplinary 'platforms' of study and value added information sharing. This should include nurturing full ownership and empowerment of the problem (and solutions) with the local communities - the solutions need to be encouraged to come from those who own and work in the catchments. The presentation will also consider some new opportunities for the sustainable management of phosphorus in catchments.

  13. Problems and Challenges in Human Resource Management: Case of a Large Organization in Pakistan

    Directory of Open Access Journals (Sweden)

    Ali Irshad

    2008-09-01

    Full Text Available This paper critically analyzes the work culture for a mainstream financial organization operating within Pakistan, while drawing a specific example to elucidate certain dilemmas that impede the potential growth for the financial sector and its constituent workforce, besides hampering the performance of the organizations. The case study is related to an organization in financial sector which conducts a Management Trainee Program with the purpose to select, train and develop a high-potential pool of talent into future leaders and fore-runners of the organization. This paper critically analyzes several inherent problems that face the successful implementation of the trainee program under the frameworks of various theories of organizational management. To solve these problems, this article presents a detailed diagnosis of the management shortcomings to improve the firm‟s corporate culture, work ethics and employee handling strategy and mechanism. Recommendations are also made to minimize the problems and maximize the success of the Management Trainee Program in the case study organization.

  14. Problems of Vortex Dynamics in the Thermal Physics of Power Plants

    NARCIS (Netherlands)

    Mitrofanova, O. V.

    2006-01-01

    The first section gives examples of flows with the formation of determinate vortex structures characteristic of power-generating plants. An approach to the solution of collector problems for nuclear reactors of the type of fast-neutron and water-moderated water-cooled power reactors is proposed. It

  15. From functional genomics to functional immunomics: new challenges, old problems, big rewards.

    Directory of Open Access Journals (Sweden)

    Ulisses M Braga-Neto

    2006-07-01

    Full Text Available The development of DNA microarray technology a decade ago led to the establishment of functional genomics as one of the most active and successful scientific disciplines today. With the ongoing development of immunomic microarray technology-a spatially addressable, large-scale technology for measurement of specific immunological response-the new challenge of functional immunomics is emerging, which bears similarities to but is also significantly different from functional genomics. Immunonic data has been successfully used to identify biological markers involved in autoimmune diseases, allergies, viral infections such as human immunodeficiency virus (HIV, influenza, diabetes, and responses to cancer vaccines. This review intends to provide a coherent vision of this nascent scientific field, and speculate on future research directions. We discuss at some length issues such as epitope prediction, immunomic microarray technology and its applications, and computation and statistical challenges related to functional immunomics. Based on the recent discovery of regulation mechanisms in T cell responses, we envision the use of immunomic microarrays as a tool for advances in systems biology of cellular immune responses, by means of immunomic regulatory network models.

  16. Diagnosis of tuberculosis in camelids: old problems, current solutions and future challenges.

    Science.gov (United States)

    Alvarez, J; Bezos, J; Juan, L de; Vordermeier, M; Rodriguez, S; Fernandez-de-Mera, I G; Mateos, A; Domínguez, L

    2012-02-01

    In spite of great efforts for its control and eradication, tuberculosis remains one of the most important zoonosis worldwide. Its causative agents, the members of the Mycobacterium tuberculosis complex, have a wide host range that complicates the epidemiology of this disease. Among susceptible species to these pathogens, camelids from the New World (llama, alpaca and vicuña) and Old World (Bactrian camel and dromedary) are acquiring an increasing importance in several European countries because of its growing number and could act as reservoirs of the disease for livestock and humans in their natural habitat. In addition, tuberculosis caused by a number of M. tuberculosis complex members is a life-threatening disease in these animal species. Although tuberculosis has been known to affect camelids for a long time, ante-mortem diagnosis is still challenging because of the lack of standardized diagnostic techniques and the limited sensitivity and specificity of the most widely applied tests. However, in recent years, several techniques that can at least partially overcome these limitations have been developed. This paper reviews the results and advances achieved in tuberculosis diagnosis in camelids in the last decade as well as the progresses on ongoing investigations, with special attention to the remaining challenges that still have to be faced to assure the availability of reliable tools for the detection of tuberculosis-infected animals and herds. © 2011 Blackwell Verlag GmbH.

  17. What Is Robustness?: Problem Framing Challenges for Water Systems Planning Under Change

    Science.gov (United States)

    Herman, J. D.; Reed, P. M.; Zeff, H. B.; Characklis, G. W.

    2014-12-01

    Water systems planners have long recognized the need for robust solutions capable of withstanding deviations from the conditions for which they were designed. Faced with a set of alternatives to choose from—for example, resulting from a multi-objective optimization—existing analysis frameworks offer competing definitions of robustness under change. Robustness analyses have moved from expected utility to exploratory "bottom-up" approaches in which vulnerable scenarios are identified prior to assigning likelihoods; examples include Robust Decision Making (RDM), Decision Scaling, Info-Gap, and Many-Objective Robust Decision Making (MORDM). We propose a taxonomy of robustness frameworks to compare and contrast these approaches, based on their methods of (1) alternative selection, (2) sampling of states of the world, (3) quantification of robustness measures, and (4) identification of key uncertainties using sensitivity analysis. Using model simulations from recent work in multi-objective urban water supply portfolio planning, we illustrate the decision-relevant consequences that emerge from each of these choices. Results indicate that the methodological choices in the taxonomy lead to substantially different planning alternatives, underscoring the importance of an informed definition of robustness. We conclude with a set of recommendations for problem framing: that alternatives should be searched rather than prespecified; dominant uncertainties should be discovered rather than assumed; and that a multivariate satisficing measure of robustness allows stakeholders to achieve their problem-specific performance requirements. This work highlights the importance of careful problem formulation, and provides a common vocabulary to link the robustness frameworks widely used in the field of water systems planning.

  18. Challenges and benefits for teachers in online Problem-Based learning

    DEFF Research Database (Denmark)

    Nortvig, Anne-Mette; Kolbæk, Ditte

    2017-01-01

    in the impact of the material conditions for educational practices, when education and learning are founded on PBL, the learning environment is mainly online, and the teachers and students are situated in Denmark and Norway. More specifically this study explores PBL when it takes place online at Aalborg......Research topic/aim Original problem based and project organized learning (PBL) was developed for collaboration between physically present students, but political decisions at many universities also require that collaboration, dialogues and other PBL activities take place online. We are interested...

  19. Multiple equilibria, bifurcations and selection scenarios in cosymmetric problem of thermal convection in porous medium

    Science.gov (United States)

    Govorukhin, Vasily N.; Shevchenko, Igor V.

    2017-12-01

    We study convection in a two-dimensional container of porous material saturated with fluid and heated from below. This problem belongs to the class of dynamical systems with nontrivial cosymmetry. The cosymmetry gives rise to a hidden parameter in the system and continuous families of infinitely many equilibria, and leads to non-trivial bifurcations. In this article we present our numerical studies that demonstrate nonlinear phenomena resulting from the existence of cosymmetry. We give a comprehensive picture of different bifurcations which occur in cosymmetric dynamical systems and in the convection problem. It includes internal and external (as an invariant set) bifurcations of one-parameter families of equilibria, as well as bifurcations leading to periodic, quasiperiodic and chaotic behaviour. The existence of infinite number of stable steady-state regimes begs the important question as to which of them can realize in physical experiments. In this paper, this question (known as the selection problem) is studied in detail. In particular, we show that the selection scenarios strongly depend on the initial temperature distribution of the fluid. The calculations are carried out by the global cosymmetry-preserving Galerkin method, and numerical methods used to analyse cosymmetric systems are also described.

  20. Construction of anthropological knowledge and ethnographic co-research. Problems and challenges

    Directory of Open Access Journals (Sweden)

    Elena L. Achilli

    2017-09-01

    Full Text Available Discussing anthropological knowledge construction processes entails reflecting upon different connected dimensions. Epistemological and theoretical-methodological  positionings with different political consequences are intertwined. In addition, institutional conditions and the socio-historical context in which certain local and global disciplinary trends are inscribed must be taken into account. This paper looks into the processes of socio-anthropological research I have participated in over the last decades with schools, teachers, teacher unions, indigenous peoples and groups in conditions of structural poverty. I will particularly focus on the modalities of ethnographic co-research that we have implemented in several projects. I will attempt to show some of the theoretical-methodological potentialities that ethnography contributes to group/collective processes of research as well as limits in its development. Finally, I will mention some of the contemporary challenges anthropological knowledge faces in present Latin America.

  1. Translational challenges in targeting latent HIV infection and the CNS reservoir problem.

    Science.gov (United States)

    Garrido, Carolina; Margolis, David M

    2015-06-01

    Too controversial to discuss only a short time ago, achieving a cure for HIV infection has become a priority in HIV research. However, substantial challenges must be overcome. Among key hurdles to be surmounted is the definition of a reliable, validated model in which to test latency reversal agents (LRAs), as current primary cell models differ in their response to such agents. Animal models such as the HIV-infected humanized BLT mouse and SIV-infected macaque will be essential to study LRAs and to quantify their effects in anatomic reservoirs. Of several potential anatomic reservoirs, the central nervous system presents a significant obstacle, as it is known to harbor persistent HIV infection and is difficult to access for study and therapeutic intervention.

  2. Attempting a first translation of the Septuagint psalms into Afrikaans: problems and challenges

    Directory of Open Access Journals (Sweden)

    Gert J. Steyn

    2007-07-01

    Full Text Available A translation project was started during October 2004 with a small number of senior students in order to translate the Sep- tuagint (LXX psalms into Afrikaans for the first time. The importance of the LXX for Christianity cannot be overestimated and this is an attempt to make people aware of this important first translation of the Jewish Scriptures on the African con- tinent, to give people access to it in a translation in their mother tongue, and to contribute to the importance of the psalms as a collection of hymns and prayers that is of value for the liturgy and the ministry of the church. However, a number of significant problems were encountered, among them the fact that (a no satisfactory Greek critical text edition of the LXX psalms exists currently; (b the LXX is already a translation from the Hebrew; (c words have different connotations and meanings in the receptor language (Afrikaans for different members in the group; (d being poetic language, to what extent would a literal or a dynamic translation be more appropriate?; (e given the pace of translation and the extent of the project, it will take quite a number of years to complete; and (f existing dictionaries and grammars are mainly focused on the New Testament – not on the LXX. These problems are discussed by means of practical examples encountered in Psalms 1-3.

  3. Black boxes on wheels: research challenges and ethical problems in MEA-based robotics

    DEFF Research Database (Denmark)

    Bentzen, Martin Mose

    2016-01-01

    Robotic systems consisting of a neuron culture grown on a multielectrode array (MEA) which is connected to a virtual or mechanical robot have been studied for approximately 15 years. It is hoped that these MEA-based robots will be able to address the problem that robots based on conventional...... and that they are not likely to be solved within the field. After that, I discuss whether MEA-based robotics should be considered pop science. Finally, I investigate the ethical aspects of this research....... computer technology are not very good at adapting to surprising or unusual situations, at least not when compared to biological organisms. It is also hoped that insights gained from MEA-based robotics can have applications within human enhancement and medicine. In this paper, I argue that researchers...

  4. Grand Challenge Problems in Real-Time Mission Control Systems for NASA's 21st Century Missions

    Science.gov (United States)

    Pfarr, Barbara B.; Donohue, John T.; Hughes, Peter M.

    1999-01-01

    Space missions of the 21st Century will be characterized by constellations of distributed spacecraft, miniaturized sensors and satellites, increased levels of automation, intelligent onboard processing, and mission autonomy. Programmatically, these missions will be noted for dramatically decreased budgets and mission development lifecycles. Current progress towards flexible, scaleable, low-cost, reusable mission control systems must accelerate given the current mission deployment schedule, and new technology will need to be infused to achieve desired levels of autonomy and processing capability. This paper will discuss current and future missions being managed at NASA's Goddard Space Flight Center in Greenbelt, MD. It will describe the current state of mission control systems and the problems they need to overcome to support the missions of the 21st Century.

  5. English as Medium of Instruction in Economic University Education: Problems and Challenges

    Directory of Open Access Journals (Sweden)

    Anna Y. Polenova

    2016-09-01

    Full Text Available The paper attempts to analyze several approaches to learning a foreign language based on using English as Medium of Instruction (EMI in High School. Special attention is given to the «content and language integrated learning» (CLIL as the most progressive approach to defining the scope of professional education. The author classifies the models of language teaching within the statedapproaches that promote the efficiency of professional training of future economists in solving professional problems on the basis of implementation of foreign language competence. The paper defines the conditions of subject and language integrated models implementation into the learning process. In conclusion, it is noted that the integration of subject and language experience contributes to the optimization of foreign language training and a significant improvement in the quality of the educational process.

  6. Problems and challenges of educational policies in Latin America. The Argentina viewpoint

    Directory of Open Access Journals (Sweden)

    Francisco Muscará

    2013-07-01

    Full Text Available The objective of this article is to describe the most significant changes which are being carried out in Latin-American educational systems, taking Argentina as a point of reference. To that end, this comparative study tackles the following essential aspects: the principle of equal opportunities and social cohesion; decentralisation of educational systems at an institutional level; educational quality and equity problems; the career of teaching; and financial resources. The reforms carried out at university level have not been analysed, since their complexity exceeds the limits of this article. To conclude, we briefly mention the future goals which have been agreed by those responsible for education in diverse Latin-American countries.

  7. [The problems and challenges in the current eye health management in China].

    Science.gov (United States)

    Zou, H D

    2017-07-11

    The core goal of "Thirteenth Five-Year Plan for National Eye Health (2016 to 2020)" is to obtain eye health. At present, there are still several problems hampering Chinese eye health management system development, including the lack of top policy design, system protection and financial investment, weak support from primary health care institutions, other medical disciplines and social forces, and insufficient digital information. To achieve effective eye health management, it is necessary to address the sustainability of eye health management, the integrity of eye health digital information data and the feasibility of eye health payment. It is recommended that eye health-related medical workers take positive actions to strengthen the digital information construction and service capacity construction of eye disease prevention and control network, carry out health promotion extensively, and conduct eye health management mode research and practice.(Chin J Ophthalmol, 2017, 53: 481-483).

  8. Cognitive and behavioral problems in children with neurofibromatosis type 1: challenges and future directions.

    Science.gov (United States)

    Schwetye, Katherine E; Gutmann, David H

    2014-10-01

    Cognitive and behavioral disorders affect nearly 80% of all children with the neurofibromatosis type 1 inherited cancer syndrome, and are among the most significant clinical manifestations for patients and their families. One of the barriers to successful therapeutic intervention is the wide spectrum of clinical phenotypic expression, ranging from visuospatial learning problems to social perceptual deficits (autism). Leveraging numerous small-animal models of neurofibromatosis type 1, several promising targets have been identified to treat the learning, attention, and autism spectrum phenotypes in this at-risk population. In this review, we provide an up-to-date summary of our current understanding of these disorders in NF1, and propose future research directions aimed at designing more effective therapeutic approaches and clinical trials.

  9. New concept of geographical education in the Russian Federation: challenges, problems, contradictions, prospects

    Directory of Open Access Journals (Sweden)

    Сергей Сухинин

    2017-09-01

    Full Text Available The concept of geographical education is the main document regulating the structure and content of the subject study. The new Concept of geographical education in the Russian Federation was developed in 2016 by the Russian Geographical Society in conjunction with the Ministry of science and education of the Russian Federation. It was submitted for the discussion of the pedagogical and scientific community and adopted at the second All-Russian Congress of geography teachers 2-3 November, 2016 in M.V. Lomonosov Moscow State University. A new Concept of geographical education in the Russian Federation was adopted at the end of 2016. It contains the main principles, priorities, goals, objectives and main directions of geographical education development in school and in extracurricular activities; defines the mechanisms, tools, resources, and expected implementation results. There are significant contradictions and problems of implementation of the Concept, putting some purpose into the category of impossible. This requires coordination and adjustment of the Concept’s provisions with the realities of educational activities at school and at the university. At the same time, in the Concept there are significant differences that put some of its goals in the category of impossible. Their main reason is the inconsistency of some provisions of the concept with a real educational process. In this regard, there is the problem of matching and adjustment of the Concept’s provisions, bringing them into conformity with other normative documents in the field of education and real teaching activities at school and at the University.

  10. Challenging factors for enuresis treatment: Psychological problems and non-adherence.

    Science.gov (United States)

    Van Herzeele, Charlotte; De Bruyne, Pauline; De Bruyne, Elke; Walle, Johan Vande

    2015-12-01

    The evidence for organic pathogenetic factors in enuresis and the discovery of effective therapies targeting the bladder and/or nocturnal diuresis have overwhelmed every potential role of psychological factors in pathogenesis and treatment. However, psychopathology is still important in enuresis because according to the document of the International Children's Continence Society (ICCS) 20-30% of the children with enuresis have at least one psychological/psychiatric disorder at rates two times higher than non-wetting children. The most common comorbid disorder with enuresis is attention deficit hyperactivity disorder. The aim of this review is to translate the existing evidence on the importance of a psychological screening into daily clinical practice of the medical practitioner. The use of the minimal psychological screening tool should be considered mandatory in each primary setting. If psychological problems are indicated, referral of the patient to a multidisciplinary setting should be considered, not only to allow psychological assessment to screen for a possible psychopathology, but also since therapy resistance might be expected. This review concentrates on two items from psychopathology/psychotherapy that might predict insufficient treatment response: the psychological comorbidities as described according to the DSM-5 criteria and the underestimated importance of therapy adherence. Adherence is a cornerstone of effective therapy in enuresis. It is a problem involving the doctor, the patient, and the parents. Increasing adherence takes effort and is time-consuming. But it is worthwhile knowing that several studies have demonstrated that high adherence is associated with high therapy success of enuresis. Eventually, this is the ultimate goal of treatment. Copyright © 2015 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.

  11. California residential energy standards: problems and recommendations relating to implementation, enforcement, and design. [Thermal insulation

    Energy Technology Data Exchange (ETDEWEB)

    1977-08-01

    Documents relevant to the development and implementation of the California energy insulation standards for new residential buildings were evaluated and a survey was conducted to determine problems encountered in the implementation, enforcement, and design aspects of the standards. The impact of the standards on enforcement agencies, designers, builders and developers, manufacturers and suppliers, consumers, and the building process in general is summarized. The impact on construction costs and energy savings varies considerably because of the wide variation in prior insulation practices and climatic conditions in California. The report concludes with a series of recommendations covering all levels of government and the building process. (MCW)

  12. “It's Your Problem. Deal with It.” Performers' Experiences of Psychological Challenges in Music

    Directory of Open Access Journals (Sweden)

    Ellis Pecen

    2018-01-01

    Full Text Available Musicians need to deal with a range of challenges during their performance career and in response to these have reported a number of conditions that impact on their performance. Although social support from peers and teachers has been identified as part of the process of dealing with these challenges, little is understood about musicians' coping methods, beliefs and their attitudes toward support. Therefore, this study aimed to explore (a performers' previous experiences of psychological challenges, (b the types of support they used and, (c how this might inform future support programs in learning environments. Fifteen interviews were conducted with pre-elite (n = 5 transitioning elite (n = 3 and established elite performers (n = 7 in order to elicit data on psychological challenges, coping, beliefs and preferences for support. Inductive content analysis suggested that elite performers in this sample reported positive health habits, philosophical views of performance, health and life, positive anxiety reappraisal, and use of various psychological strategies, albeit without being explicitly aware of it. The need for various professional skills (e.g., communication, business, self-management, and organizational skills was emphasized by all participants. Transition into conservatoire was marked by severe psychological challenges, disorders and trauma. Primary sources of support included friends, family and self-help literature. Professional help was predominantly sought for physical problems. The impact of teachers was paramount, yet securing good teachers was considered a matter of “luck.” The most negative aspects recounted included abusive teachers, unsupportive environments, social comparison, competition, and disillusionment after entering the profession. Participants believed that talent could be developed and also valued wellbeing in relation to performance. Positive effects of late specialization on social development and professional

  13. Challenges and actual problems in reforming the public administration in the Republic of Macedonia

    Directory of Open Access Journals (Sweden)

    Argëtim Saliu

    2016-03-01

    Full Text Available Taking into consideration the fact that the public administration has a very important role in offering services and being a public service to the citizens and business community, as well as the need of improvement and harmonization of the norms and standards with the European Union, as one of the most important demands toward the integration process of Macedonia in the EU, makes this paper necessary to be taken into consideration for at least as a humble research in the area of public administration. Primary goal of this paper is that through comparative and quantitative methods to represent the challenges of reforming the public and state administration in Macedonia. De-politicization, more professional administration services and lowering the number of clerks in administration is one of the main criteria that our country needs to fulfil towards full integration in NATO and EU. The more time passes, the least progress is seen in this process, as we see stagnation in the aspect of quality of services, as well as in the aspect of total number of administrative clerks.

  14. Technological incorporation in the Unified Health System (SUS: the problem and ensuing challenges

    Directory of Open Access Journals (Sweden)

    Reinaldo Guimarães

    2014-12-01

    Full Text Available Technological incorporation is a central topic among the concerns regarding health care systems. This paper discusses the role of technology dynamics in health systems' cost increases, suggesting two different approaches - a 'pragmatic-economic' approach and a 'rational-defensive' approach - as guidelines to explain the reasons for this centrality. The paper shows how judicialization results from this situation and discusses two doctrinal views - 'reserve for contingencies' and 'rational use' - as the views that usually guide the debates in the courts and among health policy makers. The paper suggests that the attitude currently prevalent in the Brazilian judiciary system can prejudice the principle of equity by improperly evaluating the principle of integrality. We present a brief genealogy of HTA and a timeline of HTA in Brazil. We also discuss the relevance and the impact of Law 12401/2011, which regulates the principle of integrality in the Unified Health System (SUS and propose three challenges to the development of HTA actions aiming at technology incorporation in Brazil. Finally, we discuss the entry and the role of private health insurance companies, emphasizing changes in the scenario and in their position.

  15. DOE Network 2025: Network Research Problems and Challenges for DOE Scientists. Workshop Report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2016-02-01

    The growing investments in large science instruments and supercomputers by the US Department of Energy (DOE) hold enormous promise for accelerating the scientific discovery process. They facilitate unprecedented collaborations of geographically dispersed teams of scientists that use these resources. These collaborations critically depend on the production, sharing, moving, and management of, as well as interactive access to, large, complex data sets at sites dispersed across the country and around the globe. In particular, they call for significant enhancements in network capacities to sustain large data volumes and, equally important, the capabilities to collaboratively access the data across computing, storage, and instrument facilities by science users and automated scripts and systems. Improvements in network backbone capacities of several orders of magnitude are essential to meet these challenges, in particular, to support exascale initiatives. Yet, raw network speed represents only a part of the solution. Indeed, the speed must be matched by network and transport layer protocols and higher layer tools that scale in ways that aggregate, compose, and integrate the disparate subsystems into a complete science ecosystem. Just as important, agile monitoring and management services need to be developed to operate the network at peak performance levels. Finally, these solutions must be made an integral part of the production facilities by using sound approaches to develop, deploy, diagnose, operate, and maintain them over the science infrastructure.

  16. Challenges in Education Research in Taiwan: Research Institutes and Organizations, Research Policies, and Problems

    Directory of Open Access Journals (Sweden)

    Jia Li Huang

    2017-02-01

    Full Text Available Since the 1990s, many education researchers and policy makers worldwide have reviewed education research to attempt to provide strategies to improve the quality of such research in their countries. Taiwan’s government has launched policies and funded support to set the benchmark for Taiwan’s leading universities in international academic competition. The external environment of global competition based on research policy influences the ecosystem of social science research production. To assure the quality of education policy, peer review from within the education community is one approach to supplementing the government’s governance, including the establishment of research institutes, promotion, rewards, and research value. This study tracked the mode of academic research and provides an overview of the status of academic education research in Taiwan. Because education research is part of the humanities and social sciences fields, this study identified the challenges in educational research by examining the trend of social science research and by analyzing research organizations, policy, and the evaluation of research performance. Due to the environment of education research in Taiwan is not friendly to education researcher to accumulate papers in SSCI or international journal, additional concerns entail how education research communities can develop and agree on its quality.

  17. Continuous grasp algorithm applied to economic dispatch problem of thermal units

    Energy Technology Data Exchange (ETDEWEB)

    Vianna Neto, Julio Xavier [Pontifical Catholic University of Parana - PUCPR, Curitiba, PR (Brazil). Undergraduate Program at Mechatronics Engineering; Bernert, Diego Luis de Andrade; Coelho, Leandro dos Santos [Pontifical Catholic University of Parana - PUCPR, Curitiba, PR (Brazil). Industrial and Systems Engineering Graduate Program, LAS/PPGEPS], e-mail: leandro.coelho@pucpr.br

    2010-07-01

    The economic dispatch problem (EDP) is one of the fundamental issues in power systems to obtain benefits with the stability, reliability and security. Its objective is to allocate the power demand among committed generators in the most economical manner, while all physical and operational constraints are satisfied. The cost of power generation, particularly in fossil fuel plants, is very high and economic dispatch helps in saving a significant amount of revenue. Recently, as an alternative to the conventional mathematical approaches, modern heuristic optimization techniques such as simulated annealing, evolutionary algorithms, neural networks, ant colony, and tabu search have been given much attention by many researchers due to their ability to find an almost global optimal solution in EDPs. On other hand, continuous GRASP (C-GRASP) is a stochastic local search meta-heuristic for finding cost-efficient solutions to continuous global optimization problems subject to box constraints. Like a greedy randomized adaptive search procedure (GRASP), a C-GRASP is a multi-start procedure where a starting solution for local improvement is constructed in a greedy randomized fashion. The C-GRASP algorithm is validated for a test system consisting of fifteen units, test system that takes into account spinning reserve and prohibited operating zones constrains. (author)

  18. Optimization Problem of Thermal Field on Surface of Revolving Susceptor in Vapor-Phase Epitaxy Reactor

    Science.gov (United States)

    Zhilenkov, A. A.; Chernyi, S. G.; Nyrkov, A. P.; Sokolov, S. S.

    2017-10-01

    Nitrides of group III elements are a very suitable basis for deriving light-emitting devices with the radiating modes lengths of 200-600 nm. The use of such semiconductors allows obtaining full-color RGB light sources, increasing record density of a digital data storage device, getting high-capacity and efficient sources of white light. Electronic properties of such semi-conductors allow using them as a basis for high-power and high-frequency transistors and other electronic devices, the specifications of which are competitive with those of SiC-based devices. Only since 2000, the technology of cultivation of crystals III-N of group has come to the level of wide recognition by both abstract science, and the industry that has led to the creation of the multi-billion dollar market. And this is despite a rather low level of development of the production technology of devices on the basis of III-N of materials. The progress that has happened in the last decade requires the solution of the main problem, constraining further development of this technology today – ensuring cultivation of III-N structures of necessary quality. For this purpose, it is necessary to solve problems of the analysis and optimization of processes in installations of epitaxial growth, and, as a result, optimization of its constructions.

  19. Open science, e-science and the new technologies: Challenges and old problems in qualitative research in the social sciences

    Directory of Open Access Journals (Sweden)

    Ercilia García-Álvarez

    2012-12-01

    Full Text Available Purpose: As well as introducing the articles in the special issue titled "Qualitative Research in the Social Sciences", this article reviews the challenges, problems and main advances made by the qualitative paradigm in the context of the new European science policy based on open science and e-Science and analysis alternative technologies freely available in the 2.0 environment and their application to fieldwork and data analysis. Design/methodology: Theoretical review. Practical implications: The article identifies open access technologies with applications in qualitative research such as applications for smartphones and tablets, web platforms and specific qualitative data analysis software, all developed in both the e-Science context and the 2.0 environment. Social implications: The article discusses the possible role to be played by qualitative research in the open science and e-Science context and considers the impact of this new context on the size and structure of research groups, the development of truly collaborative research, the emergence of new ethical problems and quality assessment in review processes in an open environment. Originality/value: The article describes the characteristics that define the new scientific environment and the challenges posed for qualitative research, reviews the latest open access technologies available to researchers in terms of their main features and proposes specific applications suitable for fieldwork and data analysis.

  20. THE SOCIAL AND OCCUPATIONAL HEALTH PROBLEMS OF CHILD LABOUR: A CHALLENGE THE WORLD IS FACING

    Directory of Open Access Journals (Sweden)

    Kapil Goel

    2012-03-01

    Full Text Available Eliminating child labour is one of the biggest challenges that the world is facing. Child labour not only causes damage to a child’s physical and mental health but also keeps him deprived of his basic rights to education, development, and freedom. Children of lower socio-economic class are known to be inducted as child labour. The main causes of child labour include poverty, unemployment, excess population and urbanization. The construction sector is one of the most hazardous working environments especially for children. Children are exposed to dangerous machinery causing fatal and non-fatal injuries, while operating or working near them. Children are exposed to strenuous labour, which can affect the musculo-skeletal development of the children. In industries, child workers are exposed to various physical, mental, social occupational hazards resulting in lower growth and poor health status. Working long hours, child labourers are often denied a basic school education, normal social interaction, personal development and emotional support from their family. The Child Labour Act was implemented in India in 1986 that outlaws child labour in certain areas and sets the minimum age of employment at fourteen. Eradicating poverty is only the first step on the road for eliminating child labour. There is an urgent need for intensive focus and research along with political and practical decisions to improve the conditions of working children for the betterment of their health and development. Proper education of the children and banning child labor will help in boosting the success of the country.

  1. An enhanced artificial bee colony algorithm (EABC for solving dispatching of hydro-thermal system (DHTS problem.

    Directory of Open Access Journals (Sweden)

    Yi Yu

    Full Text Available The dispatching of hydro-thermal system is a nonlinear programming problem with multiple constraints and high dimensions and the solution techniques of the model have been a hotspot in research. Based on the advantage of that the artificial bee colony algorithm (ABC can efficiently solve the high-dimensional problem, an improved artificial bee colony algorithm has been proposed to solve DHTS problem in this paper. The improvements of the proposed algorithm include two aspects. On one hand, local search can be guided in efficiency by the information of the global optimal solution and its gradient in each generation. The global optimal solution improves the search efficiency of the algorithm but loses diversity, while the gradient can weaken the loss of diversity caused by the global optimal solution. On the other hand, inspired by genetic algorithm, the nectar resource which has not been updated in limit generation is transformed to a new one by using selection, crossover and mutation, which can ensure individual diversity and make full use of prior information for improving the global search ability of the algorithm. The two improvements of ABC algorithm are proved to be effective via a classical numeral example at last. Among which the genetic operator for the promotion of the ABC algorithm's performance is significant. The results are also compared with those of other state-of-the-art algorithms, the enhanced ABC algorithm has general advantages in minimum cost, average cost and maximum cost which shows its usability and effectiveness. The achievements in this paper provide a new method for solving the DHTS problems, and also offer a novel reference for the improvement of mechanism and the application of algorithms.

  2. An enhanced artificial bee colony algorithm (EABC) for solving dispatching of hydro-thermal system (DHTS) problem.

    Science.gov (United States)

    Yu, Yi; Wu, Yonggang; Hu, Binqi; Liu, Xinglong

    2018-01-01

    The dispatching of hydro-thermal system is a nonlinear programming problem with multiple constraints and high dimensions and the solution techniques of the model have been a hotspot in research. Based on the advantage of that the artificial bee colony algorithm (ABC) can efficiently solve the high-dimensional problem, an improved artificial bee colony algorithm has been proposed to solve DHTS problem in this paper. The improvements of the proposed algorithm include two aspects. On one hand, local search can be guided in efficiency by the information of the global optimal solution and its gradient in each generation. The global optimal solution improves the search efficiency of the algorithm but loses diversity, while the gradient can weaken the loss of diversity caused by the global optimal solution. On the other hand, inspired by genetic algorithm, the nectar resource which has not been updated in limit generation is transformed to a new one by using selection, crossover and mutation, which can ensure individual diversity and make full use of prior information for improving the global search ability of the algorithm. The two improvements of ABC algorithm are proved to be effective via a classical numeral example at last. Among which the genetic operator for the promotion of the ABC algorithm's performance is significant. The results are also compared with those of other state-of-the-art algorithms, the enhanced ABC algorithm has general advantages in minimum cost, average cost and maximum cost which shows its usability and effectiveness. The achievements in this paper provide a new method for solving the DHTS problems, and also offer a novel reference for the improvement of mechanism and the application of algorithms.

  3. Arsenic in marine tissues — The challenging problems to electrothermal and hydride generation atomic absorption spectrometry

    Science.gov (United States)

    Karadjova, Irina B.; Petrov, Panayot K.; Serafimovski, Ivan; Stafilov, Trajče; Tsalev, Dimiter L.

    2007-03-01

    Analytical problems in determination of arsenic in marine tissues are addressed. Procedures for the determination of total As in solubilized or extracted tissues with tetramethylammonium hydroxide and methanol have been elaborated. Several typical lyophilized tissues were used: NIST SRM 1566a 'Oyster Tissue', BCR-60 CRM 'Trace Elements in an Aquatic Plant ( Lagarosiphon major)', BCR-627 'Forms of As in Tuna Fish Tissue', IAEA-140/TM 'Sea Plant Homogenate', NRCC DOLT-1 'Dogfish Liver' and two representatives of the Black Sea biota, Mediterranean mussel ( Mytilus galloprovincialis) and Brown algae ( Cystoseira barbata). Tissues (nominal 0.3 g) were extracted in tetramethylammonium hydroxide (TMAH) 1 ml of 25% m/v TMAH and 2 ml of water) or 5 ml of aqueous 80% v/v methanol (MeOH) in closed vessels in a microwave oven at 50 °C for 30 min. Arsenic in solubilized or extracted tissues was determined by electrothermal atomic absorption spectrometry (ETAAS) after appropriate dilution (nominally to 25 ml, with further dilution as required) under optimal instrumental parameters (pyrolysis temperature 900 °C and atomization temperature 2100 °C) with 1.5 μg Pd as modifier on Zr-Ir treated platform. Platforms have been pre-treated with 2.7 μmol of zirconium and then with 0.10 μmol of iridium which served as a permanent chemical modifier in direct ETAAS measurements and as an efficient hydride sequestration medium in flow injection hydride generation (FI-HG)-ETAAS. TMAH and methanol extract 96-108% and 51-100% of As from CRMs. Various calibration approaches have been considered and critically evaluated. The effect of species-dependent slope of calibration graph or standard additions plot for total As determination in a sample comprising of several individual As species with different ETAAS behavior has been considered as a kind of 'intrinsic element speciation interference' that cannot be completely overcome by standard additions technique. Calibration by means of CRMs has

  4. E-waste: a problem or an opportunity? Review of issues, challenges and solutions in Asian countries.

    Science.gov (United States)

    Herat, Sunil; Agamuthu, P

    2012-11-01

    Safe management of electronic and electrical waste (e-waste/WEEE) is becoming a major problem for many countries around the world. In particular, developing countries face a number of issues with the generation, transboundary movement and management of e-waste. It is estimated that the world generates around 20-50 million tonnes of e-waste annually, most of it from Asian countries. Improper handling of e-waste can cause harm to the environment and human health because of its toxic components. Several countries around the world are now struggling to deal with this emerging threat. Although the current emphasis is on end-of-life management of e-waste activities, such as reuse, servicing, remanufacturing, recycling and disposal, upstream reduction of e-waste generation through green design and cleaner production is gaining much attention. Environmentally sound management (ESM) of e-waste in developing countries is absent or very limited. Transboundary movement of e-waste is a major issue throughout the region. Dealing with the informal recycling sector is a complex social and environmental issue. There are significant numbers of such challenges faced by these countries in achieving ESM of e-waste. This article aims to present a review of challenges and issues faced by Asian countries in managing their e-waste in a sustainable way.

  5. Conference on "Multidisciplinary approaches to nutritional problems". Rank Prize Lecture. Global nutrition challenges for optimal health and well-being.

    Science.gov (United States)

    Uauy, Ricardo; Corvalan, Camila; Dangour, Alan D

    2009-02-01

    Optimal health and well-being are now considered the true measures of human development. Integrated strategies for infant, child and adult nutrition are required that take a life-course perspective to achieve life-long health. The major nutrition challenges faced today include: (a) addressing the pending burden of undernutrition (low birth weight, severe wasting, stunting and Zn, retinol, Fe, iodine and folic acid deficits) affecting those individuals living in conditions of poverty and deprivation; (b) preventing nutrition-related chronic diseases (obesity, diabetes, CVD, some forms of cancer and osteoporosis) that, except in sub-Saharan Africa, are the main causes of death and disability globally. This challenge requires a life-course perspective as effective prevention starts before conception and continues at each stage of life. While death is unavoidable, premature death and disability can be postponed by providing the right amount and quality of food and by maintaining an active life; (c) delaying or avoiding, via appropriate nutrition and physical activity interventions, the functional declines associated with advancing age. To help tackle these challenges, it is proposed that the term 'malnutrition in all its forms', which encompasses the full spectrum of nutritional disorders, should be used to engender a broader understanding of global nutrition problems. This term may prove particularly helpful when interacting with policy makers and the public. Finally, a greater effort by the UN agencies and private and public development partners is called for to strengthen local, regional and international capacity to support the much needed change in policy and programme activities focusing on all forms of malnutrition with a unified agenda.

  6. On Inverse Coefficient Heat-Conduction Problems on Reconstruction of Nonlinear Components of the Thermal-Conductivity Tensor of Anisotropic Bodies

    Science.gov (United States)

    Formalev, V. F.; Kolesnik, S. A.

    2017-11-01

    The authors are the first to present a closed procedure for numerical solution of inverse coefficient problems of heat conduction in anisotropic materials used as heat-shielding ones in rocket and space equipment. The reconstructed components of the thermal-conductivity tensor depend on temperature (are nonlinear). The procedure includes the formation of experimental data, the implicit gradient-descent method, the economical absolutely stable method of numerical solution of parabolic problems containing mixed derivatives, the parametric identification, construction, and numerical solution of the problem for elements of sensitivity matrices, the development of a quadratic residual functional and regularizing functionals, and also the development of algorithms and software systems. The implicit gradient-descent method permits expanding the quadratic functional in a Taylor series with retention of the linear terms for the increments of the sought functions. This substantially improves the exactness and stability of solution of the inverse problems. Software systems are developed with account taken of the errors in experimental data and disregarding them. On the basis of a priori assumptions of the qualitative behavior of the functional dependences of the components of the thermal-conductivity tensor on temperature, regularizing functionals are constructed by means of which one can reconstruct the components of the thermal-conductivity tensor with an error no higher than the error of the experimental data. Results of the numerical solution of the inverse coefficient problems on reconstruction of nonlinear components of the thermal-conductivity tensor have been obtained and are discussed.

  7. Using Nanobiotechnology to circumvent the "Nonpoint" problem in nonpoint source pollution: Possibilities, challenges, and progress to date

    Science.gov (United States)

    Sharma, Dr; Meyer, Dr; Luo, Dr; Regan, Dr; Walter, Dr

    2009-04-01

    Applying the power of nanoscale technology to answer landscape-scale questions constitutes an exciting new frontier in science and engineering. In this project, we are exploring a possible method of reducing the "nonpoint" problem associated with nonpoint source (NPS) pollution, a problem that has hampered agricultural sustainability and water quality protection for decades. We are developing superparamagnetic polylactic acid (PLA) microspheres incorporating DNA "nanobarcodes" as potential tracers. The eventual goal of this project is to develop technologies for identifying and characterizing different flowpaths at field and watershed scales by using multiple sets of polymer microspheres, each coded with unique DNA sequences, of which there are essentially limitless combinations, i.e., many flowpaths can be uniquely coded. Our ultimate vision is to have the capacity of introducing microsphere-encapsulated DNA at different points in a watershed and collecting these microspheres elsewhere in the watershed; using quantitative, real-time polymerase chain reaction targeted at the specific DNA, we would be able to determine the hydrological linkages and transport times between the collection point(s) and the points of DNA introduction. The potential advantages of this nanotechnology strategy compared to conventional tracers are the elimination of background interferences, the ability to segregate superimposed flowpaths through the design of strictly unique DNA tracers and the biodegradability of the tracers. This presentation highlights recent advances, new challenges, and potential applications for this tracer technology.

  8. Le Resolution de problemes--defi des mathematiques--secondaire--premier cycle (Problem Solving Challenge for Mathematics. Junior High School Curriculum).

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    This document is designed to assist teachers in helping students in further development of problem-solving skills. It consists of: a statement of purpose; an introduction (noting the place of problem-solving in junior high school mathematics curricula); a definition of problem-solving; a four-stage general framework for solving problems (which…

  9. Thermal Conductivity of Diamond Composites

    OpenAIRE

    Fedor M. Shakhov; Kidalov, Sergey V.

    2009-01-01

    A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K) and 400 W/(m·K), respectively. Significantly, the thermal expansion coefficient of metals differ...

  10. Thermal solar power. New Schemes of Principle. Multifamily facilities and his problems; Energia solar termica. Instalaciones multifamiliares y su problematica. Nuevos esquemas de principio

    Energy Technology Data Exchange (ETDEWEB)

    Acedo, M. A.

    2008-07-01

    Article checks the production of warm sanitary water no-central facilities for thermal solar power of low temperature in the multifamily buildings. In order that the governmental incentives are destined only to the objectively well facilities, also some technical problems are checked. (Author)

  11. Usage of Non-Explicit Numerical Diagram of Triple Dimensional Equation of Heat Conduction in Problems of Thermal Treatment Optimization

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available A mathematical model and a program for determination of temperature field dynamics in industrial-scale blanks of unspecified and three-dimensional configuration at thermal treatment according to preset mode are presented in the paper. The paper contains computer-based calculations of temperature field dynamics for a number of blanks at various thermal treatment modes.

  12. Management Strategies of Perceived Challenges and Problems of Old People in Ihitte-Uboma Local Government Area of Imo State, Nigeria

    Science.gov (United States)

    Ojukwu, M. O.; Woko, S. I.

    2016-01-01

    It has been revealed that over the years, the number of the aged in the world has been on a steady increase. This rising number has great implications for government, researchers, families, youth and the society at large. There is therefore, the proper need for the understanding of the nature problems and challenges as well as the management…

  13. Mental health problems among individuals with persistent health challenges from adolescence to young adulthood: a population-based longitudinal study in Norway

    Directory of Open Access Journals (Sweden)

    Sølvi Helseth

    2016-09-01

    Full Text Available Abstract Background Persistent health challenges are increasing throughout the world. It has been shown that adolescents with persistent health challenges are at greater risk of having mental health problems than their healthy peers. However, these studies are mainly cross-sectional, and little is known about the transition to adulthood. Thus, the aim of this study was to examine how mental health problems in adolescents and young adults with persistent health challenges vary during adolescence and in the transition to young adulthood. Methods The study used longitudinal and time-series data from the “Young in Norway” study. A sample of adolescents was prospectively followed from adolescence to young adulthood with measures at four different time points (n = 3,087; T1–T4: 2921 adolescents (12–19 years participated at T1 and T2, while 2448 young adults participated at T3 and T4. Persistent health challenges, age, gender, mental health problems and parental socio-economic status were measured in the longitudinal survey. Regression models were applied to estimate associations between persistent health challenges (understood as having a chronic health condition or disability and mental health problems during adolescence and young adulthood. Different models were tested for chronic health conditions and disability. Results Adolescents with disability had higher scores for depressive and anxiety symptoms, loneliness and self-concept instability, and lower scores for self-worth, appearance satisfaction, scholastic competence and social acceptance compared with adolescents without disability. In young adulthood, there were also significant associations between disability and most mental health problems. The longitudinal associations between chronic health conditions and mental health problems during adolescence and young adulthood showed that significant associations between chronic health conditions and mental health problems were only

  14. A Challenging Issue in the Etiology of Speech Problems: The Effect of Maternal Exposure to Electromagnetic Fields on Speech Problems in the Offspring

    Directory of Open Access Journals (Sweden)

    Zarei S

    2015-05-01

    Full Text Available Background: Nowadays, mothers are continuously exposed to different sources of electromagnetic fields before and even during pregnancy. It has recently been shown that exposure to mobile phone radiation during pregnancy may lead to adverse effects on the brain development in offspring and cause hyperactivity. Researchers have shown that behavioral problems in laboratory animals which have a similar appearance to ADHD are caused by intrauterine exposure to mobile phones. Objective: The purpose of this study was to investigate whether the maternal exposure to different sources of electromagnetic fields affect on the rate and severity of speech problems in their offspring. Methods: In this study, mothers of 35 healthy 3-5 year old children (control group and 77 children and diagnosed with speech problems who had been referred to a speech treatment center in Shiraz, Iran were interviewed. These mothers were asked whether they had exposure to different sources of electromagnetic fields such as mobile phones, mobile base stations, Wi-Fi, cordless phones, laptops and power lines. Results: We found a significant association between either the call time (P=0.002 or history of mobile phone use (months used and speech problems in the offspring (P=0.003. However, other exposures had no effect on the occurrence of speech problems. To the best of our knowledge, this is the first study to investigate a possible association between maternal exposure to electromagnetic field and speech problems in the offspring. Although a major limitation in our study is the relatively small sample size, this study indicates that the maternal exposure to common sources of electromagnetic fields such as mobile phones can affect the occurrence of speech problems in the offspring.

  15. Dancing hot on Ecstasy: physical activity and thermal comfort ratings are associated with the memory and other psychobiological problems reported by recreational MDMA users.

    Science.gov (United States)

    Parrott, A C; Rodgers, J; Buchanan, T; Ling, J; Heffernan, T; Scholey, A B

    2006-07-01

    Non-drug factors such as ambient temperature can heighten the adverse effects of MDMA (3,4-methylendioxymethamphetamine) in animals. We assessed whether dancing and feeling hot on Ecstasy would be associated with more psychobiological problems in recreational users. In an internet study, 206 unpaid participants (modal age 16-24) reported that they had used recreational Ecstasy/MDMA. They completed a drug use questionnaire, the Prospective Memory Questionnaire (PMQ), questions about dancing and feeling hot when on Ecstasy, and psychobiological problems afterwards. Those who danced 'all the time' when on Ecstasy, reported significantly more PMQ memory problems than the less intensive dancers. Prolonged dancing was also associated with more complaints of depression, memory problems, concentration and organizational difficulties afterwards. Feeling hot when on Ecstasy was associated with poor concentration in the comedown period, and with mood fluctuation and impulsivity off-drug. PMQ long-term problems demonstrated a significant curvilinear relationship with thermal self-ratings; more memory problems were noted by those who felt very hot, and by those who did not feel hot when on Ecstasy. Non-drug factors such as dancing and feeling hot are associated with the incidence of psychobiological problems reported by recreational Ecstasy/MDMA users.

  16. An inverse problem in estimating the laser irradiance and thermal damage in laser-irradiated biological tissue with a dual-phase-lag model.

    Science.gov (United States)

    Yang, Yu-Ching; Lee, Haw-Long; Chang, Win-Jin; Chen, Wen-Lih

    2017-03-01

    The aim of this study is to solve an inverse heat conduction problem to estimate the unknown time-dependent laser irradiance and thermal damage in laser-irradiated biological tissue from the temperature measurements taken within the tissue. The dual-phase-lag model is considered in the formulation of heat conduction equation. The inverse algorithm used in the study is based on the conjugate gradient method and the discrepancy principle. The effect of measurement errors and measurement locations on the estimation accuracy is also investigated. Two different examples of laser irradiance are discussed. Results show that the unknown laser irradiance and thermal damage can be predicted precisely by using the present approach for the test cases considered in this study.

  17. Responding to the Problem of Prison Overcrowding in Nigeria through Restorative Justice: A Challenge to the Traditional Criminal Justice System

    National Research Council Canada - National Science Library

    Macpherson U Nnam

    2017-01-01

      The intrinsic interest of this article is to address the problem of prison overcrowding in Nigeria using restorative justice initiative against the traditional criminal justice system, which places...

  18. Responding to the Problem of Prison Overcrowding in Nigeria through Restorative Justice: A Challenge to the Traditional Criminal Justice System

    National Research Council Canada - National Science Library

    Macpherson U Nnam

    2016-01-01

      The intrinsic interest of this article is to address the problem of prison overcrowding in Nigeria using restorative justice initiative against the traditional criminal justice system, which places...

  19. A unified analysis of kinetic models for the problem of thermal creep based on the boundary conditions of Cercignani-Lampis for heterogeneous plates

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Cinara Ewerling da, E-mail: cinara@pb.ifarroupilha.edu.br [Universidade Federal do Rio Grande do Sul (IFF/UFRS), Porto Alegre, RS (Brazil); Instituto Federal Farroupilha, Panambi, RS (Brazil); Knackfuss, Rosenei Felippe, E-mail: knackfuss@smail.ufsm.br [Universidade Federal de Santa Maria (UFSM), Santa Maria, RS (Brazil)

    2013-07-01

    In this work is presented a series of numerical results and graphical comparisons of the physical quantities of interest such as: the velocity profile and the heat on profile. This formulation is developed for the problem of Thermal Creep, where the gas is moving between two parallel plates with different chemical constitutions (heterogeneous plates) due to a temperature gradient. The flow of a rarefied gas, is investigated with special attention to the gas-surface interaction, modeled by the Cercignani-Lampis kernel, that unlike Maxwell's scattering kernel, is defined in terms of two accommodation coefficients (normal and tangential) to represent the physical properties of the gas. The kinetic theory for rarefied gas dynamics, derived from the linearized Boltzmann equation, is developed in an unified approach, to the BGK model, S model, GJ model and MRS model. In the search for solutions to solve the problem of Thermal Creep with kernel of the Cercignani-Lampis, we used a analytical version of the discrete ordinates method (ADO) based on an arbitrary quadrature scheme, under which is determined a problem of eigenvalues and their respective separation constants. Numerical results are developed by the computer program FORTRAN. (author)

  20. Numerical simulation of long-period fluid temperature fluctuation at a mixing tee for the thermal fatigue problem

    Energy Technology Data Exchange (ETDEWEB)

    Utanohara, Yoichi, E-mail: utanohara@inss.co.jp [Institute of Nuclear Safety System, Inc., 64 Sata, Mihama-cho, Mikata-gun, Fukui 919-1205 (Japan); Nakamura, Akira, E-mail: a-naka@inss.co.jp [Institute of Nuclear Safety System, Inc., 64 Sata, Mihama-cho, Mikata-gun, Fukui 919-1205 (Japan); Miyoshi, Koji, E-mail: miyoshi.koji@inss.co.jp [Institute of Nuclear Safety System, Inc., 64 Sata, Mihama-cho, Mikata-gun, Fukui 919-1205 (Japan); Kasahara, Naoto, E-mail: kasahara@n.t.u-tokyo.ac.jp [University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2016-08-15

    Highlights: • A large eddy simulation of a mixing tee was carried out. • Fluid temperature fluctuation could be predicted qualitatively. • Grid convergence was almost attained and the simulation continued until 100 s. • A longer-period temperature fluctuation than the well-known St = 0.2 appeared. • Prediction of long-period temperature fluctuations improves the thermal fatigue assessment. - Abstract: Thermal fatigue cracks may be initiated at mixing tees where high and low temperature fluids flow in and mix. According to a previous study, damage by thermal fatigue depends on the frequency of the fluid temperature fluctuation near the wall surface. Structures have the time constant of structural response that depends on physical properties of the structure and the gain of the frequency response tends to become maximum at the frequency lower than the typical frequency of fluid temperature fluctuation. Hence the effect of the lower frequency, that is, long-period temperature fluctuation is important for the thermal fatigue assessment. The typical frequency of fluid temperature fluctuation is about St = 0.2 (nearly 6 Hz), where St is Strouhal number and means non-dimensional frequency. In the experimental study by Miyoshi et al. (2014), a longer-period fluctuation than St = 0.2 was also observed. Results of a fluid–structure coupled analysis by Kamaya et al. (2011) showed this long-period temperature fluctuation causes severer damage to piping. In the present study, a large eddy simulation was carried out to investigate the predictive performance of the long-period fluid temperature fluctuation more quantitatively. Numerical simulation was conducted for the WATLON experiment which was the water experiment of a mixing tee performed at the Japan Atomic Energy Agency. Four computational grids were used to confirm grid convergence. In the short time (9 s) simulations, tendencies of time-averaged and fluctuated velocities could be followed. Time

  1. Problems and Challenges for the Politics of Education before the Change of Prominence Experienced by Educational Actors

    Science.gov (United States)

    Fernández-Soria, Juan Manuel

    2013-01-01

    This paper deals with some of the problems that the Politics of Education has to face both as a subject and as a government action. Based above all on the literature appeared in specialized journals during the last five years, our attention is firstly focused on the concern for using an active methodology in the teaching of this subject which…

  2. Nutritional Problems of the Sixties and Seventies and Challenges of the Eighties. Occasional Paper, Volume II, Number 8.

    Science.gov (United States)

    High, Edward G.

    Summarized in this address are the results of a number of nutritional surveys from the sixties and seventies. Nutritional problems have been identified in a number of areas that cut across all socioeconomic and racial groups, the focus being on studies in rural South Carolina, Georgia, and Tennessee. Changes in nutrition with age and changes in…

  3. Challenging Temperament, Teacher-Child Relationships, and Behavior Problems in Urban Low-Income Children: A Longitudinal Examination

    Science.gov (United States)

    McCormick, Meghan P.; Turbeville, Ashley R.; Barnes, Sophie P.; McClowry, Sandee G.

    2014-01-01

    Research Findings: Racial/ethnic minority low-income children with temperaments high in negative reactivity are at heightened risk for developing disruptive behavior problems. Teacher-child relationships characterized by high levels of closeness and low levels of conflict may protect against the development of disruptive behaviors in school. The…

  4. Mesoscale Benchmark Demonstration Problem 1: Mesoscale Simulations of Intra-granular Fission Gas Bubbles in UO2 under Post-irradiation Thermal Annealing

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert; Gao, Fei; Sun, Xin; Tonks, Michael; Biner, Bullent; Millet, Paul; Tikare, Veena; Radhakrishnan, Balasubramaniam; Andersson , David

    2012-04-11

    A study was conducted to evaluate the capabilities of different numerical methods used to represent microstructure behavior at the mesoscale for irradiated material using an idealized benchmark problem. The purpose of the mesoscale benchmark problem was to provide a common basis to assess several mesoscale methods with the objective of identifying the strengths and areas of improvement in the predictive modeling of microstructure evolution. In this work, mesoscale models (phase-field, Potts, and kinetic Monte Carlo) developed by PNNL, INL, SNL, and ORNL were used to calculate the evolution kinetics of intra-granular fission gas bubbles in UO2 fuel under post-irradiation thermal annealing conditions. The benchmark problem was constructed to include important microstructural evolution mechanisms on the kinetics of intra-granular fission gas bubble behavior such as the atomic diffusion of Xe atoms, U vacancies, and O vacancies, the effect of vacancy capture and emission from defects, and the elastic interaction of non-equilibrium gas bubbles. An idealized set of assumptions was imposed on the benchmark problem to simplify the mechanisms considered. The capability and numerical efficiency of different models are compared against selected experimental and simulation results. These comparisons find that the phase-field methods, by the nature of the free energy formulation, are able to represent a larger subset of the mechanisms influencing the intra-granular bubble growth and coarsening mechanisms in the idealized benchmark problem as compared to the Potts and kinetic Monte Carlo methods. It is recognized that the mesoscale benchmark problem as formulated does not specifically highlight the strengths of the discrete particle modeling used in the Potts and kinetic Monte Carlo methods. Future efforts are recommended to construct increasingly more complex mesoscale benchmark problems to further verify and validate the predictive capabilities of the mesoscale modeling

  5. Thermal Conductivity of Diamond Composites

    Science.gov (United States)

    Kidalov, Sergey V.; Shakhov, Fedor M.

    2009-01-01

    A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K) and 400 W/(m·K), respectively. Significantly, the thermal expansion coefficient of metals differs markedly from those of the materials employed in semiconductor electronics (mostly silicon); one should add here the low electrical resistivity metals possess. By contrast, natural single-crystal diamond is known to feature the highest thermal conductivity of all the bulk materials studied thus far, as high as 2,200 W/(m·K). Needless to say, it cannot be applied in heat removal technology because of high cost. Recently, SiC- and AlN-based ceramics have started enjoying wide use as heat sink materials; the thermal conductivity of such composites, however, is inferior to that of metals by nearly a factor two. This prompts a challenging scientific problem to develop diamond-based composites with thermal characteristics superior to those of aluminum and copper, adjustable thermal expansion coefficient, low electrical conductivity and a moderate cost, below that of the natural single-crystal diamond. The present review addresses this problem and appraises the results reached by now in studying the possibility of developing composites in diamond-containing systems with a view of obtaining materials with a high thermal conductivity.

  6. Thermal Conductivity of Diamond Composites

    Directory of Open Access Journals (Sweden)

    Fedor M. Shakhov

    2009-12-01

    Full Text Available A major problem challenging specialists in present-day materials sciences is the development of compact, cheap to fabricate heat sinks for electronic devices, primarily for computer processors, semiconductor lasers, high-power microchips, and electronics components. The materials currently used for heat sinks of such devices are aluminum and copper, with thermal conductivities of about 250 W/(m·K and 400 W/(m·K, respectively. Significantly, the thermal expansion coefficient of metals differs markedly from those of the materials employed in semiconductor electronics (mostly silicon; one should add here the low electrical resistivity metals possess. By contrast, natural single-crystal diamond is known to feature the highest thermal conductivity of all the bulk materials studied thus far, as high as 2,200 W/(m·K. Needless to say, it cannot be applied in heat removal technology because of high cost. Recently, SiC- and AlN-based ceramics have started enjoying wide use as heat sink materials; the thermal conductivity of such composites, however, is inferior to that of metals by nearly a factor two. This prompts a challenging scientific problem to develop diamond-based composites with thermal characteristics superior to those of aluminum and copper, adjustable thermal expansion coefficient, low electrical conductivity and a moderate cost, below that of the natural single-crystal diamond. The present review addresses this problem and appraises the results reached by now in studying the possibility of developing composites in diamond-containing systems with a view of obtaining materials with a high thermal conductivity.

  7. Integrating on campus problem based learning and practice based learning: issues and challenges in using computer mediated communication.

    Science.gov (United States)

    Conway, J; Sharkey, R

    2002-10-01

    The Faculty of Nursing, University of Newcastle, Australia, has been keen to initiate strategies that enhance student learning and nursing practice. Two strategies are problem based learning (PBL) and clinical practice. The Faculty has maintained a comparatively high proportion of the undergraduate hours in the clinical setting in times when financial constraints suggest that simulations and on campus laboratory experiences may be less expensive.Increasingly, computer based technologies are becoming sufficiently refined to support the exploration of nursing practice in a non-traditional lecture/tutorial environment. In 1998, a group of faculty members proposed that computer mediated instruction would provide an opportunity for partnership between students, academics and clinicians that would promote more positive outcomes for all and maintain the integrity of the PBL approach. This paper discusses the similarities between problem based and practice based learning and presents the findings of an evaluative study of the implementation of a practice based learning model that uses computer mediated communication to promote integration of practice experiences with the broader goals of the undergraduate curriculum.

  8. Challenges in designing appropriate scaffolding to improve students' representational consistency: The case of a Gauss's law problem

    Science.gov (United States)

    Maries, Alexandru; Lin, Shih-Yin; Singh, Chandralekha

    2017-12-01

    Prior research suggests that introductory physics students have difficulty with graphing and interpreting graphs. Here, we discuss an investigation of student difficulties in translating between mathematical and graphical representations for a problem in electrostatics and the effect of increasing levels of scaffolding on students' representational consistency. Students in calculus-based introductory physics were given a typical problem that can be solved using Gauss's law involving a spherically symmetric charge distribution in which they were asked to write a mathematical expression for the electric field in various regions and then plot the electric field. In study 1, we found that students had great difficulty in plotting the electric field as a function of the distance from the center of the sphere consistent with the mathematical expressions in various regions, and interviews with students suggested possible reasons which may account for this difficulty. Therefore, in study 2, we designed two scaffolding interventions with levels of support which built on each other (i.e., the second scaffolding level built on the first) in order to help students plot their expressions consistently and compared the performance of students provided with scaffolding with a comparison group which was not given any scaffolding support. Analysis of student performance with different levels of scaffolding reveals that scaffolding from an expert perspective beyond a certain level may sometimes hinder student performance and students may not even discern the relevance of the additional support. We provide possible interpretations for these findings based on in-depth, think-aloud student interviews.

  9. Emotional and Behavioral Problems in Children Living With Addicted Family Members: Prevention Challenges in an Underprivileged Suburban Community

    Directory of Open Access Journals (Sweden)

    Thaís dos Reis Vilela

    2016-08-01

    Full Text Available Abstract Children living with substance abusers are more likely to experience negative outcomes. Our goal was to compare caregivers' reports on the Child Behavior Checklist (CBCL and a socioeconomic and risk form of psychological aspects of children exposed to substance abuse assisted versus not assisted by a preventive intervention program in an underprivileged community. This observational intervention study was conducted with 66 caregivers of children who attended the program and 35 caregivers of children from the same community who did not attend. Ages ranged between six and 11 years old. Chi-square and logistic regression tests indicate that children exposed to substance abusers have more mental health problems than the general population and those who did not participate in the preventive intervention program presented worse outcomes, with higher rates of behavioral/emotional problems and exposure to risk situations. Results suggest that preventive actions might be helpful to promote the mental health of children at risk, validating the need for public policies and services.

  10. The Formation of the Urban Environment in the West Siberian Oil and Gas Region: Problems and Challenges

    Science.gov (United States)

    Bauer, N. V.; Speranskaya, N. I.; Shabatura, L. N.; Iatsevich, O. E.

    2016-10-01

    The article deals with the problems faced by the person in relation to the culture of creating a sustainable urban environment. The urban environment is seen as space of human existence, influencing its spiritual and physical health. All the experts involved in the urban environment, think about the culture of its formation, unfortunately, only from a departmental point of view. Differently organized human environment inevitably affects behavior, emotional state of a man, his perception and understanding of space. The cultural heritage of society fits in the space of an artificial environment created by a man, and determines the behavior of people.For the solution of problems of formation of the urban environment, it is necessary to apply a set of interrelated technical, social, environmental, aesthetic and other measures. In this capacity, landscape design as a set of methods has to build a sustainable urban environment to ensure harmonious living.Current trends, methods, and techniques of landscape design are to create sustainable environment for a person - creative, spiritual, comfortable, attractive, safe, harmonious.

  11. The learning potentials and challenges when integrating Web 2.0 in a problem-based learning approach

    DEFF Research Database (Denmark)

    Buus, Lillian

    The research makes a triple co-construction between problem-based learning (PBL), learning design and action research within the area of networked learning. The complexity this creates in the research can lead it in many different directions, because it builds on collaboration, interaction...... and “elements” in motion. The authors' assumption is built on the perspective that knowledge is constructed in social collaborative interactions between people. Furthermore, she claims that the ideology of Web 2.0 provides research opportunities to study phenomena also found in PBL and networked learning...... such as student-centred (user-generated) content, active participation (creating), interaction, (social) networking, knowledge sharing, and collaborating and cooperating in a social context. Based on the findings in the research, the authors' claim has proved to be valid. She presents different learning...

  12. Challenges in designing appropriate scaffolding to improve students’ representational consistency: The case of a Gauss’s law problem

    Directory of Open Access Journals (Sweden)

    Alexandru Maries

    2017-08-01

    Full Text Available Prior research suggests that introductory physics students have difficulty with graphing and interpreting graphs. Here, we discuss an investigation of student difficulties in translating between mathematical and graphical representations for a problem in electrostatics and the effect of increasing levels of scaffolding on students’ representational consistency. Students in calculus-based introductory physics were given a typical problem that can be solved using Gauss’s law involving a spherically symmetric charge distribution in which they were asked to write a mathematical expression for the electric field in various regions and then plot the electric field. In study 1, we found that students had great difficulty in plotting the electric field as a function of the distance from the center of the sphere consistent with the mathematical expressions in various regions, and interviews with students suggested possible reasons which may account for this difficulty. Therefore, in study 2, we designed two scaffolding interventions with levels of support which built on each other (i.e., the second scaffolding level built on the first in order to help students plot their expressions consistently and compared the performance of students provided with scaffolding with a comparison group which was not given any scaffolding support. Analysis of student performance with different levels of scaffolding reveals that scaffolding from an expert perspective beyond a certain level may sometimes hinder student performance and students may not even discern the relevance of the additional support. We provide possible interpretations for these findings based on in-depth, think-aloud student interviews.

  13. Challenges and opportunities in coding the commons: problems, procedures, and potential solutions in large-N comparative case studies

    Directory of Open Access Journals (Sweden)

    Elicia Ratajczyk

    2016-09-01

    Full Text Available On-going efforts to understand the dynamics of coupled social-ecological (or more broadly, coupled infrastructure systems and common pool resources have led to the generation of numerous datasets based on a large number of case studies. This data has facilitated the identification of important factors and fundamental principles which increase our understanding of such complex systems. However, the data at our disposal are often not easily comparable, have limited scope and scale, and are based on disparate underlying frameworks inhibiting synthesis, meta-analysis, and the validation of findings. Research efforts are further hampered when case inclusion criteria, variable definitions, coding schema, and inter-coder reliability testing are not made explicit in the presentation of research and shared among the research community. This paper first outlines challenges experienced by researchers engaged in a large-scale coding project; then highlights valuable lessons learned; and finally discusses opportunities for further research on comparative case study analysis focusing on social-ecological systems and common pool resources.

  14. Simulated Annealing Approach to the Temperature-Emissivity Separation Problem in Thermal Remote Sensing Part One: Mathematical Background

    CERN Document Server

    Morgan, John A

    2016-01-01

    The method of simulated annealing is adapted to the temperature-emissivity separation (TES) problem. A patch of surface at the bottom of the atmosphere is assumed to be a greybody emitter with spectral emissivity $\\epsilon(k)$ describable by a mixture of spectral endmembers. We prove that a simulated annealing search conducted according to a suitable schedule converges to a solution maximizing the $\\textit{A-Posteriori}$ probability that spectral radiance detected at the top of the atmosphere originates from a patch with stipulated $T$ and $\\epsilon(k)$. Any such solution will be nonunique. The average of a large number of simulated annealing solutions, however, converges almost surely to a unique Maximum A-Posteriori solution for $T$ and $\\epsilon(k)$. The limitation to a stipulated set of endmember emissivities may be relaxed by allowing the number of endmembers to grow without bound, and to be generic continuous functions of wavenumber with bounded first derivatives with respect to wavenumber.

  15. Problem trap final repository. Social challenges concerning nuclear waste; Problemfalle Endlager. Gesellschaftliche Herausforderungen im Umgang mit Atommuell

    Energy Technology Data Exchange (ETDEWEB)

    Brunnengraeber, Achim (ed.)

    2016-07-01

    How is it possible that there is still no final storage facility in the entire world for highly radioactive waste from nuclear power stations? How is it possible that electricity has been generated by industrial-scale nuclear installations for decades without the issue of the disposal of nuclear waste having been resolved? The events in Chernobyl in 1986 and Fukushima in 2011 have made it blatantly obvious how risky this technology is and how important it is to keep humans and the environment at a safe distance from radioactivity. This anthology examines the technological, political, social and economic dimensions of the permanent disposal of nuclear waste. It provides an insight into the emergence of the problem and the people involved and their interests. It describes and analyses the changes that are taking place in Germany (for instance, in relation to the government's commission on nuclear repositories) and other countries with regard to how they handle nuclear waste. The book deals with both questions related to socio-technical aspects of the permanent disposal of nuclear waste and calls for the democratic need for participation and new ways of doing so, without which the search for a permanent disposal site will not bear fruit. This anthology presents a comprehensive discussion of the disposal of nuclear waste and the search for a permanent repository for it. Not only will students and teachers find it extremely useful, but so will any readers who are interested in its subject matter and wish to gain a more in-depth insight into it.

  16. The Pitt Innovation Challenge (PInCh): Driving Innovation in Translational Research Through an Incentive-Based, Problem-Focused Competition.

    Science.gov (United States)

    Fitzpatrick, Nicole Edgar; Maier, John; Yasko, Laurel; Mathias, David; Qua, Kacy; Wagner, Erika; Miller, Elizabeth; Reis, Steven E

    2017-05-01

    Translational research aims to move scientific discoveries across the biomedical spectrum from the laboratory to humans, and to ultimately transform clinical practice and public health policies. Despite efforts to accelerate translational research through national initiatives, several major hurdles remain. The authors created the Pitt Innovation Challenge (PInCh) as an incentive-based, problem-focused approach to solving identified clinical or public health problems at the University of Pittsburgh Clinical and Translational Science Institute in spring 2014. With input from a broad range of stakeholders, PInCh leadership arrived at the challenge question: How do we empower individuals to take control of their own health outcomes? The authors developed the PInCh's three-round proposal submission and review process as well as an online contest management tool to support the process. Ninety-two teams submitted video proposals in round one. Proposals included mobile applications (29; 32%), other information technology (19; 21%), and community program (22; 24%) solutions. Ten teams advanced to the final round, where three were awarded $100,000 to implement their solution over 12 months. In a 6-month follow-up survey, 6/11 (55%) team leaders stated the PInCh helped to facilitate connections outside their normal sphere of collaborators. Additional educational training sessions related to problem-focused research will be developed. The PInCh will be expanded to engage investment and industry communities to facilitate the translation of solutions to clinical practice via commercialization pathways. External organizations and other universities will be engaged to use the PInCh as a mechanism to fuel innovation in their spaces.

  17. Fundamentals of Thermal Expansion and Thermal Contraction

    OpenAIRE

    Liu, Zi-Kui; Shang, Shun-Li; Wang, Yi

    2017-01-01

    Thermal expansion is an important property of substances. Its theoretical prediction has been challenging, particularly in cases the volume decreases with temperature, i.e., thermal contraction or negative thermal expansion at high temperatures. In this paper, a new theory recently developed by the authors has been reviewed and further examined in the framework of fundamental thermodynamics and statistical mechanics. Its applications to cerium with colossal thermal expansion and Fe3Pt with th...

  18. [A challenge to primary open-angle glaucoma including normal-pressure. Clinical problems and their scientific solution].

    Science.gov (United States)

    Sugiyama, Kazuhisa

    2012-03-01

    Primary open-angle glaucoma (POAG), including normal-tension glaucoma (NTG), is reported by the Tajimi Study to afflict 3.9% of the total population, and this represents about 80% of all total glaucoma cases which, in total, afflict 5.0% of the population. We tried to analyze the clinical problems relating to POAG by looking at the pathogenesis, intraocular pressure (IOP), therapy, neuroprotection and surgery of the disease. To elucidate the pathogenesis of glaucoma progression, we measured retinal nerve fiber layer defect (RNFLD) angles', and divided the NTG cases into 2 groups, enlarged RNFLD and stable RNFLD. Disc hemorrhages were found to be significantly more frequent in the enlarged group than in the stable group. RNFLD was enlarged in the direction of disc hemorrhage in over 80% of the eyes. In the majority of the eyes of the enlarged group, the enlargement of RNFLD was toward the fovea. The enlargement of RNFLD in NTG was closely associated with disc hemorrhage and the deterioration of the visual field. We developed a simultaneous structure and function evaluation technique combining spectral-domain (SD) optical coherence tomography (OCT) and fundus-oriented perimeters for the detection of visual field abnormalities in the RNFLD area. We superimposed the ganglion cell complex map obtained by SD-OCT on the fundus-oriented perimeter image. We observed very early or preperimetric normal pressure glaucoma as well as disc hemorrhage adjacent to the borders of the RNFLD. The borderline of the RNFLD seemed to be the thinnest RNFL and had the lowest retinal sensitivity (Active site for RNFLD progression). To clarify the role of the circadian clock genes in the generation of a 24-hour IOP rhythm, we used the microneedle method to measure the IOP at eight time points daily, both in wild type mice and Cry-deficient (Cry 1-/-Cry 2-/-) mice. In the wild-type mice living in light-dark conditions, the pressure measured in the light phase was significantly lower than in

  19. 'A Labour of Love': A King's College London Psychiatry Society Event to challenge the stigma attached to mental health problems in post-natal women.

    Science.gov (United States)

    Hankir, Ahmed; Brothwood, Phillipa; Crocker, Bethany; Lim, Mao Fong; Lever, Isabel; Carrick, Frederick; Zaman, Rashid; Jones, Charlotte Wilson

    2017-09-01

    On the 9th October 2000, Dr Daksha Emson, a London based psychiatrist with bipolar affective disorder, tragically killed herself and her three-month-old baby daughter during a psychotic episode. An independent inquiry into Dr Emson's death concluded that mental health stigma in the National Health Service was a factor that contributed to her death. Despite the morbidity and mortality attributed to the stigma attached to post-natal mental health problems there are very few programmes that have been developed to challenge it. King's College London Undergraduate Psychiatry Society organized an event entitled, 'A Labour of Love': Perinatal Mental Health to address this issue. The event included a talk from an expert by experience, a mother who developed post-partum mental health problems. We conducted a single-arm, pre-post comparison study on participants who attended the KCL Psych Soc event. Validated stigma scales on knowledge (Mental Health Knowledge Schedule (MAKS)), attitudes (Community Attitudes towards the Mentally Ill (CAMI)) and behaviour (Reported and Intended Behaviour Scale (RIBS)) were administered before and immediately after exposure to the event. 27/27 (100%) of participants recruited responded. There was a statistically significant difference in the pre-MAKS score compared to the post-MAKS score (p=0.0003), the pre-RIBS score compared to the post-RIBS score (p=0.0068) and in the pre-CAMI score compared to the post-CAMI score (p=0.0042). There were statistically significant reductions in stigma in the domains of knowledge, attitude and behavior following exposure to the KCL Psych Soc event and no adverse effects were reported. Our study revealed that a brief intervention made a highly significant impact and maybe useful in challenging the stigma around post-natal mental illness. However, more research in this area is required to determine if the changes are sustained before we can consider rolling out and scaling up such an initiative nationally and

  20. Recruitment, advising, and retention programs - Challenges and solutions to the international problem of poor nursing student retention: A narrative literature review.

    Science.gov (United States)

    Mooring, Quanza E

    2016-05-01

    The aim of this literature review was to identify emerging themes in current research to identify challenges to nursing student retention internationally, as well as strategies to improve persistence. A narrative literature review was conducted. Using CINAHL and HealthSource databases, journal articles were reviewed and evaluated for emerging themes related to the causes of high nursing student attrition rates and strategies to overcome this issue. A five-step approach was used to complete the narrative review, beginning with problem identification, followed by the literature search, data analysis, theme emergence and synthesis of the information. The literature review supports the idea that poor retention is related not only to student ability, but also to a lack of necessary intervention by faculty beginning with the admission process and continuing throughout the curriculum. Alterations should be made in the recruitment and student selection process. Aggressive academic advising strategies should be implemented, and retention programs should be interwoven in to the nursing curriculum. Student retention is a multifaceted issue that requires a multi-modal approach. Changes in recruitment, implementation of academic advising, and curriculum integration have the potential to help correct the problem. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Theory of thermal stresses

    CERN Document Server

    Boley, Bruno A

    1997-01-01

    Highly regarded text presents detailed discussion of fundamental aspects of theory, background, problems with detailed solutions. Basics of thermoelasticity, heat transfer theory, thermal stress analysis, more. 1985 edition.

  2. Mercury emissions from flooded soils and sediments in Germany are an underestimated problem: challenges for reliable risk assessments and management strategies

    Directory of Open Access Journals (Sweden)

    Rinklebe J.

    2013-04-01

    -polluted floodplain soils in Germany and that those emissions are an underestimated problem. Current needs for reliable risk assessments, the induced implications for authorities, and future challenges will be discussed. The presented data will contribute to a better understanding of seasonal dynamics of Hg fluxes and its controlling factors. This presentation should be of large interest for a wide international audience, such as environmental scientists and managers, applied ecologists, and authorities.

  3. Parallel thermal radiation transport in two dimensions

    Energy Technology Data Exchange (ETDEWEB)

    Smedley-Stevenson, R.P.; Ball, S.R. [AWE Aldermaston (United Kingdom)

    2003-07-01

    This paper describes the distributed memory parallel implementation of a deterministic thermal radiation transport algorithm in a 2-dimensional ALE hydrodynamics code. The parallel algorithm consists of a variety of components which are combined in order to produce a state of the art computational capability, capable of solving large thermal radiation transport problems using Blue-Oak, the 3 Tera-Flop MPP (massive parallel processors) computing facility at AWE (United Kingdom). Particular aspects of the parallel algorithm are described together with examples of the performance on some challenging applications. (author)

  4. Behavioural treatment for sleep problems in children with severe learning disabilities and challenging daytime behaviour: effect on sleep patterns of mother and child

    National Research Council Canada - National Science Library

    Wiggs, L; Stores, G

    1998-01-01

    .... This randomized controlled trial of behavioural interventions for the children's sleep problems was conducted to explore the efficacy and mechanisms of treatment in children with the most extreme forms of problems...

  5. The lesser known challenge of climate change: thermal variance and sex-reversal in vertebrates with temperature-dependent sex determination.

    Directory of Open Access Journals (Sweden)

    Jennifer L Neuwald

    Full Text Available Climate change is expected to disrupt biological systems. Particularly susceptible are species with temperature-dependent sex determination (TSD, as in many reptiles. While the potentially devastating effect of rising mean temperatures on sex ratios in TSD species is appreciated, the consequences of increased thermal variance predicted to accompany climate change remain obscure. Surprisingly, no study has tested if the effect of thermal variance around high-temperatures (which are particularly relevant given climate change predictions has the same or opposite effects as around lower temperatures. Here we show that sex ratios of the painted turtle (Chrysemys picta were reversed as fluctuations increased around low and high unisexual mean-temperatures. Unexpectedly, the developmental and sexual responses around female-producing temperatures were decoupled in a more complex manner than around male-producing values. Our novel observations are not fully explained by existing ecological models of development and sex determination, and provide strong evidence that thermal fluctuations are critical for shaping the biological outcomes of climate change.

  6. The ITER project technological challenges

    CERN Document Server

    CERN. Geneva; Lister, Joseph; Marquina, Miguel A; Todesco, Ezio

    2005-01-01

    The first lecture reminds us of the ITER challenges, presents hard engineering problems, typically due to mechanical forces and thermal loads and identifies where the physics uncertainties play a significant role in the engineering requirements. The second lecture presents soft engineering problems of measuring the plasma parameters, feedback control of the plasma and handling the physics data flow and slow controls data flow from a large experiment like ITER. The last three lectures focus on superconductors for fusion. The third lecture reviews the design criteria and manufacturing methods for 6 milestone-conductors of large fusion devices (T-7, T-15, Tore Supra, LHD, W-7X, ITER). The evolution of the designer approach and the available technologies are critically discussed. The fourth lecture is devoted to the issue of performance prediction, from a superconducting wire to a large size conductor. The role of scaling laws, self-field, current distribution, voltage-current characteristic and transposition are...

  7. Turbulent Thermalization

    CERN Document Server

    Micha, Raphael; Micha, Raphael; Tkachev, Igor I.

    2004-01-01

    We study, analytically and with lattice simulations, the decay of coherent field oscillations and the subsequent thermalization of the resulting stochastic classical wave-field. The problem of reheating of the Universe after inflation constitutes our prime motivation and application of the results. We identify three different stages of these processes. During the initial stage of ``parametric resonance'', only a small fraction of the initial inflaton energy is transferred to fluctuations in the physically relevant case of sufficiently large couplings. A major fraction is transfered in the prompt regime of driven turbulence. The subsequent long stage of thermalization classifies as free turbulence. During the turbulent stages, the evolution of particle distribution functions is self-similar. We show that wave kinetic theory successfully describes the late stages of our lattice calculation. Our analytical results are general and give estimates of reheating time and temperature in terms of coupling constants and...

  8. The Algebra Teacher's Activity-a-Day, Grades 6-12 Over 180 Quick Challenges for Developing Math and Problem-Solving Skills

    CERN Document Server

    Thompson, Frances McBroom

    2010-01-01

    Fun-filled math problems that put the emphasis on problem-solving strategies and reasoning. The Algebra Teacher's Activity-a-Day offers activities for test prep, warm-ups, down time, homework, or just for fun. These unique activities are correlated with national math education standards and emphasize problem-solving strategies and logical reasoning skills. In many of the activities, students are encouraged to communicate their different approaches to other students in the class.: Filled with dozens of quick and fun algebra activities that can be used inside and outside the classroom; Designed

  9. Conceptual thermal design

    NARCIS (Netherlands)

    Strijk, R.

    2008-01-01

    Present thermal design tools and methods insufficiently support the development of structural concepts engaged by typical practicing designers. Research described in this thesis identifies the main thermal design problems in practice. In addition, models and methods are developed that support an

  10. Dynamic thermal environment and thermal comfort.

    Science.gov (United States)

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Description of the manufacturing challenges in producing the high-temperature reusable surface insulation for the thermal protection system of the Space Shuttle

    Science.gov (United States)

    Forsberg, K.

    1979-01-01

    The paper describes the high-temperature reusable surface insulation for the thermal protection system of the Space Shuttle. This system protects the Space Shuttle Orbiter on reentry and it is an externally attached, rigidized, fibrous silica, machined into 15 x 20 cm tiles. The tiles constitute the High-Temperature Reusable Surface Insulation (HRSI) system, and are used on over 70 percent of the exterior surface where peak temperatures range from 400 to 1260 C. Carbon-carbon leading edges are used in areas where peak temperatures exceed 1650 C, and a Nomex felt flexible insulation system is used in regions below 400 C. Approximately 32,000 tiles are used in the HRSI system, and due to vehicle configuration and aerodynamic requirements no two tiles are alike.

  12. Advanced fingerprinting of high-quality cocoa: Challenges in transferring methods from thermal to differential-flow modulated comprehensive two dimensional gas chromatography.

    Science.gov (United States)

    Magagna, Federico; Liberto, Erica; Reichenbach, Stephen E; Tao, Qingping; Carretta, Andrea; Cobelli, Luigi; Giardina, Matthew; Bicchi, Carlo; Cordero, Chiara

    2017-07-08

    The possibility to transfer methods from thermal to differential-flow modulated comprehensive two-dimensional gas chromatographic (GC×GC) platforms opens interesting perspectives for routine analysis of complex samples. Flow modulated platforms avoid the use of cryogenics, thereby simplifying laboratory operations and analyst supervision during intensive analytical sessions. This study evaluates the feasibility of transferring a fingerprinting method capable of classifying and discriminating cocoa samples based on the volatiles fraction composition according to their origin and processing steps. Previously developed principles of GC×GC method translation are applied to an original fingerprinting method, developed for a loop-type thermal modulated GC×GC-MS system, to engineer a method for a reverse-injection differential flow modulated platform (GC×2GC-MS/FID) with a dual-parallel secondary column and dual detection. Effective method translation preserves analytes elution order, 1D resolution, and 2D pattern coherence. The experimental results confirm the feasibility of translating fingerprinting method conditions while preserving the informative power of 2D peak patterns for sample classification and discrimination. Correct translation enables effective transfer of metadata (e.g., compound names and MS fragmentation patterns) by automatic template transformation and matching from the original/reference method to its translated counterpart. Although the adoption of a narrow bore (i.e. 0.1mm dc) column in the first-dimension enabled operation under close-to-optimal conditions with the differential-flow modulation platform, due to the dual-parallel columns in the second-dimension, it resulted in lower overall method sensitivity. Nevertheless, fingerprinting accuracy was preserved and most of the key-aroma compounds and technological markers were effectively mapped, thus limiting the loss of fingerprinting information. Copyright © 2017 Elsevier B.V. All rights

  13. Diagnosing plant problems

    Science.gov (United States)

    Cheryl A. Smith

    2008-01-01

    Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...

  14. The challenge of estimating the SWOT signal and error spectra over the Ocean and its applications to CalVal and state estimation problems

    Science.gov (United States)

    Ubelmann, C.; Gerald, D.

    2016-12-01

    The SWOT data validation will be a first challenge after launch, as the nature of the measurement, in particular the two-dimensionality at short spatial scales, is new in altimetry. If the comparison with independent observations may be locally possible, a validation of the full signal and error spectrum will be challenging. However, some recent analyses in simulations have shown the possibility to separate the geophysical signals from the spatially coherent instrumental errors in the spectral space, through cross-spectral analysis. These results suggest that rapidly after launch, the instrument error canl be spectrally separated providing some validations and insights on the Ocean energy spectrum, as well as optimal calibrations. Beyond CalVal, such spectral computations will be also essential for producing high-level Ocean estimates (two and three dimensional Ocean state reconstructions).

  15. Integrated Cognitive-neuroscience Architectures for Understanding Sensemaking (ICArUS): A Computational Basis for ICArUS Challenge Problem Design

    Science.gov (United States)

    2014-11-01

    Critical Thinking with Bayesian HELP Storytelling is a powerful device, widely used for organizational learning and personnel training. But a problem... Interaction with Information. Oxford, UK: Oxford University Press. Richey, M. (2014). The mind’s lie: Games-based learning for critical thinking

  16. Solving the problems we face: the United States Environmental Protection Agency, sustainability, and the challenges of the twenty-first century

    Science.gov (United States)

    Addressing the problems of the twenty-first century will require new initiatives that complement traditional regulatory activities. Existing regulations, such as the Clean Air Act and Clean Water Act are important safety nets in the United States for protecting human health and t...

  17. Knapsack problems

    CERN Document Server

    Kellerer, Hans; Pisinger, David

    2004-01-01

    Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num­ ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...

  18. Interplay between thermal and immune ecology: effect of environmental temperature on insect immune response and energetic costs after an immune challenge.

    Science.gov (United States)

    Catalán, Tamara P; Wozniak, Aniela; Niemeyer, Hermann M; Kalergis, Alexis M; Bozinovic, Francisco

    2012-03-01

    Although the study of thermoregulation in insects has shown that infected animals tend to prefer higher temperatures than healthy individuals, the immune response and energetic consequences of this preference remain unknown. We examined the effect of environmental temperature and the energetic costs associated to the activation of the immune response of Tenebrio molitor larvae following a lipopolysaccharide (LPS) challenge. We measured the effect of temperature on immune parameters including phenoloxidase (PO) activity and antibacterial responses. Further as proximal and distal costs of the immune response we determined the standard metabolic rate (SMR) and the loss of body mass (m(b)), respectively. Immune response was stronger at 30°C than was at 10 or 20°C. While SMR at 10 and 20°C did not differ between immune treatments, at 30°C SMR of LPS-treated larvae was almost 25-60% higher than SMR of PBS-treated and naïve larvae. In addition, the loss in m(b) was 1.9 and 4.2 times higher in LPS-treated larvae than in PBS-treated and naïve controls. The immune responses exhibited a positive correlation with temperature and both, SMR and m(b) change, were sensitive to environmental temperature. These data suggest a significant effect of environmental temperature on the immune response and on the energetic costs of immunity. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Ultrahigh Thermal Conductive yet Superflexible Graphene Films.

    Science.gov (United States)

    Peng, Li; Xu, Zhen; Liu, Zheng; Guo, Yan; Li, Peng; Gao, Chao

    2017-07-01

    Electrical devices generate heat at work. The heat should be transferred away immediately by a thermal manager to keep proper functions, especially for high-frequency apparatuses. Besides high thermal conductivity (K), the thermal manager material requires good foldability for the next generation flexible electronics. Unfortunately, metals have satisfactory ductility but inferior K (≤429 W m(-1) K(-1) ), and highly thermal-conductive nonmetallic materials are generally brittle. Therefore, fabricating a foldable macroscopic material with a prominent K is still under challenge. This study solves the problem by folding atomic thin graphene into microfolds. The debris-free giant graphene sheets endow graphene film (GF) with a high K of 1940 ± 113 W m(-1) K(-1) . Simultaneously, the microfolds render GF superflexible with a high fracture elongation up to 16%, enabling it more than 6000 cycles of ultimate folding. The large-area multifunctional GFs can be easily integrated into high-power flexible devices for highly efficient thermal management. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. "Should I prioritize medical problem solving or attentive listening?": the dilemmas and challenges that medical students experience when learning to conduct consultations.

    Science.gov (United States)

    Aper, Leen; Veldhuijzen, Wemke; Dornan, Tim; van de Ridder, Monica; Koole, Sebastiaan; Derese, Anselme; Reniers, Jan

    2015-01-01

    Communication skills can be trained alongside clinical reasoning, history taking or clinical examination skills. This is advocated as a solution to the low transfer of communication skills. Still, students have to integrate the knowledge/skills acquired during different curriculum parts in patient consultations at some point. How do medical students experience these integrated consultations within a simulated environment and in real practice when dealing with responsibility? Six focus groups were conducted with (pre-)/clerkship students. Students were motivated to practice integrated consultations with simulated patients and felt like 'real physicians'. However, their focus on medical problem solving drew attention away from improving their communication skills. Responsibility for real patients triggered students' identity development. This identity formation guided the development of an own consultation style, a process that was hampered by conflicting demands of role models. Practicing complete consultations results in the dilemma of prioritizing medical problem solving above attention for patient communication. Integrated consultation training advances this dilemma to the pre-clerkship period. During clerkships this dilemma is heightened because real patients trigger empathy and responsibility, which invites students to define their role as doctor. When training integrated consultations, educators should pay attention to students' learning priorities and support the development of students' professional identity. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  1. CHALLENGING PROBLEMS OF HYPERTENSION MANAGEMENT: THE EFFECT OF INCREASED HEART RATE AND COMORBIDITIES ON THE CHOICE OF ANTIHYPERTENSIVE THERAPY IN PRACTICE OF CARDIOLOGIST AND THERAPIST. The Conclusion of the Expert Council

    Directory of Open Access Journals (Sweden)

    G. P. Arutyunov

    2015-09-01

    Full Text Available The conclusion of the Expert Council "Challenging problems of hypertension management: the effect of increased heart rate and comorbidities on the choice of antihypertensive therapy in practice of cardiologist and therapist" is presented. Topical issues of hypertensive patient’s treatment, the role of heart rate in hypertension and ways to influence it are considered. The possibility of treatment of hypertensive patients with trandolapril/verapamil SR fixed combination is analyzed separately. The data on the clinical efficacy and protective effects of trandolapril/verapamil SR fixed combination are presented.

  2. Strategies for the Assessment of Metabolic Profiles of Steroid Hormones in View of Diagnostics and Drug Monitoring: Analytical Problems and Challenges.

    Science.gov (United States)

    Plenis, Alina; Oledzka, Ilona; Kowalski, Piotr; Baczek, Tomasz

    2016-01-01

    During the last few years there has been a growing interest in research focused on the metabolism of steroid hormones despite that the study of metabolic hormone pathways is still a difficult and demanding task because of low steroid concentrations and a complexity of the analysed matrices. Thus, there has been an increasing interest in the development of new, more selective and sensitive methods for monitoring these compounds in biological samples. A lot of bibliographic databases for world research literature were structurally searched using selected review question and inclusion/exclusion criteria. Next, the reports of the highest quality were selected using standard tools (181) and they were described to evaluate the advantages and limitations of different approaches in the measurements of the steroids and their metabolites. The overview of the analytical challenges, development of methods used in the assessment of the metabolic pathways of steroid hormones, and the priorities for future research with a special consideration for liquid chromatography (LC) and capillary electrophoresis (CE) techniques have been presented. Moreover, many LC and CE applications in pharmacological and psychological studies as well as endocrinology and sports medicine, taking into account the recent progress in the area of the metabolic profiling of steroids, have been critically discussed. The latest reports show that LC systems coupled with mass spectrometry have the predominant position in the research of steroid profiles. Moreover, CE techniques are going to gain a prominent position in the diagnosis of hormone levels in the near future.

  3. El envejecimiento en España: ¿un reto o problema social? Ageing in Spain: it's a challenge or social problem?

    Directory of Open Access Journals (Sweden)

    Mercedes Abades Porcel

    2012-12-01

    Full Text Available España está sufriendo un proceso de envejecimiento demográfico mucho más rápido que en otros países de la Unión Europea. Las previsiones futuras señalan un crecimiento del subgrupo de mayores de 80 años denominado "sobreenvejecimiento" y sugieren que la tasa de dependencia aumentará en los próximos años. Este estudio presenta una actualización que proporciona la base para la reflexión sobre la importancia del envejecimiento en España. Discute elementos de reflexión sobre el rol del cuidador de la persona mayor y la influencia de los cambios constantes en los sistemas sociales y de salud. Señala el envejecimiento como un serio desafío a la sociedad, y hace hincapié en la necesidad de cambios en el modelo de atención, una mayor sensibilidad y compromiso ético y moral para garantizar la calidad de la atención a las personas mayores.The pace of population ageing is presently faster in Spain than in other European Union countries. Predictions that the over-80-year group will continue to swell suggest that the dependency ratio will increase in coming years. In this paper we present an update that provides the basis for reflection about the significance of aging in Spain. We discuss the role of caregivers for the elderly and the impact of the constant changes on the social and health systems. We examine ageing as a serious challenge to the society, and emphasize the need for changes in the healthcare model, greater sensitivity, and ethical and moral commitment to ensure quality of care.

  4. The Electric Car Challenge.

    Science.gov (United States)

    Diehl, Brian E.

    1997-01-01

    Describes the Electric Car Challenge during which students applied methods of construction to build lightweight, strong vehicles that were powered by electricity. The activity required problem solving, sheet metal work, electricity, design, and construction skills. (JOW)

  5. A Novel Hybridization of Applied Mathematical, Operations Research and Risk-based Methods to Achieve an Optimal Solution to a Challenging Subsurface Contamination Problem

    Science.gov (United States)

    Johnson, K. D.; Pinder, G. F.

    2013-12-01

    The objective of the project is the creation of a new, computationally based, approach to the collection, evaluation and use of data for the purpose of determining optimal strategies for investment in the solution of remediation of contaminant source areas and similar environmental problems. The research focuses on the use of existing mathematical tools assembled in a unique fashion. The area of application of this new capability is optimal (least-cost) groundwater contamination source identification; we wish to identify the physical environments wherein it may be cost-prohibitive to identify a contaminant source, the optimal strategy to protect the environment from additional insult and formulate strategies for cost-effective environmental restoration. The computational underpinnings of the proposed approach encompass the integration into a unique of several known applied-mathematical tools. The resulting tool integration achieves the following: 1) simulate groundwater flow and contaminant transport under uncertainty, that is when the physical parameters such as hydraulic conductivity are known to be described by a random field; 2) define such a random field from available field data or be able to provide insight into the sampling strategy needed to create such a field; 3) incorporate subjective information, such as the opinions of experts on the importance of factors such as locations of waste landfills; 4) optimize a search strategy for finding a potential source location and to optimally combine field information with model results to provide the best possible representation of the mean contaminant field and its geostatistics. Our approach combines in a symbiotic manner methodologies found in numerical simulation, random field analysis, Kalman filtering, fuzzy set theory and search theory. Testing the algorithm for this stage of the work, we will focus on fabricated field situations wherein we can a priori specify the degree of uncertainty associated with the

  6. Intercomparison of Pb-210, Cs-137, Pu-239,240 and C-14-Based Chronologies of Recent Sediments - Problems and Challenges

    Science.gov (United States)

    Baskaran, M. M.

    2016-12-01

    Short-lived naturally-occurring Pb-210 and anthropogenically-delivered Cs-137 are the two most extensively utilized chronometers over the time scale of less than a decade to 60 (Cs-137) to 120 yrs (Pb-210) in a variety of environment including terrestrial and aqueous systems and glaciers. Despite all the advances in the field, still major issues, we confront several issues on the robustness of their applications in these environments. Those include: i) how does the temporal and spatial variations of Pb-210 input to an aqueous environment affect the Pb-210 chronology? ii) how well we are able to quantify the multiple source inputs (atmospheric fallout, watershed erosional input, production of Pb-210 from the decay of SGD-derived Rn-222 and Ra-226, etc); iii) How well are we able to sort out a number of processes that affect the vertical profiles of both Cs-137 and Pb-210 which include sediment mixing (biological and/or physical), sediment focusing/erosion due to bottom currents and transport of sediments in subsurface environment and post-depositional mobility of Cs-137 and Pb-210. In this presentation, the following case studies will be discussed: 1) where there is excellent as well non-agreement between Pb-210 and Cs-137-based chronologies; 2) agreement between Cs-137-based chronology with historical time-marker from Hg mining, while no chronology obtainable from Pb-210; 3) agreement between five different methods of dating in a reservoir; 4) evidence of Cs-137 diffusion in some of the sediment cores, but not in all cores in a small reservoir; and 5) evidence of long-term remineralization based on a comparison of C-14-based ages with those of Pb-210, Cs-137 and Pu-239,240-based methods. We also show evidence Cs-137 diffusion based on a set of laboratory-based diffusion experiments under different pore water chemical conditions. A brief discussion on time resolution and error estimation on ages will be discussed. The challenges in the field of `Anthropocene

  7. Intellectual technologies in the problems of thermal power engineering control: formalization of fuzzy information processing results using the artificial intelligence methodology

    Science.gov (United States)

    Krokhin, G.; Pestunov, A.

    2017-11-01

    Exploitation conditions of power stations in variable modes and related changes of their technical state actualized problems of creating models for decision-making and state recognition basing on diagnostics using the fuzzy logic for identification their state and managing recovering processes. There is no unified methodological approach for obtaining the relevant information is a case of fuzziness and inhomogeneity of the raw information about the equipment state. The existing methods for extracting knowledge are usually unable to provide the correspondence between of the aggregates model parameters and the actual object state. The switchover of the power engineering from the preventive repair to the one, which is implemented according to the actual technical state, increased the responsibility of those who estimate the volume and the duration of the work. It may lead to inadequacy of the diagnostics and the decision-making models if corresponding methodological preparations do not take fuzziness into account, because the nature of the state information is of this kind. In this paper, we introduce a new model which formalizes the equipment state using not only exact information, but fuzzy as well. This model is more adequate to the actual state, than traditional analogs, and may be used in order to increase the efficiency and the service period of the power installations.

  8. Dewey's Challenge to Teachers

    Science.gov (United States)

    Fishman, Stephen M.; McCarthy, Lucille

    2010-01-01

    Given the serious social problems confronting Americans and others worldwide, the authors propose that Dewey's 1932 challenge to teachers is worthy of reconsideration by educators at all levels. In times similar to our own, Dewey challenged teachers to cultivate students' capacities to identify their happiness with what they can do to improve the…

  9. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  10. Thermal properties of nanofluids.

    Science.gov (United States)

    Philip, John; Shima, P D

    2012-11-15

    Colloidal suspensions of fine nanomaterials in the size range of 1-100 nm in carrier fluids are known as nanofluids. For the last one decade, nanofluids have been a topic of intense research due to their enhanced thermal properties and possible heat transfer applications. Miniaturization and increased operating speeds of gadgets warranted the need for new and innovative cooling concepts for better performance. The low thermal conductivity of conventional heat transfer fluid has been a serious impediment for improving the performance and compactness of engineering equipments. Initial studies on thermal conductivity of suspensions with micrometer-sized particles encountered problems of rapid settling of particles, clogging of flow channels and increased pressure drop in the fluid. These problems are resolved by using dispersions of fine nanometer-sized particles. Despite numerous experimental and theoretical studies, it is still unclear whether the thermal conductivity enhancement in nanofluids is anomalous or within the predictions of effective medium theory. Further, many reports on thermal conductivity of nanofluids are conflicting due to the complex issues associated with the surface chemistry of nanofluids. This review provides an overview of recent advances in the field of nanofluids, especially the important material properties that affect the thermal properties of nanofluids and novel approaches to achieve extremely high thermal conductivities. The background information is also provided for beginners to better understand the subject. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Topology Optimization for Convection Problems

    DEFF Research Database (Denmark)

    Alexandersen, Joe

    2011-01-01

    This report deals with the topology optimization of convection problems.That is, the aim of the project is to develop, implement and examine topology optimization of purely thermal and coupled thermomechanical problems,when the design-dependent eects of convection are taken into consideration...... problems, steady-state thermal problems and coupled thermomechanical problems, for a range of objective functions subjected to a volume-fraction constraint. The programme utilises the GCMMA algorithm, by K. Svanberg, to optimize the given problems. Design-dependent side convection has been formulated...... and implemented, where the convection is interpolated into the design-domain and applied upon the boundaries of the design using a density-based interpolation function.The implementation has been tested for both pure thermal analysis, along with thermal and thermomechanical optimization. The solutions to the test...

  12. Ear Problems

    Science.gov (United States)

    ... Women Hair Loss Hand/Wrist/Arm Problems Headaches Hearing Problems Hip Problems Knee Problems Leg Problems Lower Back ... have ear pain or redness but is having problems hearing?YesNo Back to Questions Step 3 Possible Causes ...

  13. Thermal stability and thermal conductivity of phosphorene in phosphorene/graphene van der Waals heterostructures.

    Science.gov (United States)

    Pei, Qing-Xiang; Zhang, Xiaoliang; Ding, Zhiwei; Zhang, Ying-Yan; Zhang, Yong-Wei

    2017-07-14

    Phosphorene, a new two-dimensional (2D) semiconducting material, has attracted tremendous attention recently. However, its structural instability under ambient conditions poses a great challenge to its practical applications. A possible solution for this problem is to encapsulate phosphorene with more stable 2D materials, such as graphene, forming van der Waals heterostructures. In this study, using molecular dynamics simulations, we show that the thermal stability of phosphorene in phosphorene/graphene heterostructures can be enhanced significantly. By sandwiching phosphorene between two graphene sheets, its thermally stable temperature is increased by 150 K. We further study the thermal transport properties of phosphorene and find surprisingly that the in-plane thermal conductivity of phosphorene in phosphorene/graphene heterostructures is much higher than that of the free-standing one, with a net increase of 20-60%. This surprising increase in thermal conductivity arises from the increase in phonon group velocity and the extremely strong phonon coupling between phosphorene and the graphene substrate. Our findings have an important meaning for the practical applications of phosphorene in nanodevices.

  14. Thermal Hydraulic Analysis Using GIS on Application of HTR to Thermal Recovery of Heavy Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Yangping Zhou

    2012-01-01

    Full Text Available At present, large water demand and carbon dioxide (CO2 emissions have emerged as challenges of steam injection for oil thermal recovery. This paper proposed a strategy of superheated steam injection by the high-temperature gas-cooled reactor (HTR for thermal recovery of heavy oil, which has less demand of water and emission of CO2. The paper outlines the problems of conventional steam injection and addresses the advantages of superheated steam injection by HTR from the aspects of technology, economy, and environment. A Geographic Information System (GIS embedded with a thermal hydraulic analysis function is designed and developed to analyze the strategy, which can make the analysis work more practical and credible. Thermal hydraulic analysis using this GIS is carried out by applying this strategy to a reference heavy oil field. Two kinds of injection are considered and compared: wet steam injection by conventional boilers and superheated steam injection by HTR. The heat loss, pressure drop, and possible phase transformation are calculated and analyzed when the steam flows through the pipeline and well tube and is finally injected into the oil reservoir. The result shows that the superheated steam injection from HTR is applicable and promising for thermal recovery of heavy oil reservoirs.

  15. Numerically modeling Brownian thermal noise in amorphous and crystalline thin coatings

    Science.gov (United States)

    Lovelace, Geoffrey; Demos, Nicholas; Khan, Haroon

    2018-01-01

    Thermal noise is expected to be one of the noise sources limiting the astrophysical reach of Advanced LIGO (once commissioning is complete) and third-generation detectors. Adopting crystalline materials for thin, reflecting mirror coatings, rather than the amorphous coatings used in current-generation detectors, could potentially reduce thermal noise. Understanding and reducing thermal noise requires accurate theoretical models, but modeling thermal noise analytically is especially challenging with crystalline materials. Thermal noise models typically rely on the fluctuation-dissipation theorem, which relates the power spectral density of the thermal noise to an auxiliary elastic problem. In this paper, we present results from a new, open-source tool that numerically solves the auxiliary elastic problem to compute the Brownian thermal noise for both amorphous and crystalline coatings. We employ the open-source deal.ii and PETSc frameworks to solve the auxiliary elastic problem using a finite-element method, adaptive mesh refinement, and parallel processing that enables us to use high resolutions capable of resolving the thin reflective coating. We verify numerical convergence, and by running on up to hundreds of compute cores, we resolve the coating elastic energy in the auxiliary problem to approximately 0.1%. We compare with approximate analytic solutions for amorphous materials, and we verify that our solutions scale as expected with changing beam size, mirror dimensions, and coating thickness. Finally, we model the crystalline coating thermal noise in an experiment reported by Cole et al (2013 Nat. Photon. 7 644–50), comparing our results to a simpler numerical calculation that treats the coating as an ‘effectively amorphous’ material. We find that treating the coating as a cubic crystal instead of as an effectively amorphous material increases the thermal noise by about 3%. Our results are a step toward better understanding and reducing thermal noise to

  16. Numerical thermal back-calculation of the Kerava Solar Village underground thermal energy storage

    OpenAIRE

    Oosterbaan, Harm; Janiszewski, Mateusz; Uotinen, Lauri; Siren, Topias; Rinne, Mikael

    2017-01-01

    With increasing pressure to reduce the fraction of energy coming from fossil fuels, there is an increased need for research into feasible, and sustainable energy sources, such as solar energy. The problem with solar energy is the mismatch between supply and demand, and so the energy needs to be stored. This research paper is a part of the project titled “Tackling the Challenges of a Solar-Community Concept in High Latitudes”, and aims in helping to design a thermal energy storage system for s...

  17. Thermal comfort

    CSIR Research Space (South Africa)

    Osburn, L

    2010-01-01

    Full Text Available wider range of temperature limits, saving energy while still satisfying the majority of building occupants. It is also noted that thermal comfort varies significantly between individuals and it is generally not possible to provide a thermal environment...

  18. James Webb Space Telescope Integrated Science Instrument Module Thermal Vacuum Thermal Balance Test Campaign at NASA's Goddard Space Flight Center

    Science.gov (United States)

    Glazer, Stuart; Comber, Brian (Inventor)

    2016-01-01

    The James Webb Space Telescope is a large infrared telescope with a 6.5-meter primary mirror, designed as a successor to the Hubble Space Telescope when launched in 2018. Three of the four science instruments contained within the Integrated Science Instrument Module (ISIM) are passively cooled to their operational temperature range of 36K to 40K with radiators, and the fourth instrument is actively cooled to its operational temperature of approximately 6K. Thermal-vacuum testing of the flight science instruments at the ISIM element level has taken place in three separate highly challenging and extremely complex thermal tests within a gaseous helium-cooled shroud inside Goddard Space Flight Centers Space Environment Simulator. Special data acquisition software was developed for these tests to monitor over 1700 flight and test sensor measurements, track over 50 gradients, component rates, and temperature limits in real time against defined constraints and limitations, and guide the complex transition from ambient to final cryogenic temperatures and back. This extremely flexible system has proven highly successful in safeguarding the nearly $2B science payload during the 3.5-month-long thermal tests. Heat flow measurement instrumentation, or Q-meters, were also specially developed for these tests. These devices provide thermal boundaries o the flight hardware while measuring instrument heat loads up to 600 mW with an estimated uncertainty of 2 mW in test, enabling accurate thermal model correlation, hardware design validation, and workmanship verification. The high accuracy heat load measurements provided first evidence of a potentially serious hardware design issue that was subsequently corrected. This paper provides an overview of the ISIM-level thermal-vacuum tests and thermal objectives; explains the thermal test configuration and thermal balances; describes special measurement instrumentation and monitoring and control software; presents key test thermal results

  19. Cognitive Challenges

    Science.gov (United States)

    ... Privacy Policy Sitemap Learn Engage Donate About TSC Cognitive Challenges Approximately 45% to 60% of individuals with TSC develop cognitive challenges (intellectual disabilities), although the degree of intellectual ...

  20. High Performance Flexible Thermal Link

    Science.gov (United States)

    Sauer, Arne; Preller, Fabian

    2014-06-01

    The paper deals with the design and performance verification of a high performance and flexible carbon fibre thermal link.Project goal was to design a space qualified thermal link combining low mass, flexibility and high thermal conductivity with new approaches regarding selected materials and processes. The idea was to combine the advantages of existing metallic links regarding flexibility and the thermal performance of high conductive carbon pitch fibres. Special focus is laid on the thermal performance improvement of matrix systems by means of nano-scaled carbon materials in order to improve the thermal performance also perpendicular to the direction of the unidirectional fibres.One of the main challenges was to establish a manufacturing process which allows handling the stiff and brittle fibres, applying the matrix and performing the implementation into an interface component using unconventional process steps like thermal bonding of fibres after metallisation.This research was funded by the German Federal Ministry for Economic Affairs and Energy (BMWi).

  1. A numerical study of the inverse problem of breast infrared thermography modeling

    Science.gov (United States)

    Jiang, Li; Zhan, Wang; Loew, Murray H.

    2010-03-01

    Infrared thermography has been shown to be a useful adjunctive tool for breast cancer detection. Previous thermography modeling techniques generally dealt with the "forward problem", i.e., to estimate the breast thermogram from known properties of breast tissues. The present study aims to deal with the so-called "inverse problem", namely to estimate the thermal properties of the breast tissues from the observed surface temperature distribution. By comparison, the inverse problem is a more direct way of interpreting a breast thermogram for specific physiological and/or pathological information. In tumor detection, for example, it is particularly important to estimate the tumor-induced thermal contrast, even though the corresponding non-tumor thermal background usually is unknown due to the difficulty of measuring the individual thermal properties. Inverse problem solving is technically challenging due to its ill-posed nature, which is evident primarily by its sensitivity to imaging noise. Taking advantage of our previously developed forward-problemsolving techniques with comprehensive thermal-elastic modeling, we examine here the feasibility of solving the inverse problem of the breast thermography. The approach is based on a presumed spatial constraint applied to three major thermal properties, i.e., thermal conductivity, blood perfusion, and metabolic heat generation, for each breast tissue type. Our results indicate that the proposed inverse-problem-solving scheme can be numerically stable under imaging noise of SNR ranging 32 ~ 40 dB, and that the proposed techniques can be effectively used to improve the estimation to the tumor-induced thermal contrast, especially for smaller and deeper tumors.

  2. Thermal Management and Thermal Protection Systems

    Science.gov (United States)

    Hasnain, Aqib

    2016-01-01

    During my internship in the Thermal Design Branch (ES3), I contributed to two main projects: i) novel passive thermal management system for future human exploration, ii) AVCOAT undercut thermal analysis. i) As NASA prepares to further expand human and robotic presence in space, it is well known that spacecraft architectures will be challenged with unprecedented thermal environments. Future exploration activities will have the need of thermal management systems that can provide higher reliability, mass and power reduction and increased performance. In an effort to start addressing the current technical gaps the NASA Johnson Space Center Passive Thermal Discipline has engaged in technology development activities. One of these activities was done through an in-house Passive Thermal Management System (PTMS) design for a lunar lander. The proposed PTMS, functional in both microgravity and gravity environments, consists of three main components: a heat spreader, a novel hybrid wick Variable Conductance Heat Pipe (VCHP), and a radiator. The aim of this PTMS is to keep electronics on a vehicle within their temperature limits (0 and 50 C for the current design) during all mission phases including multiple lunar day/night cycles. The VCHP was tested to verify its thermal performance. I created a thermal math model using Thermal Desktop (TD) and analyzed it to predict the PTMS performance. After testing, the test data provided a means to correlate the thermal math model. This correlation took into account conduction and convection heat transfer, representing the actual benchtop test. Since this PTMS is proposed for space missions, a vacuum test will be taking place to provide confidence that the system is functional in space environments. Therefore, the model was modified to include a vacuum chamber with a liquid nitrogen shroud while taking into account conduction and radiation heat transfer. Infrared Lamps were modelled and introduced into the model to simulate the sun

  3. Benchmark Problems of the Geothermal Technologies Office Code Comparison Study

    Energy Technology Data Exchange (ETDEWEB)

    White, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Podgorney, Robert [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kelkar, Sharad M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McClure, Mark W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Danko, George [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ghassemi, Ahmad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fu, Pengcheng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bahrami, Davood [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Barbier, Charlotte [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Cheng, Qinglu [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chiu, Kit-Kwan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Detournay, Christine [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Elsworth, Derek [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fang, Yi [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Furtney, Jason K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gan, Quan [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gao, Qian [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guo, Bin [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hao, Yue [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Horne, Roland N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Huang, Kai [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Im, Kyungjae [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Norbeck, Jack [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rutqvist, Jonny [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Safari, M. R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sesetty, Varahanaresh [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sonnenthal, Eric [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tao, Qingfeng [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); White, Signe K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wong, Yang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Xia, Yidong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-12-02

    A diverse suite of numerical simulators is currently being applied to predict or understand the performance of enhanced geothermal systems (EGS). To build confidence and identify critical development needs for these analytical tools, the United States Department of Energy, Geothermal Technologies Office has sponsored a Code Comparison Study (GTO-CCS), with participants from universities, industry, and national laboratories. A principal objective for the study was to create a community forum for improvement and verification of numerical simulators for EGS modeling. Teams participating in the study were those representing U.S. national laboratories, universities, and industries, and each team brought unique numerical simulation capabilities to bear on the problems. Two classes of problems were developed during the study, benchmark problems and challenge problems. The benchmark problems were structured to test the ability of the collection of numerical simulators to solve various combinations of coupled thermal, hydrologic, geomechanical, and geochemical processes. This class of problems was strictly defined in terms of properties, driving forces, initial conditions, and boundary conditions. Study participants submitted solutions to problems for which their simulation tools were deemed capable or nearly capable. Some participating codes were originally developed for EGS applications whereas some others were designed for different applications but can simulate processes similar to those in EGS. Solution submissions from both were encouraged. In some cases, participants made small incremental changes to their numerical simulation codes to address specific elements of the problem, and in other cases participants submitted solutions with existing simulation tools, acknowledging the limitations of the code. The challenge problems were based on the enhanced geothermal systems research conducted at Fenton Hill, near Los Alamos, New Mexico, between 1974 and 1995. The problems

  4. Wildfires in Algeria: problems and challenges

    OpenAIRE

    Meddour-Sahar O

    2015-01-01

    In the scenario of the Mediterranean area, where about 54 000 fires and 0.4 million hectares of forest are burned and annually registered (2006-2010), the rank for Algeria is non-negligible with 4.11 million hectares of forest. The annual number of fires and the size of area burned depict a critical situation, which became rather dramatic in 2012. Climate change projections and the estimated changes to wildfire risk for the future decades (2030-2060) indicate that the entire Maghreb region, i...

  5. Academic Inbreeding: Local Challenge, Global Problem

    Science.gov (United States)

    Altbach, Philip G.; Yudkevich, Maria; Rumbley, Laura E.

    2015-01-01

    "Academic inbreeding"--involving the appointment of faculty members who graduated from the institution employing them--is considered a small and peripheral aspect of the academic profession but is quite widespread globally. This paper analyzes the nature of inbreeding and its impact on universities. Data from eight countries where…

  6. Vulvodynia – still a challenging therapeutic problem

    Directory of Open Access Journals (Sweden)

    Magdalena Pawlaczyk

    2017-04-01

    Full Text Available Introduction . Vulvodynia is a chronic condition characterized by pain and burning in the vulvar area without any abnormalities in clinical and laboratory examinations. The diagnosis is based on detailed assessment of medical history, physical examination and exclusion of other potential causes of vulvar pain. As yet, no definitive treatment algorithm has been universally accepted for vulvodynia. Objective . To present a case of successful treatment of generalized spontaneous vulvodynia with low doses of amitriptyline. Case report . A 42-year-old patient presented to a dermatology outpatient clinic with chronic generalized vulvar pain of 2 years’ duration. She was diagnosed with generalized spontaneous vulvodynia. Amitriptyline treatment was introduced and supported by topical application of lignocaine gel. After 13 months of amitriptyline therapy a complete remission was achieved. Conclusions . Vulvodynia is a complex disease with numerous presentations, the symptoms of which often overlap. Since the diagnosis of vulvodynia requires the exclusion of other abnormalities, it is fundamental to raise the awareness of the disease among clinicians, so as to enable early correct diagnosis and adequate treatment.

  7. Aquifer Thermal Energy Storage for Seasonal Thermal Energy Balance

    Science.gov (United States)

    Rostampour, Vahab; Bloemendal, Martin; Keviczky, Tamas

    2017-04-01

    Aquifer Thermal Energy Storage (ATES) systems allow storing large quantities of thermal energy in subsurface aquifers enabling significant energy savings and greenhouse gas reductions. This is achieved by injection and extraction of water into and from saturated underground aquifers, simultaneously. An ATES system consists of two wells and operates in a seasonal mode. One well is used for the storage of cold water, the other one for the storage of heat. In warm seasons, cold water is extracted from the cold well to provide cooling to a building. The temperature of the extracted cold water increases as it passes through the building climate control systems and then gets simultaneously, injected back into the warm well. This procedure is reversed during cold seasons where the flow direction is reversed such that the warmer water is extracted from the warm well to provide heating to a building. From the perspective of building climate comfort systems, an ATES system is considered as a seasonal storage system that can be a heat source or sink, or as a storage for thermal energy. This leads to an interesting and challenging optimal control problem of the building climate comfort system that can be used to develop a seasonal-based energy management strategy. In [1] we develop a control-oriented model to predict thermal energy balance in a building climate control system integrated with ATES. Such a model however cannot cope with off-nominal but realistic situations such as when the wells are completely depleted, or the start-up phase of newly installed wells, etc., leading to direct usage of aquifer ambient temperature. Building upon our previous work in [1], we here extend the mathematical model for ATES system to handle the above mentioned more realistic situations. Using our improved models, one can more precisely predict system behavior and apply optimal control strategies to manage the building climate comfort along with energy savings and greenhouse gas reductions

  8. Waterfront Challenges

    DEFF Research Database (Denmark)

    Kiib, Hans

    2007-01-01

    An overall view on the waterfront transformation and the planning challenges related to this process. It contributes to the specific challenges and potentials related to Aalborg Waterfront.......An overall view on the waterfront transformation and the planning challenges related to this process. It contributes to the specific challenges and potentials related to Aalborg Waterfront....

  9. Paradoxes of thermal radiation

    Energy Technology Data Exchange (ETDEWEB)

    Besson, U [Department of Physics ' A Volta' , University of Pavia, Via A Bassi 6, 27100 Pavia (Italy)], E-mail: ugo.besson@unipv.it

    2009-09-15

    This paper presents an analysis of the thermal behaviour of objects exposed to a solar-type flux of thermal radiation. It aims to clarify certain apparent inconsistencies between theory and observation, and to give a detailed exposition of some critical points that physics textbooks usually treat in an insufficient or incorrect way. In particular, the paper examines the equilibrium temperature reached by objects exposed to solar thermal radiation and the temperature difference between their illuminated and shaded sides. These problems are studied first by analysing the simple ideal case of an isolated object, subsequently by taking into account the thermal radiation emitted by the environment, and finally by considering also the heat exchange with the surrounding air. Some examples are developed and numerical data are provided. The topic is developed in a way that can be suitable for both undergraduate student and general physicist.

  10. Mathematical olympiad challenges

    CERN Document Server

    Andreescu, Titu

    2000-01-01

    Mathematical Olympiad Challenges is a rich collection of problems put together by two experienced and well-known professors and coaches of the U.S. International Mathematical Olympiad Team. Hundreds of beautiful, challenging, and instructive problems from algebra, geometry, trigonometry, combinatorics, and number theory were selected from numerous mathematical competitions and journals. An important feature of the work is the comprehensive background material provided with each grouping of problems. The problems are clustered by topic into self-contained sections with solutions provided separately. All sections start with an essay discussing basic facts and one or two representative examples. A list of carefully chosen problems follows and the reader is invited to take them on. Additionally, historical insights and asides are presented to stimulate further inquiry. The emphasis throughout is on encouraging readers to move away from routine exercises and memorized algorithms toward creative solutions to open-e...

  11. Controlling Thermal Expansion: A Metal–Organic Frameworks Route

    Science.gov (United States)

    2016-01-01

    Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal–organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host–guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion. PMID:28190918

  12. Controlling Thermal Expansion: A Metal-Organic Frameworks Route.

    Science.gov (United States)

    Balestra, Salvador R G; Bueno-Perez, Rocio; Hamad, Said; Dubbeldam, David; Ruiz-Salvador, A Rabdel; Calero, Sofia

    2016-11-22

    Controlling thermal expansion is an important, not yet resolved, and challenging problem in materials research. A conceptual design is introduced here, for the first time, for the use of metal-organic frameworks (MOFs) as platforms for controlling thermal expansion devices that can operate in the negative, zero, and positive expansion regimes. A detailed computer simulation study, based on molecular dynamics, is presented to support the targeted application. MOF-5 has been selected as model material, along with three molecules of similar size and known differences in terms of the nature of host-guest interactions. It has been shown that adsorbate molecules can control, in a colligative way, the thermal expansion of the solid, so that changing the adsorbate molecules induces the solid to display positive, zero, or negative thermal expansion. We analyze in depth the distortion mechanisms, beyond the ligand metal junction, to cover the ligand distortions, and the energetic and entropic effect on the thermo-structural behavior. We provide an unprecedented atomistic insight on the effect of adsorbates on the thermal expansion of MOFs as a basic tool toward controlling the thermal expansion.

  13. Problems in quantum mechanics

    CERN Document Server

    Goldman, Iosif Ilich; Geilikman, B T

    2006-01-01

    This challenging book contains a comprehensive collection of problems in nonrelativistic quantum mechanics of varying degrees of difficulty. It features answers and completely worked-out solutions to each problem. Geared toward advanced undergraduates and graduate students, it provides an ideal adjunct to any textbook in quantum mechanics.

  14. Experimental Preparation and Numerical Simulation of High Thermal Conductive Cu/CNTs Nanocomposites

    Directory of Open Access Journals (Sweden)

    Muhsan Ali Samer

    2014-07-01

    Full Text Available Due to the rapid growth of high performance electronics devices accompanied by overheating problem, heat dissipater nanocomposites material having ultra-high thermal conductivity and low coefficient of thermal expansion was proposed. In this work, a nanocomposite material made of copper (Cu reinforced by multi-walled carbon nanotubes (CNTs up to 10 vol. % was prepared and their thermal behaviour was measured experimentally and evaluated using numerical simulation. In order to numerically predict the thermal behaviour of Cu/CNTs composites, three different prediction methods were performed. The results showed that rules of mixture method records the highest thermal conductivity for all predicted composites. In contrast, the prediction model which takes into account the influence of the interface thermal resistance between CNTs and copper particles, has shown the lowest thermal conductivity which considered as the closest results to the experimental measurement. The experimentally measured thermal conductivities showed remarkable increase after adding 5 vol.% CNTs and higher than the thermal conductivities predicted via Nan models, indicating that the improved fabrication technique of powder injection molding that has been used to produced Cu/CNTs nanocomposites has overcome the challenges assumed in the mathematical models.

  15. Problems in problem analysis

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2014-01-01

    The majority of literature on engineering design methods is focused on the processes of fulfilling the design goals as efficiently as possible. This paper will focus on - and discuss - the processes of determining the design goals: the specifications. The purpose is to draw attention to the inher...... to the inherent problems, dilemmas and possibilities in these processes bearing in mind that that the most important decisions in a design project are taken in the beginning of the project....

  16. Balance Problems

    Science.gov (United States)

    ... it could be a sign of a balance problem. Balance problems can make you feel unsteady. You may also ... injuries, such as a hip fracture. Some balance problems are due to problems in the inner ear. ...

  17. Hemp Thermal Insulation Concrete with Alternative Binders, Analysis of their Thermal and Mechanical Properties

    Science.gov (United States)

    Sinka, M.; Sahmenko, G.; Korjakins, A.; Radina, L.; Bajare, D.

    2015-11-01

    One of the main challenges that construction industry faces today is how to address the demands for more sustainable, environmentally friendly and carbon neutral construction materials and building upkeep processes. One of the answers to these demands is lime-hemp concrete (LHC) building materials - carbon negative materials that have sufficient thermal insulation capabilities to be used as thermal insulation materials for new as well as for existing buildings. But one problem needs to be overcome before these materials can be used on a large scale - current manufacturing technology allows these materials to be used only as self-bearing thermal insulation material with large labour intensity in the manufacturing process. In order to lower the labour intensity and allow the material to be used in wider applications, a LHC block and board production is necessary, which in turn calls for the binders different from the classically used ones, as they show insufficient mechanical strength for this new use. The particular study focuses on alternative binders produced using gypsum-cement compositions ensuring they are usable in outdoor applications together with hemp shives. Physical, mechanical, thermal and water absorption properties of hemp concrete with various binders are addressed in the current study.

  18. An Automatic System to Detect Thermal Leakages and Damages on Building Facade Using Thermal Images

    OpenAIRE

    Sirmacek, Beril; Hoegner, Ludwig; Stilla, Uwe

    2011-01-01

    In recent years, very high energy consumption is the major problem of the big cities. Most of the energy of the cities are disbursed to warm and cool buildings. Thus, detecting heat leakages on building walls is a new research problem. In this study, we propose a novel system to detect thermal leakages automatically from thermal camera images. To this end, we use sequential thermal images of buildings. First, we start with fusing thermal image sequences to obtain rectified building facade wit...

  19. PV-enhanced solar thermal power

    OpenAIRE

    Platzer, W.

    2014-01-01

    Solar electricity generation using concentrating solar thermal collectors faces the challenge of strongly decreased levelized electricity costs by photovoltaic power plants. One of the selling points favouring solar thermal power is the possibility to generate dispatchable power. Concepts discussed here are solar hybridization of conventional or biomass thermal power plants. Another option is the use of thermal energy storage (TES) charged with solar heat which allow to drive the generation o...

  20. Thermal management of batteries

    Science.gov (United States)

    Gibbard, H. F.; Chen, C.-C.

    Control of the internal temperature during high rate discharge or charge can be a major design problem for large, high energy density battery systems. A systematic approach to the thermal management of such systems is described for different load profiles based on: thermodynamic calculations of internal heat generation; calorimetric measurements of heat flux; analytical and finite difference calculations of the internal temperature distribution; appropriate system designs for heat removal and temperature control. Examples are presented of thermal studies on large lead-acid batteries for electrical utility load levelling and nickel-zinc and lithium-iron sulphide batteries for electric vehicle propulsion.

  1. Thermal Network Modelling Handbook

    Science.gov (United States)

    1972-01-01

    Thermal mathematical modelling is discussed in detail. A three-fold purpose was established: (1) to acquaint the new user with the terminology and concepts used in thermal mathematical modelling, (2) to present the more experienced and occasional user with quick formulas and methods for solving everyday problems, coupled with study cases which lend insight into the relationships that exist among the various solution techniques and parameters, and (3) to begin to catalog in an orderly fashion the common formulas which may be applied to automated conversational language techniques.

  2. Challenges of serious games

    Directory of Open Access Journals (Sweden)

    B. Fernández-Manjón

    2015-11-01

    Full Text Available Although educational games have revealed to be a very effective focus in diverse situations, their use in education is still very limited. In this paper we analyse the main challenges concerning educational games that, from our perspective, have to be approached so that the use of this kind of games can be widespread. These challenges are classified in three main dimensions: socio-cultural, educational and technological. Once the challenges are identified, some possible measures are suggested to address or reduce these problems so that the use of educational games may be widespread.

  3. Problems in equilibrium theory

    CERN Document Server

    Aliprantis, Charalambos D

    1996-01-01

    In studying General Equilibrium Theory the student must master first the theory and then apply it to solve problems. At the graduate level there is no book devoted exclusively to teaching problem solving. This book teaches for the first time the basic methods of proof and problem solving in General Equilibrium Theory. The problems cover the entire spectrum of difficulty; some are routine, some require a good grasp of the material involved, and some are exceptionally challenging. The book presents complete solutions to two hundred problems. In searching for the basic required techniques, the student will find a wealth of new material incorporated into the solutions. The student is challenged to produce solutions which are different from the ones presented in the book.

  4. The WCET Tool Challenge 2011

    DEFF Research Database (Denmark)

    Hanxleden, Reinhard von; Holsti, Niklas; Lisper, Björn

    of problems to be solved by the Challenge participants with their tools, WCET problems, which ask for bounds on the execution time, and ow-analysis problems, which ask for bounds on the number of times certain parts of the code can be executed. The benchmarks to be used in WCC'11 were debie1, Papa...

  5. Issues and future direction of thermal-hydraulics research and development in nuclear power reactors

    Energy Technology Data Exchange (ETDEWEB)

    Saha, P., E-mail: pradip.saha@ge.com [GE Hitachi Nuclear Energy, Wilmington, NC (United States); Aksan, N. [GRNSPG Group, University of Pisa (Italy); Andersen, J. [GE Hitachi Nuclear Energy, Wilmington, NC (United States); Yan, J. [Westinghouse Electric Co., Columbia, SC (United States); Simoneau, J.P. [AREVA, Lyon (France); Leung, L. [Atomic Energy of Canada Ltd., Chalk River, Ontario (Canada); Bertrand, F. [CEA, DEN, DER, F-13108 Saint-Paul-Lez-Durance (France); Aoto, K.; Kamide, H. [Japan Atomic Energy Agency, Chiyoda-ku, Tokyo (Japan)

    2013-11-15

    The paper archives the proceedings of an expert panel discussion on the issues and future direction of thermal-hydraulic research and development in nuclear power reactors held at the NURETH-14 conference in Toronto, Canada, in September 2011. Thermal-hydraulic issues related to both operating and advanced reactors are presented. Advances in thermal-hydraulics have significantly improved the performance of operating reactors. Further thermal-hydraulics research and development is continuing in both experimental and computational areas for operating reactors, reactors under construction or ready for near-term deployment, and advanced Generation-IV reactors. As the computing power increases, the fine-scale multi-physics computational models, coupled with the systems analysis code, are expected to provide answers to many challenging problems in both operating and advanced reactor designs.

  6. Accelerating evaluation of converged lattice thermal conductivity

    Science.gov (United States)

    Qin, Guangzhao; Hu, Ming

    2018-01-01

    High-throughput computational materials design is an emerging area in materials science, which is based on the fast evaluation of physical-related properties. The lattice thermal conductivity (κ) is a key property of materials for enormous implications. However, the high-throughput evaluation of κ remains a challenge due to the large resources costs and time-consuming procedures. In this paper, we propose a concise strategy to efficiently accelerate the evaluation process of obtaining accurate and converged κ. The strategy is in the framework of phonon Boltzmann transport equation (BTE) coupled with first-principles calculations. Based on the analysis of harmonic interatomic force constants (IFCs), the large enough cutoff radius (rcutoff), a critical parameter involved in calculating the anharmonic IFCs, can be directly determined to get satisfactory results. Moreover, we find a simple way to largely ( 10 times) accelerate the computations by fast reconstructing the anharmonic IFCs in the convergence test of κ with respect to the rcutof, which finally confirms the chosen rcutoff is appropriate. Two-dimensional graphene and phosphorene along with bulk SnSe are presented to validate our approach, and the long-debate divergence problem of thermal conductivity in low-dimensional systems is studied. The quantitative strategy proposed herein can be a good candidate for fast evaluating the reliable κ and thus provides useful tool for high-throughput materials screening and design with targeted thermal transport properties.

  7. Optimal control in thermal engineering

    CERN Document Server

    Badescu, Viorel

    2017-01-01

    This book is the first major work covering applications in thermal engineering and offering a comprehensive introduction to optimal control theory, which has applications in mechanical engineering, particularly aircraft and missile trajectory optimization. The book is organized in three parts: The first part includes a brief presentation of function optimization and variational calculus, while the second part presents a summary of the optimal control theory. Lastly, the third part describes several applications of optimal control theory in solving various thermal engineering problems. These applications are grouped in four sections: heat transfer and thermal energy storage, solar thermal engineering, heat engines and lubrication.Clearly presented and easy-to-use, it is a valuable resource for thermal engineers and thermal-system designers as well as postgraduate students.

  8. ASSESSING LONGITUDINAL THERMAL CONNECTIVITY ...

    Science.gov (United States)

    Water temperature is a key driver of ecological processes in aquatic environments and can influence biological connectivity among riverine habitats. Riverine fish and other mobile aquatic species often must navigate a variety of physical barriers such as dams and culverts. For Pacific salmon, warm water can also pose barriers to migration, but the presence of patches of cooler water within rivers can serve as important refuges and potentially as stepping stones at times of day when temperatures are elsewhere unsuitable along the migratory corridor. Rising water temperature associated with climate change has become a major conservation concern for freshwater species and poses challenges for natural resource managers who must consider multiple factors in addition to uncertainty in climate predictions. Thermal refuges can contribute to watershed-scale thermal resilience and are increasingly considered in water quality regulations; however, monitoring such refuges and effectively operationalizing the concept for management has proved difficult. We review what is known about use of thermal refuges by coldwater fishes in natural systems, and then we present two case study applications in which we characterize thermal patterns in rivers (e.g., the frequency, size, spacing, and location of thermal patches) and consider effects on salmon in a management context. In our first example, we illustrate methods for quantifying spatial heterogeneity in stream temperatures at bi

  9. Ankle Problems

    Science.gov (United States)

    ... Nausea and Vomiting in Infants and Children Neck Pain Neck Swelling Shortness of Breath Shortness of Breath in Infants and Children Shoulder Problems Skin Rashes & Other Skin Problems Throat Problems Tooth Problems Urination Problems Back to Symptoms Step 2 Answering Questions Did you begin to ...

  10. Urination Problems

    Science.gov (United States)

    ... Nausea and Vomiting in Infants and Children Neck Pain Neck Swelling Shortness of Breath Shortness of Breath in Infants and Children Shoulder Problems Skin Rashes & Other Skin Problems Throat Problems Tooth Problems Urination Problems Back to Symptoms Step 2 Answering Questions Do you have pain ...

  11. Knee Problems

    Science.gov (United States)

    ... Nausea and Vomiting in Infants and Children Neck Pain Neck Swelling Shortness of Breath Shortness of Breath in Infants and Children Shoulder Problems Skin Rashes & Other Skin Problems Throat Problems Tooth Problems Urination Problems Back to Symptoms Step 2 Answering Questions Did your knee pain ...

  12. Electrical and Thermal Conductivity

    Science.gov (United States)

    Ventura, Guglielmo; Perfetti, Mauro

    After a Sect. 1.1 devoted to electrical conductivity and a section that deals with magnetic and dielectric losses ( 1.2 ), this chapter explores the theory of thermal conduction in solids. The examined categories of solids are: metals Sect. 1.3.2 , Dielectrics Sects. 1.3.3 and 1.3.4 and Nanocomposites Sect. 1.3.5 . In Sect. 1.3.6 the problem of thermal and electrical contact between materials is considered because contact resistance occurring at conductor joints in magnets or other high power applications can lead to undesirable electrical losses. At low temperature, thermal contact is also critical in the mounting of temperature sensors, where bad contacts can lead to erroneous results, in particular when superconductivity phenomena are involved.

  13. Thermal modelling using discrete vasculature for thermal therapy: A review.

    Science.gov (United States)

    Kok, H Petra; Gellermann, Johanna; van den Berg, Cornelis A T; Stauffer, Paul R; Hand, Jeffrey W; Crezee, Johannes

    2013-06-01

    Reliable temperature information during clinical hyperthermia and thermal ablation is essential for adequate treatment control, but conventional temperature measurements do not provide 3D temperature information. Treatment planning is a very useful tool to improve treatment quality, and substantial progress has been made over the last decade. Thermal modelling is a very important and challenging aspect of hyperthermia treatment planning. Various thermal models have been developed for this purpose, with varying complexity. Since blood perfusion is such an important factor in thermal redistribution of energy in in vivo tissue, thermal simulations are most accurately performed by modelling discrete vasculature. This review describes the progress in thermal modelling with discrete vasculature for the purpose of hyperthermia treatment planning and thermal ablation. There has been significant progress in thermal modelling with discrete vasculature. Recent developments have made real-time simulations possible, which can provide feedback during treatment for improved therapy. Future clinical application of thermal modelling with discrete vasculature in hyperthermia treatment planning is expected to further improve treatment quality.

  14. Thermal physics kinetic theory and thermodynamics

    CERN Document Server

    Singh, Devraj; Yadav, Raja Ram

    2016-01-01

    THERMAL PHYSICS: Kinetic Theory and Thermodynamics is designed for undergraduate course in Thermal Physics and Thermodynamics. The book provides thorough understanding of the fundamental principles of the concepts in Thermal Physics. The book begins with kinetic theory, then moves on liquefaction, transport phenomena, the zeroth, first, second and third laws, thermodynamics relations and thermal conduction. The book concluded with radiation phenomenon. KEY FEATURES: * Include exercises * Short Answer Type Questions * Long Answer Type Questions * Numerical Problems * Multiple Choice Questions

  15. TIGER: Development of Thermal Gradient Compensation Algorithms and Techniques

    Science.gov (United States)

    Hereford, James; Parker, Peter A.; Rhew, Ray D.

    2004-01-01

    In a wind tunnel facility, the direct measurement of forces and moments induced on the model are performed by a force measurement balance. The measurement balance is a precision-machined device that has strain gages at strategic locations to measure the strain (i.e., deformations) due to applied forces and moments. The strain gages convert the strain (and hence the applied force) to an electrical voltage that is measured by external instruments. To address the problem of thermal gradients on the force measurement balance NASA-LaRC has initiated a research program called TIGER - Thermally-Induced Gradients Effects Research. The ultimate goals of the TIGER program are to: (a) understand the physics of the thermally-induced strain and its subsequent impact on load measurements and (b) develop a robust thermal gradient compensation technique. This paper will discuss the impact of thermal gradients on force measurement balances, specific aspects of the TIGER program (the design of a special-purpose balance, data acquisition and data analysis challenges), and give an overall summary.

  16. Speech Problems

    Science.gov (United States)

    ... Plan Hot Topics Flu Facts Arrhythmias Abuse Speech Problems KidsHealth > For Teens > Speech Problems Print A A ... form speech sounds into words. What Causes Speech Problems? Normal speech might seem effortless, but it's actually ...

  17. The Better Boat Challenge

    Science.gov (United States)

    Schomburg, Aaron

    2008-01-01

    "On your mark, get set, go!" Elementary students love to hear these words as they participate in the annual Third Grade Better Boat Challenge. This highly motivational project started a few years ago as the author was developing the third-grade science curriculum to include a study that revolved around models, design, and problem solving. It has…

  18. Centennial Challenges Program

    Science.gov (United States)

    Ortega, Sam; Eberly, Eric

    2015-01-01

    NASA's Centennial Challenges Program was initiated in 2005 to directly engage the public in the process of advanced technology development. The program offers incentive prizes to generate revolutionary solutions to problems of interest to NASA and the nation. The program seeks innovations from diverse and nontraditional sources. Competitors are not supported by government funding and awards are only made to successful teams when the challenges are met. In keeping with the spirit of the Wright Brothers and other American innovators, the Centennial Challenge prizes are offered to independent inventors including small businesses, student groups, and individuals. These independent inventors are sought to generate innovative solutions for technical problems of interest to NASA and the nation and to provide them with the opportunity to stimulate or create new business ventures.

  19. Dispersion stability of thermal nanofluids

    Directory of Open Access Journals (Sweden)

    Fan Yu

    2017-10-01

    Full Text Available Thermal nanofluids, the engineered fluids with dispersed functional nanoparticles, have exhibited extraordinary thermophysical properties and added functionalities, and thus have enabled a broad range of important applications. The poor dispersion stability of thermal nanofluids, however, has been considered as a long-existing issue that limits their further development and practical application. This review overviews the recent efforts and progresses in improving the dispersion stability of thermal nanofluids such as mechanistic understanding of dispersion behavior of nanofluids, examples of both water-based and oil-based nanofluids, strategies to stabilize nanofluids, and characterization techniques for dispersion behavior of nanofluids. Finally, on-going research needs, and possible solutions to research challenges and future research directions in exploring stably dispersed thermal nanofluids are discussed. Keywords: Thermal nanofluids, Dispersion, Aggregation, Electrostatic stabilization, Steric stabilization

  20. Academic Training: The ITER project: technological challenges

    CERN Document Server

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 31 May, 1, 2, 3, June from 11:00 to 12:00 on 31 May and 2, 3, June. From 10:00 to 12:00 on 1 June - Main Auditorium, bldg. 500 The ITER project: technological challenges J. LISTER / CRPP-EPFL, Lausanne, CH and P. BRUZZONE / CRPP-EPFL, Zürich, CH The first lecture reminds us of the ITER challenges, presents hard engineering problems, typically due to mechanical forces and thermal loads and identifies where the physics uncertainties play a significant role in the engineering requirements. The second lecture presents soft engineering problems of measuring the plasma parameters, feedback control of the plasma and handling the physics data flow and slow controls data flow from a large experiment like ITER. The last three lectures focus on superconductors for fusion. The third lecture reviews the design criteria and manufacturing methods for 6 milestone-conductors of large fusion devices (T-7, T-15, Tore Supra, LHD, W-7X, ITER). The evolution of the...

  1. Academic Training: The ITER project: technological challenges

    CERN Document Server

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 31 May, 1, 2, 3, June from 11:00 to 12:00 on 31 May and 2, 3, June. From 10:00 to 12:00 on 1 June - Main Auditorium, bldg. 500 The ITER project: technological challenges J. LISTER / CRPP-EPFL, Lausanne and P. BRUZZONE / CRPP-EPFL, Zürich The first lecture reminds us of the ITER challenges, presents hard engineering problems, typically due to mechanical forces and thermal loads and identifies where the physics uncertainties play a significant role in the engineering requirements. The second lecture presents soft engineering problems of measuring the plasma parameters, feedback control of the plasma and handling the physics data flow and slow controls data flow from a large experiment like ITER. The last three lectures focus on superconductors for fusion. The third lecture reviews the design criteria and manufacturing methods for 6 milestone-conductors of large fusion devices (T-7, T-15, Tore Supra, LHD, W-7X, ITER). The evolution of the de...

  2. De los problemas a los retos de la población rural de Castilla y León. (From the problems to the challenges of the rural population in Castile-Leon.

    Directory of Open Access Journals (Sweden)

    José Manuel del Barrio Aliste

    2013-12-01

    Full Text Available Uno de los temas que más preocupan en la actualidad en Castilla y León es el relacionado con los problemas y desafíos de la población en las zonas rurales. Con el fin de contribuir al debate sobre esta cuestión, este texto pretende ofrecer algunas reflexiones sobre este importante y controvertido tema. En primer lugar, se reflexiona sobre la importancia de las cuestiones de población en el imaginario colectivo de la región, en el estado de la autonomía y en la “Agenda para la Población de Castilla y León”. En segundo lugar, se aportan algunos datos poblacionales básicos, poniendo de relieve las disparidades, las diferencias demográficas y los contrastes que existen en la región. Por último, en tercer lugar, proporcionar algunas propuestas para la acción, centrándose en particular en las implicaciones de los nuevos escenarios de la ruralidad. One of the issues that most concern in Castile-Leon are related to the problems and challenges of the population in rural areas. In order to contribute to the debate on this question, this text seeks to provide some thoughts about this important and controversial issue. First, some reflections about the importance of population issues in the collective imagination of the region, in the status of autonomy and in the “Agenda for the Population of Castile-Leon”. Secondly, there is some basic population data, highlighting the disparities, demographic differences and contrasts that exist in the region. Finally, thirdly, some proposals for action are provided, focusing in particular on the implications of the new context in the rural areas.

  3. The challenge of conceiving

    DEFF Research Database (Denmark)

    Hansen, Claus Thorp; Jørgensen, Ulrik

    2011-01-01

    solving and optimization methods. Going back to the earlier days of engineering education problems were defined through the repertoire of existing technologies and solutions taken up and handled as given cases in the education. With the growing emphasis on scientific methods leading to a continued change...... in engineering disciplines throughout the mid 20th century the focus changed and problems were defined in more theoretical terms. Engineering education remained dominated by its introduction of a more and more dense repertoire of methods and theoretical models. In this paper we will approach this problem from...... the perspective of engineering design challenges where the need for problem identification is obvious to avoid the pitfall to reproduce and piecemeal engineer already existing product or service concepts. Problem identification is not a simple desk research task as it often involves a multitude of actors having...

  4. What can Recycling in Thermal Reactors Accomplish?

    Energy Technology Data Exchange (ETDEWEB)

    Steven Piet; Gretchen E. Matthern; Jacob J. Jacobson

    2007-09-01

    Thermal recycle provides several potential benefits when used as stop-gap, mixed, or backup recycling to recycling in fast reactors. These three roles involve a mixture of thermal and fast recycling; fast reactors are required to some degree at some time. Stop-gap uses thermal reactors only until fast reactors are adequately deployed and until any thermal-recycle-only facilities have met their economic lifetime. Mixed uses thermal and fast reactors symbiotically for an extended period of time. Backup uses thermal reactors only if problems later develop in the fast reactor portion of a recycling system. Thermal recycle can also provide benefits when used as pure thermal recycling, with no intention to use fast reactors. However, long term, the pure thermal recycling approach is inadequate to meet several objectives.

  5. The Effect of Core Configuration on Thermal Barrier Thermal Performance

    Science.gov (United States)

    DeMange, Jeffrey J.; Bott, Robert H.; Druesedow, Anne S.

    2015-01-01

    Thermal barriers and seals are integral components in the thermal protection systems (TPS) of nearly all aerospace vehicles. They are used to minimize heat transfer through interfaces and gaps and protect underlying temperature-sensitive components. The core insulation has a significant impact on both the thermal and mechanical properties of compliant thermal barriers. Proper selection of an appropriate core configuration to mitigate conductive, convective and radiative heat transfer through the thermal barrier is challenging. Additionally, optimization of the thermal barrier for thermal performance may have counteracting effects on mechanical performance. Experimental evaluations have been conducted to better understand the effect of insulation density on permeability and leakage performance, which can significantly impact the resistance to convective heat transfer. The effect of core density on mechanical performance was also previously investigated and will be reviewed. Simple thermal models were also developed to determine the impact of various core parameters on downstream temperatures. An extended understanding of these factors can improve the ability to design and implement these critical TPS components.

  6. Managing the Mars Science Laboratory Thermal Vacuum Test for Safety and Success

    Science.gov (United States)

    Evans, Jordan P.

    2010-01-01

    The Mars Science Laboratory is a NASA/JPL mission to send the next generation of rover to Mars. Originally slated for launch in 2009, development problems led to a delay in the project until the next launch opportunity in 2011. Amidst the delay process, the Launch/Cruise Solar Thermal Vacuum Test was undertaken as risk reduction for the project. With varying maturity and capabilities of the flight and ground systems, undertaking the test in a safe manner presented many challenges. This paper describes the technical and management challenges and the actions undertaken that led to the ultimate safe and successful execution of the test.

  7. Engineering-Based Thermal CFD Simulations on Massive Parallel Systems

    Directory of Open Access Journals (Sweden)

    Jérôme Frisch

    2015-05-01

    Full Text Available The development of parallel Computational Fluid Dynamics (CFD codes is a challenging task that entails efficient parallelization concepts and strategies in order to achieve good scalability values when running those codes on modern supercomputers with several thousands to millions of cores. In this paper, we present a hierarchical data structure for massive parallel computations that supports the coupling of a Navier–Stokes-based fluid flow code with the Boussinesq approximation in order to address complex thermal scenarios for energy-related assessments. The newly designed data structure is specifically designed with the idea of interactive data exploration and visualization during runtime of the simulation code; a major shortcoming of traditional high-performance computing (HPC simulation codes. We further show and discuss speed-up values obtained on one of Germany’s top-ranked supercomputers with up to 140,000 processes and present simulation results for different engineering-based thermal problems.

  8. Engineering-Based Thermal CFD Simulations on Massive Parallel Systems

    KAUST Repository

    Frisch, Jérôme

    2015-05-22

    The development of parallel Computational Fluid Dynamics (CFD) codes is a challenging task that entails efficient parallelization concepts and strategies in order to achieve good scalability values when running those codes on modern supercomputers with several thousands to millions of cores. In this paper, we present a hierarchical data structure for massive parallel computations that supports the coupling of a Navier–Stokes-based fluid flow code with the Boussinesq approximation in order to address complex thermal scenarios for energy-related assessments. The newly designed data structure is specifically designed with the idea of interactive data exploration and visualization during runtime of the simulation code; a major shortcoming of traditional high-performance computing (HPC) simulation codes. We further show and discuss speed-up values obtained on one of Germany’s top-ranked supercomputers with up to 140,000 processes and present simulation results for different engineering-based thermal problems.

  9. Thermal measurements and inverse techniques

    CERN Document Server

    Orlande, Helcio RB; Maillet, Denis; Cotta, Renato M

    2011-01-01

    With its uncommon presentation of instructional material regarding mathematical modeling, measurements, and solution of inverse problems, Thermal Measurements and Inverse Techniques is a one-stop reference for those dealing with various aspects of heat transfer. Progress in mathematical modeling of complex industrial and environmental systems has enabled numerical simulations of most physical phenomena. In addition, recent advances in thermal instrumentation and heat transfer modeling have improved experimental procedures and indirect measurements for heat transfer research of both natural phe

  10. Thermal comfort

    DEFF Research Database (Denmark)

    d’Ambrosio Alfano, Francesca Romana; Olesen, Bjarne W.; Palella, Boris Igor

    2014-01-01

    Thermal comfort is one of the most important aspects of the indoor environmental quality due to its effects on well-being, people's performance and building energy requirements. Its attainment is not an easy task requiring advanced design and operation of building and HVAC systems, taking...... under specific conditions. At operation level, only few variables are taken into account with unpredictable effects on the assessment of comfort indices. In this paper, the main criteria for the design and assessment of thermal comfort are discussed in order to help building and HVAC systems designers...... into account all parameters involved. Even though thermal comfort fundamentals are consolidated topics for more than forty years, often designers seem to ignore or apply them in a wrong way. Design input values from standards are often considered as universal values rather than recommended values to be used...

  11. Explaining the Mind: Problems, Problems

    OpenAIRE

    Harnad, Stevan

    2001-01-01

    The mind/body problem is the feeling/function problem: How and why do feeling systems feel? The problem is not just "hard" but insoluble (unless one is ready to resort to telekinetic dualism). Fortunately, the "easy" problems of cognitive science (such as the how and why of categorization and language) are not insoluble. Five books (by Damasio, Edelman/Tononi...

  12. Challenging Identities

    DEFF Research Database (Denmark)

    , cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...

  13. Encyclopedia of thermal stresses

    CERN Document Server

    2014-01-01

    The Encyclopedia of Thermal Stresses is an important interdisciplinary reference work.  In addition to topics on thermal stresses, it contains entries on related topics, such as the theory of elasticity, heat conduction, thermodynamics, appropriate topics on applied mathematics, and topics on numerical methods. The Encyclopedia is aimed at undergraduate and graduate students, researchers and engineers. It brings together well established knowledge and recently received results. All entries were prepared  by leading experts from all over the world, and are presented in an easily accessible format. The work is lavishly illustrated, examples and applications are given where appropriate, ideas for further development abound, and the work will challenge many students and researchers to pursue new results of their own. This work can also serve as a one-stop resource for all who need succinct, concise, reliable and up to date information in short encyclopedic entries, while the extensive references will be of inte...

  14. Thermal Ignition

    Science.gov (United States)

    Boettcher, Philipp Andreas

    Accidental ignition of flammable gases is a critical safety concern in many industrial applications. Particularly in the aviation industry, the main areas of concern on an aircraft are the fuel tank and adjoining regions, where spilled fuel has a high likelihood of creating a flammable mixture. To this end, a fundamental understanding of the ignition phenomenon is necessary in order to develop more accurate test methods and standards as a means of designing safer air vehicles. The focus of this work is thermal ignition, particularly auto-ignition with emphasis on the effect of heating rate, hot surface ignition and flame propagation, and puffing flames. Combustion of hydrocarbon fuels is traditionally separated into slow reaction, cool flame, and ignition regimes based on pressure and temperature. Standard tests, such as the ASTM E659, are used to determine the lowest temperature required to ignite a specific fuel mixed with air at atmospheric pressure. It is expected that the initial pressure and the rate at which the mixture is heated also influences the limiting temperature and the type of combustion. This study investigates the effect of heating rate, between 4 and 15 K/min, and initial pressure, in the range of 25 to 100 kPa, on ignition of n-hexane air mixtures. Mixtures with equivalence ratio ranging from 0.6 to 1.2 were investigated. The problem is also modeled computationally using an extension of Semenov's classical auto-ignition theory with a detailed chemical mechanism. Experiments and simulations both show that in the same reactor either a slow reaction or an ignition event can take place depending on the heating rate. Analysis of the detailed chemistry demonstrates that a mixture which approaches the ignition region slowly undergoes a significant modification of its composition. This change in composition induces a progressive shift of the explosion limit until the mixture is no longer flammable. A mixture that approaches the ignition region

  15. Transient thermal analysis of a titanium multiwall thermal protection system

    Science.gov (United States)

    Blosser, M. L.

    1982-01-01

    The application of the SPAR thermal analyzer to the thermal analysis of a thermal protection system concept is discussed. The titanium multiwall thermal protection system concept consists of alternate flat and dimpled sheets which are joined together at the crests of the dimples and formed into 30 cm by 30 cm (12 in. by 12 in.) tiles. The tiles are mechanically attached to the structure. The complex tile geometry complicates thermal analysis. Three modes of heat transfer were considered: conduction through the gas inside the tile, conduction through the metal, and radiation between the various layers. The voids between the dimpled and flat sheets were designed to be small enough so that natural convection is insignificant (e.g., Grashof number 1000). A two step approach was used in the thermal analysis of the multiwall thermal protection system. First, an effective normal (through-the-thickness) thermal conductivity was obtained from a steady state analysis using a detailed SPAR finite element model of a small symmetric section of the multiwall tile. This effective conductivity was then used in simple one dimensional finite element models for preliminary analysis of several transient heat transfer problems.

  16. CAp 2017 challenge: Twitter Named Entity Recognition

    OpenAIRE

    Lopez, Cédric; Partalas, Ioannis; Balikas, Georgios; Derbas, Nadia; Martin, Amélie; Reutenauer, Coralie; Segond, Frédérique; Amini, Massih-Reza

    2017-01-01

    The paper describes the CAp 2017 challenge. The challenge concerns the problem of Named Entity Recognition (NER) for tweets written in French. We first present the data preparation steps we followed for constructing the dataset released in the framework of the challenge. We begin by demonstrating why NER for tweets is a challenging problem especially when the number of entities increases. We detail the annotation process and the necessary decisions we made. We provide statistics on the inter-...

  17. Childbirth Problems

    Science.gov (United States)

    ... the mother, baby, or both. Possible complications include Preterm (premature) labor, when labor starts before 37 completed weeks of pregnancy Problems with the umbilical cord Problems with the position of the baby, such as breech, in which ...

  18. Foot Problems

    Science.gov (United States)

    ... e-newsletter! Aging & Health A to Z Foot Problems Basic Facts & Information Foot pain and foot disorders ... keep you active and independent. What are Foot Problems? Decades of standing changes your feet. Much of ...

  19. Breathing Problems

    Science.gov (United States)

    ... enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense exercise. ... Lung conditions such as asthma, emphysema, or pneumonia Problems with your trachea or bronchi, which are part ...

  20. Walking Problems

    Science.gov (United States)

    ... your legs or feet Movement disorders such as Parkinson's disease Diseases such as arthritis or multiple sclerosis Vision or balance problems Treatment of walking problems depends on the cause. Physical therapy, surgery, or mobility aids may help.

  1. Thermal defoliation

    Science.gov (United States)

    The negative perception some consumers hold regarding agricultural chemicals has resulted in an increased demand for organic foods and fibers, and in increasing political pressure for the regulation of agricultural production practices. This has revived interest in thermal defoliation of cotton and ...

  2. Holographic thermalization

    NARCIS (Netherlands)

    Balasubramanian, V.; Bernamonti, A.; de Boer, J.; Copland, N.; Craps, B.; Keski-Vakkuri, E.; Müller, B.; Schäfer, A.; Shigemori, M.; Staessens, W.

    2011-01-01

    Using the AdS/CFT correspondence, we probe the scale-dependence of thermalization in strongly coupled field theories following a quench, via calculations of two-point functions, Wilson loops and entanglement entropy in d=2,3,4. In the saddlepoint approximation these probes are computed in AdS space

  3. Problems in abstract algebra

    CERN Document Server

    Wadsworth, A R

    2017-01-01

    This is a book of problems in abstract algebra for strong undergraduates or beginning graduate students. It can be used as a supplement to a course or for self-study. The book provides more variety and more challenging problems than are found in most algebra textbooks. It is intended for students wanting to enrich their learning of mathematics by tackling problems that take some thought and effort to solve. The book contains problems on groups (including the Sylow Theorems, solvable groups, presentation of groups by generators and relations, and structure and duality for finite abelian groups); rings (including basic ideal theory and factorization in integral domains and Gauss's Theorem); linear algebra (emphasizing linear transformations, including canonical forms); and fields (including Galois theory). Hints to many problems are also included.

  4. Thermal Hardware for the Thermal Analyst

    Science.gov (United States)

    Steinfeld, David

    2015-01-01

    The presentation will be given at the 26th Annual Thermal Fluids Analysis Workshop (TFAWS 2015) hosted by the Goddard Space Flight Center (GSFC) Thermal Engineering Branch (Code 545). NCTS 21070-1. Most Thermal analysts do not have a good background into the hardware which thermally controls the spacecraft they design. SINDA and Thermal Desktop models are nice, but knowing how this applies to the actual thermal hardware (heaters, thermostats, thermistors, MLI blanketing, optical coatings, etc...) is just as important. The course will delve into the thermal hardware and their application techniques on actual spacecraft. Knowledge of how thermal hardware is used and applied will make a thermal analyst a better engineer.

  5. Deformation due to mechanical and thermal sources in generalised ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    dimensional problem of thermoelasticity has been considered to investigate the disturbance due to mechanical (horizontal or verti- cal) and thermal source in a homogeneous, thermally conducting orthorhombic material. Laplace–Fourier ...

  6. Coordinated Exploration for Grand Challenges

    DEFF Research Database (Denmark)

    Ørding Olsen, Anders; Sofka, Wolfgang; Grimpe, Christoph

    2016-01-01

    Grand challenges are among the most complex problems for modern societies. Many governments and foundations provide substantial resources to encourage the search for solutions. Due to the significance of these problems, organizations often form partnerships in what we call search consortia to eng...... that advocacy groups benefit search consortia, particularly when consortia exhibit a high dispersion of technological knowledge and when they are inexperienced....

  7. The NASA Langley Multidisciplinary Uncertainty Quantification Challenge

    Science.gov (United States)

    Crespo, Luis G.; Kenny, Sean P.; Giesy, Daniel P.

    2014-01-01

    This paper presents the formulation of an uncertainty quantification challenge problem consisting of five subproblems. These problems focus on key aspects of uncertainty characterization, sensitivity analysis, uncertainty propagation, extreme-case analysis, and robust design.

  8. Challenges & Prizes

    Science.gov (United States)

    Prize competitions are open innovation tools championed by the America COMPETES ACT that EPA and other federal agencies use to attract fresh thinkers and creative problem solvers from across the country and the world.

  9. Thermal Conductivity of Foam Glass

    DEFF Research Database (Denmark)

    Petersen, Rasmus Rosenlund; König, Jakob; Yue, Yuanzheng

    Due to the increased focus on energy savings and waste recycling foam glass materials have gained increased attention. The production process of foam glass is a potential low-cost recycle option for challenging waste, e.g. CRT glass and industrial waste (fly ash and slags). Foam glass is used...... as thermal insulating material in building and chemical industry. The large volume of gas (porosity 90 – 95%) is the main reason of the low thermal conductivity of the foam glass. If gases with lower thermal conductivity compared to air are entrapped in the glass melt, the derived foam glass will contain...... only closed pores and its overall thermal conductivity will be much lower than that of the foam glass with open pores. In this work we have prepared foam glass using different types of recycled glasses and different kinds of foaming agents. This enabled the formation of foam glasses having gas cells...

  10. Thermal biology of domestic animals.

    Science.gov (United States)

    Collier, Robert J; Gebremedhin, Kifle G

    2015-01-01

    The thermal environment is the most important ecological factor determining the growth, development, and productivity of domestic animals. Routes of energy exchange (sensible heat and latent heat) between animals and their environment are greatly influenced by body weight, fat deposition, hair-coat properties, functional activity, and number of sweat glands, as well as the presence or absence of anatomical respiratory countercurrent heat exchange capability. Differences in these anatomical features across species have led to specialization of heat exchange. Thermal plasticity and degree of acclimation are critical factors determining the ability of animals to respond to environmental change. Increases in productive capability of domestic animals can compromise thermal acclimation and plasticity, requiring greater investments in housing systems that reduce variability of the thermal environment. The combination of steadily increasing metabolic heat production as domestic animal productivity increases and a rising world temperature poses ongoing and future challenges to maintaining health and well-being of domestic animals.

  11. About some types of constraints in problems of routing

    Science.gov (United States)

    Petunin, A. A.; Polishuk, E. G.; Chentsov, A. G.; Chentsov, P. A.; Ukolov, S. S.

    2016-12-01

    Many routing problems arising in different applications can be interpreted as a discrete optimization problem with additional constraints. The latter include generalized travelling salesman problem (GTSP), to which task of tool routing for CNC thermal cutting machines is sometimes reduced. Technological requirements bound to thermal fields distribution during cutting process are of great importance when developing algorithms for this task solution. These requirements give rise to some specific constraints for GTSP. This paper provides a mathematical formulation for the problem of thermal fields calculating during metal sheet thermal cutting. Corresponding algorithm with its programmatic implementation is considered. The mathematical model allowing taking such constraints into account considering other routing problems is discussed either.

  12. Aeroelastic analysis of versatile thermal insulation (VTI) panels with pinched boundary conditions

    Science.gov (United States)

    Carrera, Erasmo; Zappino, Enrico; Patočka, Karel; Komarek, Martin; Ferrarese, Adriano; Montabone, Mauro; Kotzias, Bernhard; Huermann, Brian; Schwane, Richard

    2014-03-01

    Launch vehicle design and analysis is a crucial problem in space engineering. The large range of external conditions and the complexity of space vehicles make the solution of the problem really challenging. The problem considered in the present work deals with the versatile thermal insulation (VTI) panel. This thermal protection system is designed to reduce heat fluxes on the LH2 tank during the long coasting phases. Because of the unconventional boundary conditions and the large-scale geometry of the panel, the aeroelastic behaviour of VTI is investigated in the present work. Known available results from literature related to similar problem, are reviewed by considering the effect of various Mach regimes, including boundary layer thickness effects, in-plane mechanical and thermal loads, non-linear effects and amplitude of limit cycle oscillations. A dedicated finite element model is developed for the supersonic regime. The models used for coupling the orthotropic layered structural model with Piston Theory aerodynamic models allow the calculations of flutter conditions in case of curved panels supported in a discrete number of points. An advanced computational aeroelasticity tool is developed using various dedicated commercial softwares (CFX, ZAERO, EDGE). A wind tunnel test campaign is carried out to assess the computational tool in the analysis of this type of problem.

  13. Detection of Incipient Thermal Damage in Carbon Fiber-Bismaleimide Composites using Hand-Held FTIR (Preprint)

    Science.gov (United States)

    2017-11-24

    work. 14. ABSTRACT (Maximum 200 words) Bismaleimide (BMI) resins are gaining popularity as matrix materials in carbon fiber composites, especially ...BMI) resins are gaining popularity as matrix materials in carbon fiber composites, especially in high temperature applications, due to their very...address the unique challenges they present. An especially interesting problem in composite NDE/NDI is damage caused by thermal exposure. After visual

  14. Meeting the Challenge

    Directory of Open Access Journals (Sweden)

    T. Reg Bott

    2009-01-01

    Full Text Available The first Chempor Conference held in Lisbon in 1975 under the auspices of the Calouste Gulbenkian Foundation, heralded a regular wide-ranging review of research and development in Portugal and the UK Progressively in later years the Conferences have attracted contributions from other European countries and indeed further afield. There is an increasing awareness of the problems for the environment, notably global warming, brought about by human activities. Recent predictions about the future are dire, particularly regarding food and water for a rapidly growing world population. They represent a substantial challenge to the scientific and technical fraternity. In response to that challenge it is important to keep up to date with technical developments, to meet and keep in touch with coworkers in associated fields, and to cooperate wherever possible. The papers presented at the Chempor and other conferences have made and continue to make a significant contribution to that objective of meeting the challenge.

  15. Thermal Clothing

    Science.gov (United States)

    1997-01-01

    Gateway Technologies, Inc. is marketing and developing textile insulation technology originally developed by Triangle Research and Development Corporation. The enhanced thermal insulation stems from Small Business Innovation Research contracts from NASA's Johnson Space Center and the U.S. Air Force. The effectiveness of the insulation comes from the microencapsulated phase-change materials originally made to keep astronauts gloved hands warm. The applications for the product range from outer wear, housing insulation, and blankets to protective firefighting gear and scuba diving suits. Gateway has developed and begun marketing thermal regulating products under the trademark, OUTLAST. Products made from OUTLAST are already on the market, including boot and shoe liners, winter headgear, hats and caps for hunting and other outdoor sports, and a variety of men's and women's ski gloves.

  16. Applying Systems Engineering on Energy Challenges

    NARCIS (Netherlands)

    Safi, J.; Muller, G.; Bonnema, Gerrit Maarten

    2012-01-01

    Systems engineering is a discipline with methods and techniques to address complex problems. We want to study how Systems Engineering methods can help to address today's grand challenges, such as the energy problem. The first step is problem definition which aims at articulating the problem in its

  17. A new simple method for analysing of thermal noise in switched-capacitor filters

    Science.gov (United States)

    Rashtian, Mohammad; Afshin Hemmatyar, Ali Mohammad; Hashemipour, Omid

    2012-12-01

    Thermal noise is one of the most important challenges in analogue integrated circuits design. This problem is more crucial in switched-capacitor (SC) filters due to the aliasing effect of wide-band thermal noise. In this article, a new simple method is proposed for estimating the power spectrum density of output thermal noise in SC filters, which have acceptable accuracy and short running time. In the proposed method, first using HSPICE simulator, accurate value of accumulated sampled noise on sampler capacitors in each clock state is achieved. Next, using difference equations of the SC filter, frequency response of the SC filter is shaped by time domain analysis. Based on the proposed method, a SC low-pass filter and a second-order SC band-pass filter are analysed. The results are validated by comparing to the previously measured data.

  18. Conjugate problems in convective heat transfer

    CERN Document Server

    Dorfman, Abram S

    2009-01-01

    The conjugate heat transfer (CHT) problem takes into account the thermal interaction between a body and fluid flowing over or through it, a key consideration in both mechanical and aerospace engineering. Presenting more than 100 solutions of non-isothermal and CHT problems, this title considers the approximate solutions of CHT problems.

  19. Thermal Analysis of AC Contactor Using Thermal Network Finite Difference Analysis Method

    Science.gov (United States)

    Niu, Chunping; Chen, Degui; Li, Xingwen; Geng, Yingsan

    To predict the thermal behavior of switchgear quickly, the Thermal Network Finite Difference Analysis method (TNFDA) is adopted in thermal analysis of AC contactor in the paper. The thermal network model is built with nodes, thermal resistors and heat generators, and it is solved using finite difference method (FDM). The main circuit and the control system are connected by thermal resistors network, which solves the problem of multi-sources interaction in the application of TNFDA. The temperature of conducting wires is calculated according to the heat transfer process and the fundamental equations of thermal conduction. It provides a method to solve the problem of boundary conditions in applying the TNFDA. The comparison between the results of TNFDA and measurements shows the feasibility and practicability of the method.

  20. Random Constraint Satisfaction Problems

    Directory of Open Access Journals (Sweden)

    Amin Coja-Oghlan

    2009-11-01

    Full Text Available Random instances of constraint satisfaction problems such as k-SAT provide challenging benchmarks. If there are m constraints over n variables there is typically a large range of densities r=m/n where solutions are known to exist with probability close to one due to non-constructive arguments. However, no algorithms are known to find solutions efficiently with a non-vanishing probability at even much lower densities. This fact appears to be related to a phase transition in the set of all solutions. The goal of this extended abstract is to provide a perspective on this phenomenon, and on the computational challenge that it poses.

  1. Low thermal expansion glass ceramics

    CERN Document Server

    1995-01-01

    This book is one of a series reporting on international research and development activities conducted by the Schott group of companies With the series, Schott aims to provide an overview of its activities for scientists, engineers, and managers from all branches of industry worldwide where glasses and glass ceramics are of interest Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated This volume describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization Thus glass ceramics with thermal c...

  2. CHALLENGES IN BRONCHIAL CHALLENGE TESTING

    NARCIS (Netherlands)

    Lexmond, A. J.; Hagedoorn, P.; Frijlink, H. W.; de Boer, A. H.

    2013-01-01

    Background: In the adenosine 5'-monophosphate (AMP) bronchial challenge test, AMP is usually administered according to dosing protocols developed for histamine/methacholine. It has never been thoroughly investigated whether these protocols are suitable for AMP as well. Methods: The setup of the

  3. Mobility Challenges

    DEFF Research Database (Denmark)

    Jensen, Ole B.; Lassen, Claus

    2011-01-01

    This article takes point of departure in the challenges to understand the importance of contemporary mobility. The approach advocated is a cross-disciplinary one drawing on sociology, geography, urban planning and design, and cultural studies. As such the perspective is to be seen as a part...... mobilities. In particular the article discusses 1) the physical city, its infrastructures and technological hardware/software, 2) policies and planning strategies for urban mobility and 3) the lived everyday life in the city and the region....... of the so-called ‘mobility turn’ within social science. The perspective is illustrative for the research efforts at the Centre for Mobility and Urban Studies (C-MUS), Aalborg University. The article presents the contours of a theoretical perspective meeting the challenges to research into contemporary urban...

  4. Challenging Identities

    DEFF Research Database (Denmark)

    Identity is a keyword in a number of academic fields as well as in public debate and in politics. During the last decades, references to identity have proliferated, yet there is no simple definition available that corresponds to the use of the notion in all contexts. The significance of the notion...... depends on the conceptual or ideological constellation in which it takes part. This volume on one hand demonstrates the role of notions of identity in a variety of European contexts, and on the other hand highlights how there may be reasons to challenge the use of the term and corresponding social......, cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...

  5. Challenging Identities

    DEFF Research Database (Denmark)

    , cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...... Rask Madsen, JUR Center for International CourtsOrganisation ; Henning Koch, JUR Center for retskulturelle studierOrganisation ; Peter E. Nielsen ; Catharina Raudvere, Institut for Tværkulturelle og Regionale StudierOrganisation: Institut ; Barbara Törnqvist-Plewa, University of Lund, Sweden ; Karl...

  6. P78-2 (SCATHA) satellite thermal balance test, a laboratory test

    Science.gov (United States)

    Parrish, R. P., Jr.

    1980-01-01

    Space simulation test programs can be carried out with a high probability of being troublefree with a competent staff, a well-maintained test facility and attention to interfaces; however, full-up thermal balance tests using the solar simulator, temperature control of infrared sources, the gimbal, a large number of thermocouples, and other requirements for a high fidelity thermal balance are still a challenge. The P78-2 (Scatha) satellite was successfully tested with one interruption and a four-day abbreviated retest to verify a modification. This was accomplished in spite of the new test crew, a facility beset with several operational problems, and marginal interface control. These problems were addressed with very good results. Subsequent tests have been highly successful.

  7. Facial Component Detection in Thermal Imagery

    NARCIS (Netherlands)

    Martinez, Brais; Binefa, Xavier; Pantic, Maja

    2010-01-01

    This paper studies the problem of detecting facial components in thermal imagery (specifically eyes, nostrils and mouth). One of the immediate goals is to enable the automatic registration of facial thermal images. The detection of eyes and nostrils is performed using Haar features and the

  8. Popular Problems

    Science.gov (United States)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…

  9. Hearing Problems

    Science.gov (United States)

    ... Read MoreDepression in Children and TeensRead MoreBMI Calculator Hearing ProblemsLoss in the ability to hear or discriminate ... This flow chart will help direct you if hearing loss is a problem for you or a ...

  10. Parametric Thermal Soak Model for Earth Entry Vehicles

    Science.gov (United States)

    Agrawal, Parul; Samareh, Jamshid; Doan, Quy D.

    2013-01-01

    The analysis and design of an Earth Entry Vehicle (EEV) is multidisciplinary in nature, requiring the application many disciplines. An integrated tool called Multi Mission System Analysis for Planetary Entry Descent and Landing or M-SAPE is being developed as part of Entry Vehicle Technology project under In-Space Technology program. Integration of a multidisciplinary problem is a challenging task. Automation of the execution process and data transfer among disciplines can be accomplished to provide significant benefits. Thermal soak analysis and temperature predictions of various interior components of entry vehicle, including the impact foam and payload container are part of the solution that M-SAPE will offer to spacecraft designers. The present paper focuses on the thermal soak analysis of an entry vehicle design based on the Mars Sample Return entry vehicle geometry and discusses a technical approach to develop parametric models for thermal soak analysis that will be integrated into M-SAPE. One of the main objectives is to be able to identify the important parameters and to develop correlation coefficients so that, for a given trajectory, can estimate the peak payload temperature based on relevant trajectory parameters and vehicle geometry. The models are being developed for two primary thermal protection (TPS) materials: 1) carbon phenolic that was used for Galileo and Pioneer Venus probes and, 2) Phenolic Impregnated Carbon Ablator (PICA), TPS material for Mars Science Lab mission. Several representative trajectories were selected from a very large trade space to include in the thermal analysis in order to develop an effective parametric thermal soak model. The selected trajectories covered a wide range of heatload and heatflux combinations. Non-linear, fully transient, thermal finite element simulations were performed for the selected trajectories to generate the temperature histories at the interior of the vehicle. Figure 1 shows the finite element model

  11. Problem Solving through Paper Folding

    Science.gov (United States)

    Wares, Arsalan

    2014-01-01

    The purpose of this article is to describe a couple of challenging mathematical problems that involve paper folding. These problem-solving tasks can be used to foster geometric and algebraic thinking among students. The context of paper folding makes some of the abstract mathematical ideas involved relatively concrete. When implemented…

  12. Thermal insulator

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, R.; Asada, Y.; Matsuo, Y.; Mikoda, M.

    1985-07-16

    A thermal insulator comprises an expanded resin body having embedded therein an evacuated powder insulation portion which consists of fine powder and a container of film-like plastics or a film-like composite of plastics and metal for enclosing the powder. The resin body has been expanded by a Freon gas as a blowing agent. Since a Freon gas has a larger molecular diameter than the constituent gases of air, it is less likely to permeate through the container than air. Thus present invention provides a novel composite insulator which fully utilizes the benefits of vacuum insulation without necessitating a strong and costly material for a vacuum container.

  13. Green Building Construction Thermal Isolation Materials (Rockwool)

    OpenAIRE

    M. Itewi

    2011-01-01

    Problem statement: Building insulation consisting roughly to anything in a structure that is utilizes as insulation for any reason. Thermal insulation in structures is a significant feature to attaining thermal comfort for its tenants. Approach: Insulation decreases unnecessary warmth loss or gain and can reduce the power burdens of heating and cooling structures. It does not automatically having anything to do with problems of sufficient exposure to air and might or might...

  14. Application of self-adaptive procedure to the thermal problems analysis under steady-state and transient regimens; Aplicacao de procedimento auto-adaptativo na analise de problemas termicos no regime permanente e transiente

    Energy Technology Data Exchange (ETDEWEB)

    Lyra, Paulo Roberto Maciel [Pernambuco Univ., Recife, PE (Brazil). Dept. de Engenharia Civil

    1990-12-31

    This work describes a procedure for the adaptive time dependent Finite Element Method using an automatic mesh refinement (H-Version) that efficiently reduces estimated errors ( a posteriori) below pre-assigned limits. Classical model problem for steady-state heat transfer are investigated, and the results are compared with the analytical solution. Then some typical time-dependent problem are qualitatively analysed. (author) 10 refs., 7 figs.

  15. Thermal radiation heat transfer.

    Science.gov (United States)

    Siegel, R.; Howell, J. R.

    1972-01-01

    A comprehensive discussion of heat transfer by thermal radiation is presented, including the radiative behavior of materials, radiation between surfaces, and gas radiation. Among the topics considered are property prediction by electromagnetic theory, the observed properties of solid materials, radiation in the presence of other modes of energy transfer, the equations of transfer for an absorbing-emitting gas, and radiative transfer in scattering and absorbing media. Also considered are radiation exchange between black isothermal surfaces, radiation exchange in enclosures composed of diffuse gray surfaces and in enclosures having some specularly reflecting surfaces, and radiation exchange between nondiffuse nongray surfaces. The use of the Monte Carlo technique in solving radiant-exchange problems and problems of radiative transfer through absorbing-emitting media is explained.

  16. Multiobjective optimization approach: thermal food processing.

    Science.gov (United States)

    Abakarov, A; Sushkov, Y; Almonacid, S; Simpson, R

    2009-01-01

    The objective of this study was to utilize a multiobjective optimization technique for the thermal sterilization of packaged foods. The multiobjective optimization approach used in this study is based on the optimization of well-known aggregating functions by an adaptive random search algorithm. The applicability of the proposed approach was illustrated by solving widely used multiobjective test problems taken from the literature. The numerical results obtained for the multiobjective test problems and for the thermal processing problem show that the proposed approach can be effectively used for solving multiobjective optimization problems arising in the food engineering field.

  17. Challenging Identities

    DEFF Research Database (Denmark)

    , cultural, and political practices. Notions of national identity and national politics are challenged by European integration, as well as by increasing demographic heterogeneity due to migration, and migrants experience conflicts of identification stemming from clashes between cultural heritage...... and the cultures of the new habitat. European horizons—frames of mind, historical memories, and expectations at the level of groups or communities, at the national level, and at the general European level—are at odds. Analyzing a series of issues in European countries from Turkey to Spain and from Scandinavia...

  18. The challenge

    Science.gov (United States)

    Freeman, Roger L.

    1988-01-01

    Radio systems in space are on the brink of achieving throughout data rates in the hundred of megabits. At present, radio systems operate below 60 GHz and are the traditional workhorses of satellite communications. Legal constraints and the laws of physics limit data rates on the systems. It is maintained that the challenge to provide high technology tools to develop viable high-data-rate space transmission systems can be met before the next century if three optical system and technology issues are overcome. In declining order of importance, the issues are: precise optical pointing, acquisition, and tracking; efficient laser diode optical sources producing sufficient output power; and advanced optical detector technology.

  19. Challenged Pragmatism

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet; Vinding, Niels Valdemar

    2013-01-01

    Against the backdrop of a well-regulated and pragmatic Danish labour market, the question of reasonable accommodation is discussed on the basis of current legislation, recent legal cases and substantial interview material drawn from the RELIGARE sociolegal research done in Denmark. Employees...... of religious faith have made religious claims and thereby challenged a secular understanding of the Danish labour market. This raises the question of the extent to which the religion of the individual can be accepted in the general public sphere. At the same time, religious ethos organisations have argued...

  20. Thermal fluid mixing behavior during medium break LOCA in evaluation of pressurized thermal shock

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jae Won; Bang, Young Seok; Seul, Kwang Won; Kim, Hho Jung [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of)

    1998-12-31

    Thermal fluid mixing behavior during a postulated medium-size hot leg break loss of coolant accident is analyzed for the international comparative assessment study on pressurized thermal shock (PTS-ICAS) proposed by OECD-NEA. The applicability of RELAP5 code to analyze the thermal fluid mixing behavior is evaluated through a simple modeling relevant to the problem constraints. Based on the calculation result, the onset of thermal stratification is investigated using Theofanous`s empirical correlation. Sensitivity calculations using a fine node model and crossflow model are also performed to evaluate the modeling capability on multi-dimensional characteristics related to thermal fluid mixing. 6 refs., 8 figs. (Author)

  1. Kidney Problems

    Science.gov (United States)

    ... High Blood Pressure Nutrition Join our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & ... build-up of waste products, and other serious consequences in later years. Doses of medications must also ...

  2. Popular problems

    DEFF Research Database (Denmark)

    Skovhus, Randi Boelskifte; Thomsen, Rie

    2017-01-01

    This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....

  3. School Problems

    Science.gov (United States)

    Kinsbourne, Marcel

    1973-01-01

    Intended for pediatricians, the article considers aspects of diagnosis and treatment of learning problems including definitions and documentation, the examination, developmental lag, intelligence and psychometry, reversals, serial ordering, cognitive processes in reading, and hyperactivity. (DB)

  4. Experimental challenges to reproduce seismic fault motion

    Science.gov (United States)

    Shimamoto, T.

    2011-12-01

    This presentation briefly reviews scientific and technical development in the studies of intermediate to high-velocity frictional properties of faults and summarizes remaining technical challenges to reproduce nucleation to growth processes of large earthquakes in laboratory. Nearly 10 high-velocity or low to high-velocity friction apparatuses have been built in the last several years in the world and it has become possible now to produce sub-plate velocity to seismic slip rate in a single machine. Despite spreading of high-velocity friction studies, reproducing seismic fault motion at high P and T conditions to cover the entire seismogenic zone is still a big challenge. Previous studies focused on (1) frictional melting, (2) thermal pressurization, and (3) high-velocity gouge behavior without frictional melting. Frictional melting process was solved as a Stefan problem with very good agreement with experimental results. Thermal pressurization has been solved theoretically based on measured transport properties and has been included successfully in the modeling of earthquake generation. High-velocity gouge experiments in the last several years have revealed that a wide variety of gouges exhibit dramatic weakening at high velocities (e.g., Di Toro et al., 2011, Nature). Most gouge experiments were done under dry conditions partly to separate gouge friction from the involvement of thermal pressurization. However, recent studies demonstrated that dehydration or degassing due to mineral decomposition can occur during seismic fault motion. Those results not only provided a new view of looking at natural fault zones in search of geological evidence of seismic fault motion, but also indicated that thermal pressurization and gouge weakening can occur simultaneously even in initially dry gouge. Thus experiments with controlled pore pressure are needed. I have struggled to make a pressure vessel for wet high-velocity experiments in the last several years. A technical

  5. Data Challenges

    CERN Multimedia

    McCubbin, N A

    Some two years ago we planned a series of Data Challenges starting at the end of 2001. At the time, that seemed to be comfortingly far in the future... Well, as the saying goes, doesn't time fly when you are having fun! ATLAS Computing is now deep in the throes of getting the first Data Challenge (DC0) up and running. One of the main aims of DC0 is to have a software 'release' in which we can generate full physics events, track all particles through the detector, simulate the detector response, reconstruct the event, and study it, with appropriate data storage en route. As all software is "always 95% ready" (!), we have been able to do most of this, more or less, for some time. But DC0 forces us to have everything working, together, at the same time: a reality check. DC0 should finish early next year, and it will be followed almost immediately afterwards by DC1 (DC0 was foreseen as the 'check' for DC1). DC1 will last into the middle of 2002, and has two major goals. The first is generation, simulation, and r...

  6. Transport of thermal water from well to thermal baths

    Science.gov (United States)

    Montegrossi, Giordano; Vaselli, Orlando; Tassi, Franco; Nocentini, Matteo; Liccioli, Caterina; Nisi, Barbara

    2013-04-01

    The main problem in building a thermal bath is having a hot spring or a thermal well located in an appropriate position for customer access; since Roman age, thermal baths were distributed in the whole empire and often road and cities were built all around afterwards. Nowadays, the perspectives are changed and occasionally the thermal resource is required to be transported with a pipeline system from the main source to the spa. Nevertheless, the geothermal fluid may show problems of corrosion and scaling during transport. In the Ambra valley, central Italy, a geothermal well has recently been drilled and it discharges a Ca(Mg)-SO4, CO2-rich water at the temperature of 41 °C, that could be used for supplying a new spa in the surrounding areas of the well itself. The main problem is that the producing well is located in a forest tree ca. 4 km far away from the nearest structure suitable to host the thermal bath. In this study, we illustrate the pipeline design from the producing well to the spa, constraining the physical and geochemical parameters to reduce scaling and corrosion phenomena. The starting point is the thermal well that has a flow rate ranging from 22 up to 25 L/sec. The thermal fluid is heavily precipitating calcite (50-100 ton/month) due to the calcite-CO2 equilibrium in the reservoir, where a partial pressure of 11 bar of CO2 is present. One of the most vexing problems in investigating scaling processed during the fluid transport in the pipeline is that there is not a proper software package for multiphase fluid flow in pipes characterized by such a complex chemistry. As a consequence, we used a modified TOUGHREACT with Pitzer database, arranged to use Darcy-Weisbach equation, and applying "fictitious" material properties in order to give the proper y- z- velocity profile in comparison to the analytical solution for laminar fluid flow in pipes. This investigation gave as a result the lowest CO2 partial pressure to be kept in the pipeline (nearly 2

  7. Advances in Thermal Insulation. Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Thorsell, Thomas

    2012-07-01

    We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment. Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60 % if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hydrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The

  8. The Cybersecurity Challenge in Acquisition

    Science.gov (United States)

    2016-04-30

    modern supply chain will add vulnerabilities to these linked supplier systems. Introduction Cyber Threat Challenges The accelerated growth in cyber...cyber challenges of their systems at the right level of detail is the only viable solution to this problem in the long run. Securing Supply Chains ...in turn introduce new vulnerabilities in the organization and must be managed by those acquisition specialists focused most on the supply chain

  9. Thermal-to-visible face recognition using multiple kernel learning

    Science.gov (United States)

    Hu, Shuowen; Gurram, Prudhvi; Kwon, Heesung; Chan, Alex L.

    2014-06-01

    Recognizing faces acquired in the thermal spectrum from a gallery of visible face images is a desired capability for the military and homeland security, especially for nighttime surveillance and intelligence gathering. However, thermal-tovisible face recognition is a highly challenging problem, due to the large modality gap between thermal and visible imaging. In this paper, we propose a thermal-to-visible face recognition approach based on multiple kernel learning (MKL) with support vector machines (SVMs). We first subdivide the face into non-overlapping spatial regions or blocks using a method based on coalitional game theory. For comparison purposes, we also investigate uniform spatial subdivisions. Following this subdivision, histogram of oriented gradients (HOG) features are extracted from each block and utilized to compute a kernel for each region. We apply sparse multiple kernel learning (SMKL), which is a MKLbased approach that learns a set of sparse kernel weights, as well as the decision function of a one-vs-all SVM classifier for each of the subjects in the gallery. We also apply equal kernel weights (non-sparse) and obtain one-vs-all SVM models for the same subjects in the gallery. Only visible images of each subject are used for MKL training, while thermal images are used as probe images during testing. With subdivision generated by game theory, we achieved Rank-1 identification rate of 50.7% for SMKL and 93.6% for equal kernel weighting using a multimodal dataset of 65 subjects. With uniform subdivisions, we achieved a Rank-1 identification rate of 88.3% for SMKL, but 92.7% for equal kernel weighting.

  10. Theoretical Modelling Methods for Thermal Management of Batteries

    Directory of Open Access Journals (Sweden)

    Bahman Shabani

    2015-09-01

    Full Text Available The main challenge associated with renewable energy generation is the intermittency of the renewable source of power. Because of this, back-up generation sources fuelled by fossil fuels are required. In stationary applications whether it is a back-up diesel generator or connection to the grid, these systems are yet to be truly emissions-free. One solution to the problem is the utilisation of electrochemical energy storage systems (ESS to store the excess renewable energy and then reusing this energy when the renewable energy source is insufficient to meet the demand. The performance of an ESS amongst other things is affected by the design, materials used and the operating temperature of the system. The operating temperature is critical since operating an ESS at low ambient temperatures affects its capacity and charge acceptance while operating the ESS at high ambient temperatures affects its lifetime and suggests safety risks. Safety risks are magnified in renewable energy storage applications given the scale of the ESS required to meet the energy demand. This necessity has propelled significant effort to model the thermal behaviour of ESS. Understanding and modelling the thermal behaviour of these systems is a crucial consideration before designing an efficient thermal management system that would operate safely and extend the lifetime of the ESS. This is vital in order to eliminate intermittency and add value to renewable sources of power. This paper concentrates on reviewing theoretical approaches used to simulate the operating temperatures of ESS and the subsequent endeavours of modelling thermal management systems for these systems. The intent of this review is to present some of the different methods of modelling the thermal behaviour of ESS highlighting the advantages and disadvantages of each approach.

  11. Challenging makerspaces

    DEFF Research Database (Denmark)

    Sandvik, Kjetil; Thestrup, Klaus

    . The Danish part of the project will be undertaken by a small network of partners: DOKK1, a public library and open urban space in Aarhus, that is experimenting with different kind of makerspaces, spaces and encounters between people, The LEGO-LAB situated at Computer Science, Aarhus University, that has......-8 will be developed through participation in creative activities in specially-designed spaces termed ‘makerspaces’. This paper discusses, develops and challenges this term in relation to Danish pedagogical traditions, to expanding makerspaces onto the internet and on how to combine narratives and construction...... developed a number of work space activities on children and technology and finally Katrinebjergskolen, a public school that has built a new multi-functional room, that among other things are meant for makerspaces and new combinations of media and materials. This group will work with the notion of Next...

  12. A Cauchy problem in nonlinear heat conduction

    Energy Technology Data Exchange (ETDEWEB)

    De Lillo, S [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Perugia (Italy); Lupo, G [Dipartimento di Matematica e Informatica, Universita degli Studi di Perugia, Via Vanvitelli, 1, 06123 Perugia (Italy); Sanchini, G [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, Perugia (Italy)

    2006-06-09

    A Cauchy problem on the semiline for a nonlinear diffusion equation is considered, with a boundary condition corresponding to a prescribed thermal conductivity at the origin. The problem is mapped into a moving boundary problem for the linear heat equation with a Robin-type boundary condition. Such a problem is then reduced to a linear integral Volterra equation of II type which admits a unique solution.

  13. [Halitosis. A common problem].

    Science.gov (United States)

    Laine, M L; Slot, D E; Danser, M M

    2011-12-01

    Halitosis is a frequently occurring problem, the cause of which is generally to be found in the mouth. The challenge for oral health care providers is to diagnose it correctly and treat it effectively. Differential diagnosis is of great importance in making a distinction between halitosis which originates in the mouth and which does not originate in the mouth. Oral halitosis can be treated effectively by good oral health care. Plaque accumulation on the tongue is the most common cause of oral halitosis. Tongue cleansing, possibly in combination with a specific mouth wash, is consequently recommended as an element of oral hygiene care. Other oral health problems, such as periodontal disease, caries and ill-fitting removable dentures should be treated adequately to eliminate these problems as potential causes of halitosis.

  14. Calculus problems

    CERN Document Server

    Baronti, Marco; van der Putten, Robertus; Venturi, Irene

    2016-01-01

    This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...

  15. Challenges of Antibacterial Discovery

    Science.gov (United States)

    Silver, Lynn L.

    2011-01-01

    Summary: The discovery of novel small-molecule antibacterial drugs has been stalled for many years. The purpose of this review is to underscore and illustrate those scientific problems unique to the discovery and optimization of novel antibacterial agents that have adversely affected the output of the effort. The major challenges fall into two areas: (i) proper target selection, particularly the necessity of pursuing molecular targets that are not prone to rapid resistance development, and (ii) improvement of chemical libraries to overcome limitations of diversity, especially that which is necessary to overcome barriers to bacterial entry and proclivity to be effluxed, especially in Gram-negative organisms. Failure to address these problems has led to a great deal of misdirected effort. PMID:21233508

  16. Scrapheap Challenge

    CERN Document Server

    2004-01-01

    Three British guys at CERN recently took a break from work to try their hand at Scrapheap Challenge. Shown on Channel 4 in the UK, it is a show where two teams must construct a machine for a specific task using only the junk they can scavenge from the scrap yard around them. And they have just 10 hours to build their contraption before it is put to the test. The first round, aired 19 September, pitted a team of three women, from the British Army's Royal Electrical and Mechanical Engineers, against the CERN guys - the Up 'n Atoms: Ali Day, David McFarlane and James Ridewood. Each team, with the help of an appointed expert, had the task of making a giant, 3-metre self-propelled "bowling ball", to roll down a 50 metre bowling alley at skittles 4 metres high. The Up 'n Atoms' contraption featured a small car with a huge wheel on its back. Once up to speed, slamming on the brakes caused the wheel to roll over and take the car with it. On their very last run they managed to take out seven pins. Luckily, though, ...

  17. Balance Problems

    Science.gov (United States)

    ... most common source of vertigo) headache (including migraines) anxiety or panic ringing in the ears allergies or infections getting up quickly from sitting or lying down a growth on the auditory nerve that works with the ear (such as an acoustic neuroma) problems with nerves in your legs and ...

  18. Prostate Problems

    Science.gov (United States)

    ... problems can cause you to go to the bathroom frequently feel as if you need to rush to the bathroom, only to find you can’t urinate or ... and disseminates research findings through its clearinghouses and education programs to increase knowledge and understanding about health ...

  19. 2008+ solved problems in electromagnetics

    CERN Document Server

    Nasar, Syed

    2007-01-01

    SciTech Publishing is reissuing this extremely valuable learning resource, originally published in 1992 in the Schaum's Problem-Solving Series for students of electromagnetics and those who wish to refresh and solidify their understanding of its challenging applications. Problem-solving drill helps develop confidence, but few textbooks offer the answers, never mind the complete solutions, to their chapter exercises. Here noted author Professor Syed Nasar has divided the book's problems into topic areas similar to a textbook and presented a wide array of problems, followed immediately by their

  20. Seasonal thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Allen, R.D.; Kannberg, L.D.; Raymond, J.R.

    1984-05-01

    This report describes the following: (1) the US Department of Energy Seasonal Thermal Energy Storage Program, (2) aquifer thermal energy storage technology, (3) alternative STES technology, (4) foreign studies in seasonal thermal energy storage, and (5) economic assessment.

  1. Low Thermal Expansion Glass Ceramics

    CERN Document Server

    Bach, Hans

    2005-01-01

    This book appears in the authoritative series reporting the international research and development activities conducted by the Schott group of companies. This series provides an overview of Schott's activities for scientists, engineers, and managers from all branches of industry worldwide in which glasses and glass ceramics are of interest. Each volume begins with a chapter providing a general idea of the current problems, results, and trends relating to the subjects treated. This new extended edition describes the fundamental principles, the manufacturing process, and applications of low thermal expansion glass ceramics. The composition, structure, and stability of polycrystalline materials having a low thermal expansion are described, and it is shown how low thermal expansion glass ceramics can be manufactured from appropriately chosen glass compositions. Examples illustrate the formation of this type of glass ceramic by utilizing normal production processes together with controlled crystallization. Thus g...

  2. Tunable Multifunctional Thermal Metamaterials: Manipulation of Local Heat Flux via Assembly of Unit-Cell Thermal Shifters

    Science.gov (United States)

    Park, Gwanwoo; Kang, Sunggu; Lee, Howon; Choi, Wonjoon

    2017-01-01

    Thermal metamaterials, designed by transformation thermodynamics are artificial structures that can actively control heat flux at a continuum scale. However, fabrication of them is very challenging because it requires a continuous change of thermal properties in materials, for one specific function. Herein, we introduce tunable thermal metamaterials that use the assembly of unit-cell thermal shifters for a remarkable enhancement in multifunctionality as well as manufacturability. Similar to the digitization of a two-dimensional image, designed thermal metamaterials by transformation thermodynamics are disassembled as unit-cells thermal shifters in tiny areas, representing discretized heat flux lines in local spots. The programmed-reassembly of thermal shifters inspired by LEGO enable the four significant functions of thermal metamaterials—shield, concentrator, diffuser, and rotator—in both simulation and experimental verification using finite element method and fabricated structures made from copper and PDMS. This work paves the way for overcoming the structural and functional limitations of thermal metamaterials. PMID:28106156

  3. Thermophysical properties of selected powders for thermal barrier coatings

    OpenAIRE

    M. Drajewicz; M. Góral; M. Pytel; J. Sieniawski

    2012-01-01

    Purpose: Plasma-sprayed thermal barrier coatings often have the problems of spallation and cracking in service owing to their poor bond strength and high residual stresses. Functionally graded thermal barrier coatings with a gradual compositional variation from heat resistant ceramics to fracture-resistant metals are proposed to mitigate these problems.Design/methodology/approach: The results of measurements of thermal diffusivity by using one of the most modern experimental sets LFA 427 (Las...

  4. Reliability challenge of ESD protection: From planner SOI MOSFET to SOI FinFET

    Science.gov (United States)

    Jiang, Yibo; Bi, Hui; Dong, Liangwei; Li, Qinglong

    2017-07-01

    Implementation of Electrostatic Discharge (ESD) protection in Silicon on Insulator (SOI) technology is a challenge because of the inherent properties of poor heat conductor and heat trapping. In this paper, a novel device as ESD clamp is proposed as Fix-Base SOI FinFET clamp which addresses the troublesome problem of floating base. Moreover, its manufacturing process is compatible to the normal SOI process flow well. Finally, a detailed discussion including current density and thermal distribution are presented with the technique of 3D TCAD simulation.

  5. Transformational fluctuation electrodynamics: application to thermal radiation illusion

    OpenAIRE

    Alwakil, Ahmed; Zerrad, Myriam; Bellieud, Michel; Veynante, Denis; Enguehard, Franck; Rolland, Nathalie; Volz, Sebastian; Amra, Claude

    2017-01-01

    International audience; Thermal radiation is a universal property for all objects with temperatures above 0K. Every object with a specific shape and emissivity has its own thermal radiation signature; such signature allows the object to be detected and recognized which can be an undesirable situation. In this paper, we apply transformation optics theory to a thermal radiation problem to develop an electromagnetic illusion by controlling the thermal radiation signature of a given object. Start...

  6. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review

    Science.gov (United States)

    Chamsa-ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

    2017-01-01

    The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented. PMID:28561802

  7. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review.

    Science.gov (United States)

    Chamsa-Ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

    2017-05-31

    The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

  8. DOE-Managed HLW and SNF Research: FY15 EBS and Thermal Analysis Work Package Status.

    Energy Technology Data Exchange (ETDEWEB)

    Matteo, Edward N. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hadgu, Teklu [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-11-01

    This report examines the technical elements necessary to evaluate EBS concepts and perform thermal analysis of DOE-Managed SNF and HLW in the disposal settings of primary interest – argillite, crystalline, salt, and deep borehole. As the disposal design concept is composed of waste inventory, geologic setting, and engineered concept of operation, the engineered barrier system (EBS) falls into the last component of engineered concept of operation. The waste inventory for DOE-Managed HLW and SNF is closely examined, with specific attention to the number of waste packages, the size of waste packages, and the thermal output per package. As expected, the DOE-Managed HLW and SNF inventory has a much smaller volume, and hence smaller number of canisters, as well a lower thermal output, relative to a waste inventory that would include commercial spent nuclear fuel (CSNF). A survey of available data and methods from previous studies of thermal analysis indicates that, in some cases, thermo-hydrologic modeling will be necessary to appropriately address the problem. This report also outlines scope for FY16 work -- a key challenge identified is developing a methodology to effectively and efficiently evaluate EBS performance in each disposal setting on the basis of thermal analyses results.

  9. Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review

    Directory of Open Access Journals (Sweden)

    Wisut Chamsa-ard

    2017-05-01

    Full Text Available The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

  10. Embedded Systems Design: Optimization Challenges

    DEFF Research Database (Denmark)

    Pop, Paul

    2005-01-01

    -to-market, and reduce development and manufacturing costs. In this paper, the author introduces several embedded systems design problems, and shows how they can be formulated as optimization problems. Solving such challenging design optimization problems are the key to the success of the embedded systems design...... of designing such systems is becoming increasingly important and difficult at the same time. New automated design optimization techniques are needed, which are able to: successfully manage the complexity of embedded systems, meet the constraints imposed by the application domain, shorten the time...

  11. Optimization Problems

    Directory of Open Access Journals (Sweden)

    Yaping Hu

    2015-01-01

    the nonsmooth convex optimization problem. First, by using Moreau-Yosida regularization, we convert the original objective function to a continuously differentiable function; then we use approximate function and gradient values of the Moreau-Yosida regularization to substitute the corresponding exact values in the algorithm. The global convergence is proved under suitable assumptions. Numerical experiments are presented to show the effectiveness of this algorithm.

  12. Challenges for Relational Reinforcement Learning

    NARCIS (Netherlands)

    van Otterlo, M.; Kersting, Kristian; Tadepalli, P.; Givan, R; Driessens, K.

    2004-01-01

    We present a perspective and challenges for Relational Reinforcement Learning (RRL). We first survey existing work and distinguish a number of main directions. We then highlight some research problems that are intrinsically involved in abstracting over relational Markov Decision Processes. These are

  13. Meeting the Challenges of Inclusion

    Science.gov (United States)

    Hills, Joanne

    2011-01-01

    Managing practical science activities effectively is demanding for any teacher and especially so for inexperienced practitioners. Add the problems posed by integrating children with learning and behavioural difficulties and one has the sort of challenge that makes working in education rewarding--but not easy! As a newly qualified teacher, the…

  14. A Water-Service Challenge

    Science.gov (United States)

    Roman, Harry T.

    2011-01-01

    It is important to let students see the value of mathematics in design--and how mathematics lends perspective to problem solving. In this article, the author describes a water-service challenge which enables students to design a water utility system that uses surface runoff into an open reservoir as the potable water source. This challenge…

  15. Using a Thermal Imaging Camera to Locate Perforators on the Lower Limb

    Directory of Open Access Journals (Sweden)

    Sharad P. Paul

    2017-05-01

    Full Text Available Reconstruction of the lower limb presents a complex problem after skin cancer surgery, as proximity of skin and bone present vascular and technical challenges. Studies on vascular anatomy have confirmed that the vascular plane on the lower limb lies deep to the deep fascia. Yet, many flaps are routinely raised superficial to this plane and therefore flap failure rates in the lower limb are high. Fascio-cutaneous flaps based on perforators offer a better cosmetic alternative to skin grafts. In this paper, we detail use of a thermal imaging camera to identify perforator ‘compartments’ that can help in designing such flaps.

  16. Space Evaporator Absorber Radiator (SEAR) for Thermal Storage on Manned Spacecraft Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future manned exploration spacecraft will need to operate in challenging thermal environments. State-of-the-art technology for active thermal control relies on...

  17. Thermal tachyacoustic cosmology

    Science.gov (United States)

    Agarwal, Abhineet; Afshordi, Niayesh

    2014-08-01

    An intriguing possibility that can address pathologies in both early Universe cosmology (i.e. the horizon problem) and quantum gravity (i.e. nonrenormalizability), is that particles at very high energies and/or temperatures could propagate arbitrarily fast. A concrete realization of this possibility for the early Universe is the tachyacoustic (or speedy sound) cosmology, which could also produce a scale-invariant spectrum for scalar cosmological perturbations. Here, we study thermal tachyacoustic cosmology (TTC), i.e. this scenario with thermal initial conditions. We find that a phase transition in the early Universe, around the scale of the grand unified theory (GUT scale; T ˜1015 GeV), during which the speed of sound drops by 25 orders of magnitude within a Hubble time, can fit current CMB observations. We further discuss how production of primordial black holes constrains the cosmological acoustic history, while coupling TTC to Horava-Lifshitz gravity leads to a lower limit on the amplitude of tensor modes (r≳10-3), that are detectable by CMBpol (and might have already been seen by the BICEP-Keck Collaboration).

  18. Power Electronics Thermal Management R&D

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert; Bennion, Kevin

    2016-06-08

    This project will develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter designs). The use of WBG-based devices in automotive power electronics will improve efficiency and increase driving range in electric-drive vehicles; however, the implementation of this technology is limited, in part, due to thermal issues. This project will develop system-level thermal models to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components. WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.

  19. Ten Problems in Experimental Mathematics

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, David H.; Borwein, Jonathan M.; Kapoor, Vishaal; Weisstein, Eric

    2004-09-30

    This article was stimulated by the recent SIAM ''100 DigitChallenge'' of Nick Trefethen, beautifully described in a recent book. Indeed, these ten numeric challenge problems are also listed in a recent book by two of present authors, where they are followed by the ten symbolic/numeric challenge problems that are discussed in this article. Our intent was to present ten problems that are characteristic of the sorts of problems that commonly arise in ''experimental mathematics''. The challenge in each case is to obtain a high precision numeric evaluation of the quantity, and then, if possible, to obtain a symbolic answer, ideally one with proof. Our goal in this article is to provide solutions to these ten problems, and in the process present a concise account of how one combines symbolic and numeric computation, which may be termed ''hybrid computation'', in the process of mathematical discovery.

  20. Environmental problems

    OpenAIRE

    Neschuk, Nancy Carolina

    1998-01-01

    Los problemas ambientales constituyen una preocupación creciente en las sociedades humanas. La Ecología, considerada como una ciencia teórica diseñada sólo para grupos académicos restringidos, adquiere ahora un valor práctico y sin duda será el mayor problema comercial que habrá que resolver en el siglo XXI. Environmental problems constitute an increasing concern in human societies. Ecology, regarded as a theoretical science designed for only restricted academic groups,...

  1. Psychosexual problems.

    Science.gov (United States)

    Tunnadine, P

    1985-05-01

    Individual anxieties about sexuality remain surprisingly repetitive despite changing public attitudes toward sexuality. This discussion includes case histories which demonstrate the indirect presentation, using nonverbal and physical cues, adopted by some patients who experience difficulty in verbalizing their sexual problems. When seeking contraceptive consultation, the patient must have no conscious or unconscious anxiety about her desire for sexual pleasure without pregnancy and is entitled to assume, when seeking such advice, that the doctor who offers it has no such prejudices either. When the presenting symptom relates to otherwise illogical contraceptive difficulty, or otherwise invites examination of the genitals, one may suspect that the problem may be sexual and too difficult to express in other than the physical language the patient expects the physician to want. For a couple whose sexual life is comfortably confident and provides pleasure, any contraceptive method will serve its purpose of removing the fear of pregnancy. Such a couple may be advised on logical grounds. For the rest, an open-ended comment such as "I wonder what the real worry is" usually leads to the true anxiety. Yet, at this point, the doctor's anxiety often replaces the patient's since the management of psychosomatic disorders is not part of normal medical training. The temptation to send for the partner and advise a program of relearning, or to make referral to a sex therapy clinic which will do likewise, is strong for any busy doctor who has no psychosexual training. Skill in dealing with such common dilemmas in the context of the brief period allotted to each patient cannot be obtained from a short article, but it is worthwhile for a physician, confronted with a patient whose symptoms do not make sense, to ask what the symptom itself may indicate in terms of the unspoken problem at hand. Most family doctors who understand the training of the Institute of Psychosexual Medicine find

  2. Applying infrared measurements in a measuring system for determining thermal parameters of thermal insulation materials

    Science.gov (United States)

    Chudzik, S.

    2017-03-01

    The paper presents results of research on an innovative method for determining thermal parameters of thermal insulating materials. The method is based on harmonic thermal excitations. Temperature measurements at selected points of a specimen under test are performed by means of semiconductor infrared sensors. The study also employs a 3D model of thermal diffusion. To obtain a solution of the coefficient inverse problem a method based on an artificial neural network is presented. The heat transfer coefficient on the specimen surface is estimated on the basis of a reference specimen. The validity of the adopted model of heat diffusion and the usefulness of the method proposed are verified experimentally.

  3. Problems in Biotechnology Research

    Directory of Open Access Journals (Sweden)

    Parveen Jamal and Hamzah M. Salleh

    2012-08-01

    Full Text Available To meet the challenges posed by the growing population of the world, biotechnology research is being pursued in all countries. In the area of medicine remarkable success has been achieved. It is believed that in future this trend will continue. In the area food also scientists and technocrats have shown considerable success, but in this area they have not received appreciation because of many objections. The paper discusses issues pertaining to biotechnology researches, because if these issues are not thoroughly discussed and problems are not hammered out, biotechnology researches will go on but will fail to serve the humanity.Key Words: biodiversity, biotechnology, cloning, germ cell, genetic materials, biosafety.

  4. THE CHALLENGE OF THE “ECONOMIC INDEPENDENCE” AND THE “SOVEREIGNTY OF STATES”: A REVIEW OF THE PROBLEM OF LEGITIMACY OF ECONOMIC SANCTIONS IN THE REALITY OF THE INTERNATIONAL LEGAL ORDER

    Directory of Open Access Journals (Sweden)

    AKBAR ADIBI

    2017-01-01

    Full Text Available One of the problems faced by the international community is to find a basis for regulating economic relations between the states. While the third world states still emphasize their economic sovereignty to encounter and maintain their positions against the North States, the analysis of the international legal realities shows that merely relying on the “economic independence” and “permanent sovereignty over natural resources” cannot be a practical way to achieve the ideals of states known as the “South.” Like the Sword of Damocles, sovereignty can pave the way for maintaining the “status quo” or the domination of the premier economic powers in the international equation. Merely relying on international law as a branch based on the states’ sovereignty will be actually misleading to change the status quo. By a realistic analysis of the less positive role of sovereignty in the procedure of regulating the relations between the North and the South, this study seeks to focus on the fact that going out of the impasse of unjust economic relations between the North and the South will be possible only by creating a gap in the traditional concept of economic sovereignty in a sense that has been formed by the third world states in the 60s and 70s of the past century.

  5. Challenges in Designing Mechatronic Systems

    DEFF Research Database (Denmark)

    Torry-Smith, Jonas; Qamar, Ahsan; Achiche, Sofiane

    2013-01-01

    Development of mechatronic products is traditionally carried out by several design experts from different design domains. Performing development of mechatronic products is thus greatly challenging. In order to tackle this, the critical challenges in mechatronics have to be well understood and well...... supported through applicable methods and tools. This paper aims at identifying the major challenges, by conducting a systematic and thorough survey of the most relevant research work in mechatronic design. Solutions proposed in literature are assessed and illustrated through a case study in order...... to investigate if the challenges can be handled appropriately by the methods, tools, and mindsets suggested by the mechatronic community. Using a real world mechatronics case, the paper identifies the areas where further research is required, by showing a clear connection between the actual problems faced during...

  6. Perfect Thermal Emission by Nanoscale Transmission Line Resonators.

    Science.gov (United States)

    Liu, Baoan; Gong, Wei; Yu, Bowen; Li, Pengfei; Shen, Sheng

    2017-02-08

    Thermal radiation with a narrow-band emission spectrum is of great importance in a variety of applications such as infrared sensing, thermophotovoltaics, radiation cooling, and thermal circuits. Although resonant nanophotonic structures such as metamaterials and nanocavities have been demonstrated to achieve the narrow-band thermal emission, maximizing their radiation power toward perfect emission still remains challenging. Here, based on the recently developed quasi-normal mode theory, we prove that thermal emission from a nanoscale transmission line resonator can always be maximized by tuning the waveguiding loss of the resonator or bending the structure. By use of nanoscale transmission line resonators as basic building blocks, we experimentally demonstrate a new type of macroscopic perfect and tunable thermal emitters. Our experimental demonstration in conjunction with the general theoretical framework from the quasi-normal mode theory lays the foundation for designing tunable narrow-band thermal emitters with applications in thermal infrared light sources, thermal management, and infrared sensing and imaging.

  7. Electron thermal transport in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Konings, J.A.

    1994-11-30

    The process of fusion of small nuclei thereby releasing energy, as it occurs continuously in the sun, is essential for the existence of mankind. The same process applied in a controlled way on earth would provide a clean and an abundant energy source, and be the long term solution of the energy problem. Nuclear fusion requires an extremely hot (10{sup 8} K) ionized gas, a plasma, that can only be maintained if it is kept insulated from any material wall. In the so called `tokamak` this is achieved by using magnetic fields. The termal insulation, which is essential if one wants to keep the plasma at the high `fusion` temperature, can be predicted using basic plasma therory. A comparison with experiments in tokamaks, however, showed that the electron enery losses are ten to hundred times larger than this theory predicts. This `anomalous transport` of thermal energy implies that, to reach the condition for nuclear fusion, a fusion reactor must have very large dimensions. This may put the economic feasibility of fusion power in jeopardy. Therefore, in a worldwide collaboration, physicists study tokamak plasmas in an attempt to understand and control the energy losses. From a scientific point of view, the mechanisms driving anomalous transport are one of the challenges in fudamental plasma physics. In Nieuwegein, a tokamak experiment (the Rijnhuizen Tokamak Project, RTP) is dedicated to the study of anomalous transport, in an international collaboration with other laboratories. (orig./WL).

  8. Cryogenic Fluid Management Technology Development for Nuclear Thermal Propulsion

    Science.gov (United States)

    Taylor, Brian; Caffrey, Jarvis; Hedayat, Ali; Stephens, Jonathan; Polsgrove, Robert

    2015-01-01

    The purpose of this paper is to investigate, facilitate a discussion and determine a path forward for technology development of cryogenic fluid management technology that is necessary for long duration deep space missions utilizing nuclear thermal propulsion systems. There are a number of challenges in managing cryogenic liquids that must be addressed before long durations missions into deep space, such as a trip to Mars can be successful. The leakage rate of hydrogen from pressure vessels, seals, lines and valves is a critical factor that must be controlled and minimized. For long duration missions, hydrogen leakage amounts to large increases in hydrogen and therefore vehicle mass. The size of a deep space vehicle, such as a mars transfer vehicle, must be kept small to control cost and the logistics of a multi launch, assembled in orbit vehicle. The boil off control of the cryogenic fluid is an additional obstacle to long duration missions. The boil off caused by heat absorption results in the growth of the propellant needs of the vehicle and therefore vehicle mass. This is a significant problem for a vehicle using nuclear (fission) propulsion systems. Radiation from the engines deposits large quantities of heat into the cryogenic fluid, greatly increasing boil off beyond that caused by environmental heat leakage. Addressing and resolving these challenges is critical to successful long duration space exploration. This paper discusses the state of the technology needed to address these challenges and discuss the path forward needed in technology development.

  9. Thermal Properties and Phonon Spectral Characterization of Synthetic Boron Phosphide for High Thermal Conductivity Applications.

    Science.gov (United States)

    Kang, Joon Sang; Wu, Huan; Hu, Yongjie

    2017-12-13

    Heat dissipation is an increasingly critical technological challenge in modern electronics and photonics as devices continue to shrink to the nanoscale. To address this challenge, high thermal conductivity materials that can efficiently dissipate heat from hot spots and improve device performance are urgently needed. Boron phosphide is a unique high thermal conductivity and refractory material with exceptional chemical inertness, hardness, and high thermal stability, which holds high promises for many practical applications. So far, however, challenges with boron phosphide synthesis and characterization have hampered the understanding of its fundamental properties and potential applications. Here, we describe a systematic thermal transport study based on a synergistic synthesis-experimental-modeling approach: we have chemically synthesized high-quality boron phosphide single crystals and measured their thermal conductivity as a record-high 460 W/mK at room temperature. Through nanoscale ballistic transport, we have, for the first time, mapped the phonon spectra of boron phosphide and experimentally measured its phonon mean free-path spectra with consideration of both natural and isotope-pure abundances. We have also measured the temperature- and size-dependent thermal conductivity and performed corresponding calculations by solving the three-dimensional and spectral-dependent phonon Boltzmann transport equation using the variance-reduced Monte Carlo method. The experimental results are in good agreement with that predicted by multiscale simulations and density functional theory, which together quantify the heat conduction through the phonon mode dependent scattering process. Our finding underscores the promise of boron phosphide as a high thermal conductivity material for a wide range of applications, including thermal management and energy regulation, and provides a detailed, microscopic-level understanding of the phonon spectra and thermal transport mechanisms of

  10. Presidential Green Chemistry Challenge: 1996 Small Business Award

    Science.gov (United States)

    Presidential Green Chemistry Challenge 1996 award winner, Donlar, developed thermal polyaspartate, a nontoxic, biodegradable, biobased polymer made in a highly efficient process for use in agriculture, water treatment, etc.

  11. Perioperative thermal insulation.

    Science.gov (United States)

    Bräuer, Anselm; Perl, Thorsten; English, Michael J M; Quintel, Michael

    2007-01-01

    Perioperative hypothermia remains a common problem during anesthesia and surgery. Unfortunately, the implementation of new minimally invasive surgical procedures has not lead to a reduction of this problem. Heat losses from the skin can be reduced by thermal insulation to avoid perioperative hypothermia. However, only a small amount of information is available regarding the physical properties of insulating materials used in the Operating Room (OR). Therefore, several materials using validated manikins were tested. Heat loss from the surface of the manikin can be described as:"Q = h . DeltaT . A" where Q = heat flux, h = heat exchange coefficient, DeltaT = temperature gradient between the environment and surface, and A = covered area. Heat flux per unit area and surface temperature were measured with calibrated heat flux transducers. Environmental temperature was measured using a thermoanemometer. The temperature gradient between the surface and environment (DeltaT) was varied and "h" was determined by linear regression analysis as the slope of "DeltaT" versus heat flux per unit area. The reciprocal of the heat exchange coefficient defines the insulation. The insulation values of the materials varied between 0.01 Clo (plastic bag) to 2.79 Clo (2 layers of a hospital duvet). Given the range of insulating materials available for outdoor activities, significant improvement in insulation of patients in the OR is both possible and desirable.

  12. A transient divided-bar method for simultaneous measurements of thermal conductivity and thermal diffusivity

    DEFF Research Database (Denmark)

    Bording, Thue Sylvester; Nielsen, Søren Bom; Balling, Niels

    2016-01-01

    Accurate information on thermal conductivity and thermal diffusivity of materials is of central importance in relation to geoscience and engineering problems involving the transfer of heat. Within the geosciences, this applies to all aspects regarding the determination of terrestrial heat flow...... and subsurface temperature modelling. Several methods, including the classical divided-bar technique, are available for laboratory measurements of thermal conductivity, and much fewer for thermal diffusivity. We have generalized the divided-bar technique to the transient case, in which thermal conductivity...... and volumetric heat capacity, and thereby also thermal diffusivity, are measured simultaneously. As the density of samples is easily determined independently, specific heat capacity may also be determined. Finite element formulation provides a flexible forward solution for heat transfer across the bar...

  13. Thermal explosion in oscillating ambient conditions

    Science.gov (United States)

    Novozhilov, Vasily

    2016-01-01

    Thermal explosion problem for a medium with oscillating ambient temperature at its boundaries is considered. This is a new problem in thermal explosion theory, not previously considered in a distributed system formulation, but important for combustion and fire science. It describes autoignition of wide range of fires (such as but not limited to piles of biosolids and other organic matter; storages of munitions, explosives, propellants) subjected to temperature variations, such as seasonal or day/night variation. The problem is considered in formulation adopted in classical studies of thermal explosion. Critical conditions are determined by frequency and amplitude of ambient temperature oscillations, as well as by a number of other parameters. Effects of all the parameters on critical conditions are quantified. Results are presented for the case of planar symmetry. Development of thermal explosion in time is also considered, and a new type of unsteady thermal explosion development is discovered where thermal runaway occurs after several periods of temperature oscillations within the medium. PMID:27443235

  14. High efficiency thermal storage system for solar plants (HELSOLAR). Final report

    Energy Technology Data Exchange (ETDEWEB)

    Villarroel, Eduardo; Fernandez-Pello, Carlos; Lenartz, Jeff; Parysek, Karen

    2013-02-27

    The project objective was to develop a high temperature Thermal Storage System (TES) based on graphite and able to provide both economical and technical advantages with respect to existing solutions contributing to increase the share of Concentrated Solar Plants (CSP). One of the main disadvantages of most of the renewable energy systems is their dependence to instantaneous irradiation and, thus, lack of predictability. CSP plants with thermal storage have proved to offer a good solution to this problem although still at an elevated price. The identification of alternative concepts able to work more efficiently would help to speed up the convergence of CSP towards grid parity. One way to reduce costs is to work in a range of temperatures higher than those allowed by the actual molten salt systems, currently the benchmark for TES in CSP. This requires the use of alternative energy storage materials such as graphite, as well as the utilization of Heat Transfer Fluids (HTF) other than molten salts or organic oils. The main technical challenges identified are derived from the high temperatures and significant high pressures, which pose risks such as potential graphite and insulation oxidation, creep, fatigue, corrosion and stress-corrosion in the pipes, leakages in the joints, high blower drivers’ electrical power consumption, thermal compatibility or relative deformations of the different materials. At the end, the main challenge of the project, is to identify a technical solution able to overcome all these problems but still at a competitive cost when compared to already existing thermal storage solutions. Special attention is given to all these issues during this project.

  15. Thermal energy systems design and analysis

    CERN Document Server

    Penoncello, Steven G

    2015-01-01

    IntroductionThermal Energy Systems Design and AnalysisSoftwareThermal Energy System TopicsUnits and Unit SystemsThermophysical PropertiesEngineering DesignEngineering EconomicsIntroductionCommon Engineering Economics NomenclatureEconomic Analysis Tool: The Cash Flow DiagramTime Value of MoneyTime Value of Money ExamplesUsing Software to Calculate Interest FactorsEconomic Decision MakingDepreciation and TaxesProblemsAnalysis of Thermal Energy SystemsIntroductionNomenclatureThermophysical Properties of SubstancesSuggested Thermal Energy Systems Analysis ProcedureConserved and Balanced QuantitiesConservation of MassConservation of Energy (The First Law of Thermodynamics)Entropy Balance (The Second Law of Thermodynamics)Exergy Balance: The Combined LawEnergy and Exergy Analysis of Thermal Energy CyclesDetailed Analysis of Thermal Energy CyclesProblemsFluid Transport in Thermal Energy SystemsIntroductionPiping and Tubing StandardsFluid Flow FundamentalsValves and FittingsDesign and Analysis of Pipe NetworksEconomi...

  16. CubeSat Form Factor Thermal Control Louvers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal control of small spacecraft, including CubeSats, is a challenge for the next era of NASA spaceflight. Science objectives and components will still require...

  17. The Global Energy Challenge

    DEFF Research Database (Denmark)

    Connolly, David

    2011-01-01

    . Afterwards, the security of the world’s energy supply is investigated and it becomes clear that there is both an inevitable shortage of fossil fuels and a dangerous separation of supply and demand. The final topic discussed is renewable energy, since it is one sustainable solution to the global energy......This report gives a brief overview of the global energy challenge and subsequently outlines how and where renewable energy could be developed to solve these issues. The report does not go into a lot of detail on these issues and hence, it is meant as an overview only. The report begins by outlining...... the causes of global climate change, concluding that energy-related emissions are the primary contributors to the problem. As a result, global energy production is analysed in more detail, discussing how it has evolved over the last 30 years and also, how it is expected to evolve in the coming 30 years...

  18. Hand's Academy Challenge: Some Starter Questions

    Science.gov (United States)

    Gardner, Peter

    2014-01-01

    Michael Hand has recently challenged certain religious organisations that run Academies in the United Kingdom to devise and pursue their own faith-based curricula in their schools. In this short article I examine some of the problems Hand's challenge might encounter, including whether religious conceptions of worthwhile activities and of human…

  19. Advances in LED packaging and thermal management materials

    Science.gov (United States)

    Zweben, Carl

    2008-02-01

    Heat dissipation, thermal stresses and cost are key light-emitting diode (LED) packaging issues. Heat dissipation limits power levels. Thermal stresses affect performance and reliability. Copper, aluminum and conventional polymeric printed circuit boards (PCBs) have high coefficients of thermal expansion, which can cause high thermal stresses. Most traditional low-coefficient-of-thermal-expansion (CTE) materials like tungsten/copper, which date from the mid 20th century, have thermal conductivities that are no better than those of aluminum alloys, about 200 W/m-K. An OIDA LED workshop cited a need for better thermal materials. There are an increasing number of low-CTE materials with thermal conductivities ranging between that of copper (400 W/m-K) and 1700 W/m-K, and many other low-CTE materials with lower thermal conductivities. Some of these materials are low cost. Others have the potential to be low cost in high-volume production. High-thermal-conductivity materials enable higher power levels, potentially reducing the number of required LEDs. Advanced thermal materials can constrain PCB CTE and greatly increase thermal conductivity. This paper reviews traditional packaging materials and advanced thermal management materials. The latter provide the packaging engineer with a greater range of options than in the past. Topics include properties, status, applications, cost, using advanced materials to fix manufacturing problems, and future directions, including composites reinforced with carbon nanotubes and other thermally conductive materials.

  20. Configuração institucional e gestão do Sistema Único de Saúde: problemas e desafios Institutional configuration and administration of Brazil's National Health System (SUS: problems and challenges

    Directory of Open Access Journals (Sweden)

    Jairnilson Silva Paim

    2007-11-01

    Full Text Available O trabalho analisa a problemática da "institucionalidade" do SUS, destacando alguns nós críticos a serem enfrentados para a retomada do projeto da Reforma Sanitária Brasileira. A reflexão diz respeito à configuração institucional do SUS, abarcando também aspectos relativos ao processo de condução político-gerencial do sistema, parte da cultura organizacional do Estado brasileiro, patrimonialista, autoritário, burocrático e colonizado por interesses privados. Descreve um conjunto de problemas, como o "engessamento" da gestão, por conta das limitações legais estabelecidas em função da política econômica, a exemplo da Lei de Responsabilidade Fiscal, a inadequação das "alternativas" subsidiárias das reformas gerencialistas, que geram a fragmentação do processo de gestão, e o marcado amadorismo conseqüente à insuficiência de quadros profissionalizados, reprodução de práticas clientelistas e corporativas na indicação de ocupantes dos cargos de direção em todos os níveis. São apresentados argumentos favoráveis à introdução e consolidação de inovações institucionais, a exemplo das fundações estatais de direito privado e discute-se estratégias de fortalecimento da capacidade de governo das instituições gestoras do SUS, em particular a profissionalização da gestão e a formação profissional nesta área.This paper analyzes the 'institutionality' of Brazil's National Health System, stressing crucial aspects to be dealt with, due to a return to the Public Health Reform Project. The reflection focus on the System´s institutional configuration, covering issues related to the process for its political and management conduct, rooted in the authoritarian/patrimonialistic organizational culture of the Brazilian State, entangled in red tape and colonized by private interests. It describes matters such as strategic resources/services management, hobbled by legal constraints imposed through economic policies, e

  1. Understanding the LHC Controls Challenges

    CERN Document Server

    Van den Eynden, M

    2000-01-01

    The analysis, design and construction of the LHC control system is a complex problem which will challenge CERN's capability to provide a modern controls infrastructure fulfilling the stringent operational requirements of this machine. The first part of this talk will review the present LHC project context in which several controls initiatives have already been taken. The second part will try to highlight the important technical aspects and engineering steps involved in the process of defining a control system architecture. The importance of understanding the major LHC operational challenges will be stressed along with some practical proposals and examples on how to conduct such activity with all stakeholders.

  2. Methods of solving nonstandard problems

    CERN Document Server

    Grigorieva, Ellina

    2015-01-01

    This book, written by an accomplished female mathematician, is the second to explore nonstandard mathematical problems – those that are not directly solved by standard mathematical methods but instead rely on insight and the synthesis of a variety of mathematical ideas.   It promotes mental activity as well as greater mathematical skills, and is an ideal resource for successful preparation for the mathematics Olympiad. Numerous strategies and techniques are presented that can be used to solve intriguing and challenging problems of the type often found in competitions.  The author uses a friendly, non-intimidating approach to emphasize connections between different fields of mathematics and often proposes several different ways to attack the same problem.  Topics covered include functions and their properties, polynomials, trigonometric and transcendental equations and inequalities, optimization, differential equations, nonlinear systems, and word problems.   Over 360 problems are included with hints, ...

  3. Electric Motor Thermal Management R&D. Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-04-01

    With the push to reduce component volumes, lower costs, and reduce weight without sacrificing performance or reliability, the challenges associated with thermal management increase for power electronics and electric motors. Thermal management for electric motors will become more important as the automotive industry continues the transition to more electrically dominant vehicle propulsion systems. The transition to more electrically dominant propulsion systems leads to higher-power duty cycles for electric drive systems. Thermal constraints place significant limitations on how electric motors ultimately perform, and as thermal management improves, there will be a direct trade-off between motor performance, efficiency, cost, and the sizing of electric motors to operate within the thermal constraints. The goal of this research project is to support broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management. Work in FY15 focused on two areas related to motor thermal management: passive thermal performance and active convective cooling. Passive thermal performance emphasized the thermal impact of materials and thermal interfaces among materials within an assembled motor. The research tasks supported the publication of test methods and data for thermal contact resistances and direction-dependent thermal conductivity within an electric motor. Active convective cooling focused on measuring convective heat-transfer coefficients using automatic transmission fluid (ATF). Data for average convective heat transfer coefficients for direct impingement of ATF jets was published. Also, experimental hardware for mapping local-scale and stator-scale convective heat transfer coefficients for ATF jet impingement were developed.

  4. Progress in thermal comfort research over the last twenty years

    DEFF Research Database (Denmark)

    Dear, R. J. de; Akimoto, T.; Arens, E. A.

    2013-01-01

    developed, driven by the continuous challenge to model thermal comfort at the same anatomical resolution and to combine these localized signals into a coherent, global thermal perception. Finally, the demand for ever increasing building energy efficiency is pushing technological innovation in the way we...

  5. Thermal design of the Wide Field/Planetary Camera

    Science.gov (United States)

    Garcia, R. D.; Jones, J. A.; Stultz, J. W.

    1989-01-01

    The Wide Field/Planetary Camera is an imaging system developed by the Jet Propulsion Laboratory for the NASA Hubble Space Telescope currently scheduled to be launched in December 1989 aboard the space shuttle. The temperature control design of the instrument utilizes multilayered insulation, electric resistance heaters, aluminum/ammonia heat pipes, thermoelectric coolers, temperature control coatings, and space radiators. A feedback control system maintains stable sensor temperatures. Thermal capacitance maintains stable optics and electronics temperatures during transient conditions. Schedule slips and launch delays have allowed extensive thermal testing of the instrument. Six instrument thermal vacuum tests and a spacecraft thermal vacuum test were performed. Several modifications have been made to the instrument to correct icing and contamination problems that have been discovered during thermal vacuum testing. This paper describes the thermal design, last instrument thermal vacuum test, results, and thermal model correlation.

  6. Thermal insulation properties of walls

    Directory of Open Access Journals (Sweden)

    Zhukov Aleksey Dmitrievich

    2014-05-01

    Full Text Available Heat-protective qualities of building structures are determined by the qualities of the used materials, adequate design solutions and construction and installation work of high quality. This rule refers both to the structures made of materials similar in their structure and nature and mixed, combined by a construction system. The necessity to ecaluate thermal conductivity is important for a product and for a construction. Methods for evaluating the thermal protection of walls are based on the methods of calculation, on full-scale tests in a laboratory or on objects. At the same time there is a reason to believe that even deep and detailed calculation may cause deviation of the values from real data. Using finite difference method can improve accuracy of the results, but it doesn’t solve all problems. The article discusses new approaches to evaluating thermal insulation properties of walls. The authors propose technique of accurate measurement of thermal insulation properties in single blocks and fragments of walls and structures.

  7. High Resolution Decision Maps for Urban Planning: A Combined Analysis of Urban Flooding and Thermal Stress Potential In Asia and Europe

    Directory of Open Access Journals (Sweden)

    Boogaard Floris

    2017-01-01

    Full Text Available Urban flooding and thermal stress have become key issues for many cities around the world. With the continuing effects of climate change, these two issues will become more acute and will add to the serious problems already experienced in dense urban areas. Therefore, the sectors of public health and disaster management are in the need of tools that can assess the vulnerability to floods and thermal stress. The present paper deals with the combination of innovative tools to address this challenge. Three cities in different climatic regions with various urban contexts have been selected as the pilot areas to demonstrate these tools. These cities are Tainan (Taiwan, Ayutthaya (Thailand and Groningen (Netherlands. For these cities, flood maps and heat stress maps were developed and used for the comparison analysis. The flood maps produced indicate vulnerable low-lying areas, whereas thermal stress maps indicate open, unshaded areas where high Physiological Equivalent Temperature (PET values (thermal comfort can be expected. The work to date indicates the potential of combining two different kinds of maps to identify and analyse the problem areas. These maps could be further improved and used by urban planners and other stakeholders to assess the resilience and well-being of cities. The work presented shows that the combined analysis of such maps also has a strong potential to be used for the analysis of other challenges in urban dense areas such as air and water pollution, immobility and noise disturbance.

  8. Hypersonic propulsion - Breaking the thermal barrier

    Science.gov (United States)

    Weidner, J. P.

    1993-01-01

    The challenges of hypersonic propulsion impose unique features on the hypersonic vehicle - from large volume requirements to contain cryogenic fuel to airframe-integrated propulsion required to process sufficient quantities of air. Additional challenges exist in the design of the propulsion module that must be capable of efficiently processing air at very high enthalpies, adding and mixing fuel at supersonic speeds and expanding the exhaust products to generate thrust greater than drag. The paper explores the unique challenges of the integrated hypersonic propulsion system, addresses propulsion cycle selection to cope with the severe thermal environment and reviews the direction of propulsion research at hypervelocity speeds.

  9. On vacuum-insulated thermal storage

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Benjamin [Georg-Simon-Ohm Univ. of Applied Sciences, Nuernberg (Germany); Technische Univ. Muenchen (Germany). Inst. of Resource and Energy Technology; Hofbeck, Klaus [Georg-Simon-Ohm Univ. of Applied Sciences, Nuernberg (Germany)

    2011-07-01

    Nowadays, the insulation for thermal energy storage (TES) is not as good as it should be. One reason for this is the higher investment cost for better insulation. Nevertheless, most of the recent studies show that the thermal losses of long-term storage have been underestimated. Therefore, recent research studies have focused on vacuum-insulated thermal storage. There are two common concepts with regard to the use of vacuum insulation for thermal storage. On the one hand, the Center for Applied Energy Research (ZAE) in Munich uses an evacuated double vessel filled with pearlite. On the other hand, the Ohm University uses vacuum insulation panels (VIP). Both the insulation concepts are based on the Knudsen effect. Thus, the thermal conductivity is lowered by a factor of 6-10, when compared with the conventional insulation materials, such as EPS, XPS, or mineral wool. Both the concepts are adoptions of the existing insulation applications. The filled double vessel tank is already being used for cryogenic storage for liquid gases. Furthermore, VIPs are being used to insulate passive houses. However, the use of vacuum insulation for thermal energy storage causes different problems due to higher temperatures and moisture. Nevertheless, vacuum insulations are a promising solution for small thermal long-tenn storage. This study presents the first state-of-the-art review on vacuum-insulated thermal tanks.

  10. Provisional maps of thermal areas in Yellowstone National Park, based on satellite thermal infrared imaging and field observations

    Science.gov (United States)

    Vaughan, R. Greg; Heasler, Henry; Jaworowski, Cheryl; Lowenstern, Jacob B.; Keszthelyi, Laszlo P.

    2014-01-01

    Maps that define the current distribution of geothermally heated ground are useful toward setting a baseline for thermal activity to better detect and understand future anomalous hydrothermal and (or) volcanic activity. Monitoring changes in the dynamic thermal areas also supports decisions regarding the development of Yellowstone National Park infrastructure, preservation and protection of park resources, and ensuring visitor safety. Because of the challenges associated with field-based monitoring of a large, complex geothermal system that is spread out over a large and remote area, satellite-based thermal infrared images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to map the location and spatial extent of active thermal areas, to generate thermal anomaly maps, and to quantify the radiative component of the total geothermal heat flux. ASTER thermal infrared data acquired during winter nights were used to minimize the contribution of solar heating of the surface. The ASTER thermal infrared mapping results were compared to maps of thermal areas based on field investigations and high-resolution aerial photos. Field validation of the ASTER thermal mapping is an ongoing task. The purpose of this report is to make available ASTER-based maps of Yellowstone’s thermal areas. We include an appendix containing the names and characteristics of Yellowstone’s thermal areas, georeferenced TIFF files containing ASTER thermal imagery, and several spatial data sets in Esri shapefile format.

  11. Dynamic thermal characteristics of heat pipe via segmented thermal resistance model for electric vehicle battery cooling

    Science.gov (United States)

    Liu, Feifei; Lan, Fengchong; Chen, Jiqing

    2016-07-01

    Heat pipe cooling for battery thermal management systems (BTMSs) in electric vehicles (EVs) is growing due to its advantages of high cooling efficiency, compact structure and flexible geometry. Considering the transient conduction, phase change and uncertain thermal conditions in a heat pipe, it is challenging to obtain the dynamic thermal characteristics accurately in such complex heat and mass transfer process. In this paper, a ;segmented; thermal resistance model of a heat pipe is proposed based on thermal circuit method. The equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete three-dimensional (3D) computational fluid dynamics (CFD) simulation. The proposed ;segmented; model shows more precise than the ;non-segmented; model by the comparison of simulated and experimental temperature distribution and variation of an ultra-thin micro heat pipe (UMHP) battery pack, and has less calculation error to obtain dynamic thermal behavior for exact thermal design, management and control of heat pipe BTMSs. Using the ;segmented; model, the cooling effect of the UMHP pack with different natural/forced convection and arrangements is predicted, and the results correspond well to the tests.

  12. Challenges in Piaget's legacy.

    Science.gov (United States)

    Bibace, Roger

    2013-03-01

    The publication of After Piaget (Martí and Rodríguez 2012) hopefully triggers a new effort to understand the richness of the efforts of that major psychologist of the 20th century. Piaget was consistently concerned with part/whole relationships throughout his life. He addressed this issue philosophically, epistemologically, and psychologically. Conceptually Piaget struggled with the issue of continuity/discontinuity in development and changed his mind about how to reconcile the discontinuities of stages with his concept of development. I also attribute his variability to the implications of his important work on perception, and to his willingness to get involved in widespread concrete applications of his approach to education including the education of children with special needs; his center for genetic epistemology, and his interest in psychoanalysis. Benefiting from all the authors of After Piaget, I want to point out that Piaget has identified many major issues that will continue to constitute challenges to psychology in this century. These include specifying terms such as 'development;' methodological issues such as sampling both quantitatively in one culture and across cultures; comprehensive inclusion of the psychological processes covered by introductory textbooks in psychology; and conceptual issues such as the relationships among all these parts within a whole. I make a distinction between an 'issue' and a 'problem'--problems have solutions; while issues refer to controversies in science generally as well as in psychology that have persisted for centuries.

  13. The Kiki-Bouba Challenge

    DEFF Research Database (Denmark)

    Sturm, Bob L.; Collins, Nick

    2014-01-01

    We propose the “Kiki-Bouba Challenge” (KBC) for the re- search and development of content-based music informa- tion retrieval (MIR) systems. This challenge is unencum- bered by several problems typically encountered in MIR research: insufficient data, restrictive copyrights, imper- fect ground...... truth, a lack of specific criteria for classes (e.g., genre), a lack of explicit problem definition, and irrepro- ducibility. KBC provides a limitless amount of free data, a perfect ground truth, and well-specifiable and meaningful characteristics defining each class. These ideal conditions are made...

  14. Revisiting the medical diagnosis problem

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Leron, Uri

    2014-01-01

    Abstract. A recurrent concern in mathematics education – both theory and practice – is a family of mathematical tasks which elicit from most people strong immediate ("intuitive") responses, which on further reflection turn out to clash with the normative analytical solution. We call such tasks...... cognitive challenges, because they challenge cognitive psychologists to postulate mechanisms of the mind which could account for these phenomena. For the educational community, these cognitive challenges raise a corresponding educational challenge: What can mathematics educators do in the face...... in the context of probability, with special focus on one case study – the Medical Diagnosis Problem – which figures prominently in the cognitive psychology research literature and in the so-called rationality debate. Our case study involves a combination of theory, design and experiment: Using the extensive...

  15. Applying optimization software libraries to engineering problems

    Science.gov (United States)

    Healy, M. J.

    1984-01-01

    Nonlinear programming, preliminary design problems, performance simulation problems trajectory optimization, flight computer optimization, and linear least squares problems are among the topics covered. The nonlinear programming applications encountered in a large aerospace company are a real challenge to those who provide mathematical software libraries and consultation services. Typical applications include preliminary design studies, data fitting and filtering, jet engine simulations, control system analysis, and trajectory optimization and optimal control. Problem sizes range from single-variable unconstrained minimization to constrained problems with highly nonlinear functions and hundreds of variables. Most of the applications can be posed as nonlinearly constrained minimization problems. Highly complex optimization problems with many variables were formulated in the early days of computing. At the time, many problems had to be reformulated or bypassed entirely, and solution methods often relied on problem-specific strategies. Problems with more than ten variables usually went unsolved.

  16. Practices and challenges of implementing locally available ...

    African Journals Online (AJOL)

    The main challenges of implementing LAE in teaching chemistry are lack of skills, interest and knowledge; lack of facilities and awareness problem of school principals. Therefore, giving planned and consecutive training for chemistry teachers and creating awareness for school principals solve the problems of utilizing LAE ...

  17. Health Concern and Challenges Among School Adolescents

    African Journals Online (AJOL)

    Health Concern and Challenges Among School Adolescents Abebe G. et al 37. ORIGINAL „4 RTJ CLE. Health Concern and ... of adolescents behavioral, social and physical health problems should be given high priority; establishment of special ..... approach dealing with the full range of their health problems (7, 8, 21).

  18. A Personal Perspective on Challenging Behaviour: ADHD?

    Science.gov (United States)

    Young-Loveridge, Jenny

    1997-01-01

    Presents author's perspective on the challenging behavior of her son, theorizing about that behavior while drawing on research into temperament. Outlines history of "attention and behavior problems," culminating in most recent work on neuropsychological factors. Considers ways various approaches assign blame for "problems" to…

  19. The challenges from globalisation and migration

    DEFF Research Database (Denmark)

    Siim, Birte

    2008-01-01

    Globalization and migration has increased diversities and inequalities within and between nation states and has created new problems for public policies to regulate political and socio- economic problems on the national and global levels. The paper addresses the challenges from globalisation...

  20. Method for solving the problem of nonlinear heating a cylindrical body with unknown initial temperature

    Science.gov (United States)

    Yaparova, N.

    2017-10-01

    We consider the problem of heating a cylindrical body with an internal thermal source when the main characteristics of the material such as specific heat, thermal conductivity and material density depend on the temperature at each point of the body. We can control the surface temperature and the heat flow from the surface inside the cylinder, but it is impossible to measure the temperature on axis and the initial temperature in the entire body. This problem is associated with the temperature measurement challenge and appears in non-destructive testing, in thermal monitoring of heat treatment and technical diagnostics of operating equipment. The mathematical model of heating is represented as nonlinear parabolic PDE with the unknown initial condition. In this problem, both the Dirichlet and Neumann boundary conditions are given and it is required to calculate the temperature values at the internal points of the body. To solve this problem, we propose the numerical method based on using of finite-difference equations and a regularization technique. The computational scheme involves solving the problem at each spatial step. As a result, we obtain the temperature function at each internal point of the cylinder beginning from the surface down to the axis. The application of the regularization technique ensures the stability of the scheme and allows us to significantly simplify the computational procedure. We investigate the stability of the computational scheme and prove the dependence of the stability on the discretization steps and error level of the measurement results. To obtain the experimental temperature error estimates, computational experiments were carried out. The computational results are consistent with the theoretical error estimates and confirm the efficiency and reliability of the proposed computational scheme.

  1. A review of micromachined thermal accelerometers

    Science.gov (United States)

    Mukherjee, Rahul; Basu, Joydeep; Mandal, Pradip; Guha, Prasanta Kumar

    2017-12-01

    A thermal convection based micro-electromechanical accelerometer is a relatively new kind of acceleration sensor that does not require a solid proof mass, yielding unique benefits like high shock survival rating, low production cost, and integrability with CMOS integrated circuit technology. This article provides a comprehensive survey of the research, development, and current trends in the field of thermal acceleration sensors, with detailed enumeration on the theory, operation, modeling, and numerical simulation of such devices. Different reported varieties and structures of thermal accelerometers have been reviewed highlighting key design, implementation, and performance aspects. Materials and technologies used for fabrication of such sensors have also been discussed. Further, the advantages and challenges for thermal accelerometers vis-à-vis other prominent accelerometer types have been presented, followed by an overview of associated signal conditioning circuitry and potential applications.

  2. Robust tracking of respiratory rate in high-dynamic range scenes using mobile thermal imaging

    Science.gov (United States)

    Cho, Youngjun; Julier, Simon J.; Marquardt, Nicolai; Bianchi-Berthouze, Nadia

    2017-01-01

    The ability to monitor the respiratory rate, one of the vital signs, is extremely important for the medical treatment, healthcare and fitness sectors. In many situations, mobile methods, which allow users to undertake everyday activities, are required. However, current monitoring systems can be obtrusive, requiring users to wear respiration belts or nasal probes. Alternatively, contactless digital image sensor based remote-photoplethysmography (PPG) can be used. However, remote PPG requires an ambient source of light, and does not work properly in dark places or under varying lighting conditions. Recent advances in thermographic systems have shrunk their size, weight and cost, to the point where it is possible to create smart-phone based respiration rate monitoring devices that are not affected by lighting conditions. However, mobile thermal imaging is challenged in scenes with high thermal dynamic ranges (e.g. due to the different environmental temperature distributions indoors and outdoors). This challenge is further amplified by general problems such as motion artifacts and low spatial resolution, leading to unreliable breathing signals. In this paper, we propose a novel and robust approach for respiration tracking which compensates for the negative effects of variations in the ambient temperature and motion artifacts and can accurately extract breathing rates in highly dynamic thermal scenes. The approach is based on tracking the nostril of the user and using local temperature variations to infer inhalation and exhalation cycles. It has three main contributions. The first is a novel Optimal Quantization technique which adaptively constructs a color mapping of absolute temperature to improve segmentation, classification and tracking. The second is the Thermal Gradient Flow method that computes thermal gradient magnitude maps to enhance the accuracy of the nostril region tracking. Finally, we introduce the Thermal Voxel method to increase the reliability of the

  3. Robust tracking of respiratory rate in high-dynamic range scenes using mobile thermal imaging.

    Science.gov (United States)

    Cho, Youngjun; Julier, Simon J; Marquardt, Nicolai; Bianchi-Berthouze, Nadia

    2017-10-01

    The ability to monitor the respiratory rate, one of the vital signs, is extremely important for the medical treatment, healthcare and fitness sectors. In many situations, mobile methods, which allow users to undertake everyday activities, are required. However, current monitoring systems can be obtrusive, requiring users to wear respiration belts or nasal probes. Alternatively, contactless digital image sensor based remote-photoplethysmography (PPG) can be used. However, remote PPG requires an ambient source of light, and does not work properly in dark places or under varying lighting conditions. Recent advances in thermographic systems have shrunk their size, weight and cost, to the point where it is possible to create smart-phone based respiration rate monitoring devices that are not affected by lighting conditions. However, mobile thermal imaging is challenged in scenes with high thermal dynamic ranges (e.g. due to the different environmental temperature distributions indoors and outdoors). This challenge is further amplified by general problems such as motion artifacts and low spatial resolution, leading to unreliable breathing signals. In this paper, we propose a novel and robust approach for respiration tracking which compensates for the negative effects of variations in the ambient temperature and motion artifacts and can accurately extract breathing rates in highly dynamic thermal scenes. The approach is based on tracking the nostril of the user and using local temperature variations to infer inhalation and exhalation cycles. It has three main contributions. The first is a novel Optimal Quantization technique which adaptively constructs a color mapping of absolute temperature to improve segmentation, classification and tracking. The second is the Thermal Gradient Flow method that computes thermal gradient magnitude maps to enhance the accuracy of the nostril region tracking. Finally, we introduce the Thermal Voxel method to increase the reliability of the

  4. What is a problem?: On problem-oriented interdisciplinarity.

    Science.gov (United States)

    Schmidt, Jan C

    2011-06-01

    Among others, the term "problem" plays a major role in the various attempts to characterize interdisciplinarity or transdisciplinarity, as used synonymously in this paper. Interdisciplinarity (ID) is regarded as "problem solving among science, technology and society" and as "problem orientation beyond disciplinary constraints" (cf. Frodeman et al.: The Oxford Handbook of Interdisciplinarity. Oxford University Press, Oxford, 2010). The point of departure of this paper is that the discourse and practice of ID have problems with the "problem". The objective here is to shed some light on the vague notion of "problem" in order to advocate a specific type of interdisciplinarity: problem-oriented interdisciplinarity. The outline is as follows: Taking an ex negativo approach, I will show what problem-oriented ID does not mean. Using references to well-established distinctions in philosophy of science, I will show three other types of ID that should not be placed under the umbrella term "problem-oriented ID": object-oriented ID ("ontology"), theory-oriented ID (epistemology), and method-oriented ID (methodology). Different philosophical thought traditions can be related to these distinguishable meanings. I will then clarify the notion of "problem" by looking at three systematic elements: an undesired (initial) state, a desired (goal) state, and the barriers in getting from the one to the other. These three elements include three related kinds of knowledge: systems, target, and transformation knowledge. This paper elaborates further methodological and epistemological elements of problem-oriented ID. It concludes by stressing that problem-oriented ID is the most needed as well as the most challenging type of ID.

  5. Solar Thermal Energy Technology

    Energy Technology Data Exchange (ETDEWEB)

    Cason, D.L.; Pitsenbarger, J. [eds.

    1996-02-01

    Solar Thermal Energy Technology (PST) announces on a bimonthly basis the current worldwide research and development information that would expand the technology base required for the advancement of solar thermal systems as a significant energy resource.

  6. Ouellette Thermal Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Thermal Test Facility is a joint Army/Navy state-of-the-art facility (8,100 ft2) that was designed to:Evaluate and characterize the effect of flame and thermal...

  7. Analyzing Control Challenges for Thermal Energy Storage in Foodstuffs

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Skovrup, Morten Juel

    2012-01-01

    of refrigerated goods in a supermarket to shift the load of the system in time without deteriorating the quality of the foodstuffs. The analyses in this paper go before closing any control loops. In the first part, we introduce and validate a new model with which we can estimate the actual temperatures...... foodstuffs make them behave differently when exposed to changes in air temperature. We present a novel analysis based on Biot and Fourier numbers for the different foodstuffs. This provides a valuable tool for determining how different items can be utilized in load-shifting schemes on different timescales...

  8. Survival tactics within thermally-challenging roosts: heat tolerance ...

    African Journals Online (AJOL)

    ured ambient dry bulb temperature, relative humidity, solar radiation levels and windspeed. Data were ... their location(s) in the roost was determined in- directly using a stethoscope placed against the wooden panel- ling. .... ing the peak of the day (10:00-14:00), external solar radiation levels were highly variable owing to ...

  9. Thermal and cytokine responses to endotoxin challenge during early life.

    Science.gov (United States)

    McDonald, Fiona B; Khawaja, Ahmad M; Imran, Ahmad A; Ellis, Margot E; Chandrasekharan, Kumaran; Hasan, Shabih U

    2017-12-01

    Sudden infant death syndrome (SIDS) remains the leading cause of infant mortality beyond the neonatal period. An increase in body temperature as a result of high environmental temperature, overwrapping of infants, and (or) infection are associated with SIDS. Endotoxins such as lipopolysaccharide (LPS) and heat stress may perturb cardiorespiratory function and thermoregulation. Although LPS-mediated body temperature and cytokine responses are well documented in older animals, the capacity of LPS to induce fever and cytokine response in young rats remains unclear. Therefore, we sought to investigate the acute effects of LPS on body temperature and cytokine concentrations in rat pups. Postnatal day 7 rat pups were divided into 3 groups: Group 1, rats were administered LPS intraperitoneally (200 μg/kg); Group 2, rats received saline at volume equal to that administered in the LPS group; Group 3, rats received no treatment. Pups were placed in custom-made chambers maintained at ambient temperature of 33 °C. Body surface temperature was continuously monitored for 4 h. Thereafter, the rats were euthanized and serum was collected for cytokine analysis. We demonstrate that LPS treatment increased MIP-1α, IL-10, MCP-1, IP-10, fractalkine, and TNF-α with no concurrent rise in body surface temperature. Although neonatal rats produced an array of cytokines in response to LPS, there was no evidence of fever.

  10. Thermal sensors principles and applications for semiconductor industries

    CERN Document Server

    2015-01-01

    This book is a comprehensive guide to both the fundamentals of thermal sensors and their advanced functions. Key topics include sensor materials, CMOS-compatible sensors, measurement capabilities, thermal management and manufacturing processes. The introductory chapter covers the basic principles of thermal sensors from the essentials of heat transfer to smart wireless sensors. Later chapters illustrate the wide range of thermal sensor uses, from microprocessor thermal sensing to energy converter applications. Modeling and simulation techniques are used to explain the future direction of the field. Designed for researchers and practitioners working with wireless sensors and thermal management, Thermal Sensors: Principles and Applications for Semiconductor Industries is a valuable reference to the benefits and challenges these sensors offer. Advanced-level students studying mechanical or electrical engineering and networks will also find the content useful.

  11. The ambiguous challenge of intranets

    DEFF Research Database (Denmark)

    Thommesen, Jacob

    2003-01-01

    media, email and the web, partly in the perspective of media richness theory, partly compared with philosophical discussions of classical media. The fourth chapter presents an intranet in a global company, in which problems and challenges related to ambiguity have proven significant.......In this thesis I shall present the argument that intranets increase the role of ambiguity – confrontation between contradicting frames of interpretation – in organisational communication by encouraging processes across organisational borders. In the first chapter I discuss philosophical aspects...

  12. Electric Motor Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Bennion, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-01

    Thermal management enables more efficient and cost-effective motors. This Annual Merit Review presentation describes the technical accomplishments and progress in electric motor thermal management R&D over the last year. This project supports a broad industry demand for data, analysis methods, and experimental techniques to improve and better understand motor thermal management.

  13. Thermal Performance Benchmarking (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, G.

    2014-11-01

    This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

  14. Diabetes and Foot Problems

    Science.gov (United States)

    ... Damage (Diabetic Neuropathies) Diabetic Kidney Disease Diabetes and Foot Problems Diabetic Eye Disease Diabetes, Gum Disease, & Other Dental Problems Diabetes & Sexual & Urologic Problems Diabetes and Foot Problems Foot problems are common in people with ...

  15. Incorporating Sustainability and 21st-Century Problem Solving into Physics Courses

    Science.gov (United States)

    Rogers, Michael; Pfaff, Tom; Hamilton, Jason; Erkan, Ali

    2013-09-01

    As educators we are facing an unprecedented challenge to prepare our students not only for traditional careers but also for future careers that don't exist today. Many of these careers will require a firm grounding in disciplines such as physics, along with multidisciplinary, Global, and systems thinking skill sets. Our Multidisciplinary Sustainability Education (MSE) project is addressing this challenge by creating sustainability-themed modules where a variety of courses in a range of disciplines tackle relevant, real-world problems from each discipline's perspective. Each course involved in a module, which addresses an overarching question, has students write technical reports, using their discipline knowledge to address the question, and they are expected to read and synthesize reports from other discipline-based courses. This paper discusses one of our modules, "What Are the Current and Future Impacts of Global Climate Change on Polar Bears?" and how students studying thermal physics can help answer this question.

  16. Monitoring challenges and innovative ideas

    Energy Technology Data Exchange (ETDEWEB)

    O' Neill, R.V.; Hunsaker, C.T.; Levine, D.A.

    1990-01-01

    Monitoring programs are difficult to design even when they focus on specific problems. Ecosystems are complex, and it is often impossible to predetermine what aspects of system structure or dynamics will respond to a specific insult. It is equally difficult to interpret whether a response is a stabilizing compensatory mechanism or a real loss of capacity to maintain the ecosystem. The problems are compounded in a broad monitoring program designed to assess ecosystem health'' at regional and continental scales. It is challenging in the extreme to monitor ecosystem response, at any scale, to past insults as well as an unknown future array of impacts. The present paper will examine some of the fundamental issues and challenges raised by large-scale monitoring efforts. The challenges will serve as a framework and as an excuse to discuss several important topics in more detail. Following the discussion of challenges, we suggest some basic innovations that could be important across a range of monitoring programs. The innovations include integrative measures, innovative methodology, and creative interpretation. 59 refs., 1 tab.

  17. Thermal preference predicts animal personality in Nile tilapia Oreochromis niloticus.

    Science.gov (United States)

    Cerqueira, Marco; Rey, Sonia; Silva, Tome; Featherstone, Zoe; Crumlish, Margaret; MacKenzie, Simon

    2016-09-01

    Environmental temperature gradients provide habitat structure in which fish orientate and individual thermal choice may reflect an essential integrated response to the environment. The use of subtle thermal gradients likely impacts upon specific physiological and behavioural processes reflected as a suite of traits described by animal personality. In this study, we examine the relationship between thermal choice, animal personality and the impact of infection upon this interaction. We predicted that thermal choice in Nile tilapia Oreochromis niloticus reflects distinct personality traits and that under a challenge individuals exhibit differential thermal distribution. Nile tilapia were screened following two different protocols: 1) a suite of individual behavioural tests to screen for personality and 2) thermal choice in a custom-built tank with a thermal gradient (TCH tank) ranging from 21 to 33 °C. A first set of fish were screened for behaviour and then thermal preference, and a second set were tested in the opposite fashion: thermal then behaviour. The final thermal distribution of the fish after 48 h was assessed reflecting final thermal preferendum. Additionally, fish were then challenged using a bacterial Streptococcus iniae model infection to assess the behavioural fever response of proactive and reactive fish. Results showed that individuals with preference for higher temperatures were also classified as proactive with behavioural tests and reactive contemporaries chose significantly lower water temperatures. All groups exhibited behavioural fever recovering personality-specific thermal preferences after 5 days. Our results show that thermal preference can be used as a proxy to assess personality traits in Nile tilapia and it is a central factor to understand the adaptive meaning of animal personality within a population. Importantly, response to infection by expressing behavioural fever overrides personality-related thermal choice. © 2016 The Authors

  18. Lasing at 300 nm and below: Optical challenges and perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Garzella, D. [Universite de Paris-Sud, Orsay (France); Couprie, M.E. [Universite de Paris-Sud, Orsay (France)]|[CEA DSM DRECAM SPAM, Gif Sur Yvette (France); Billardon, M. [ESPCI, Paris (France)

    1995-12-31

    The FEL experiment in the visible and near UV on the Super ACO storage ring has given, since 1989, important informations on the SRFEL dynamics and, furthermore, a very good beam stability has been achieved. In addition, the operation at 350 nm with this good stability and a long beam lifetime allowed us to perform the first user experiment in biology and to start with a campaign for using the laser as photons source for experiments in other domains, coupling FEL light and the Synchrotron Radiation. For this, FEL starts to be very competitive with respect to the other conventional laser sources, provided that it could oscillate further in the UV, say at 300 nm and below. So, the real challenge is now given by the lasing at shorter wavelengths and, for this, by the optical technology existing nowadays. Since 1992 the efforts have been concentrating to look for every kind of solution allowing us to overcome the problem of having a very low gain. From an optical point of view, in the range of wavelengths explored, there is a lack of transparents dielectric materials for substrates and coatings. Substrates are required at the same time to be relatively not absorbing (a few tens 10{sup -6}), to have a very good surface quality (RMS roughness below 10 {Angstrom}) because of scattering losses dramatically increasing in this spectral range and, due to the thermal load of the undulator emission, to have adequate thermal characteristics. In order to fulfill all these requirements, a good characterisation and modelisation of the substrates is needed, especially to correlate thermal loading and mechanical deformations from one hand, and roughness and scattering losses from the other hand. Coatings must be not absorbing too and, above all, the most amorphous as possible (this could be obtained with IBS deposition technique), in order to insure a good reproduction of the substrate roughness at the interfaces and on the top layer and an higher resistance to the XUV photons load.

  19. Cyanides in the environment-analysis-problems and challenges.

    Science.gov (United States)

    Jaszczak, Ewa; Polkowska, Żaneta; Narkowicz, Sylwia; Namieśnik, Jacek

    2017-07-01

    Cyanide toxicity and their environmental impact are well known. Nevertheless, they are still used in the mining, galvanic and chemical industries. As a result of industrial activities, cyanides are released in various forms to all elements of the environment. In a natural environment, cyanide exists as cyanogenic glycosides in plants seeds. Too much consumption can cause unpleasant side effects. However, environmental tobacco smoke (ETS) is the most common source of cyanide. Live organisms have the ability to convert cyanide into less toxic compounds excreted with physiological fluids. The aim of this paper is to review the current state of knowledge on the behaviour of cyanide in the environment and its impact on the health and human life.

  20. Problems, Challenges and Prospects of Female Entrepreneurs in ...

    African Journals Online (AJOL)

    Many women are becoming more educated and the idea that a woman should stay at home, baby sit, cook, go to market, take care of the children and the home is no longer current. The number of women who are gainfully employed increases per day. Girl-child education is also on the increase in Nigeria. This study was ...

  1. Problems, Challenges and Prospects of Female Entrepreneurs in ...

    African Journals Online (AJOL)

    User

    2011-05-20

    May 20, 2011 ... practices; changing societal attitudes towards women in the work place; and organizations' desire to place qualified women in managerial positions to project a favourable image. Many women are becoming more educated and the idea that a woman should stay at home, baby sit, cook, go to market, take.

  2. Indoor Air Pollution: An Old Problem with New Challenges

    Directory of Open Access Journals (Sweden)

    Gary Adamkiewicz

    2009-11-01

    Full Text Available Hazards in our indoor environments have been recognized since biblical times. The advice in Leviticus 14:33–48 for treating mold infested houses has contemporary meaning in the recent World Health Organization (WHO document on damp and moldy indoor spaces [1]. In the developed world, faulty combustion, carbon monoxide from coal gas, lead paint, poor ventilation of tenement housing and hospitals have been recognized for decades as unhealthy. Indoor air quality, however, was not appreciated as an important component of public health until the proliferation of sealed buildings, energy conservation programs (urea formaldehyde foam insulation, new products, and the recognition of the health effects of radon, asbestos and latex. [...

  3. Problems, Challenges and Prospects of Female Entrepreneurs in ...

    African Journals Online (AJOL)

    User

    2011-05-20

    May 20, 2011 ... practices; changing societal attitudes towards women in the work place; and organizations' desire to place qualified women in managerial positions to project a favourable image. Many women are becoming .... marketing management and book-keeping. This was to enable the women take care of their ...

  4. Refugees in the Eastern Mediterranean Region: Needs, Problems and Challenges

    Directory of Open Access Journals (Sweden)

    Habibolah Taghizadeh Moghaddam

    2017-03-01

    Full Text Available As host to some of the world’s biggest emergencies and protracted crises, the Eastern Mediterranean Region carries the largest burden of displaced populations globally. Out of 58 million displaced persons worldwide, almost 30 million (52% come from the Region. Syria is currently the world’s biggest producer of refugees and internally displaced persons, with more than 40% of the population now displaced. Afghanistan and Somalia face two of the longest-spanning refugee situations, with Afghanis constituting the second-largest refugee group in the world after Syrians, and Somalia facing one of the world’s most complex refugee situations. The Region is also witness to massive internal displacement. More than 4 million people in Iraq are now displaced inside the country. In Yemen, one of the world humanitarian crises in the world, more than 2.4 million people have relocated to safer areas to escape the violence.Countries in the Eastern Mediterranean Region have shown generous hospitality towards displaced populations. Lebanon, a country of four million people, is now the highest per capita host of refugees in the world, with refugees comprising almost a third of the total population. In Jordan, Syrians make up 10% of the population. Iran is host to 3 million Afghan refugees, during the last thirty years. Pakistan, a country with more than 1.5 million internally displaced persons, is also host to more than 1.5 million refugees from Afghanistan. With the majority of refugees and internally displaced persons across the region living outside camp settings, both displaced populations and host communities, are exposed to increased public health risks. These include infectious diseases due to overcrowded living conditions, limited access to safe water and sanitation, and varying degrees of access to primary health care services.

  5. Challenges to Sustainability: Applying the Problem Tree Analysis ...

    African Journals Online (AJOL)

    ... the ADPs through deduction of state and federal governments counter-part funds for the ADPs from source i.e. the federation account and formation of an Agricultural Development Tax Fund (ADTF) fashioned not in line with the Education Tax Fund (ETF) to provide additional and sustainable source of funds for agricultural ...

  6. Modal data for the BARC challenge problem Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Rohe, Daniel Peter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-01-22

    Modal testing was performed on the uncut BARC structure as a whole and broken into its two sub-assemblies. The structure was placed on soft foam during the test. Excitation was provided with a small modal hammer attached to an actuator. Responses were measured using a 3D Scanning Laser Doppler Vibrometer. Data, shapes, and geometry from this test can be downloaded in Universal File Format from the Sandia Connect SharePoint site.

  7. Problems and Challenges in Medical Education in India

    Science.gov (United States)

    Goswami, Sribas; Sahai, Manjari

    2015-01-01

    As India marches towards an exciting new future of growth and progress, medical education will play a pivotal role in crafting a sustained development agenda. The idea of creating a healthy society is no longer a debatable luxury; its significance has been grasped by policy shapers worldwide. In a developing nation like India, medical services…

  8. The impaired practitioner- scope of the problem and ethical challenges

    African Journals Online (AJOL)

    Practitioner impairment occurs when a physical, mental or substance-related disorder interferes with his or her ability to engage in professional activities competently and safely. The Health Professions Council of South Africa makes reporting of impaired colleagues and students mandatory. The ethical dilemma faced by ...

  9. Diphtheria in Europe: current problems and new challenges.

    Science.gov (United States)

    Zakikhany, Katherina; Efstratiou, Androulla

    2012-05-01

    Diphtheria, caused by toxigenic strains of Corynebacterium diphtheriae, is an ancient disease with high incidence and mortality that has always been characterized by epidemic waves of occurrence. Whilst towards the beginning of the 1980s, many European countries were progressing towards the elimination of diphtheria, an epidemic re-emergence of diphtheria in the Russian Federation and the Newly Independent States of the former Soviet Union demonstrated a continuous threat of the disease into the 1990s. At present, the epidemic is under control and only sporadic cases are observed in Europe. However, the circulation of toxigenic strains is still observed in all parts of the world, posing a constant threat to the population with low levels of seroprotection. More recently, Corynebacterium ulcerans has been increasingly isolated as emerging zoonotic agent of diphtheria from companion animals such as cats or dogs, indicating the enduring threat of this thought-to-be controlled disease.

  10. China's natural wetlands: past problems, current status, and future challenges

    Science.gov (United States)

    Shuqing An; Harbin Li; Baohua Guan; Changfang Zhou; Zhongsheng Wang; Zifa Deng; Yingbiao Zhi; Yuhong Liu; Chi Xu; Shubo Fang; Jinhui Jiang; Hongli Li

    2007-01-01

    Natural wetlands, occupying 3.8% of China's land and providing 54.9% of ecosystem services, are unevenly distributed among eight wetland regions. Natural wetlands in China suffered great loss and degradation (e.g., 23.0% freshwater swamps, 51.2% coastal wetlands) because of the wetland reclamation during China's long history of civilization, and the...

  11. [Problems and ethical challenges in public health communication].

    Science.gov (United States)

    Loss, J; Nagel, E

    2009-05-01

    Health communication, e.g., mass media campaigns, patient information leaflets or websites, plays an important role in public health. It contributes to citizen empowerment and helps them make informed decisions in health matters. However, public health communication can lead to adverse effects on both individual and societal level, e.g., by inaccurate or partial information, discriminatory messages, scandalizing coverage or inadequate tailoring to relevant target groups. It seems important to suggest ethical criteria for health information, e.g., (1) accuracy, completeness and balance, (2) transparency, (3) participation of the target group, (4) respect for human dignity, (5) social justice and equity, (6) appropriateness. Thoughtfulness is important in order not to stigmatize population subgroups. In addition, it is laborious to comprehensively and correctly present benefits and risks of a certain health behavior. Marketing principles guide how to 'sell' a certain health behavior, but health campaigns should not manipulate target persons for the sake of a population health aim. It remains unclear, however, how the different providers of health information can be held ethically responsible.

  12. Newcastle disease vaccines- a solved problem or a continuous challenge?

    Science.gov (United States)

    Newcastle disease (ND) has been defined by the World Organization for Animal Health as infection of poultry with virulent strains of Newcastle disease virus (NDV). Lesions affecting the neurological, gastrointestinal, respiratory, and reproductive systems are most often observed. The control of ND m...

  13. Activity restriction in mild COPD: a challenging clinical problem

    Directory of Open Access Journals (Sweden)

    O'Donnell DE

    2014-06-01

    Full Text Available Denis E O'Donnell,1 Kevin B Gebke2 1Division of Respiratory and Critical Care Medicine, Respiratory Investigation Unit, Queen's University and Kingston General Hospital, Kingston, ON, Canada; 2Primary Care Sports Medicine Program, Indiana University School of Medicine, Indianapolis, IN, USA Abstract: Dyspnea, exercise intolerance, and activity restriction are already apparent in mild chronic obstructive pulmonary disease (COPD. However, patients may not seek medical help until their symptoms become troublesome and persistent and significant respiratory impairment is already present; as a consequence, further sustained physical inactivity may contribute to disease progression. Ventilatory and gas exchange impairment, cardiac dysfunction, and skeletal muscle dysfunction are present to a variable degree in patients with mild COPD, and collectively may contribute to exercise intolerance. As such, there is increasing interest in evaluating exercise tolerance and physical activity in symptomatic patients with COPD who have mild airway obstruction, as defined by spirometry. Simple questionnaires, eg, the modified British Medical Research Council dyspnea scale and the COPD Assessment Test, or exercise tests, eg, the 6-minute or incremental and endurance exercise tests can be used to assess exercise performance and functional status. Pedometers and accelerometers are used to evaluate physical activity, and endurance tests (cycle or treadmill using constant work rate protocols are used to assess the effects of interventions such as pulmonary rehabilitation. In addition, alternative outcome measurements, such as tests of small airway dysfunction and laboratory-based exercise tests, are used to measure the extent of physiological impairment in individuals with persistent dyspnea. This review describes the mechanisms of exercise limitation in patients with mild COPD and the interventions that can potentially improve exercise tolerance. Also discussed are the benefits of pulmonary rehabilitation and the potential role of pharmacologic treatment in symptomatic patients with mild COPD. Keywords: chronic obstructive pulmonary disease (COPD, small airway dysfunction, dyspnea, physical activity, exercise

  14. Basic Theoretical Principles Pertaining to Thermal Protection of Oil Transformer

    Directory of Open Access Journals (Sweden)

    O. G. Shirokov

    2008-01-01

    Full Text Available The paper contains formulation of basic theoretical principles pertaining to thermal protection of an oil transformer in accordance with classical theory of relay protection and theory of diagnostics with the purpose of unification of terminological and analytical information which is presently available in respect of this problem. Classification of abnormal thermal modes of an oil transformer and also algorithms and methods for operation of diagnostic thermal protection of a transformer have been proposed.

  15. Quantum Thermal Transistor.

    Science.gov (United States)

    Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

    2016-05-20

    We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

  16. Homogeneous Charge Compression Ignition Combustion: Challenges and Proposed Solutions

    Directory of Open Access Journals (Sweden)

    Mohammad Izadi Najafabadi

    2013-01-01

    Full Text Available Engine and car manufacturers are experiencing the demand concerning fuel efficiency and low emissions from both consumers and governments. Homogeneous charge compression ignition (HCCI is an alternative combustion technology that is cleaner and more efficient than the other types of combustion. Although the thermal efficiency and NOx emission of HCCI engine are greater in comparison with traditional engines, HCCI combustion has several main difficulties such as controlling of ignition timing, limited power output, and weak cold-start capability. In this study a literature review on HCCI engine has been performed and HCCI challenges and proposed solutions have been investigated from the point view of Ignition Timing that is the main problem of this engine. HCCI challenges are investigated by many IC engine researchers during the last decade, but practical solutions have not been presented for a fully HCCI engine. Some of the solutions are slow response time and some of them are technically difficult to implement. So it seems that fully HCCI engine needs more investigation to meet its mass-production and the future research and application should be considered as part of an effort to achieve low-temperature combustion in a wide range of operating conditions in an IC engine.

  17. Modeling of thermal mass energy storage in buildings with phase change materials

    Science.gov (United States)

    Delcroix, Benoit

    Building thermal mass is a key parameter defining the ability of a building to mitigate inside temperature variations and to maintain a better thermal comfort. Increasing the thermal mass of a lightweight building can be achieved by using Phase Change Materials (PCMs). These materials offer a high energy storage capacity (using latent energy) and a nearly constant temperature phase change. They can be integrated conveniently in net-zero energy buildings. The current interest for these buildings and for better power demand management strategies requires accurate transient simulation of heavy and highly insulated slabs or walls with short time-steps (lower than or equal to 5 minutes). This represents a challenge for codes that were mainly developed for yearly energy load calculations with a time-step of 1 hour. It is the case of the TRNSYS building model (called Type 56) which presents limitations when modeling heavy and highly insulated slabs with short time-steps. These limitations come from the method used by TRNSYS for modeling conduction heat transfer through walls which is known as the Conduction Transfer Function (CTF) method. In particular, problems have been identified in the generation of CTF coefficients used to model the walls thermal response. This method is also unable to define layers with variable thermophysical properties, as displayed by PCMs. PCM modeling is further hindered by the limited information provided by manufacturers: physical properties are often incomplete or incorrect. Finally, current models are unable to represent the whole complexity of PCM thermal behavior: they rarely include different properties for melting and solidification (hysteresis); they sometimes take into account variable thermal conductivity; but they never model subcooling effects. All these challenges are tackled in this thesis and solutions are proposed. The first part (chapter 4) focuses on improving the CTF method in TRNSYS through state-space modeling

  18. Modelling of a Solar Thermal Power Plant for Benchmarking Blackbox Optimization Solvers

    Science.gov (United States)

    Lemyre Garneau, Mathieu

    A new family of problems is provided to serve as a benchmark for blackbox optimization solvers. The problems are single or bi-objective and vary in complexity in terms of the number of variables used (from 5 to 29), the type of variables (integer, real, category), the number of constraints (from 5 to 17) and their types (binary or continuous). In order to provide problems exhibiting dynamics that reflect real engineering challenges, they are extracted from an original numerical model of a concentrated solar power (CSP) power plant with molten salt thermal storage. The model simulates the performance of the power plant by using a high level modeling of each of its main components, namely, an heliostats field, a central cavity receiver, a molten salt heat storage, a steam generator and an idealized powerblock. The heliostats field layout is determined through a simple automatic strategy that finds the best individual positions on the field by considering their respective cosine efficiency, atmospheric scattering and spillage losses as a function of the design parameters. A Monte-Carlo integral method is used to evaluate the heliostats field's optical performance throughout the day so that shadowing effects between heliostats are considered, and the results of this evaluation provide the inputs to simulate the levels and temperatures of the thermal storage. The molten salt storage inventory is used to transfer thermal energy to the powerblock, which simulates a simple Rankine cycle with a single steam turbine. Auxiliary models are used to provide additional optimization constraints on the investment cost, parasitic losses or components failure. The results of preliminary optimizations performed with the NOMAD software using default settings are provided to show the validity of the problems.

  19. The Role of Higher-Order Modes on the Electromagnetic Whistler-Cyclotron Wave Fluctuations of Thermal and Non-Thermal Plasmas

    Science.gov (United States)

    Vinas, Adolfo F.; Moya, Pablo S.; Navarro, Roberto; Araneda, Jamie A.

    2014-01-01

    Two fundamental challenging problems of laboratory and astrophysical plasmas are the understanding of the relaxation of a collisionless plasmas with nearly isotropic velocity distribution functions and the resultant state of nearly equipartition energy density with electromagnetic plasma turbulence. Here, we present the results of a study which shows the role that higher-order-modes play in limiting the electromagnetic whistler-like fluctuations in a thermal and non-thermal plasma. Our main results show that for a thermal plasma the magnetic fluctuations are confined by regions that are bounded by the least-damped higher order modes. We further show that the zone where the whistler-cyclotron normal modes merges the electromagnetic fluctuations shifts to longer wavelengths as the beta(sub e) increases. This merging zone has been interpreted as the beginning of the region where the whistler-cyclotron waves losses their identity and become heavily damped while merging with the fluctuations. Our results further indicate that in the case of nonthermal plasmas, the higher-order modes do not confine the fluctuations due to the effective higher-temperature effects and the excess of suprathermal plasma particles. The analysis presented here considers the second-order theory of fluctuations and the dispersion relation of weakly transverse fluctuations, with wave vectors parallel to the uniform background magnetic field, in a finite temperature isotropic bi-Maxwellian and Tsallis-kappa-like magnetized electron-proton plasma. Our results indicate that the spontaneously emitted electromagnetic fluctuations are in fact enhanced over these quasi modes suggesting that such modes play an important role in the emission and absorption of electromagnetic fluctuations in thermal or quasi-thermal plasmas.

  20. Merging Thermal Plumes in the Indoor Environment

    DEFF Research Database (Denmark)

    Bjørn, Erik; Nielsen, Peter V.

    This experimental work deals with the basic problem of merging thermal plumes from heat sources situated in the vicinity of each other. No studies have been made yet of how close two heat sources must be to each other, before they can be considered as a single source with a cumulative heat effect...